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  • how do I set quad buffering with jogl 2.0

    - by tony danza
    I'm trying to create a 3d renderer for stereo vision with quad buffering with Processing/Java. The hardware I'm using is ready for this so that's not the problem. I had a stereo.jar library in jogl 1.0 working for Processing 1.5, but now I have to use Processing 2.0 and jogl 2.0 therefore I have to adapt the library. Some things are changed in the source code of Jogl and Processing and I'm having a hard time trying to figure out how to tell Processing I want to use quad buffering. Here's the previous code: public class Theatre extends PGraphicsOpenGL{ protected void allocate() { if (context == null) { // If OpenGL 2X or 4X smoothing is enabled, setup caps object for them GLCapabilities capabilities = new GLCapabilities(); // Starting in release 0158, OpenGL smoothing is always enabled if (!hints[DISABLE_OPENGL_2X_SMOOTH]) { capabilities.setSampleBuffers(true); capabilities.setNumSamples(2); } else if (hints[ENABLE_OPENGL_4X_SMOOTH]) { capabilities.setSampleBuffers(true); capabilities.setNumSamples(4); } capabilities.setStereo(true); // get a rendering surface and a context for this canvas GLDrawableFactory factory = GLDrawableFactory.getFactory(); drawable = factory.getGLDrawable(parent, capabilities, null); context = drawable.createContext(null); // need to get proper opengl context since will be needed below gl = context.getGL(); // Flag defaults to be reset on the next trip into beginDraw(). settingsInited = false; } else { // The following three lines are a fix for Bug #1176 // http://dev.processing.org/bugs/show_bug.cgi?id=1176 context.destroy(); context = drawable.createContext(null); gl = context.getGL(); reapplySettings(); } } } This was the renderer of the old library. In order to use it, I needed to do size(100, 100, "stereo.Theatre"). Now I'm trying to do the stereo directly in my Processing sketch. Here's what I'm trying: PGraphicsOpenGL pg = ((PGraphicsOpenGL)g); pgl = pg.beginPGL(); gl = pgl.gl; glu = pg.pgl.glu; gl2 = pgl.gl.getGL2(); GLProfile profile = GLProfile.get(GLProfile.GL2); GLCapabilities capabilities = new GLCapabilities(profile); capabilities.setSampleBuffers(true); capabilities.setNumSamples(4); capabilities.setStereo(true); GLDrawableFactory factory = GLDrawableFactory.getFactory(profile); If I go on, I should do something like this: drawable = factory.getGLDrawable(parent, capabilities, null); but drawable isn't a field anymore and I can't find a way to do it. How do I set quad buffering? If I try this: gl2.glDrawBuffer(GL.GL_BACK_RIGHT); it obviously doesn't work :/ Thanks.

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  • What is a good resource for learning how the .Net Framework works? [on hold]

    - by Till Death Developer
    I've been developing web apps, for a while now so i know how to get the job done, what i don't know is how every thing really works, i know some but the rest i can't get a grasp on like how abstract works, what happens when i instantiate an object from a class that inherits from an abstract class?, where things get stored Heap vs Stack?, in other words the Interview questions that i suck at, so any advice would be great, books, videos, online courses, whatever you can provide would really help me.

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  • Speaking at PASS 2012… Exciting and Scary… As usual…

    - by drsql
    I have been selected this year at the PASS Summit 2012 to do two sessions, and they are both going to be interesting. Pre-Con: Relational Database Design Workshop - Abstract Triggers: Born Evil or Misunderstood? - Abstract The pre-con session entitled Relational Database Design Workshop will be (at least) the third time I will have done this pre-con session, and I am pretty excited to take it to a bit larger scale. The one big change that I am forcing this time is a limit on the lecture time. Each...(read more)

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  • Asp.NET custom templated datalist throws argument out of range (index) on button press

    - by MrTortoise
    I have a class BaseTemplate public abstract class BaseTemplate : ITemplate This adds the controls, and provides abstract methods to implement in the inheriting class. The inheriting class then adds its html according to its data source and manages the data binding. This all works fine - I get the control appearing with properly parsed html. The problem is that the base class adds controls into the template that have their own CommandName arguments; the idea is that the class that implements the custom templated dataList will provide the logic of setting the Selected and Edit Indexes. This class also manages the data binding, etc. It sets all of the templates on the datalist in the Init method (which was another cause of this exception). The exception gets thrown when I hit one of these buttons - I have tried hooking up both their click and command events everywhere in case this was the problem. I have also ensured that their command names do not match any of the system ones. The stack trace does not include any references to my methods or objects which is why I am so stuck. It is the most unhelpful message I can imagine. The really frustrating thing is that I cannot get a breakpoint to fire - i.e. the problem is happening after I click the button, but before and of my code can execute. The last time this exception happened was when I had this code in a user control and was assigning the templates to the datalist in the PageLoad. I moved these into init to fix that problem; however, this is a problem that was there then and I have no idea what is causing it let alone how to solve it (and index out of range doesn't really help without knowing what index.) The Exception Details Exception Details: System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values. Parameter name: index The Stack Trace: [ArgumentOutOfRangeException: Specified argument was out of the range of valid values. Parameter name: index] System.Web.UI.ControlCollection.get_Item(Int32 index) +8665582 System.Web.UI.WebControls.DataList.GetItem(ListItemType itemType, Int32 repeatIndex) +8667655 System.Web.UI.WebControls.DataList.System.Web.UI.WebControls.IRepeatInfoUser.GetItemStyle(ListItemType itemType, Int32 repeatIndex) +11 System.Web.UI.WebControls.RepeatInfo.RenderVerticalRepeater(HtmlTextWriter writer, IRepeatInfoUser user, Style controlStyle, WebControl baseControl) +8640873 System.Web.UI.WebControls.RepeatInfo.RenderRepeater(HtmlTextWriter writer, IRepeatInfoUser user, Style controlStyle, WebControl baseControl) +27 System.Web.UI.WebControls.DataList.RenderContents(HtmlTextWriter writer) +208 System.Web.UI.WebControls.BaseDataList.Render(HtmlTextWriter writer) +30 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19 System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) +163 System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +32 System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output) +51 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer) +40 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19 System.Web.UI.Page.Render(HtmlTextWriter writer) +29 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1266 The code Base class: public abstract class BaseTemplate : ITemplate { ListItemType _templateType; public BaseTemplate(ListItemType theTemplateType) { _templateType = theTemplateType; } public ListItemType ListItemType { get { return _templateType; } } #region ITemplate Members public void InstantiateIn(Control container) { PlaceHolder ph = new PlaceHolder(); container.Controls.Add(ph); Literal l = new Literal(); switch (_templateType) { case ListItemType.Header: { ph.Controls.Add(new LiteralControl(@"<table><tr>")); InstantiateInHeader(ph); ph.Controls.Add(new LiteralControl(@"</tr>")); break; } case ListItemType.Footer: { ph.Controls.Add(new LiteralControl(@"<tr>")); InstantiateInFooter(ph); ph.Controls.Add(new LiteralControl(@"</tr></table>")); break; } case ListItemType.Item: { ph.Controls.Add(new LiteralControl(@"<tr>")); InstantiateInItem(ph); ph.Controls.Add(new LiteralControl(@"<td>")); Button select = new Button(); select.ID = "btnSelect"; select.CommandName = "SelectRow"; select.Text = "Select"; ph.Controls.Add(select); ph.Controls.Add(new LiteralControl(@"</td>")); ph.Controls.Add(new LiteralControl(@"</tr>")); ph.DataBinding += new EventHandler(ph_DataBinding); break; } case ListItemType.AlternatingItem: { ph.Controls.Add(new LiteralControl(@"<tr>")); InstantiateInAlternatingItem(ph); ph.Controls.Add(new LiteralControl(@"<td>")); Button select = new Button(); select.ID = "btnSelect"; select.CommandName = "SelectRow"; select.Text = "Select"; ph.Controls.Add(select); ph.Controls.Add(new LiteralControl(@"</td>")); ph.Controls.Add(new LiteralControl(@"</tr>")); ph.DataBinding+=new EventHandler(ph_DataBinding); break; } case ListItemType.SelectedItem: { ph.Controls.Add(new LiteralControl(@"<tr>")); InstantiateInItem(ph); ph.Controls.Add(new LiteralControl(@"<td>")); Button edit = new Button(); edit.ID = "btnEdit"; edit.CommandName = "EditRow"; edit.Text = "Edit"; ph.Controls.Add(edit); Button delete = new Button(); delete.ID = "btnDelete"; delete.CommandName = "DeleteRow"; delete.Text = "Delete"; ph.Controls.Add(delete); ph.Controls.Add(new LiteralControl(@"</td>")); ph.Controls.Add(new LiteralControl(@"</tr>")); ph.DataBinding += new EventHandler(ph_DataBinding); break; } case ListItemType.EditItem: { ph.Controls.Add(new LiteralControl(@"<tr>")); InstantiateInEdit(ph); ph.Controls.Add(new LiteralControl(@"<td>")); Button save = new Button(); save.ID = "btnSave"; save.CommandName = "SaveRow"; save.Text = "Save"; ph.Controls.Add(save); Button cancel = new Button(); cancel.ID = "btnCancel"; cancel.CommandName = "CancelRow"; cancel.Text = "Cancel"; ph.Controls.Add(cancel); ph.Controls.Add(new LiteralControl(@"</td>")); ph.Controls.Add(new LiteralControl(@"</tr>")); ph.DataBinding += new EventHandler(ph_DataBinding); break; } case ListItemType.Separator: { InstantiateInSeperator(ph); break; } } } void ph_DataBinding(object sender, EventArgs e) { DataBindingOverride(sender, e); } /// <summary> /// the controls placed into the PlaceHolder will get wrapped in &lt;table&gt;&lt;tr&gt; &lt;/tr&gt;. I.e. you need to provide the column names wrapped in &lt;td&gt;&lt;/td&gt; tags. /// </summary> /// <param name="header"></param> public abstract void InstantiateInHeader(PlaceHolder ph); /// <summary> /// the controls will have a column added after them and so require each column to be properly wrapped in &lt;td&gt;&lt;/td&gt; tags. The &lt;tr&gt;&lt;/tr&gt; is handled in the base class. /// </summary> /// <param name="ph"></param> public abstract void InstantiateInItem(PlaceHolder ph); /// <summary> /// the controls will have a column added after them and so require each column to be properly wrapped in &lt;td&gt;&lt;/td&gt; tags. The &lt;tr&gt;&lt;/tr&gt; is handled in the base class. /// </summary> /// <param name="ph"></param> public abstract void InstantiateInAlternatingItem(PlaceHolder ph); /// <summary> /// the controls will have a column added after them and so require each column to be properly wrapped in &lt;td&gt;&lt;/td&gt; tags. The &lt;tr&gt;&lt;/tr&gt; is handled in the base class. /// </summary> /// <param name="ph"></param> public abstract void InstantiateInEdit(PlaceHolder ph); /// <summary> /// Any html used in the footer will have &lt;/tr&gt;&lt;table&gt; appended to the end. /// &lt;tr&gt; will be appended to the front. /// </summary> /// <param name="ph"></param> public abstract void InstantiateInFooter(PlaceHolder ph); /// <summary> /// the controls will have a column added after them and so require each column to be properly wrapped in &lt;td&gt;&lt;/td&gt; tags. The &lt;tr&gt;&lt;/tr&gt; is handled in the base class. /// Adds Delete and Edit Buttons after the table contents. /// </summary> /// <param name="ph"></param> public abstract void InstantiateInSelectedItem(PlaceHolder ph); /// <summary> /// The base class provides no &lt;tr&gt;&lt;/tr&gt; tags /// </summary> /// <param name="ph"></param> public abstract void InstantiateInSeperator(PlaceHolder ph); /// <summary> /// Use this method to bind the controls to their data. /// </summary> /// <param name="sender"></param> /// <param name="e"></param> public abstract void DataBindingOverride(object sender, EventArgs e); #endregion } Inheriting class: public class NominalGroupTemplate : BaseTemplate { public NominalGroupTemplate(ListItemType theListItemType) : base(theListItemType) { } public override void InstantiateInHeader(PlaceHolder ph) { ph.Controls.Add(new LiteralControl(@"<td>ID</td><td>Group</td><td>IsPositive</td>")); } public override void InstantiateInItem(PlaceHolder ph) { ph.Controls.Add(new LiteralControl(@"<td>")); Label lblID = new Label(); lblID.ID = "lblID"; ph.Controls.Add(lblID); ph.Controls.Add(new LiteralControl(@"</td><td>")); Label lblGroup = new Label(); lblGroup.ID = "lblGroup"; ph.Controls.Add(lblGroup); ph.Controls.Add(new LiteralControl(@"</td><td>")); CheckBox chkIsPositive = new CheckBox(); chkIsPositive.ID = "chkIsPositive"; chkIsPositive.Enabled = false; ph.Controls.Add(chkIsPositive); ph.Controls.Add(new LiteralControl(@"</td>")); } public override void InstantiateInAlternatingItem(PlaceHolder ph) { InstantiateInItem(ph); } public override void InstantiateInEdit(PlaceHolder ph) { ph.Controls.Add(new LiteralControl(@"<td>")); Label lblID = new Label(); lblID.ID = "lblID"; ph.Controls.Add(lblID); ph.Controls.Add(new LiteralControl(@"</td><td>")); TextBox txtGroup = new TextBox(); txtGroup.ID = "txtGroup"; txtGroup.Visible = true; txtGroup.Enabled = true ; ph.Controls.Add(txtGroup); ph.Controls.Add(new LiteralControl(@"</td><td>")); CheckBox chkIsPositive = new CheckBox(); chkIsPositive.ID = "chkIsPositive"; chkIsPositive.Visible = true; chkIsPositive.Enabled = true ; ph.Controls.Add(chkIsPositive); ph.Controls.Add(new LiteralControl(@"</td>")); } public override void InstantiateInFooter(PlaceHolder ph) { InstantiateInHeader(ph); } public override void InstantiateInSelectedItem(PlaceHolder ph) { ph.Controls.Add(new LiteralControl(@"<td>")); Label lblID = new Label(); lblID.ID = "lblID"; ph.Controls.Add(lblID); ph.Controls.Add(new LiteralControl(@"</td><td>")); TextBox txtGroup = new TextBox(); txtGroup.ID = "txtGroup"; txtGroup.Visible = true; txtGroup.Enabled = false; ph.Controls.Add(txtGroup); ph.Controls.Add(new LiteralControl(@"</td><td>")); CheckBox chkIsPositive = new CheckBox(); chkIsPositive.ID = "chkIsPositive"; chkIsPositive.Visible = true; chkIsPositive.Enabled = false; ph.Controls.Add(chkIsPositive); ph.Controls.Add(new LiteralControl(@"</td>")); } public override void InstantiateInSeperator(PlaceHolder ph) { } public override void DataBindingOverride(object sender, EventArgs e) { PlaceHolder ph = (PlaceHolder)sender; DataListItem li = (DataListItem)ph.NamingContainer; int id = Convert.ToInt32(DataBinder.Eval(li.DataItem, "ID")); string group = (string)DataBinder.Eval(li.DataItem, "Group"); bool isPositive = Convert.ToBoolean(DataBinder.Eval(li.DataItem, "IsPositive")); switch (this.ListItemType) { case ListItemType.Item: case ListItemType.AlternatingItem: { ((Label)ph.FindControl("lblID")).Text = id.ToString(); ((Label)ph.FindControl("lblGroup")).Text = group; ((CheckBox)ph.FindControl("chkIsPositive")).Text = isPositive.ToString(); break; } case ListItemType.EditItem: case ListItemType.SelectedItem: { ((TextBox)ph.FindControl("lblID")).Text = id.ToString(); ((TextBox)ph.FindControl("txtGroup")).Text = group; ((CheckBox)ph.FindControl("chkIsPositive")).Text = isPositive.ToString(); break; } } } } From here I added the control to a page the code behind public partial class NominalGroupbroke : System.Web.UI.UserControl { public void SetNominalGroupList(IList<BONominalGroup> theNominalGroups) { XElement data = Serialiser<BONominalGroup>.SerialiseObjectList(theNominalGroups); ViewState.Add("nominalGroups", data.ToString()); dlNominalGroup.DataSource = theNominalGroups; dlNominalGroup.DataBind(); } protected void Page_init() { dlNominalGroup.HeaderTemplate = new NominalGroupTemplate(ListItemType.Header); dlNominalGroup.ItemTemplate = new NominalGroupTemplate(ListItemType.Item); dlNominalGroup.AlternatingItemTemplate = new NominalGroupTemplate(ListItemType.AlternatingItem); dlNominalGroup.SeparatorTemplate = new NominalGroupTemplate(ListItemType.Separator); dlNominalGroup.SelectedItemTemplate = new NominalGroupTemplate(ListItemType.SelectedItem); dlNominalGroup.EditItemTemplate = new NominalGroupTemplate(ListItemType.EditItem); dlNominalGroup.FooterTemplate = new NominalGroupTemplate(ListItemType.Footer); } protected void Page_Load(object sender, EventArgs e) { dlNominalGroup.ItemCommand += new DataListCommandEventHandler(dlNominalGroup_ItemCommand); } void dlNominalGroup_Init(object sender, EventArgs e) { dlNominalGroup.HeaderTemplate = new NominalGroupTemplate(ListItemType.Header); dlNominalGroup.ItemTemplate = new NominalGroupTemplate(ListItemType.Item); dlNominalGroup.AlternatingItemTemplate = new NominalGroupTemplate(ListItemType.AlternatingItem); dlNominalGroup.SeparatorTemplate = new NominalGroupTemplate(ListItemType.Separator); dlNominalGroup.SelectedItemTemplate = new NominalGroupTemplate(ListItemType.SelectedItem); dlNominalGroup.EditItemTemplate = new NominalGroupTemplate(ListItemType.EditItem); dlNominalGroup.FooterTemplate = new NominalGroupTemplate(ListItemType.Footer); } void dlNominalGroup_DataBinding(object sender, EventArgs e) { } void deleteNominalGroup(int index) { XElement data = XElement.Parse(Convert.ToString( ViewState["nominalGroups"] )); IList<BONominalGroup> list = Serialiser<BONominalGroup>.DeserialiseObjectList(data); FENominalGroup.DeleteNominalGroup(list[index].ID); list.RemoveAt(index); data = Serialiser<BONominalGroup>.SerialiseObjectList(list); ViewState["nominalGroups"] = data.ToString(); dlNominalGroup.DataSource = list; dlNominalGroup.DataBind(); } void updateNominalGroup(DataListItem theItem) { XElement data = XElement.Parse(Convert.ToString( ViewState["nominalGroups"])); IList<BONominalGroup> list = Serialiser<BONominalGroup>.DeserialiseObjectList(data); BONominalGroup old = list[theItem.ItemIndex]; BONominalGroup n = new BONominalGroup(); byte id = Convert.ToByte(((TextBox)theItem.FindControl("lblID")).Text); string group = ((TextBox)theItem.FindControl("txtGroup")).Text; bool isPositive = Convert.ToBoolean(((CheckBox)theItem.FindControl("chkIsPositive")).Text); n.ID = id; n.Group = group; n.IsPositive = isPositive; FENominalGroup.UpdateNominalGroup(old, n); list[theItem.ItemIndex] = n; data = Serialiser<BONominalGroup>.SerialiseObjectList(list); ViewState["nominalGroups"] = data.ToString(); } void dlNominalGroup_ItemCommand(object source, DataListCommandEventArgs e) { DataList l = (DataList)source; switch (e.CommandName) { case "SelectRow": { if (l.EditItemIndex == -1) { l.SelectedIndex = e.Item.ItemIndex; l.EditItemIndex = -1; } break; } case "EditRow": { if (l.SelectedIndex == e.Item.ItemIndex) { l.EditItemIndex = e.Item.ItemIndex; } break; } case "DeleteRow": { deleteNominalGroup(e.Item.ItemIndex); l.EditItemIndex = -1; try { l.SelectedIndex = e.Item.ItemIndex; } catch { l.SelectedIndex = -1; } break; } case "CancelRow": { l.SelectedIndex = l.EditItemIndex; l.EditItemIndex = -1; break; } case "SaveRow": { updateNominalGroup(e.Item); try { l.SelectedIndex = e.Item.ItemIndex; } catch { l.SelectedIndex = -1; } l.EditItemIndex = -1; break; } } } Lots of code there, I'm afraid, but it should build. Thanks if anyone manages to spot my silliness. The BONominalGroup class (please ignore my crazy getHash override, I'm not proud of it). IAudit can just be an empty interface here and all will be fine. It used to inherit from another class, I have cleaned that out - so the serialization logic may be broken here. public class BONominalGroup { public BONominalGroup() #region Fields and properties private Int16 _ID; public Int16 ID { get { return _ID; } set { _ID = value; } } private string _group; public string Group { get { return _group; } set { _group = value; } } private bool _isPositve; public bool IsPositive { get { return _isPositve; } set { _isPositve = value; } } #endregion public override bool Equals(object obj) { bool retVal = false; BONominalGroup ng = obj as BONominalGroup; if (ng!=null) if (ng._group == this._group && ng._ID == this.ID && ng.IsPositive == this.IsPositive) { retVal = true; } return retVal; } public override int GetHashCode() { return ToString().GetHashCode(); } public override string ToString() { return "BONominalGroup{ID:" + this.ID.ToString() + ",Group:" + this.Group.ToString() + ",IsPositive:" + this.IsPositive.ToString() + "," + "}"; } #region IXmlSerializable Members public override void ReadXml(XmlReader reader) { reader.ReadStartElement("BONominalGroup"); this.ID = Convert.ToByte(reader.ReadElementString("id")); this.Group = reader.ReadElementString("group"); this.IsPositive = Convert.ToBoolean(reader.ReadElementString("isPositive")); base.ReadXml(reader); reader.ReadEndElement(); } public override void WriteXml(XmlWriter writer) { writer.WriteElementString("id", this.ID.ToString()); writer.WriteElementString("group", this.Group); writer.WriteElementString("isPositive", this.IsPositive.ToString()); // writer.WriteStartElement("BOBase"); // base.WriteXml(writer); writer.WriteEndElement(); } #endregion }

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  • Parallelism in .NET – Part 16, Creating Tasks via a TaskFactory

    - by Reed
    The Task class in the Task Parallel Library supplies a large set of features.  However, when creating the task, and assigning it to a TaskScheduler, and starting the Task, there are quite a few steps involved.  This gets even more cumbersome when multiple tasks are involved.  Each task must be constructed, duplicating any options required, then started individually, potentially on a specific scheduler.  At first glance, this makes the new Task class seem like more work than ThreadPool.QueueUserWorkItem in .NET 3.5. In order to simplify this process, and make Tasks simple to use in simple cases, without sacrificing their power and flexibility, the Task Parallel Library added a new class: TaskFactory. The TaskFactory class is intended to “Provide support for creating and scheduling Task objects.”  Its entire purpose is to simplify development when working with Task instances.  The Task class provides access to the default TaskFactory via the Task.Factory static property.  By default, TaskFactory uses the default TaskScheduler to schedule tasks on a ThreadPool thread.  By using Task.Factory, we can automatically create and start a task in a single “fire and forget” manner, similar to how we did with ThreadPool.QueueUserWorkItem: Task.Factory.StartNew(() => this.ExecuteBackgroundWork(myData) ); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This provides us with the same level of simplicity we had with ThreadPool.QueueUserWorkItem, but even more power.  For example, we can now easily wait on the task: // Start our task on a background thread var task = Task.Factory.StartNew(() => this.ExecuteBackgroundWork(myData) ); // Do other work on the main thread, // while the task above executes in the background this.ExecuteWorkSynchronously(); // Wait for the background task to finish task.Wait(); TaskFactory simplifies creation and startup of simple background tasks dramatically. In addition to using the default TaskFactory, it’s often useful to construct a custom TaskFactory.  The TaskFactory class includes an entire set of constructors which allow you to specify the default configuration for every Task instance created by that factory.  This is particularly useful when using a custom TaskScheduler.  For example, look at the sample code for starting a task on the UI thread in Part 15: // Given the following, constructed on the UI thread // TaskScheduler uiScheduler = TaskScheduler.FromCurrentSynchronizationContext(); // When inside a background task, we can do string status = GetUpdatedStatus(); (new Task(() => { statusLabel.Text = status; })) .Start(uiScheduler); This is actually quite a bit more complicated than necessary.  When we create the uiScheduler instance, we can use that to construct a TaskFactory that will automatically schedule tasks on the UI thread.  To do that, we’d create the following on our main thread, prior to constructing our background tasks: // Construct a task scheduler from the current SynchronizationContext (UI thread) var uiScheduler = TaskScheduler.FromCurrentSynchronizationContext(); // Construct a new TaskFactory using our UI scheduler var uiTaskFactory = new TaskFactory(uiScheduler); If we do this, when we’re on a background thread, we can use this new TaskFactory to marshal a Task back onto the UI thread.  Our previous code simplifies to: // When inside a background task, we can do string status = GetUpdatedStatus(); // Update our UI uiTaskFactory.StartNew( () => statusLabel.Text = status); Notice how much simpler this becomes!  By taking advantage of the convenience provided by a custom TaskFactory, we can now marshal to set data on the UI thread in a single, clear line of code!

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  • How to make creating viewmodels at runtime less painful

    - by Mr Happy
    I apologize for the long question, it reads a bit as a rant, but I promise it's not! I've summarized my question(s) below In the MVC world, things are straightforward. The Model has state, the View shows the Model, and the Controller does stuff to/with the Model (basically), a controller has no state. To do stuff the Controller has some dependencies on web services, repository, the lot. When you instantiate a controller you care about supplying those dependencies, nothing else. When you execute an action (method on Controller), you use those dependencies to retrieve or update the Model or calling some other domain service. If there's any context, say like some user wants to see the details of a particular item, you pass the Id of that item as parameter to the Action. Nowhere in the Controller is there any reference to any state. So far so good. Enter MVVM. I love WPF, I love data binding. I love frameworks that make data binding to ViewModels even easier (using Caliburn Micro a.t.m.). I feel things are less straightforward in this world though. Let's do the exercise again: the Model has state, the View shows the ViewModel, and the ViewModel does stuff to/with the Model (basically), a ViewModel does have state! (to clarify; maybe it delegates all the properties to one or more Models, but that means it must have a reference to the model one way or another, which is state in itself) To do stuff the ViewModel has some dependencies on web services, repository, the lot. When you instantiate a ViewModel you care about supplying those dependencies, but also the state. And this, ladies and gentlemen, annoys me to no end. Whenever you need to instantiate a ProductDetailsViewModel from the ProductSearchViewModel (from which you called the ProductSearchWebService which in turn returned IEnumerable<ProductDTO>, everybody still with me?), you can do one of these things: call new ProductDetailsViewModel(productDTO, _shoppingCartWebService /* dependcy */);, this is bad, imagine 3 more dependencies, this means the ProductSearchViewModel needs to take on those dependencies as well. Also changing the constructor is painful. call _myInjectedProductDetailsViewModelFactory.Create().Initialize(productDTO);, the factory is just a Func, they are easily generated by most IoC frameworks. I think this is bad because Init methods are a leaky abstraction. You also can't use the readonly keyword for fields that are set in the Init method. I'm sure there are a few more reasons. call _myInjectedProductDetailsViewModelAbstractFactory.Create(productDTO); So... this is the pattern (abstract factory) that is usually recommended for this type of problem. I though it was genius since it satisfies my craving for static typing, until I actually started using it. The amount of boilerplate code is I think too much (you know, apart from the ridiculous variable names I get use). For each ViewModel that needs runtime parameters you'll get two extra files (factory interface and implementation), and you need to type the non-runtime dependencies like 4 extra times. And each time the dependencies change, you get to change it in the factory as well. It feels like I don't even use a DI container anymore. (I think Castle Windsor has some kind of solution for this [with it's own drawbacks, correct me if I'm wrong]). do something with anonymous types or dictionary. I like my static typing. So, yeah. Mixing state and behavior in this way creates a problem which don't exist at all in MVC. And I feel like there currently isn't a really adequate solution for this problem. Now I'd like to observe some things: People actually use MVVM. So they either don't care about all of the above, or they have some brilliant other solution. I haven't found an in-depth example of MVVM with WPF. For example, the NDDD-sample project immensely helped me understand some DDD concepts. I'd really like it if someone could point me in the direction of something similar for MVVM/WPF. Maybe I'm doing MVVM all wrong and I should turn my design upside down. Maybe I shouldn't have this problem at all. Well I know other people have asked the same question so I think I'm not the only one. To summarize Am I correct to conclude that having the ViewModel being an integration point for both state and behavior is the reason for some difficulties with the MVVM pattern as a whole? Is using the abstract factory pattern the only/best way to instantiate a ViewModel in a statically typed way? Is there something like an in depth reference implementation available? Is having a lot of ViewModels with both state/behavior a design smell?

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  • Why does calling CreateDXGIFactory prevent my program from exiting?

    - by smoth190
    I'm using CreateDXGIFactory to get the graphics adapters and display modes. When I call it, it works fine and I get all the data. However, when I exit my program, the main Win32 thread exits, but something stays open because it keeps debugging. Does CreateDXGIFactory create an extra thread and I'm not closing it? I don't understand. The only thing I would suspect is that in the documentation it says it doesn't work if it's called from DllMain. It is in a DLL, but it's not called from DllMain. And it doesn't fail, either. I'm using DirectX 11. Here is the function that initializes DirectX. I haven't gotten past retrieving the refresh rate because of this problem. I commented everything out to pinpoint the problem. bool CGraphicsManager::InitDirectX(HWND hWnd, int width, int height) { HRESULT result; IDXGIFactory* factory; IDXGIOutput* output; IDXGIAdapter* adapter; DXGI_MODE_DESC* displayModes; DXGI_ADAPTER_DESC adapterDesc; unsigned int modeCount = 0; unsigned int refreshNum = 0; unsigned int refreshDen = 0; //First, we need to get the monitors refresh rater result = CreateDXGIFactory(__uuidof(IDXGIFactory), (void**)&factory); //if(FAILED(result)) //{ //MemoryUtil::MessageBoxError(TEXT("InitDirectX"), 0, 0, TEXT("Failed to create DXGI factory\nError:\n%s"), DXGetErrorDescription(result)); //return false; //} /*//Create a graphics card adapter result = factory->EnumAdapters(0, &adapter); if(FAILED(result)) { MemoryUtil::MessageBoxError(TEXT("InitDirectX"), 0, 0, TEXT("Failed to get graphics adapters\nError:\n%s"), DXGetErrorDescription(result)); return false; } //Get the output result = adapter->EnumOutputs(0, &output); if(FAILED(result)) { MemoryUtil::MessageBoxError(TEXT("InitDirectX"), 0, 0, TEXT("Failed to get adapter output\nError:\n%s"), DXGetErrorDescription(result)); return false; } //Get the modes result = output->GetDisplayModeList(DXGI_FORMAT_R8G8B8A8_UNORM, DXGI_ENUM_MODES_INTERLACED, &modeCount, 0); if(FAILED(result)) { MemoryUtil::MessageBoxError(TEXT("InitDirectX"), 0, 0, TEXT("Failed to get mode count\nError:\n%s"), DXGetErrorDescription(result)); return false; } displayModes = new DXGI_MODE_DESC[modeCount]; result = output->GetDisplayModeList(DXGI_FORMAT_R8G8B8A8_UNORM, DXGI_ENUM_MODES_INTERLACED, &modeCount, displayModes); if(FAILED(result)) { MemoryUtil::MessageBoxError(TEXT("InitDirectX"), 0, 0, TEXT("Failed to get display modes\nError:\n%s"), DXGetErrorDescription(result)); return false; } //Now we need to find one for our screen size for(unsigned int i = 0; i < modeCount; i++) { if(displayModes[i].Width == (unsigned int)width) { if(displayModes[i].Height == (unsigned int)height) { refreshNum = displayModes[i].RefreshRate.Numerator; refreshDen = displayModes[i].RefreshRate.Denominator; break; } } } //Store the video card data result = adapter->GetDesc(&adapterDesc); if(FAILED(result)) { MemoryUtil::MessageBoxError(TEXT("InitDirectX"), 0, 0, TEXT("Failed to get adapter description\nError:\n%s"), DXGetErrorDescription(result)); return false; } m_videoCard = new CVideoCard(); MemoryUtil::CreateGameObject(m_videoCard); m_videoCard->VideoCardMemory = (unsigned int)(adapterDesc.DedicatedVideoMemory); wcstombs_s(0, m_videoCard->VideoCardDescription, 128, adapterDesc.Description, 128);*/ //ReleaseCOM(output); //ReleaseCOM(adapter); ReleaseCOM(factory); //DeletePointerArray(displayModes); return true; } Also, I don't know if this means anything, but this is some of the output log when the function is commented out: //... 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\msvcr100d.dll', Symbols loaded. 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\imm32.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\msctf.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\uxtheme.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Program Files (x86)\Common Files\microsoft shared\ink\tiptsf.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\ole32.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\oleaut32.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\clbcatq.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\oleacc.dll', Cannot find or open the PDB file The program '[6560] LostRock.exe: Native' has exited with code 0 (0x0). And when it isn't commented out... //... 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\cfgmgr32.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\devobj.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\wintrust.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\crypt32.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\msasn1.dll', Cannot find or open the PDB file 'LostRock.exe': Unloaded 'C:\Windows\SysWOW64\setupapi.dll' 'LostRock.exe': Unloaded 'C:\Windows\SysWOW64\devobj.dll' 'LostRock.exe': Unloaded 'C:\Windows\SysWOW64\cfgmgr32.dll' 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\clbcatq.dll', Cannot find or open the PDB file 'LostRock.exe': Loaded 'C:\Windows\SysWOW64\oleacc.dll', Cannot find or open the PDB file The thread 'Win32 Thread' (0xb94) has exited with code 0 (0x0). The program '[8096] LostRock.exe: Native' has exited with code 0 (0x0). //This is called when I click "Stop Debugging" P.S. I know it is CreateDXGIFactory because if I comment it out, the program exits correctly.

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  • MVVM - how to make creating viewmodels at runtime less painfull

    - by Mr Happy
    I apologize for the long question, it reads a bit as a rant, but I promise it's not! I've summarized my question(s) below In the MVC world, things are straightforward. The Model has state, the View shows the Model, and the Controller does stuff to/with the Model (basically), a controller has no state. To do stuff the Controller has some dependencies on web services, repository, the lot. When you instantiate a controller you care about supplying those dependencies, nothing else. When you execute an action (method on Controller), you use those dependencies to retrieve or update the Model or calling some other domain service. If there's any context, say like some user wants to see the details of a particular item, you pass the Id of that item as parameter to the Action. Nowhere in the Controller is there any reference to any state. So far so good. Enter MVVM. I love WPF, I love data binding. I love frameworks that make data binding to ViewModels even easier (using Caliburn Micro a.t.m.). I feel things are less straightforward in this world though. Let's do the exercise again: the Model has state, the View shows the ViewModel, and the ViewModel does stuff to/with the Model (basically), a ViewModel does have state! (to clarify; maybe it delegates all the properties to one or more Models, but that means it must have a reference to the model one way or another, which is state in itself) To do stuff the ViewModel has some dependencies on web services, repository, the lot. When you instantiate a ViewModel you care about supplying those dependencies, but also the state. And this, ladies and gentlemen, annoys me to no end. Whenever you need to instantiate a ProductDetailsViewModel from the ProductSearchViewModel (from which you called the ProductSearchWebService which in turn returned IEnumerable<ProductDTO>, everybody still with me?), you can do one of these things: call new ProductDetailsViewModel(productDTO, _shoppingCartWebService /* dependcy */);, this is bad, imagine 3 more dependencies, this means the ProductSearchViewModel needs to take on those dependencies as well. Also changing the constructor is painfull. call _myInjectedProductDetailsViewModelFactory.Create().Initialize(productDTO);, the factory is just a Func, they are easily generated by most IoC frameworks. I think this is bad because Init methods are a leaky abstraction. You also can't use the readonly keyword for fields that are set in the Init method. I'm sure there are a few more reasons. call _myInjectedProductDetailsViewModelAbstractFactory.Create(productDTO); So... this is the pattern (abstract factory) that is usually recommended for this type of problem. I though it was genious since it satisfies my craving for static typing, until I actually started using it. The amount of boilerplate code is I think too much (you know, apart from the ridiculous variable names I get use). For each ViewModel that needs runtime parameters you'll get two extra files (factory interface and implementation), and you need to type the non-runtime dependencies like 4 extra times. And each time the dependencies change, you get to change it in the factory as well. It feels like I don't even use an DI container anymore. (I think Castle Windsor has some kind of solution for this [with it's own drawbacks, correct me if I'm wrong]). do something with anonymous types or dictionary. I like my static typing. So, yeah. Mixing state and behavior in this way creates a problem which don't exist at all in MVC. And I feel like there currently isn't a really adequate solution for this problem. Now I'd like to observe some things: People actually use MVVM. So they either don't care about all of the above, or they have some brilliant other solution. I haven't found an indepth example of MVVM with WPF. For example, the NDDD-sample project immensely helped me understand some DDD concepts. I'd really like it if someone could point me in the direction of something similar for MVVM/WPF. Maybe I'm doing MVVM all wrong and I should turn my design upside down. Maybe I shouldn't have this problem at all. Well I know other people have asked the same question so I think I'm not the only one. To summarize Am I correct to conclude that having the ViewModel being an integration point for both state and behavior is the reason for some difficulties with the MVVM pattern as a whole? Is using the abstract factory pattern the only/best way to instantiate a ViewModel in a statically typed way? Is there something like an in depth reference implementation available? Is having a lot of ViewModels with both state/behavior a design smell?

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  • How to make creating viewmodels at runtime less painfull

    - by Mr Happy
    I apologize for the long question, it reads a bit as a rant, but I promise it's not! I've summarized my question(s) below In the MVC world, things are straightforward. The Model has state, the View shows the Model, and the Controller does stuff to/with the Model (basically), a controller has no state. To do stuff the Controller has some dependencies on web services, repository, the lot. When you instantiate a controller you care about supplying those dependencies, nothing else. When you execute an action (method on Controller), you use those dependencies to retrieve or update the Model or calling some other domain service. If there's any context, say like some user wants to see the details of a particular item, you pass the Id of that item as parameter to the Action. Nowhere in the Controller is there any reference to any state. So far so good. Enter MVVM. I love WPF, I love data binding. I love frameworks that make data binding to ViewModels even easier (using Caliburn Micro a.t.m.). I feel things are less straightforward in this world though. Let's do the exercise again: the Model has state, the View shows the ViewModel, and the ViewModel does stuff to/with the Model (basically), a ViewModel does have state! (to clarify; maybe it delegates all the properties to one or more Models, but that means it must have a reference to the model one way or another, which is state in itself) To do stuff the ViewModel has some dependencies on web services, repository, the lot. When you instantiate a ViewModel you care about supplying those dependencies, but also the state. And this, ladies and gentlemen, annoys me to no end. Whenever you need to instantiate a ProductDetailsViewModel from the ProductSearchViewModel (from which you called the ProductSearchWebService which in turn returned IEnumerable<ProductDTO>, everybody still with me?), you can do one of these things: call new ProductDetailsViewModel(productDTO, _shoppingCartWebService /* dependcy */);, this is bad, imagine 3 more dependencies, this means the ProductSearchViewModel needs to take on those dependencies as well. Also changing the constructor is painfull. call _myInjectedProductDetailsViewModelFactory.Create().Initialize(productDTO);, the factory is just a Func, they are easily generated by most IoC frameworks. I think this is bad because Init methods are a leaky abstraction. You also can't use the readonly keyword for fields that are set in the Init method. I'm sure there are a few more reasons. call _myInjectedProductDetailsViewModelAbstractFactory.Create(productDTO); So... this is the pattern (abstract factory) that is usually recommended for this type of problem. I though it was genious since it satisfies my craving for static typing, until I actually started using it. The amount of boilerplate code is I think too much (you know, apart from the ridiculous variable names I get use). For each ViewModel that needs runtime parameters you'll get two extra files (factory interface and implementation), and you need to type the non-runtime dependencies like 4 extra times. And each time the dependencies change, you get to change it in the factory as well. It feels like I don't even use an DI container anymore. (I think Castle Windsor has some kind of solution for this [with it's own drawbacks, correct me if I'm wrong]). do something with anonymous types or dictionary. I like my static typing. So, yeah. Mixing state and behavior in this way creates a problem which don't exist at all in MVC. And I feel like there currently isn't a really adequate solution for this problem. Now I'd like to observe some things: People actually use MVVM. So they either don't care about all of the above, or they have some brilliant other solution. I haven't found an indepth example of MVVM with WPF. For example, the NDDD-sample project immensely helped me understand some DDD concepts. I'd really like it if someone could point me in the direction of something similar for MVVM/WPF. Maybe I'm doing MVVM all wrong and I should turn my design upside down. Maybe I shouldn't have this problem at all. Well I know other people have asked the same question so I think I'm not the only one. To summarize Am I correct to conclude that having the ViewModel being an integration point for both state and behavior is the reason for some difficulties with the MVVM pattern as a whole? Is using the abstract factory pattern the only/best way to instantiate a ViewModel in a statically typed way? Is there something like an in depth reference implementation available? Is having a lot of ViewModels with both state/behavior a design smell?

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  • does red5 read tomcat-users.xml

    - by baba
    Hi, I have been busy creating an app for Red5. Imagine what was my surprise when I tried to configure basic/digest authentication and I couldn't. What struck me as strange is that I have a running tomcat instance that works and authenticates correctly with the following xmls: web.xml (part of) <security-constraint> <web-resource-collection> <web-resource-name>A Protected Page</web-resource-name> <url-pattern>/stats.jsp</url-pattern> </web-resource-collection> <auth-constraint> <description/> <role-name>tomcat</role-name> </auth-constraint> </security-constraint> <login-config> <auth-method>DIGEST</auth-method> <realm-name>BLAAAAAAAAAAAAAAAAA</realm-name> </login-config> <security-role> <description/> <role-name>tomcat</role-name> </security-role> and a tomcat-users.xml in /conf that looks kinda like this: <?xml version="1.0" encoding="UTF-8"?> <tomcat-users> <role rolename="tomcat"/> <user username="ide" password="bogus" roles="tomcat"/> </tomcat-users> The annoying thing is that configuration authenticates correctly when on tomcat's servlet container, but on the red5's modified one, it just keeps asking for authentication. Am I becoming mad or it should work like a charm? Red5 is version 0_9_1 The stats.jsp is accessible in both servlet containers, the only difference is that when you input the correct password and username in tomcat, you are logged in, and in red5 you are not, it just keeps asking you for the password. Any pointers? Am I missing something? Here is a stack trace of the error I receive AT the moment I try the login: Caused by: java.io.IOException: Unable to locate a login configuration at com.sun.security.auth.login.ConfigFile.init(ConfigFile.java:250) [na:1.6.0_22] at com.sun.security.auth.login.ConfigFile.<init>(ConfigFile.java:91) [na:1.6.0_22] ... 27 common frames omitted [ERROR] [http-127.0.0.1-5080-1] org.apache.catalina.realm.JAASRealm - Cannot find message associated with key jaasRealm.unexpectedError java.lang.SecurityException: Unable to locate a login configuration at com.sun.security.auth.login.ConfigFile.<init>(ConfigFile.java:93) [na:1.6.0_22] at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) [na:1.6.0_22] at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) [na:1.6.0_22] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) [na:1.6.0_22] at java.lang.reflect.Constructor.newInstance(Constructor.java:513) [na:1.6.0_22] at java.lang.Class.newInstance0(Class.java:355) [na:1.6.0_22] at java.lang.Class.newInstance(Class.java:308) [na:1.6.0_22] at javax.security.auth.login.Configuration$3.run(Configuration.java:247) [na:1.6.0_22] at java.security.AccessController.doPrivileged(Native Method) [na:1.6.0_22] at javax.security.auth.login.Configuration.getConfiguration(Configuration.java:242) [na:1.6.0_22] at javax.security.auth.login.LoginContext$1.run(LoginContext.java:237) [na:1.6.0_22] at java.security.AccessController.doPrivileged(Native Method) [na:1.6.0_22] at javax.security.auth.login.LoginContext.init(LoginContext.java:234) [na:1.6.0_22] at javax.security.auth.login.LoginContext.<init>(LoginContext.java:403) [na:1.6.0_22] at org.apache.catalina.realm.JAASRealm.authenticate(JAASRealm.java:394) [catalina-6.0.24.jar:na] at org.apache.catalina.realm.JAASRealm.authenticate(JAASRealm.java:357) [catalina-6.0.24.jar:na] at org.apache.catalina.authenticator.DigestAuthenticator.findPrincipal(DigestAuthenticator.java:283) [catalina-6.0.24.jar:na] at org.apache.catalina.authenticator.DigestAuthenticator.authenticate(DigestAuthenticator.java:176) [catalina-6.0.24.jar:na] at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:523) [catalina-6.0.24.jar:na] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) [catalina-6.0.24.jar:na] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [catalina-6.0.24.jar:na] at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:555) [catalina-6.0.24.jar:na] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [catalina-6.0.24.jar:na] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) [catalina-6.0.24.jar:na] at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852) [tomcat-coyote-6.0.24.jar:na] at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) [tomcat-coyote-6.0.24.jar:na] at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) [tomcat-coyote-6.0.24.jar:na] at java.lang.Thread.run(Thread.java:662) [na:1.6.0_22] Caused by: java.io.IOException: Unable to locate a login configuration at com.sun.security.auth.login.ConfigFile.init(ConfigFile.java:250) [na:1.6.0_22] at com.sun.security.auth.login.ConfigFile.<init>(ConfigFile.java:91) [na:1.6.0_22] ... 27 common frames omitted In addition, here is the configuration of red5-web.properties webapp.contextPath=/project Even futher information: Seems to me like it is using the right realm: MemoryRealm [INFO] [main] org.red5.server.tomcat.TomcatLoader - Setting connector: org.apache.catalina.connector.Connector [INFO] [main] org.red5.server.tomcat.TomcatLoader - Address to bind: /127.0.0.1:5080 [INFO] [main] org.red5.server.tomcat.TomcatLoader - Setting realm: org.apache.catalina.realm.MemoryRealm [INFO] [main] org.red5.server.tomcat.TomcatLoader - Loading tomcat context [INFO] [main] org.red5.server.tomcat.TomcatLoader - Server root: C:/Program Files/Red5 [INFO] [main] org.red5.server.tomcat.TomcatLoader - Config root: C:/Program Files/Red5/conf [INFO] [main] org.red5.server.tomcat.TomcatLoader - Application root: C:/Program Files/Red5/webapps [INFO] [main] org.red5.server.tomcat.TomcatLoader - Starting Tomcat servlet engine [INFO] [main] org.apache.catalina.startup.Embedded - Starting tomcat server [INFO] [main] org.apache.catalina.core.StandardEngine - Starting Servlet Engine: Apache Tomcat/6.0.26 However, immediately after bootstraping Tomcat, I am presented with the following error: Exception in thread "Launcher:/administration" org.springframework.beans.factory.BeanDefinitionStoreException: Could not resolve bean definition resource pattern [/WEB-INF/red5-*.xml]; nested exception is java.io.FileNotFoundException: ServletContext resource [/WEB-INF/] cannot be resolved to URL because it does not exist at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:190) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:149) at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:124) at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:93) at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:130) at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:458) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:388) at org.red5.server.tomcat.TomcatLoader$1.run(TomcatLoader.java:594) Caused by: java.io.FileNotFoundException: ServletContext resource [/WEB-INF/] cannot be resolved to URL because it does not exist at org.springframework.web.context.support.ServletContextResource.getURL(ServletContextResource.java:132) at org.springframework.core.io.support.PathMatchingResourcePatternResolver.isJarResource(PathMatchingResourcePatternResolver.java:414) at org.springframework.core.io.support.PathMatchingResourcePatternResolver.findPathMatchingResources(PathMatchingResourcePatternResolver.java:343) at org.springframework.core.io.support.PathMatchingResourcePatternResolver.getResources(PathMatchingResourcePatternResolver.java:282) at org.springframework.context.support.AbstractApplicationContext.getResources(AbstractApplicationContext.java:1156) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:177) ... 7 more This error is kinda strange, because after this it seems that /WEB-INF/ is found by the rest of the program by the following output: [INFO] [Launcher:/SOSample] org.springframework.beans.factory.config.PropertyPlaceholderConfigurer - Loading properties file from ServletContext resource [/WEB-INF/red5-web.properties] [INFO] [Launcher:/installer] org.springframework.beans.factory.config.PropertyPlaceholderConfigurer - Loading properties file from ServletContext resource [/WEB-INF/red5-web.properties] [INFO] [Launcher:/] org.springframework.beans.factory.config.PropertyPlaceholderConfigurer - Loading properties file from ServletContext resource [/WEB-INF/red5-web.properties] [INFO] [Launcher:/LiveMedia] org.springframework.beans.factory.config.PropertyPlaceholderConfigurer - Loading properties file from ServletContext resource [/WEB-INF/red5-web.properties] What really annoys me is that, as you can see in the output, when I try to login, I get a JAASRealm-related exception, but in the debug output when Tomcat is loading, it is clear to me that it expects a MemoryRealm. I was wondering where and how in red5.xml should I specify bean properties such that I force red5 to use MemoryRealm that is under /conf/tomcat-users.xml, because it certainly doesn't do so now. It seems like the biggest question I have posted so far, but I tried to explain it as fully as possible as to avoid confusion.

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  • Pass a Delphi class to a C++ function/method that expects a class with __thiscall methods.

    - by Alan G.
    I have some MSVC++ compiled DLL's for which I have created COM-like (lite) interfaces (abstract Delphi classes). Some of those classes have methods that need pointers to objects. These C++ methods are declared with the __thiscall calling convention (which I cannot change), which is just like __stdcall, except a this pointer is passed on the ECX register. I create the class instance in Delphi, then pass it on to the C++ method. I can set breakpoints in Delphi and see it hitting the exposed __stdcall methods in my Delphi class, but soon I get a STATUS_STACK_BUFFER_OVERRUN and the app has to exit. Is it possible to emulate/deal with __thiscall on the Delphi side of things? If I pass an object instantiated by the C++ system then all is good, and that object's methods are called (as would be expected), but this is useless - I need to pass Delphi objects. Edit 2010-04-19 18:12 This is what happens in more detail: The first method called (setLabel) exits with no error (though its a stub method). The second method called (init), enters then dies when it attempts to read the vol parameter. C++ Side #define SHAPES_EXPORT __declspec(dllexport) // just to show the value class SHAPES_EXPORT CBox { public: virtual ~CBox() {} virtual void init(double volume) = 0; virtual void grow(double amount) = 0; virtual void shrink(double amount) = 0; virtual void setID(int ID = 0) = 0; virtual void setLabel(const char* text) = 0; }; Delphi Side IBox = class public procedure destroyBox; virtual; stdcall; abstract; procedure init(vol: Double); virtual; stdcall; abstract; procedure grow(amount: Double); virtual; stdcall; abstract; procedure shrink(amount: Double); virtual; stdcall; abstract; procedure setID(val: Integer); virtual; stdcall; abstract; procedure setLabel(text: PChar); virtual; stdcall; abstract; end; TMyBox = class(IBox) protected FVolume: Double; FID: Integer; FLabel: String; // public constructor Create; destructor Destroy; override; // BEGIN Virtual Method implementation procedure destroyBox; override; stdcall; // empty - Dont need/want C++ to manage my Delphi objects, just call their methods procedure init(vol: Double); override; stdcall; // FVolume := vol; procedure grow(amount: Double); override; stdcall; // Inc(FVolume, amount); procedure shrink(amount: Double); override; stdcall; // Dec(FVolume, amount); procedure setID(val: Integer); override; stdcall; // FID := val; procedure setLabel(text: PChar); override; stdcall; // Stub method; empty. // END Virtual Method implementation property Volume: Double read FVolume; property ID: Integer read FID; property Label: String read FLabel; end; I would have half expected using stdcall alone to work, but something is messing up, not sure what, perhaps something to do with the ECX register being used? Help would be greatly appreciated. Edit 2010-04-19 17:42 Could it be that the ECX register needs to be preserved on entry and restored once the function exits? Is the this pointer required by C++? I'm probably just reaching at the moment based on some intense Google searches. I found something related, but it seems to be dealing with the reverse of this issue.

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  • Best way to reformat/recover in Windows when your CD key is no longer valid?

    - by CSarnia
    I have a copy of Windows 7 Professional that I have downloaded from the MSDN e-academy (thanks to my school). Now, the problem is that these license keys are one-use only. If I need to reformat or do a factory reset, what is the best way for me to do so, without invalidating my license and screwing me out of an operating system? Edit: I would also like to know some information on the "restore to factory settings" option in Windows 7 recovery center. Does it do exactly as the name implies and starts you off as if you had just done a fresh install? If I had some kind of nasty trojan or virus, would it be able to survive through the factory reset? The recovery center also has an option for reformatting, though I don't think that it's an actual format - it just backs up your stuff into a Windows.old folder or something like that. Does that require a valid license key?

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  • How do I use constructor dependency injection to supply Models from a collection to their ViewModels

    - by GraemeF
    I'm using constructor dependency injection in my WPF application and I keep running into the following pattern, so would like to get other people's opinion on it and hear about alternative solutions. The goal is to wire up a hierarchy of ViewModels to a similar hierarchy of Models, so that the responsibility for presenting the information in each model lies with its own ViewModel implementation. (The pattern also crops up under other circumstances but MVVM should make for a good example.) Here's a simplified example. Given that I have a model that has a collection of further models: public interface IPerson { IEnumerable<IAddress> Addresses { get; } } public interface IAddress { } I would like to mirror this hierarchy in the ViewModels so that I can bind a ListBox (or whatever) to a collection in the Person ViewModel: public interface IPersonViewModel { ObservableCollection<IAddressViewModel> Addresses { get; } void Initialize(); } public interface IAddressViewModel { } The child ViewModel needs to present the information from the child Model, so it's injected via the constructor: public class AddressViewModel : IAddressViewModel { private readonly IAddress _address; public AddressViewModel(IAddress address) { _address = address; } } The question is, what is the best way to supply the child Model to the corresponding child ViewModel? The example is trivial, but in a typical real case the ViewModels have more dependencies - each of which has its own dependencies (and so on). I'm using Unity 1.2 (although I think the question is relevant across the other IoC containers), and I am using Caliburn's view strategies to automatically find and wire up the appropriate View to a ViewModel. Here is my current solution: The parent ViewModel needs to create a child ViewModel for each child Model, so it has a factory method added to its constructor which it uses during initialization: public class PersonViewModel : IPersonViewModel { private readonly Func<IAddress, IAddressViewModel> _addressViewModelFactory; private readonly IPerson _person; public PersonViewModel(IPerson person, Func<IAddress, IAddressViewModel> addressViewModelFactory) { _addressViewModelFactory = addressViewModelFactory; _person = person; Addresses = new ObservableCollection<IAddressViewModel>(); } public ObservableCollection<IAddressViewModel> Addresses { get; private set; } public void Initialize() { foreach (IAddress address in _person.Addresses) Addresses.Add(_addressViewModelFactory(address)); } } A factory method that satisfies the Func<IAddress, IAddressViewModel> interface is registered with the main UnityContainer. The factory method uses a child container to register the IAddress dependency that is required by the ViewModel and then resolves the child ViewModel: public class Factory { private readonly IUnityContainer _container; public Factory(IUnityContainer container) { _container = container; } public void RegisterStuff() { _container.RegisterInstance<Func<IAddress, IAddressViewModel>>(CreateAddressViewModel); } private IAddressViewModel CreateAddressViewModel(IAddress model) { IUnityContainer childContainer = _container.CreateChildContainer(); childContainer.RegisterInstance(model); return childContainer.Resolve<IAddressViewModel>(); } } Now, when the PersonViewModel is initialized, it loops through each Address in the Model and calls CreateAddressViewModel() (which was injected via the Func<IAddress, IAddressViewModel> argument). CreateAddressViewModel() creates a temporary child container and registers the IAddress model so that when it resolves the IAddressViewModel from the child container the AddressViewModel gets the correct instance injected via its constructor. This seems to be a good solution to me as the dependencies of the ViewModels are very clear and they are easily testable and unaware of the IoC container. On the other hand, performance is OK but not great as a lot of temporary child containers can be created. Also I end up with a lot of very similar factory methods. Is this the best way to inject the child Models into the child ViewModels with Unity? Is there a better (or faster) way to do it in other IoC containers, e.g. Autofac? How would this problem be tackled with MEF, given that it is not a traditional IoC container but is still used to compose objects?

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  • Windows App. Thread Aborting Issue

    - by Patrick
    I'm working on an application that has to make specific decisions based on files that are placed into a folder being watched by a file watcher. Part of this decision making process involves renaming files before moving them off to another folder to be processed. Since I'm working with files of all different sizes I created an object that checks the file in a seperate thread to verify that it is "available" and when it is it fires an event. When I run the rename code from inside this available event it works. public void RenameFile_Test() { string psFilePath = @"C:\File1.xlsx"; tgt_File target = new FileObject(psFilePath); target.FileAvailable += new FileEventHandler(OnFileAvailable); target.FileUnAvailable += new FileEventHandler(OnFileUnavailable); } private void OnFileAvailable(object source, FileEventArgs e) { ((FileObject)source).RenameFile(@"C:\File2.xlsx"); } The problem I'm running into is that when the extensions are different from the source file and the rename to file I am making a call to a conversion factory that returns a factory object based on the type of conversion and then converts the file accordingly before doing the rename. When I run that particular piece of code in unit test it works, the factory object is returned, and the conversion happens correctly. But when I run it within the process I get up to the... moExcelApp = new Application(); part of converting an .xls or .xlsx to a .csv and i get a "Thread was being Aborted" error. Any thoughts? Update: There is a bit more information and a bit of map of how the application works currently. Client Application running FSW On File Created event Creates a FileObject passing in the path of the file. On construction the file is validated: if file exists is true then, Thread toAvailableCheck = new Thread(new ThreadStart(AvailableCheck)); toAvailableCheck.Start(); The AvailableCheck Method repeatedly tries to open a streamreader to the file until the reader is either created or the number of attempts times out. If the reader is opened, it fires the FileAvailable event, if not it fires the FileUnAvailable event, passing back itself in the event. The client application is wired to catch those events from inside the Oncreated event of the FSW. the OnFileAvailable method then calls the rename functionality which contains the excel interop call. If the file is being renamed (not converted, extensions stay the same) it does a move to change the name from the old file name to the new, and if its a conversion it runs a conversion factory object which returns the correct type of conversion based on the extensions of the source file and the destination file name. If it is a simple rename it works w/o a problem. If its a conversion (which is the XLS to CSV object that is returned as a part of the factory) the very first thing it does is create a new application object. That is where the application bombs. When i test the factory and conversion/rename process outside of the thread and in its own unit test the process works w/o a problem. Update: I tested the Excel Interop inside a thread by doing this: [TestMethod()] public void ExcelInteropTest() { Thread toExcelInteropThreadTest = new Thread(new ThreadStart(Instantiate_App)); toExcelInteropThreadTest.Start(); } private void Instantiate_App() { Application moExcelApp = new Application(); moExcelApp.Quit(); } And on the line where the application is instatntiated I got the 'A first chance exception of type 'System.Threading.ThreadAbortException' error. So I added; toExcelInteropThreadTest.SetApartmentState(ApartmentState.MTA); after the thread instantiation and before the thread start call and still got the same error. I'm getting the notion that I'm going to have to reconsider the design.

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  • The fastest way to resize images from ASP.NET. And it’s (more) supported-ish.

    - by Bertrand Le Roy
    I’ve shown before how to resize images using GDI, which is fairly common but is explicitly unsupported because we know of very real problems that this can cause. Still, many sites still use that method because those problems are fairly rare, and because most people assume it’s the only way to get the job done. Plus, it works in medium trust. More recently, I’ve shown how you can use WPF APIs to do the same thing and get JPEG thumbnails, only 2.5 times faster than GDI (even now that GDI really ultimately uses WIC to read and write images). The boost in performance is great, but it comes at a cost, that you may or may not care about: it won’t work in medium trust. It’s also just as unsupported as the GDI option. What I want to show today is how to use the Windows Imaging Components from ASP.NET APIs directly, without going through WPF. The approach has the great advantage that it’s been tested and proven to scale very well. The WIC team tells me you should be able to call support and get answers if you hit problems. Caveats exist though. First, this is using interop, so until a signed wrapper sits in the GAC, it will require full trust. Second, the APIs have a very strong smell of native code and are definitely not .NET-friendly. And finally, the most serious problem is that older versions of Windows don’t offer MTA support for image decoding. MTA support is only available on Windows 7, Vista and Windows Server 2008. But on 2003 and XP, you’ll only get STA support. that means that the thread safety that we so badly need for server applications is not guaranteed on those operating systems. To make it work, you’d have to spin specialized threads yourself and manage the lifetime of your objects, which is outside the scope of this article. We’ll assume that we’re fine with al this and that we’re running on 7 or 2008 under full trust. Be warned that the code that follows is not simple or very readable. This is definitely not the easiest way to resize an image in .NET. Wrapping native APIs such as WIC in a managed wrapper is never easy, but fortunately we won’t have to: the WIC team already did it for us and released the results under MS-PL. The InteropServices folder, which contains the wrappers we need, is in the WicCop project but I’ve also included it in the sample that you can download from the link at the end of the article. In order to produce a thumbnail, we first have to obtain a decoding frame object that WIC can use. Like with WPF, that object will contain the command to decode a frame from the source image but won’t do the actual decoding until necessary. Getting the frame is done by reading the image bytes through a special WIC stream that you can obtain from a factory object that we’re going to reuse for lots of other tasks: var photo = File.ReadAllBytes(photoPath); var factory = (IWICComponentFactory)new WICImagingFactory(); var inputStream = factory.CreateStream(); inputStream.InitializeFromMemory(photo, (uint)photo.Length); var decoder = factory.CreateDecoderFromStream( inputStream, null, WICDecodeOptions.WICDecodeMetadataCacheOnLoad); var frame = decoder.GetFrame(0); We can read the dimensions of the frame using the following (somewhat ugly) code: uint width, height; frame.GetSize(out width, out height); This enables us to compute the dimensions of the thumbnail, as I’ve shown in previous articles. We now need to prepare the output stream for the thumbnail. WIC requires a special kind of stream, IStream (not implemented by System.IO.Stream) and doesn’t directlyunderstand .NET streams. It does provide a number of implementations but not exactly what we need here. We need to output to memory because we’ll want to persist the same bytes to the response stream and to a local file for caching. The memory-bound version of IStream requires a fixed-length buffer but we won’t know the length of the buffer before we resize. To solve that problem, I’ve built a derived class from MemoryStream that also implements IStream. The implementation is not very complicated, it just delegates the IStream methods to the base class, but it involves some native pointer manipulation. Once we have a stream, we need to build the encoder for the output format, which could be anything that WIC supports. For web thumbnails, our only reasonable options are PNG and JPEG. I explored PNG because it’s a lossless format, and because WIC does support PNG compression. That compression is not very efficient though and JPEG offers good quality with much smaller file sizes. On the web, it matters. I found the best PNG compression option (adaptive) to give files that are about twice as big as 100%-quality JPEG (an absurd setting), 4.5 times bigger than 95%-quality JPEG and 7 times larger than 85%-quality JPEG, which is more than acceptable quality. As a consequence, we’ll use JPEG. The JPEG encoder can be prepared as follows: var encoder = factory.CreateEncoder( Consts.GUID_ContainerFormatJpeg, null); encoder.Initialize(outputStream, WICBitmapEncoderCacheOption.WICBitmapEncoderNoCache); The next operation is to create the output frame: IWICBitmapFrameEncode outputFrame; var arg = new IPropertyBag2[1]; encoder.CreateNewFrame(out outputFrame, arg); Notice that we are passing in a property bag. This is where we’re going to specify our only parameter for encoding, the JPEG quality setting: var propBag = arg[0]; var propertyBagOption = new PROPBAG2[1]; propertyBagOption[0].pstrName = "ImageQuality"; propBag.Write(1, propertyBagOption, new object[] { 0.85F }); outputFrame.Initialize(propBag); We can then set the resolution for the thumbnail to be 96, something we weren’t able to do with WPF and had to hack around: outputFrame.SetResolution(96, 96); Next, we set the size of the output frame and create a scaler from the input frame and the computed dimensions of the target thumbnail: outputFrame.SetSize(thumbWidth, thumbHeight); var scaler = factory.CreateBitmapScaler(); scaler.Initialize(frame, thumbWidth, thumbHeight, WICBitmapInterpolationMode.WICBitmapInterpolationModeFant); The scaler is using the Fant method, which I think is the best looking one even if it seems a little softer than cubic (zoomed here to better show the defects): Cubic Fant Linear Nearest neighbor We can write the source image to the output frame through the scaler: outputFrame.WriteSource(scaler, new WICRect { X = 0, Y = 0, Width = (int)thumbWidth, Height = (int)thumbHeight }); And finally we commit the pipeline that we built and get the byte array for the thumbnail out of our memory stream: outputFrame.Commit(); encoder.Commit(); var outputArray = outputStream.ToArray(); outputStream.Close(); That byte array can then be sent to the output stream and to the cache file. Once we’ve gone through this exercise, it’s only natural to wonder whether it was worth the trouble. I ran this method, as well as GDI and WPF resizing over thirty twelve megapixel images for JPEG qualities between 70% and 100% and measured the file size and time to resize. Here are the results: Size of resized images   Time to resize thirty 12 megapixel images Not much to see on the size graph: sizes from WPF and WIC are equivalent, which is hardly surprising as WPF calls into WIC. There is just an anomaly for 75% for WPF that I noted in my previous article and that disappears when using WIC directly. But overall, using WPF or WIC over GDI represents a slight win in file size. The time to resize is more interesting. WPF and WIC get similar times although WIC seems to always be a little faster. Not surprising considering WPF is using WIC. The margin of error on this results is probably fairly close to the time difference. As we already knew, the time to resize does not depend on the quality level, only the size does. This means that the only decision you have to make here is size versus visual quality. This third approach to server-side image resizing on ASP.NET seems to converge on the fastest possible one. We have marginally better performance than WPF, but with some additional peace of mind that this approach is sanctioned for server-side usage by the Windows Imaging team. It still doesn’t work in medium trust. That is a problem and shows the way for future server-friendly managed wrappers around WIC. The sample code for this article can be downloaded from: http://weblogs.asp.net/blogs/bleroy/Samples/WicResize.zip The benchmark code can be found here (you’ll need to add your own images to the Images directory and then add those to the project, with content and copy if newer in the properties of the files in the solution explorer): http://weblogs.asp.net/blogs/bleroy/Samples/WicWpfGdiImageResizeBenchmark.zip WIC tools can be downloaded from: http://code.msdn.microsoft.com/wictools To conclude, here are some of the resized thumbnails at 85% fant:

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  • Is there a way communicate or measure levels of abstraction?

    - by hydroparadise
    I'll be the first to say that this question is a bit... out there. But here are a couple questions I bear in mind : Is abstraction continuous or discrete? Is there a single unit of abstraction? But I'm not sure those questions are truly answerable or even really makes sence. My naive answer would be something along the lines of abitrarily discrete but not necescarily having a single unit measure. Here's what I mean... Take a Black Labrador; an abstraction that could be made is that a Black Lab is a type of animal. [Animal]<--[Black Lab] A Black Lab is also a type of Dog. [Dog]<--[Black Lab] One way to establish a degree of abstraction is by comparing the two the abstractions. We could say that [Animal] is more abstract than [Dog] in respect to a Black Lab. It just so happens [Animal] can also be used as an abstraction of [Dog] So, we might end up with something like [Animal]<--[Dog]<--[Black Lab] With the model above, one might be inclined to say that there's two hops of abstraction to get from [Black Lab] to [Animal]. But you can't exactly tell somebody they need one level abstraction and reasonalby expect they will come up with [Dog] given they aren't explicity given the options above. If I needed to tell someobody in a single email that they needed an abstract class with out knowing what that abstract class is, is there a way to communaticate a degree of abstraction such that they might end up on Dog instead of Animal? As a side note, what area of study might this type of analysis fall under?

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  • Podcast Show Notes: Redefining Information Management Architecture

    - by Bob Rhubart-Oracle
    Nothing in IT stands still, and this is certainly true of business intelligence and information management. Big Data has certainly had an impact, as have Hadoop and other technologies. That evolution was the catalyst for the collaborative effort behind a new Information Management Reference Architecture. The latest OTN ArchBeat series features a conversation with Andrew Bond, Stewart Bryson, and Mark Rittman, key players in that collaboration. These three gentlemen know each other quite well, which comes across in a conversation that is as lively and entertaining as it is informative. But don't take my work for it. Listen for yourself! The Panelists(Listed alphabetically) Andrew Bond, head of Enterprise Architecture at Oracle Oracle ACE Director Stewart Bryson, owner and Co-Founder of Red Pill Analytics Oracle ACE Director Mark Rittman, CIO and Co-Founder of Rittman Mead The Conversation Listen to Part 1: The panel discusses how new thinking and new technologies were the catalyst for a new approach to business intelligence projects. Listen to Part 2: Why taking an "API" approach is important in building an agile data factory. Listen to Part 3: Shadow IT, "sandboxing," and how organizational changes are driving the evolution in information management architecture. Additional Resources The Reference Architecture that is the focus of this conversation is described in detail in these blog posts by Mark Rittman: Introducing the Updated Oracle / Rittman Mead Information Management Reference Architecture Part 1: Information Architecture and the Data Factory Part 2: Delivering the Data Factory Be a Guest Producer for an ArchBeat Podcast Want to be a guest producer for an OTN ArchBeat podcast? Click here to learn how to make it happen.

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  • Understanding Visitor Pattern

    - by Nezreli
    I have a hierarchy of classes that represents GUI controls. Something like this: Control-ContainerControl-Form I have to implement a series of algoritms that work with objects doing various stuff and I'm thinking that Visitor pattern would be the cleanest solution. Let take for example an algorithm which creates a Xml representaion of a hierarchy of objects. Using 'classic' approach I would do this: public abstract class Control { public virtual XmlElement ToXML(XmlDocument document) { XmlElement xml = document.CreateElement(this.GetType().Name); // Create element, fill it with attributes declared with control return xml; } } public abstract class ContainerControl : Control { public override XmlElement ToXML(XmlDocument document) { XmlElement xml = base.ToXML(document); // Use forech to fill XmlElement with child XmlElements return xml; } } public class Form : ContainerControl { public override XmlElement ToXML(XmlDocument document) { XmlElement xml = base.ToXML(document); // Fill remaining elements declared in Form class return xml; } } But I'm not sure how to do this with visitor pattern. This is the basic implementation: public class ToXmlVisitor : IVisitor { public void Visit(Form form) { } } Since even the abstract classes help with implementation I'm not sure how to do that properly in ToXmlVisitor. Perhaps there is a better solution to this problem. The reason that I'm considering Visitor pattern is that some algorithms will need references not available in project where the classes are implemented and there is a number of different algorithms so I'm avoiding large classes. Any thoughts are welcome.

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  • Designing a plug-in system

    - by madflame991
    I'm working on a Java project and I would like to add a plug-in system. More precisely, I would like to let the user design his own module, pack it into a jar, leave it in a "plugins/" subfolder of my application and be done with it. I've managed to get a child classloader to instantiate objects of classes located in external jars, but now I'm facing a design dilemma: Say Joe makes a plug-in and he packs it in joeplugin.jar. I would really like Joe to have a class named "instantiation.Factory" and I would also like everyone to have this class with this exact location and name. (This factory class obviously implements a interface that I provide and through it I get what I want from the plug-in.) If Joe wouldn't be restricted in this way I would have to look into his entire jar for some class that implements my factory interface and I don't want to imagine how complicated things get. So my question is: should I enforce a strict naming convention for this single class? I have no idea how plug-in systems work.

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  • An alternative to multiple inheritance when creating an abstraction layer?

    - by sebf
    In my project I am creating an abstraction layer for some APIs. The purpose of the layer is to make multi-platform easier, and also to simplify the APIs to the feature set that I need while also providing some functionality, the implementation of which will be unique to each platform. At the moment, I have implemented it by defining and abstract class, which has methods which creates objects that implement interfaces. The abstract class and these interfaces define the capabilities of my abstraction layer. The implementation of these in my layer should of course be arbitrary from the POV view of my application, but I have done it, for my first API, by creating chains of subclasses which add more specific functionality as the features of the APIs they expose become less generic. An example would probably demonstrate this better: //The interface as seen by the application interface IGenericResource { byte[] GetSomeData(); } interface ISpecificResourceOne : IGenericResource { int SomePropertyOfResourceOne {get;} } interface ISpecificResourceTwo : IGenericResource { string SomePropertyOfResourceTwo {get;} } public abstract class MyLayer { ISpecificResourceOne CreateResourceOne(); ISpecificResourceTwo CreateResourceTwo(); void UseResourceOne(ISpecificResourceOne one); void UseResourceTwo(ISpecificResourceTwo two); } //The layer as created in my library public class LowLevelResource : IGenericResource { byte[] GetSomeData() {} } public class ResourceOne : LowLevelResource, ISpecificResourceOne { int SomePropertyOfResourceOne {get{}} } public class ResourceTwo : ResourceOne, ISpecificResourceTwo { string SomePropertyOfResourceTwo {get {}} } public partial class Implementation : MyLayer { override UseResourceOne(ISpecificResourceOne one) { DoStuff((ResourceOne)one); } } As can be seen, I am essentially trying to have two inheritance chains on the same object, but of course I can't do this so I simulate the second version with interfaces. The thing is though, I don't like using interfaces for this; it seems wrong, in my mind an interface defines a contract, any class that implements that interface should be able to be used where that interface is used but here that is clearly not the case because the interfaces are being used to allow an object from the layer to masquerade as something else, without the application needing to have access to its definition. What technique would allow me to define a comprehensive, intuitive collection of objects for an abstraction layer, while their implementation remains independent? (Language is C#)

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  • Serializing network messages

    - by mtsvetkov
    I am writing a network wrapper around boost::asio and was wondering what is a good and simple way to serialize my messages. I have a message factory which can take care of dispatching the data to the correct builder, but I want to know if there are any established solutions for getting the binary data on the sender side and consequently passing the data for deserialization on the receiver end. Some options I've explored are: passing a pointer to a char[] to the serialize/deserialize functions (for serialize to write to, and deserialize to read from), but it's difficult to enforce buffer size this way; building on that, I decided to have the serialize function return a boost::asio::mutable_buffer, however ownership of the memory gets blurred between multiple classes, as the network wrapper needs to clean up the memory allocated by the message builder. I have also seen solutions involving streambuf's and stringstream's, but manipulating binary data in terms of its string representation is something I want to avoid. Is there some sort of binary stream I can use instead? What I am looking for is a solution (preferrably using boost libs) that lets the message builder dictate the amount of memory allocated during serialization and what that would look like in terms of passing the data around between the wrapper and message factory/message builders. PS. Messages contain almost exclusively built-in types and PODs and form a shallow but wide hierarchy for the sake of going through a factory. Note: a link to examples of using boost::serialization for something like this would be appreciated as I'm having difficulties figuring out the relation between it and buffers.

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  • Game Asset Management

    - by user964123
    I am making my first small mobile game in C# XNA. Lets say I have 3 screens, the main menu, options and game screen. A single game session usually lasts for 1 min, so the user will alternate frequently between the main menu and game screen. Therefore, once I load the textures for either screen, I want to keep them in memory to avoid frequent reloading. Both screens share some assets like their background textures, but differ in others. The first solution I came up with is making 2 texture factory classes, MainScreenAssetFactory and GameScreenAssetFactory, each with their own content manager, and ill store them in a globally accessible point so that they persist after either screen is destroyed. There is also a OptionsScreenAssetFactory, but that I dont want to cache it since the options screen is rarely visited. A typical Factory would look something like this public class MainScreenAssetFactory { private readonly ContentManager contentManager; public MainScreenAssetFactory(IServiceProvider serviceProvider, string rootDirectory) { contentManager = new ContentManager(serviceProvider) { RootDirectory = rootDirectory }; } public Texture2D ListElementBackground { get { return return contentManager.Load<Texture2D>("UserTab"); } } public Texture2D ListElementBulletPoint { get { return return contentManager.Load<Texture2D>("TabIcon"); } } public Texture2D LoggedOutUser { get { return return contentManager.Load<Texture2D>("LoggedOutUser"); } } } Since both Main, Options and Game Screen share some common resources, instead of loading them more than once, I created another class CommonAssetTexFactory which holds the common stuff and stays in-memory during the app lifetime. For example, this class gets passed to the options screen when it is created. However, given my small game with its few assets, I am already finding this solution cumbersome and inflexible. Changing anything would require looking to see if its already in the common factory, and if not, modifying existing factories and so on. And this is just considering textures currently, i didnt add sound files yet. I cant imagine bigger games with thousands of resources using this approach. A better idea must exist. Would someone please enlighten me?

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  • request response with activemq - always send double response.

    - by Chris Valley
    Hi, I'm new at activeMq. I tried to create a simple request response like this. public Listener(string destination) { // set factory ConnectionFactory factory = new ConnectionFactory(URL); IConnection connection; try { connection = factory.CreateConnection(); connection.Start(); ISession session = connection.CreateSession(); // create consumer for designated destination IMessageConsumer consumer = session.CreateConsumer(new Apache.NMS.ActiveMQ.Commands.ActiveMQQueue(destination)); consumer.Listener += new MessageListener(consumer_Listener); Console.ReadLine(); } catch (Exception ex) { Console.WriteLine(ex.ToString()); throw new Exception("Exception in Listening ", ex); } } The OnMessage static void consumer_Listener(IMessage message) { IConnectionFactory factory = new ConnectionFactory("tcp://localhost:61616/"); using (IConnection connection = factory.CreateConnection()) { //Create the Session using (ISession session = connection.CreateSession()) { //Create the Producer for the topic/queue // IMessageProducer prod = session.CreateProducer(new Apache.NMS.ActiveMQ.Commands.ActiveMQTempQueue(message.NMSDestination)); IMessageProducer producer = session.CreateProducer(message.NMSDestination); // Create Response // IMessage response = session.CreateMessage(); ITextMessage response = producer.CreateTextMessage("Replied from VS2010 Test"); //response.NMSReplyTo = new Apache.NMS.ActiveMQ.Commands.ActiveMQQueue("testQ1"); response.NMSCorrelationID = message.NMSCorrelationID; if (message.NMSReplyTo != null) { producer.Send(message.NMSReplyTo, response); Console.WriteLine("Receive: " + ((ITextMessage)message).NMSCorrelationID); Console.WriteLine("Received from : " + message.NMSDestination.ToString()); Console.WriteLine("----------------------------------------------------"); } } } } Every time i tried to send a request to the listener, the response always send repeatedly. The first response will have NMSReplyTo properties while the other not. My workaround to stop this situation by cheking the NMSReplyTo properties if (message.NMSReplyTo != null) { producer.Send(message.NMSReplyTo, response); Console.WriteLine("Receive: " + ((ITextMessage)message).NMSCorrelationID); Console.WriteLine("Received from : " + message.NMSDestination.ToString()); Console.WriteLine("----------------------------------------------------"); } In my understanding, this happened because there was a circular send response in the listener to the same Queue. Could you guys help me how to fix this? Many Thanks, Chris

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  • Objective-c design advice for use of different data sources, swapping between test and live

    - by user200341
    I'm in the process of designing an application that is part of a larger piece of work, depending on other people to build an API that the app can make use of to retrieve data. While I was thinking about how to setup this project and design the architecture around it, something occurred to me, and I'm sure many people have been in similar situations. Since my work is depending on other people to complete their tasks, and a test server, this slows work down at my end. So the question is: What's the best practice for creating test repositories and classes, implementing them, and not having to depend on altering several places in the code to swap between the test classes and the actual repositories / proper api calls. Contemplate the following scenario: GetDataFromApiCommand *getDataCommand = [[GetDataFromApiCommand alloc]init]; getDataCommand.delegate = self; [getDataCommand getData]; Once the data is available via the API, "GetDataFromApiCommand" could use the actual API, but until then a set of mock data could be returned upon the call of [getDataCommand getData] There might be multiple instances of this, in various places in the code, so replacing all of them wherever they are, is a slow and painful process which inevitably leads to one or two being overlooked. In strongly typed languages we could use dependency injection and just alter one place. In objective-c a factory pattern could be implemented, but is that the best route to go for this? GetDataFromApiCommand *getDataCommand = [GetDataFromApiCommandFactory buildGetDataFromApiCommand]; getDataCommand.delegate = self; [getDataCommand getData]; What is the best practices to achieve this result? Since this would be most useful, even if you have the actual API available, to run tests, or work off-line, the ApiCommands would not necessarily have to be replaced permanently, but the option to select "Do I want to use TestApiCommand or ApiCommand". It is more interesting to have the option to switch between: All commands are test and All command use the live API, rather than selecting them one by one, however that would also be useful to do for testing one or two actual API commands, mixing them with test data. EDIT The way I have chosen to go with this is to use the factory pattern. I set up the factory as follows: @implementation ApiCommandFactory + (ApiCommand *)newApiCommand { // return [[ApiCommand alloc]init]; return [[ApiCommandMock alloc]init]; } @end And anywhere I want to use the ApiCommand class: GetDataFromApiCommand *getDataCommand = [ApiCommandFactory newApiCommand]; When the actual API call is required, the comments can be removed and the mock can be commented out. Using new in the message name implies that who ever uses the factory to get an object, is responsible for releasing it (since we want to avoid autorelease on the iPhone). If additional parameters are required, the factory needs to take these into consideration i.e: [ApiCommandFactory newSecondApiCommand:@"param1"]; This will work quite well with repositories as well.

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  • Unresolved External Symbol linker error (C++)

    - by Niranjan
    Hi, I am trying to develop abstract design pattern code for one of my project as below.. But, I am not able to compile the code ..giving some compile errors(like "unresolved external symbol "public: virtual void __thiscall Xsecs::draw_lines(double,double)" (?draw_lines@Xsecs@@UAEXNN@Z)" ).. Can any one please help me out in this... #include "stdafx.h" #include <iostream> #include <vector> #include "Xsecs.h" using namespace std; //Product class class Xsecs { public: virtual void draw_lines(double pt1, double pt2); virtual void draw_curves(double pt1, double rad); }; class polyline: public Xsecs { public: virtual void draw_lines(double pt1,double pt2) { cout<<"draw_line in polygon"<<endl; } virtual void draw_curves(double pt1, double rad) { cout<<"Draw_curve in circle"<<endl; } /*void create_polygons() { cout<<"create_polygon_thru_draw_lines"<<endl; }*/ }; class circle: public Xsecs { public: virtual void draw_lines(double pt1,double pt2) { cout<<"draw_line in polygon"<<endl; } virtual void draw_curves(double pt1, double rad) { cout<<"Draw_curve in circle"<<endl; } /*void create_circles() { cout<<"Create circle"<<endl; }*/ }; //Factory class class Factory { public: virtual polyline* create_polyline()=0; virtual circle* create_circle()=0; }; class Factory1: public Factory { public: polyline* create_polyline() { return new polyline(); } circle* create_circle() { return new circle(); } }; class Factory2: public Factory { public: circle* create_circle() { return new circle(); } polyline* create_polyline() { return new polyline(); } }; int _tmain(int argc, _TCHAR* argv[]) { Factory1 f1; Factory * fp=&f1; return 0; }

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