Search Results

Search found 1275 results on 51 pages for 'derived'.

Page 46/51 | < Previous Page | 42 43 44 45 46 47 48 49 50 51  | Next Page >

  • Searching over a templated tree

    - by floatingfrisbee
    So I have 2 interfaces: A node that can have children public interface INode { IEnumeration<INode> Children { get; } void AddChild(INode node); } And a derived "Data Node" that can have data associated with it public interface IDataNode<DataType> : INode { DataType Data; IDataNode<DataType> FindNode(DataType dt); } Keep in mind that each node in the tree could have a different data type associated with it as its Data (because the INode.AddChild function just takes the base INode) Here is the implementation of the IDataNode interface: internal class DataNode<DataType> : IDataNode<DataType> { List<INode> m_Children; DataNode(DataType dt) { Data = dt; } public IEnumerable<INode> Children { get { return m_Children; } } public void AddChild(INode node) { if (null == m_Children) m_Children = new List<INode>(); m_Children.Add(node); } public DataType Data { get; private set; } Question is how do I implement the FindNode function without knowing what kinds of DataType I will encounter in the tree? public IDataNode<DataType> FindNode(DataType dt) { throw new NotImplementedException(); } } As you can imagine something like this will not work out public IDataNode<DataType> FindNode(DataType dt) { IDataNode<DataType> result = null; foreach (var child in Children) { if (child is IDataNode<DataType>) { var datachild = child as IDataNode<DataType>; if (datachild.Data.Equals(dt)) { result = child as IDataNode<DataType>; break; } } else { // What?? } } return result; } Is my only option to do this when I know what kinds of DataType a particular tree I use will have? Maybe I am going about this in the wrong way, so any tips are appreciated. Thanks!

    Read the article

  • Why am I seeing a crash when trying to call CDHtmlDialog::OnInitDialog()

    - by Tim
    I added a helpAbout menu item to my mfc app. I decided to make the ddlg derive from CDHTMLDialog. I override the OnInitDialog() method in my derived class and the first thing I do is call the parent's OnInitDialog() method. I then put in code that sets the title. On some machines this works fine, but on others it crashes in the call to CDHtmlDialog::OnInitDialog() - Trying to read a null pointer. the call stack has nothing useful - it is in mfc90.dll Is this a potential problem with mismatches of mfc/win32 dlls? It works on my vista machines but crashes on a win2003 server box. BOOL HTMLAboutDlg::OnInitDialog() { // CRASHES on the following line CDHtmlDialog::OnInitDialog(); CString title = "my title"; // example of setting title // i try to get version info //set the title CModuleVersion ver; char filename[ _MAX_PATH ]; GetModuleFileName( AfxGetApp()->m_hInstance, filename, _MAX_PATH ); ver.GetFileVersionInfo(filename); // get version from VS_FIXEDFILEINFO struct CString s; s.Format("Version: %d.%d.%d.%d\n", HIWORD(ver.dwFileVersionMS), LOWORD(ver.dwFileVersionMS), HIWORD(ver.dwFileVersionLS), LOWORD(ver.dwFileVersionLS)); CString version = ver.GetValue(_T("ProductVersion")); version.Remove(' '); version.Replace(",", "."); title = "MyApp - Version " + version; SetWindowText(title); return TRUE; // return TRUE unless you set the focus to a control } And here is the relevant header file: class HTMLAboutDlg : public CDHtmlDialog { DECLARE_DYNCREATE(HTMLAboutDlg) public: HTMLAboutDlg(CWnd* pParent = NULL); // standard constructor virtual ~HTMLAboutDlg(); // Overrides HRESULT OnButtonOK(IHTMLElement *pElement); HRESULT OnButtonCancel(IHTMLElement *pElement); // Dialog Data enum { IDD = IDD_DIALOG_ABOUT, IDH = IDR_HTML_HTMLABOUTDLG }; protected: virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support virtual BOOL OnInitDialog(); DECLARE_MESSAGE_MAP() DECLARE_DHTML_EVENT_MAP() }; I can't figure out what is going on - why it works on some machins and crashes on others. Both have VS2008 installed EDIT: VS versions VISTA - no crashes 9.0.30729.1 SP 2003 server: (crashes) 9.0.21022.8 RTM

    Read the article

  • indentationLevelForRowAtIndexPath not indenting custom cell

    - by Xetius
    I have overridden the tableView:indentationLevelForRowAtIndexPath method in my UITableViewController derived class as follows: - (NSInteger)tableView:(UITableView *)tableView indentationLevelForRowAtIndexPath:(NSIndexPath *)indexPath { NSDictionary* item = [self.projects objectAtIndex:indexPath.row]; int indentationLevel = [[item objectForKey:@"indent"] intValue]; DLog (@"Indentation Level for Row %d : %d", indexPath.row, indentationLevel); return indentationLevel; } I initially thought that this was not being called but that was operator error (err, mine) and I hadn't defined the symbol DEBUG=1. However, it is being called (duh me!) and this is the log output: -[RootViewController tableView:indentationLevelForRowAtIndexPath:] [Line 129] Indentation Level for Row 0 : 1 -[RootViewController tableView:indentationLevelForRowAtIndexPath:] [Line 129] Indentation Level for Row 1 : 1 -[RootViewController tableView:indentationLevelForRowAtIndexPath:] [Line 129] Indentation Level for Row 2 : 2 -[RootViewController tableView:indentationLevelForRowAtIndexPath:] [Line 129] Indentation Level for Row 3 : 2 -[RootViewController tableView:indentationLevelForRowAtIndexPath:] [Line 129] Indentation Level for Row 4 : 2 -[RootViewController tableView:indentationLevelForRowAtIndexPath:] [Line 129] Indentation Level for Row 5 : 1 -[RootViewController tableView:indentationLevelForRowAtIndexPath:] [Line 129] Indentation Level for Row 6 : 2 -[RootViewController tableView:indentationLevelForRowAtIndexPath:] [Line 129] Indentation Level for Row 7 : 2 -[RootViewController tableView:indentationLevelForRowAtIndexPath:] [Line 129] Indentation Level for Row 8 : 1 But, this is not affecting the layout of the cells. No indentation. This is my itemCellForRowAtIndexPath implementation, if that makes any difference: -(UITableViewCell*)tableView:(UITableView *)tableView itemCellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString* cellIdentifier = @"projectItemCell"; ProjectItemTableViewCell* cell = (ProjectItemTableViewCell*)[tableView dequeueReusableCellWithIdentifier:cellIdentifier]; if (cell == nil) { NSArray* nib = [[NSBundle mainBundle] loadNibNamed:@"ProjectItemTableViewCell" owner:self options:nil]; for (id oneObject in nib) { if ([oneObject isKindOfClass:[ProjectItemTableViewCell class]]) { cell = (ProjectItemTableViewCell*)oneObject; } } } NSDictionary* item = [self.projects objectAtIndex:indexPath.row]; cell.projectDescLabel.text = [item objectForKey:@"name"]; cell.itemCountlabel.text = [NSString stringWithFormat:@"%d", [[item objectForKey:@"cache_count"] intValue]]; cell.itemCountlabel.backgroundColor = [UIColor colorForHex:[item objectForKey:@"color"]]; cell.indentationWidth = 20; return cell; } How do I indent a custom UITableViewCell which I have defined in Interface Builder? If I change the itemCellForRowAtIndexPath to use a default UITableViewCell with the code below, then it indents fine. static NSString* cellIdentifier = @"projectItemCell"; UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier] autorelease]; } NSDictionary* item = [self.projects objectAtIndex:indexPath.row]; cell.textLabel.text = [item objectForKey:@"name"]; cell.indentationWidth = 40; return cell;

    Read the article

  • How to write a cctor and op= for a factory class with ptr to abstract member field?

    - by Kache4
    I'm extracting files from zip and rar archives into raw buffers. I created the following to wrap minizip and unrarlib: Archive.hpp #include "ArchiveBase.hpp" #include "ArchiveDerived.hpp" class Archive { public: Archive(string path) { /* logic here to determine type */ switch(type) { case RAR: archive_ = new ArchiveRar(path); break; case ZIP: archive_ = new ArchiveZip(path); break; case UNKNOWN_ARCHIVE: throw; break; } } Archive(Archive& other) { archive_ = // how do I copy an abstract class? } ~Archive() { delete archive_; } void passThrough(ArchiveBase::Data& data) { archive_->passThrough(data); } Archive& operator = (Archive& other) { if (this == &other) return *this; ArchiveBase* newArchive = // can't instantiate.... delete archive_; archive_ = newArchive; return *this; } private: ArchiveBase* archive_; } ArchiveBase.hpp class ArchiveBase { public: // Is there any way to put this struct in Archive instead, // so that outside classes instantiating one could use // Archive::Data instead of ArchiveBase::Data? struct Data { int field; }; virtual void passThrough(Data& data) = 0; /* more methods */ } ArchiveDerived.hpp "Derived" being "Zip" or "Rar" #include "ArchiveBase.hpp" class ArchiveDerived : public ArchiveBase { public: ArchiveDerived(string path); void passThrough(ArchiveBase::Data& data); private: /* fields needed by minizip/unrarlib */ // example zip: unzFile zipFile_; // example rar: RARHANDLE rarFile_; } ArchiveDerived.cpp #include "ArchiveDerived.hpp" ArchiveDerived::ArchiveDerived(string path) { //implement } ArchiveDerived::passThrough(ArchiveBase::Data& data) { //implement } Somebody had suggested I use this design so that I could do: Archive archiveFile(pathToZipOrRar); archiveFile.passThrough(extractParams); // yay polymorphism! How do I write a cctor for Archive? What about op= for Archive? What can I do about "renaming" ArchiveBase::Data to Archive::Data? (Both minizip and unrarlib use such structs for input and output. Data is generic for Zip & Rar and later is used to create the respective library's struct.)

    Read the article

  • compiler warning at C++ template base class

    - by eike
    I get a compiler warning, that I don't understand in that context, when I compile the "Child.cpp" from the following code. (Don't wonder: I stripped off my class declarations to the bare minuum, so the content will not make much sense, but you will see the problem quicker). I get the warning with VS2003 and VS2008 on the highest warning level. The code AbstractClass.h : #include <iostream> template<typename T> class AbstractClass { public: virtual void Cancel(); // { std::cout << "Abstract Cancel" << std::endl; }; virtual void Process() = 0; }; //outside definition. if I comment out this and take the inline //definition like above (currently commented out), I don't get //a compiler warning template<typename T> void AbstractClass<T>::Cancel() { std::cout << "Abstract Cancel" << std::endl; } Child.h : #include "AbstractClass.h" class Child : public AbstractClass<int> { public: virtual void Process(); }; Child.cpp : #include "Child.h" #include <iostream> void Child::Process() { std::cout << "Process" << std::endl; } The warning The class "Child" is derived from "AbstractClass". In "AbstractClass" there's the public method "AbstractClass::Cancel()". If I define the method outside of the class body (like in the code you see), I get the compiler warning... AbstractClass.h(7) : warning C4505: 'AbstractClass::Cancel' : unreferenced local function has been removed with [T=int] ...when I compile "Child.cpp". I do not understand this, because this is a public function and the compiler can't know if I later reference this method or not. And, in the end, I reference this method, because I call it in main.cpp and despite this compiler warning, this method works if I compile and link all files and execute the program: //main.cpp #include <iostream> #include "Child.h" int main() { Child child; child.Cancel(); //works, despite the warning } If I do define the Cancel() function as inline (you see it as out commented code in AbstractClass.h), then I don't get the compiler warning. Of course my program works, but I want to understand this warning or is this just a compiler mistake? Furthermore, if do not implement AbsctractClass as a template class (just for a test purpose in this case) I also don't get the compiler warning...?

    Read the article

  • Recursive N-way merge/diff algorithm for directory trees?

    - by BobMcGee
    What algorithms or Java libraries are available to do N-way, recursive diff/merge of directories? I need to be able to generate a list of folder trees that have many identical files, and have subdirectories with many similar files. I want to be able to use 2-way merge operations to quickly remove as much redundancy as possible. Goals: Find pairs of directories that have many similar files between them. Generate short list of directory pairs that can be synchronized with 2-way merge to eliminate duplicates Should operate recursively (there may be nested duplicates of higher-level directories) Run time and storage should be O(n log n) in numbers of directories and files Should be able to use an embedded DB or page to disk for processing more files than fit in memory (100,000+). Optional: generate an ancestry and change-set between folders Optional: sort the merge operations by how many duplicates they can elliminate I know how to use hashes to find duplicate files in roughly O(n) space, but I'm at a loss for how to go from this to finding partially overlapping sets between folders and their children. EDIT: some clarification The tricky part is the difference between "exact same" contents (otherwise hashing file hashes would work) and "similar" (which will not). Basically, I want to feed this algorithm at a set of directories and have it return a set of 2-way merge operations I can perform in order to reduce duplicates as much as possible with as few conflicts possible. It's effectively constructing an ancestry tree showing which folders are derived from each other. The end goal is to let me incorporate a bunch of different folders into one common tree. For example, I may have a folder holding programming projects, and then copy some of its contents to another computer to work on it. Then I might back up and intermediate version to flash drive. Except I may have 8 or 10 different versions, with slightly different organizational structures or folder names. I need to be able to merge them one step at a time, so I can chose how to incorporate changes at each step of the way. This is actually more or less what I intend to do with my utility (bring together a bunch of scattered backups from different points in time). I figure if I can do it right I may as well release it as a small open source util. I think the same tricks might be useful for comparing XML trees though.

    Read the article

  • Trouble binding command in grid menu item.

    - by Pete
    I have a grid that's inside a usercontrol derived class called MediatedUserControl. I'm adding a context menu to let the user delete an item, but I've been unable to figure out how to bind the command to my command property. I'm using MVVM and my viewmodel implements a public ICommand property called DeleteSelectedItemCommand. However, when the view is displayed, I get the following message in the output window: System.Windows.Data Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='BRO.View.MediatedUserControl', AncestorLevel='1''. BindingExpression:Path=DataContext.DeleteSelectedItemCommand; DataItem=null; target element is 'BarButtonItem' (HashCode=6860584); target property is 'Command' (type 'ICommand') I feel like I generally have a good handle on bindings like this and can't figure out what it is I'm missing here. Thanks for any help you can provide. <dxg:GridControl HorizontalAlignment="Left" Margin="12,88,0,0" x:Name="gridControl1" VerticalAlignment="Top" Height="500" Width="517" DataSource="{Binding ItemList}" BorderBrush="{StaticResource {x:Static SystemColors.ActiveBorderBrushKey}}" ShowBorder="True" Background="{StaticResource {x:Static SystemColors.ControlLightBrushKey}}" UseLayoutRounding="False" DataContext="{Binding}"> <dxg:GridControl.Columns> <dxg:GridColumn FieldName="Code" Header="Code" Width="107" /> <dxg:GridColumn FieldName="Name" Header="Item" Width="173" /> <dxg:GridColumn FieldName="PricePerItem" Header="Unit Price" Width="70"> <dxg:GridColumn.EditSettings> <dxe:TextEditSettings DisplayFormat="N2" /> </dxg:GridColumn.EditSettings> </dxg:GridColumn> <dxg:GridColumn FieldName="Quantity" Header="Qty" Width="50" AllowEditing="True" /> <dxg:GridColumn FieldName="TotalPrice" Header="Total Price" Width="90"> <dxg:GridColumn.EditSettings> <dxe:TextEditSettings DisplayFormat="N2" /> </dxg:GridColumn.EditSettings> </dxg:GridColumn> </dxg:GridControl.Columns> <dxg:GridControl.View> <dxg:TableView ShowIndicator="False" ShowGroupPanel="False" MultiSelectMode="Row" AllowColumnFiltering="False" AllowBestFit="False" AllowFilterEditor="False" AllowEditing="False" AllowGrouping="False" AllowSorting="False" AllowResizing="False" AllowMoving="False" AllowMoveColumnToDropArea="False" AllowDateTimeGroupIntervalMenu="False" > <dxg:TableView.RowCellMenuCustomizations> <dxb:BarButtonItem Name="deleteRowItem" Command="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=view:MediatedUserControl, AncestorLevel=1}, Path=DataContext.DeleteSelectedItemCommand}"> </dxb:BarButtonItem> </dxg:TableView.RowCellMenuCustomizations> </dxg:TableView> </dxg:GridControl.View>

    Read the article

  • INNER JOIN code calculated value with SELECT statement

    - by sp-1986
    I have the following stored procedure which will generate mon to sun and then creates a temp table with a series of 'weeks' (start and end weeks) : USE [test_staff] GO /****** Object: StoredProcedure [dbo].[sp_timesheets_all_staff_by_week_by_job_grouping_by_site] Script Date: 03/21/2012 09:04:49 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE PROCEDURE [dbo].[sp_timesheets_all_staff_by_week_by_job_grouping_by_site] ( @grouping_ref int, @week_ref int ) AS CREATE TABLE #WeeklyList ( Start_Week date, End_Week date, week_ref int --month_name date ) DECLARE @REPORT_DATE DATETIME, @WEEK_BEGINING VARCHAR(10) SELECT @REPORT_DATE = '2011-01-19T00:00:00' --SELECT @REPORT_DATE = GETDATE() -- should grab the date now. SELECT @WEEK_BEGINING = 'MONDAY' IF @WEEK_BEGINING = 'MONDAY' SET DATEFIRST 1 ELSE IF @WEEK_BEGINING = 'TUESDAY' SET DATEFIRST 2 ELSE IF @WEEK_BEGINING = 'WEDNESDAY' SET DATEFIRST 3 ELSE IF @WEEK_BEGINING = 'THURSDAY' SET DATEFIRST 4 ELSE IF @WEEK_BEGINING = 'FRIDAY' SET DATEFIRST 5 ELSE IF @WEEK_BEGINING = 'SATURDAY' SET DATEFIRST 6 ELSE IF @WEEK_BEGINING = 'SUNDAY' SET DATEFIRST 7 DECLARE @WEEK_START_DATE DATETIME, @WEEK_END_DATE DATETIME --GET THE WEEK START DATE SELECT @WEEK_START_DATE = @REPORT_DATE - (DATEPART(DW, @REPORT_DATE) - 1) --GET THE WEEK END DATE SELECT @WEEK_END_DATE = @REPORT_DATE + (7 - DATEPART(DW, @REPORT_DATE)) PRINT 'Week Start: ' + CONVERT(VARCHAR, @WEEK_START_DATE) PRINT 'Week End: ' + CONVERT(VARCHAR, @WEEK_END_DATE) DECLARE @Interval int = datediff(WEEK,getdate(),@WEEK_START_DATE)+1 --SELECT Start_Week=@WEEK_START_DATE --, End_Week=@WEEK_END_DATE --INTO #WeekList INSERT INTO #WeeklyList SELECT Start_Week=@WEEK_START_DATE, End_Week=@WEEK_END_DATE WHILE @Interval <= 0 BEGIN set @WEEK_START_DATE=DATEADD(WEEK,1,@WEEK_START_DATE) set @WEEK_END_DATE=DATEADD(WEEK,1,@WEEK_END_DATE) INSERT INTO #WeeklyList values (@WEEK_START_DATE,@WEEK_END_DATE) SET @Interval += 1; END SELECT CONVERT(VARCHAR(11), Start_Week, 106) AS 'month_name', CONVERT(VARCHAR(11), End_Week, 106) AS 'End', DATEDIFF(DAY, 0, Start_Week) / 7 AS week_ref -- create the unique week reference number --'VIEW' AS month_name FROM #WeeklyList In this section i am creating the week_ref DATEDIFF(DAY, 0, Start_Week) / 7 AS week_ref -- create the unique week reference number I then need to combine it with this select code: DECLARE @YearString char(3) = CONVERT(char(3), SUBSTRING(CONVERT(char(5), @week_ref), 1, 3)) DECLARE @MonthString char(2) = CONVERT(char(2), SUBSTRING(CONVERT(char(5), @week_ref), 4, 2)) --Convert: DECLARE @Year int = CONVERT(int, @YearString) + 1200 DECLARE @Month int = CONVERT(int, @MonthString) **--THIS FILTERS THE REPORT** SELECT ts.staff_member_ref, sm.common_name, sm.department_name, DATENAME(MONTH, ts.start_dtm) + ' ' + DATENAME(YEAR, ts.start_dtm) AS month_name, ts.timesheet_cat_ref, cat.desc_long AS timesheet_cat_desc, grps.grouping_ref, grps.description AS grouping_desc, ts.task_ref, tsks.task_code, tsks.description AS task_desc, ts.site_ref, sits.description AS site_desc, ts.site_ref AS Expr1, CASE WHEN ts .status = 0 THEN 'Pending' WHEN ts .status = 1 THEN 'Booked' WHEN ts .status = 2 THEN 'Approved' ELSE 'Invalid Status' END AS site_status, ts.booked_time AS booked_time_sum, start_dtm, CONVERT(varchar(20), start_dtm, 108) + ' ' + CONVERT(varchar(20), start_dtm, 103) AS start_dtm_text, booked_time, end_dtm, CONVERT(varchar(20), end_dtm, 108) + ' ' + CONVERT(varchar(20), end_dtm, 103) AS end_dtm_text FROM timesheets AS ts INNER JOIN timesheet_categories AS cat ON ts.timesheet_cat_ref = cat.timesheet_cat_ref INNER JOIN timesheet_tasks AS tsks ON ts.task_ref = tsks.task_ref INNER JOIN timesheet_task_groupings AS grps ON tsks.grouping_ref = grps.grouping_ref INNER JOIN timesheet_sites AS sits ON ts.site_ref = sits.site_ref INNER JOIN vw_staff_members AS sm ON ts.staff_member_ref = sm.staff_member_ref WHERE (ts.status IN (1, 2)) AND (cat.is_leave_category = 0) GROUP BY ts.staff_member_ref, sm.common_name, sm.department_name, DATENAME(MONTH, ts.start_dtm), DATENAME(YEAR, ts.start_dtm), ts.timesheet_cat_ref, cat.desc_long, grps.grouping_ref, grps.description, ts.status, ts.booked_time, ts.task_ref, tsks.task_code, tsks.description, ts.site_ref, sits.description, ts.start_dtm, ts.end_dtm ORDER BY sm.common_name, timesheet_cat_desc, tsks.task_code, site_desc DROP TABLE #WeeklyList GO I want to pass the week_ref into the SELECT statement (refer to comment - THIS FILTERS THE REPORT) but the problem is week_ref isnt a valid column as its derived by code. Any ideas?

    Read the article

  • Question about design (inheritance, polymorphism)

    - by Dan
    Hi, I have a question about a problem I'm struggling with. Hope you can bear with me. Imagine I have an Object class representing the base class of a hierarchy of physical objects. Later I inherit from it to create an Object1D, Object2D and Object3D classes. Each of these derived classes will have some specific methods and attributes. For example, the 3d object might have functionality to download a 3d model to be used by a renderer. So I'd have something like this: class Object {}; class Object1D : public Object { Point mPos; }; class Object2D : public Object { ... }; class Object3D : public Object { Model mModel; }; Now I'd have a separate class called Renderer, which simply takes an Object as argument and well, renders it :-) In a similar way, I'd like to support different kinds of renderers. For instance, I could have a default one that every object could rely on, and then provide other specific renderers for some kind of objects: class Renderer {}; // Default one class Renderer3D : public Renderer {}; And here comes my problem. A renderer class needs to get an Object as an argument, for example in the constructor in order to retrieve whatever data it needs to render the object. So far so good. But a Renderer3D would need to get an Object3D argument, in order to get not only the basic attributes but also the specific attributes of a 3d object. Constructors would look like this: CRenderer(Object& object); CRenderer3D(Object3D& object); Now how do I specify this in a generic way? Or better yet, is there a better way to design this? I know I could rely on RTTI or similar but I'd like to avoid this if possible as I feel there is probably a better way to deal with this. Thanks in advance!

    Read the article

  • help me "dry" out this .net XML serialization code

    - by Sarah Vessels
    I have a base collection class and a child collection class, each of which are serializable. In a test, I discovered that simply having the child class's ReadXml method call base.ReadXml resulted in an InvalidCastException later on. First, here's the class structure: Base Class // Collection of Row objects [Serializable] [XmlRoot("Rows")] public class Rows : IList<Row>, ICollection<Row>, IEnumerable<Row>, IEquatable<Rows>, IXmlSerializable { public Collection<Row> Collection { get; protected set; } public void ReadXml(XmlReader reader) { reader.ReadToFollowing(XmlNodeName); do { using (XmlReader rowReader = reader.ReadSubtree()) { var row = new Row(); row.ReadXml(rowReader); Collection.Add(row); } } while (reader.ReadToNextSibling(XmlNodeName)); } } Derived Class // Acts as a collection of SpecificRow objects, which inherit from Row. Uses the same // Collection<Row> that Rows defines which is fine since SpecificRow : Row. [Serializable] [XmlRoot("MySpecificRowList")] public class SpecificRows : Rows, IXmlSerializable { public new void ReadXml(XmlReader reader) { // Trying to just do base.ReadXml(reader) causes a cast exception later reader.ReadToFollowing(XmlNodeName); do { using (XmlReader rowReader = reader.ReadSubtree()) { var row = new SpecificRow(); row.ReadXml(rowReader); Collection.Add(row); } } while (reader.ReadToNextSibling(XmlNodeName)); } public new Row this[int index] { // The cast in this getter is what causes InvalidCastException if I try // to call base.ReadXml from this class's ReadXml get { return (Row)Collection[index]; } set { Collection[index] = value; } } } And here's the code that causes a runtime InvalidCastException if I do not use the version of ReadXml shown in SpecificRows above (i.e., I get the exception if I just call base.ReadXml from within SpecificRows.ReadXml): TextReader reader = new StringReader(serializedResultStr); SpecificRows deserializedResults = (SpecificRows)xs.Deserialize(reader); SpecificRow = deserializedResults[0]; // this throws InvalidCastException So, the code above all compiles and runs exception-free, but it bugs me that Rows.ReadXml and SpecificRows.ReadXml are essentially the same code. The value of XmlNodeName and the new Row()/new SpecificRow() are the differences. How would you suggest I extract out all the common functionality of both versions of ReadXml? Would it be silly to create some generic class just for one method? Sorry for the lengthy code samples, I just wanted to provide the reason I can't simply call base.ReadXml from within SpecificRows.

    Read the article

  • Strange behaviour when posting CGEvent to PSN

    - by Ben Packard
    If I set up a loop that posts some keyboard events to a PSN, I find that it works fine except for when first launched. The event only seems to post when i do something with the mouse manually - even just moving it slightly. Here's the details, if they help. An external application has a list box of text lines, which I am reading by posting copy commands (and checking the pasteboard). Unfortunately this is my only way to get this text. Sometimes, the application pulls focus away from the list, which I can detect. When this happens, the most reliable way to return focus is by sending a mouse event to click on a text field directly above the list, then send a 'tab' keyboard event to shift the focus onto the list. So at launch, the loop runs fine, scrolling down the list and copying the text. When focus is shifted away, its is detected fine, and the events are sent to move focus back to the list. But nothing seems to happen. The loop continues detecting that focus has changed, but the events only work once I move the mouse. Or even just use the scroll wheel. Strange. Once this has happened the first time, it works fine - each time focus moves, the PSN events switch it back without me having to do anything at all. Here's the code that runs in the loop - verified as working: //copy to pasteboard - CMD-V e3 = CGEventCreateKeyboardEvent(NULL, (CGKeyCode)8, true); CGEventSetFlags(e3, kCGEventFlagMaskCommand); CGEventPostToPSN(&psn, e3); CFRelease(e3); e4 = CGEventCreateKeyboardEvent(NULL, (CGKeyCode)8, false); CGEventPostToPSN(&psn, e4); CFRelease(e4); //move cursor down e1 = CGEventCreateKeyboardEvent(NULL, (CGKeyCode)125, true); CGEventPostToPSN(&psn, e1); CFRelease(e1); e2 = CGEventCreateKeyboardEvent(NULL, (CGKeyCode)125, false); CGEventPostToPSN(&psn, e2); CFRelease(e2); And here's where I switch focus, also working (except when first required): //click in text input box - point is derived earlier e6 = CGEventCreateMouseEvent(NULL, kCGEventLeftMouseDown, point, 0); CGEventPostToPSN(&psn, e6); CFRelease(e6); e7 = CGEventCreateMouseEvent(NULL, kCGEventLeftMouseUp, point, 0); CGEventPostToPSN(&psn, e7); CFRelease(e7); //press tab key to move to chat log table CGEventRef e = CGEventCreateKeyboardEvent(NULL, (CGKeyCode)48, true); //CGEventPost(kCGSessionEventTap, e); CGEventPostToPSN(&psn, e); CFRelease(e); CGEventRef e11 = CGEventCreateKeyboardEvent(NULL, (CGKeyCode)48, false); CGEventPostToPSN(&psn, e11); CFRelease(e11);

    Read the article

  • Deriving from a component and implementing IDisposable properly

    - by PaulH
    I have a Visual Studio 2008 C# .NET 2.0 CF project with an abstract class derived from Component. From that class, I derive several concrete classes (as in my example below). But, when I go to exit my Form, though the Form's Dispose() member is called and components.Dispose() is called, my components are never disposed. Can anybody suggest how I can fix this design? public abstract class SomeDisposableComponentBase : Component { private System.ComponentModel.IContainer components; protected SomeDisposableComponentBase() { Initializecomponent(); } protected SomeDisposableComponentBase(IContainer container) { container.Add(this); Initializecomponent(); } private void InitializeComponent() { components = new System.ComponentModel.Container(); } protected abstract void Foo(); #region IDisposable Members bool disposed_; /// Warning 60 CA1063 : Microsoft.Design : Ensure that 'SomeDisposableComponentBase.Dispose()' is declared as public and sealed.* public void Dispose() { // never called Dispose(true); GC.SuppressFinalize(this); } protected virtual void Dispose(bool disposing) { // never called if (!disposed_) { if (disposing && (components != null)) { components.Dispose(); } disposed_ = true; } base.Dispose(disposing); } #endregion } public SomeDisposableComponent : SomeDisposableComponentBase { public SomeDisposableComponent() : base() { } public SomeDisposableComponent(IContainer container) : base(container) { } protected override void Foo() { // Do something... } protected override void Dispose(bool disposing) { // never called base.Dispose(disposing); } } public partial class my_form : Form { private SomeDisposableComponentBase d_; public my_form() { InitializeComponent(); if (null == components) components = new System.ComponentModel.Container(); d_ = new SomeDisposableComponent(components); } /// exit button clicked private void Exit_Click(object sender, EventArgs e) { this.Close(); } /// from the my_form.designer.cs protected override void Dispose(bool disposing) { if (disposing && (components != null)) { // this function is executed as expected when the form is closed components.Dispose(); } base.Dispose(disposing); } } *I note that FX-Cop is giving me a hint here. But, if I try to declare that function as sealed, I get the error: error CS0238: 'SomeDisposableComponentBase.Dispose()' cannot be sealed because it is not an override Declaring that function an override leads to: 'SomeDisposableComponentBase.Dispose()': cannot override inherited member 'System.ComponentModel.Component.Dispose()' because it is not marked virtual, abstract, or override Thanks, PaulH

    Read the article

  • Flatten date range memberships retaining only the highest priority membership (TRANSACT-SQL)

    - by shadowranger
    Problem statement: A table contains an item_id, a category_id and a date range (begin_date and end_date). No item may be in more than one category on any given date (in general; during daily rebuilding it can be in an invalid state temporarily). By default, all items are added (and re-added if removed) to a category (derived from outside data) automatically on a daily basis, and their membership in that category matches the lifespan of the item (items have their own begin and end date, and usually spend their entire lives in the same category, which is why this matches). For items in category X, it is occasionally desirable to override the default category by adding them to category Y. Membership in category Y could entirely replace membership in category X (that is, the begin and end dates for membership in category Y would match the begin and end dates of the item itself), or it could override it for an arbitrary period of time (at the beginning, middle or end the item's lifespan, possibly overriding for short periods at multiple times). Membership in category Y is not renewed automatically and additions to that category is done by manual data entry. Every day, when category X is rebuilt, we get an overlap, where any item in category Y will now be in category X as well (which is forbidden, as noted previously). Goal: After each repopulation of category X (which is done in a rather complicated and fragile manner, and ideally would be left alone), I'm trying to find an efficient means of writing a stored procedure that: Identifies the overlaps Changes existing entries, adds new ones where necessary (such as in the case where an item starts in category X, switches to category Y, then eventually switches back to category X before ending), or removes entries (when an item is in category Y for its entire life) such that every item remains in category Y (and only Y) where specified, while category X membership is maintained when not overridden by category Y. Does not affect memberships of categories A, B, C, Z, etc., which do not have override categories and are built separately, by completely different rules. Note: It can be assumed that X membership covers the entire lifespan of the item before this procedure is called, so it is unnecessary to query any data outside this table. Bonus credit: If for some reason there are two adjacent or overlapping memberships in for the same item in category Y, stitching them together into a single entry is appreciated, but not necessary. Example: item_id category_id begin_date end_date 1 X 20080101 20090628 1 Y 20090101 20090131 1 Y 20090601 20090628 2 X 20080201 20080731 2 Y 20080201 20080731 Should become: item_id category_id begin_date end_date 1 X 20080101 20081231 1 Y 20090101 20090131 1 X 20090201 20090531 1 Y 20090601 20090628 2 Y 20080201 20080731 If it matters, this needs to work on SQL Server 2005 and SQL Server 2008

    Read the article

  • User Control as container at design time

    - by Luca
    I'm designing a simple expander control. I've derived from UserControl, drawn inner controls, built, run; all ok. Since an inner Control is a Panel, I'd like to use it as container at design time. Indeed I've used the attributes: [Designer(typeof(ExpanderControlDesigner))] [Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))] Great I say. But it isn't... The result is that I can use it as container at design time but: The added controls go back the inner controls already embedded in the user control Even if I push to top a control added at design time, at runtime it is back again on controls embedded to the user control I cannot restrict the container area at design time into a Panel area What am I missing? Here is the code for completeness... why this snippet of code is not working? [Designer(typeof(ExpanderControlDesigner))] [Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))] public partial class ExpanderControl : UserControl { public ExpanderControl() { InitializeComponent(); .... [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")] internal class ExpanderControlDesigner : ControlDesigner { private ExpanderControl MyControl; public override void Initialize(IComponent component) { base.Initialize(component); MyControl = (ExpanderControl)component; // Hook up events ISelectionService s = (ISelectionService)GetService(typeof(ISelectionService)); IComponentChangeService c = (IComponentChangeService)GetService(typeof(IComponentChangeService)); s.SelectionChanged += new EventHandler(OnSelectionChanged); c.ComponentRemoving += new ComponentEventHandler(OnComponentRemoving); } private void OnSelectionChanged(object sender, System.EventArgs e) { } private void OnComponentRemoving(object sender, ComponentEventArgs e) { } protected override void Dispose(bool disposing) { ISelectionService s = (ISelectionService)GetService(typeof(ISelectionService)); IComponentChangeService c = (IComponentChangeService)GetService(typeof(IComponentChangeService)); // Unhook events s.SelectionChanged -= new EventHandler(OnSelectionChanged); c.ComponentRemoving -= new ComponentEventHandler(OnComponentRemoving); base.Dispose(disposing); } public override System.ComponentModel.Design.DesignerVerbCollection Verbs { get { DesignerVerbCollection v = new DesignerVerbCollection(); v.Add(new DesignerVerb("&asd", new EventHandler(null))); return v; } } } I've found many resources (Interaction, designed, limited area), but nothing was usefull for being operative... Actually there is a trick, since System.Windows.Forms classes can be designed (as usual) and have a correct behavior at runtime (TabControl, for example).

    Read the article

  • C++ Using a class template argument as a template argument for another type

    - by toefel
    Hey Everyone, I'm having this problem while writing my own HashTable. It all works, but when I try to templatize the thing, it gave me errors. I recreated the problem as follows: THIS CODE WORKS: typedef double Item; class A { public: A() { v.push_back(pair<string, Item>("hey", 5.0)); } void iterate() { for(Iterator iter = v.begin(); iter != v.end(); ++iter) cout << iter->first << ", " << iter->second << endl; } private: vector<pair<string, double> > v; typedef vector< pair<string, double> >::iterator Iterator; }; THIS CODE DOES NOT: template<typename ValueType> class B { public: B(){} void iterate() { for(Iterator iter = v.begin(); iter != v.end(); ++iter) cout << iter->first << ", " << iter->second << endl; } private: vector<pair<string, ValueType> > v; typedef vector< pair<string, ValueType> >::iterator Iterator; }; the error messages: g++ -O0 -g3 -Wall -c -fmessage-length=0 -omain.o ..\main.cpp ..\main.cpp:50: error: type std::vector<std::pair<std::string, ValueType>, std::allocator<std::pair<std::string, ValueType> > >' is not derived from typeB' ..\main.cpp:50: error: ISO C++ forbids declaration of `iterator' with no type ..\main.cpp:50: error: expected `;' before "Iterator" ..\main.cpp: In member function `void B::iterate()': ..\main.cpp:44: error: `Iterator' was not declared in this scope ..\main.cpp:44: error: expected `;' before "iter" ..\main.cpp:44: error: `iter' was not declared in this scope Does anybody know why this is happening? Thanks!

    Read the article

  • What is the best way to create related types at runtime?

    - by SniperSmiley
    How do I determine the type of a class that is related to another class at runtime? I have figured out a solution, the only problem is that I ended up having to use a define that has to be used in all of the derived classes. Is there a simpler way to do this that doesn't need the define or a copy paste? Things to note: both the class and the related class will always have their respective base class, the different classes can share a related class, and as in the example I would like the control class to own the view. #include <iostream> #include <string> class model; class view { public: view( model *m ) {} virtual std::string display() { return "view"; } }; #define RELATED_CLASS(RELATED)\ typedef RELATED relatedType;\ virtual relatedType*createRelated(){\ return new relatedType(this);} class model { public: RELATED_CLASS(view) model() {} }; class otherView : public view { public: otherView( model *m ) : view(m) {} std::string display() { return "otherView"; } }; class otherModel : public model { public: RELATED_CLASS(otherView) otherModel() {} }; class control { public: control( model *m ) : m_(m), v_( m->createRelated() ) {} ~control() { delete v_; } std::string display() { return v_->display(); } model *m_; view *v_; }; int main( void ) { model m; otherModel om; model *pm = &om; control c1( &m ); control c2( &om ); control c3( pm ); std::cout << c1.display() << std::endl; std::cout << c2.display() << std::endl; std::cout << c3.display() << std::endl; }

    Read the article

  • Overwhelmed by design patterns... where to begin?

    - by Pete
    I am writing a simple prototype code to demonstrate & profile I/O schemes (HDF4, HDF5, HDF5 using parallel IO, NetCDF, etc.) for a physics code. Since focus is on IO, the rest of the program is very simple: class Grid { public: floatArray x,y,z; }; class MyModel { public: MyModel(const int &nip1, const int &njp1, const int &nkp1, const int &numProcs); Grid grid; map<string, floatArray> plasmaVariables; }; Where floatArray is a simple class that lets me define arbitrary dimensioned arrays and do mathematical operations on them (i.e. x+y is point-wise addition). Of course, I could use better encapsulation (write accessors/setters, etc.), but that's not the concept I'm struggling with. For the I/O routines, I am envisioning applying simple inheritance: Abstract I/O class defines read & write functions to fill in the "myModel" object HDF4 derived class HDF5 HDF5 using parallel IO NetCDF etc... The code should read data in any of these formats, then write out to any of these formats. In the past, I would add an AbstractIO member to myModel and create/destroy this object depending on which I/O scheme I want. In this way, I could do something like: myModelObj.ioObj->read('input.hdf') myModelObj.ioObj->write('output.hdf') I have a bit of OOP experience but very little on the Design Patterns front, so I recently acquired the Gang of Four book "Design Patterns: Elements of Reusable Object-Oriented Software". OOP designers: Which pattern(s) would you recommend I use to integrate I/O with the myModel object? I am interested in answering this for two reasons: To learn more about design patterns in general Apply what I learn to help refactor an large old crufty/legacy physics code to be more human-readable & extensible. I am leaning towards applying the Decerator pattern to myModel, so I can attach the I/O responsibilities dynamically to myModel (i.e. whether to use HDF4, HDF5, etc.). However, I don't feel very confident that this is the best pattern to apply. Reading the Gang of Four book cover-to-cover before I start coding feels like a good way to develop an unhealthy caffeine addiction. What patterns do you recommend?

    Read the article

  • How to obtain a pointer out of a C++ vtable?

    - by Josh Haberman
    Say you have a C++ class like: class Foo { public: virtual ~Foo() {} virtual DoSomething() = 0; }; The C++ compiler translates a call into a vtable lookup: Foo* foo; // Translated by C++ to: // foo->vtable->DoSomething(foo); foo->DoSomething(); Suppose I was writing a JIT compiler and I wanted to obtain the address of the DoSomething() function for a particular instance of class Foo, so I can generate code that jumps to it directly instead of doing a table lookup and an indirect branch. My questions are: Is there any standard C++ way to do this (I'm almost sure the answer is no, but wanted to ask for the sake of completeness). Is there any remotely compiler-independent way of doing this, like a library someone has implemented that provides an API for accessing a vtable? I'm open to completely hacks, if they will work. For example, if I created my own derived class and could determine the address of its DoSomething method, I could assume that the vtable is the first (hidden) member of Foo and search through its vtable until I find my pointer value. However, I don't know a way of getting this address: if I write &DerivedFoo::DoSomething I get a pointer-to-member, which is something totally different. Maybe I could turn the pointer-to-member into the vtable offset. When I compile the following: class Foo { public: virtual ~Foo() {} virtual void DoSomething() = 0; }; void foo(Foo *f, void (Foo::*member)()) { (f->*member)(); } On GCC/x86-64, I get this assembly output: Disassembly of section .text: 0000000000000000 <_Z3fooP3FooMS_FvvE>: 0: 40 f6 c6 01 test sil,0x1 4: 48 89 74 24 e8 mov QWORD PTR [rsp-0x18],rsi 9: 48 89 54 24 f0 mov QWORD PTR [rsp-0x10],rdx e: 74 10 je 20 <_Z3fooP3FooMS_FvvE+0x20> 10: 48 01 d7 add rdi,rdx 13: 48 8b 07 mov rax,QWORD PTR [rdi] 16: 48 8b 74 30 ff mov rsi,QWORD PTR [rax+rsi*1-0x1] 1b: ff e6 jmp rsi 1d: 0f 1f 00 nop DWORD PTR [rax] 20: 48 01 d7 add rdi,rdx 23: ff e6 jmp rsi I don't fully understand what's going on here, but if I could reverse-engineer this or use an ABI spec I could generate a fragment like the above for each separate platform, as a way of obtaining a pointer out of a vtable.

    Read the article

  • Working with friends. Poor career choice?

    - by a_person
    Hi all, Hope you can help me solve somewhat of a moral dilemma. Some time ago, after just a few years of living in U.S. and having to take any job I could get my hands on a friend of mine submitted recommended me for an open position at the company that he was working for. I could have not been happier. I do not have a degree of any sort, however, by being passionate about CS and with constant drive for self education I've became a somewhat of a strong generalist. Every place I worked for recognized me for that quality and used me on various projects where set of technology in hand had no overlap with set of knowledge of the team members. Rapidly I've advanced to Sr. Programmer position and the trend of me following a friend from one place to another have started and continued on for a few years. My friend's goal always been to become an IT Director, mine is to become the best programmer I can be. To my knowledge I've accommodated his goals as much as I could by taking a back seat, and letting him take the lead. Fast forward to today. He's a manager, and I am on his team. I am unhappy and I in considerable amount of suffering. I am not being utilized to my potential, it's almost exact opposite, I am being micromanaged to an unhealthy extent, my decisions, and suggestions are constantly met with negative connotation. Last week I had to hear about how my friend is a better programmer than I am. My ego was ecstatic about this one /s. In addition to that working in the field of BI have exhausted itself for most parts. The only pleasure of my work is being derived from making everything as dynamic and parameter driven as possible. This is the only area where a friend of mine does not feel competent enough to actually micromanage. Because of my situation I feel a fair amount of guilt and ever growing resentment. I need your advice, maybe you've dealt with this expression of ego before, needs of self vs the needs of your friend. Is working with a friend a poor choice? Thank you for reading in.

    Read the article

  • Help With LINQ: Mixed Joins and Specifying Default Values

    - by Corey O.
    I am trying to figure out how to do a mixed-join in LINQ with specific access to 2 LINQ objects. Here is an example of how the actual TSQL query might look: SELECT * FROM [User] AS [a] INNER JOIN [GroupUser] AS [b] ON [a].[UserID] = [b].[UserID] INNER JOIN [Group] AS [c] ON [b].[GroupID] = [c].[GroupID] LEFT JOIN [GroupEntries] AS [d] ON [a].[GroupID] = [d].[GroupID] WHERE [a].[UserID] = @UserID At the end, basically what I would like is an enumerable object full of GroupEntry objects. What am interested is the last two tables/objects in this query. I will be displaying Groups as a group header, and all of the Entries underneath their group heading. If there are no entries for a group, I still want to see that group as a header without any entries. Here's what I have so far: So from that I'd like to make a function: public void DisplayEntriesByUser(int user_id) { MyDataContext db = new MyDataContext(); IEnumberable<GroupEntries> entries = ( from user in db.Users where user.UserID == user_id join group_user in db.GroupUsers on user.UserID = group_user.UserID into a from join1 in a join group in db.Groups on join1.GroupID equals group.GroupID into b from join2 in b join entry in db.Entries.DefaultIfEmpty() on join2.GroupID equals entry.GroupID select entry ); Group last_group_id = 0; foreach(GroupEntry entry in entries) { if (last_group_id == 0 || entry.GroupID != last_group_id) { last_group_id = entry.GroupID; System.Console.WriteLine("---{0}---", entry.Group.GroupName.ToString().ToUpper()); } if (entry.EntryID) { System.Console.WriteLine(" {0}: {1}", entry.Title, entry.Text); } } } The example above does not work quite as expected. There are 2 problems that I have not been able to solve: I still seem to be getting an INNER JOIN instead of a LEFT JOIN on the last join. I am not getting any empty results, so groups without entries do not appear. I need to figure out a way so that I can fill in the default values for blank sets of entries. That is, if there is a group without an entry, I would like to have a mostly blank entry returned, except that I'd want the EntryID to be null or 0, the GroupID to be that of of the empty group that it represents, and I'd need a handle on the entry.Group object (i.e. it's parent, empty Group object). Any help on this would be greatly appreciated. Note: Table names and real-world representation were derived purely for this example, but their relations simplify what I'm trying to do.

    Read the article

  • How do you return a pointer to a base class with a virtual function?

    - by Nick Sweet
    I have a base class called Element, a derived class called Vector, and I'm trying to redefine two virtual functions from Element in Vector. //element.h template <class T> class Element { public: Element(); virtual Element& plus(const Element&); virtual Element& minus(const Element&); }; and in another file //Vector.h #include "Element.h" template <class T> class Vector: public Element<T> { T x, y, z; public: //constructors Vector(); Vector(const T& x, const T& y = 0, const T& z =0); Vector(const Vector& u); ... //operations Element<T>& plus(const Element<T>& v) const; Element<T>& minus(const Element<T>& v) const; ... }; //sum template <class T> Element<T>& Vector<T>::plus(const Element<T>& v) const { Element<T>* ret = new Vector((x + v.x), (y + v.y), (z + v.z)); return *ret; } //difference template <class T> Element<T>& Vector<T>::minus(const Element<T>& v) const { Vector<T>* ret = new Vector((x - v.x), (y - v.y), (z - v.z)); return *ret; } but I always get error: 'const class Element' has no member named 'getx' So, can I define my virtual functions to take Vector& as an argument instead, or is there a way for me to access the data members of Vector through a pointer to Element? I'm still fairly new to inheritance polymorphism, fyi.

    Read the article

  • C++ game designing & polymorphism question

    - by Kotti
    Hi! I'm trying to implement some sort of 'just-for-me' game engine and the problem's plot goes the following way: Suppose I have some abstract interface for a renderable entity, e.g. IRenderable. And it's declared the following way: interface IRenderable { // (...) // Suppose that Backend is some abstract backend used // for rendering, and it's implementation is not important virtual void Render(Backend& backend) = 0; }; What I'm doing right now is something like declaring different classes like class Ball : public IRenderable { virtual void Render(Backend& backend) { // Rendering implementation, that is specific for // the Ball object // (...) } }; And then everything looks fine. I can easily do something like std::vector<IRenderable*> items, push some items like new Ball() in this vector and then make a call similiar to foreach (IRenderable* in items) { item->Render(backend); } Ok, I guess it is the 'polymorphic' way, but what if I want to have different types of objects in my game and an ability to manipulate their state, where every object can be manipulated via it's own interface? I could do something like struct GameState { Ball ball; Bonus bonus; // (...) }; and then easily change objects state via their own methods, like ball.Move(...) or bonus.Activate(...), where Move(...) is specific for only Ball and Activate(...) - for only Bonus instances. But in this case I lose the opportunity to write foreach IRenderable* simply because I store these balls and bonuses as instances of their derived, not base classes. And in this case the rendering procedure turns into a mess like ball.Render(backend); bonus.Render(backend); // (...) and it is bad because we actually lose our polymorphism this way (no actual need for making Render function virtual, etc. The other approach means invoking downcasting via dynamic_cast or something with typeid to determine the type of object you want to manipulate and this looks even worse to me and this also breaks this 'polymorphic' idea. So, my question is - is there some kind of (probably) alternative approach to what I want to do or can my current pattern be somehow modified so that I would actually store IRenderable* for my game objects (so that I can invoke virtual Render method on each of them) while preserving the ability to easily change the state of these objects? Maybe I'm doing something absolutely wrong from the beginning, if so, please point it out :) Thanks in advance!

    Read the article

  • User Control as container

    - by Luca
    I'm designing a simple expander control. I've derived from UserControl, drawn inner controls, built, run; all ok. Since an inner Control is a Panel, I'd like to use it as container at design time. Indeed I've used the attributes: [Designer(typeof(ExpanderControlDesigner))] [Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))] Great I say. But it isn't... The result is that I can use it as container at design time but: The added controls go back the inner controls already embedded in the user control Even if I push to top a control added at design time, at runtime it is back again on controls embedded to the user control I cannot restrict the container area at design time into a Panel area What am I missing? Here is the code for completeness... why this snippet of code is not working? [Designer(typeof(ExpanderControlDesigner))] [Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))] public partial class ExpanderControl : UserControl { public ExpanderControl() { InitializeComponent(); .... [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")] internal class ExpanderControlDesigner : ControlDesigner { private ExpanderControl MyControl; public override void Initialize(IComponent component) { base.Initialize(component); MyControl = (ExpanderControl)component; // Hook up events ISelectionService s = (ISelectionService)GetService(typeof(ISelectionService)); IComponentChangeService c = (IComponentChangeService)GetService(typeof(IComponentChangeService)); s.SelectionChanged += new EventHandler(OnSelectionChanged); c.ComponentRemoving += new ComponentEventHandler(OnComponentRemoving); } private void OnSelectionChanged(object sender, System.EventArgs e) { } private void OnComponentRemoving(object sender, ComponentEventArgs e) { } protected override void Dispose(bool disposing) { ISelectionService s = (ISelectionService)GetService(typeof(ISelectionService)); IComponentChangeService c = (IComponentChangeService)GetService(typeof(IComponentChangeService)); // Unhook events s.SelectionChanged -= new EventHandler(OnSelectionChanged); c.ComponentRemoving -= new ComponentEventHandler(OnComponentRemoving); base.Dispose(disposing); } public override System.ComponentModel.Design.DesignerVerbCollection Verbs { get { DesignerVerbCollection v = new DesignerVerbCollection(); v.Add(new DesignerVerb("&asd", new EventHandler(null))); return v; } } } I've found many resources (Interaction, designed, limited area), but nothing was usefull for being operative...

    Read the article

  • Problem on creating font using a custom ant task, which extends LWUIT's FontTask.

    - by Smithy
    Hi. I am new to LWUIT and j2me, and I am building a j2me application for showing Japanese text vertically. The phonetic symbol part of the text should be shown in relatively small font size (about half the size of the text), small Kanas need to be shown as normal ones, and some 'vertical only' characters need to be put into the Private Use Area, etc. I tried to build this font into a bitmap font using the FontTask ant task LWUIT provided, but found that it does support the customizations mentioned above. So I decided to write my own task and add those. Below is what I have achieved: 1 An ant task extending the LWUITTask task to support a new nested element <verticalfont>. public class VerticalFontBuildTask extends LWUITTask { public void addVerticalfont(VerticalFontTask anVerticalFont) { super.addFont(anVerticalFont); } } 2 The VerticalFontTask task, which extends the original FontTask. Instead of inserting a EditorFont object, it inserts a VerticalEditorFont object(derived from EditorFont) into the resource. public class VerticalFontTask extends FontTask { // some constants are omitted public VerticalFontTask() { StringBuilder sb = new StringBuilder(); sb.append(UPPER_ALPHABET); sb.append(UPPER_ALPHABET.toLowerCase()); sb.append(HALFWIDTH); sb.append(HIRAGANA); sb.append(HIRAGANA_SMALL); sb.append(KATAKANA); sb.append(KATAKANA_SMALL); sb.append(WIDE); this.setCharset(sb.toString()); } @Override public void addToResources(EditableResources e) { log("Putting rigged font into resource..."); super.addToResources(e); //antialias settings Object aa = this.isAntiAliasing() ? RenderingHints.VALUE_TEXT_ANTIALIAS_ON :RenderingHints.VALUE_TEXT_ANTIALIAS_OFF; VerticalEditorFont ft = new VerticalEditorFont( Font.createSystemFont( this.systemFace, this.systemStyle, this.systemSize), null, getLogicalName(), isCreateBitmap(), aa, getCharset()); e.setFont(getName(), ft); } VerticalEditorFont is just a bunch of methods logging to output and call the super. I am still trying to figure out how to extend it. But things are not going well: none of the methods on the VerticalEditorFont object get called when executing this task. My questions are: 1 where did I do wrong? 2 I want to embed a truetype font to support larger screens. I only need a small part of the font inside my application and I don't want it to carry a font resource weighing 1~2MB. Is there a way to extract only the characters needed and pack them into LWUIT?

    Read the article

  • changing restriction on simple type in extended complex type

    - by rotary_engine
    I am trying to create a schema that has 2 address types. The first AdressType requires an element Line 1 to have a value at least 10 characters. The second type OtherAdressType derives from this with the same elements, but does not require a value for Line 1. I've tried different ways but always get schema errors, this error is: Invalid particle derivation by restriction - 'Derived element '{namespace}:Line1' is not a valid restriction of base element '{namespace}:Line1' according to Elt:Elt -- NameAndTypeOK.'. If I add a type xs:string to OtherAdressType:Line1 then I get other errors. <xs:complexType name="AdressType"> <xs:sequence> <xs:element name="Line1" minOccurs="1" maxOccurs="1"> <xs:simpleType> <xs:restriction base="xs:string"> <xs:minLength value="10" /> </xs:restriction> </xs:simpleType> </xs:element> <xs:element name="Line2" type="xs:string" minOccurs="1" maxOccurs="1" /> </xs:sequence> </xs:complexType> <xs:complexType name="OtherAdressType"> <xs:complexContent> <xs:restriction base="AdressType"> <xs:sequence> <xs:element name="Line1" nillable="true"> <xs:simpleType> <xs:restriction base="xs:string"> <xs:minLength value="0" /> </xs:restriction> </xs:simpleType> </xs:element> <xs:element name="Line2" type="xs:string" minOccurs="1" maxOccurs="1" /> </xs:sequence> </xs:restriction> </xs:complexContent> </xs:complexType>

    Read the article

< Previous Page | 42 43 44 45 46 47 48 49 50 51  | Next Page >