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  • QT: I've inherited from QTreeView. I've inherited from QStandardItem. How do i Style the items?

    - by San Jacinto
    My Google skills must be failing me today. I've inherited from QTreeView to create a TreeView that stores a QStandardItemModel instead of a QAbstractItemModel. I have also inherited from QStandardItem to create a class to store my data in an item as is necessary. I've successfully inserted my derived QStandardItem into my derived QTreeView's QStandardItemModel. Now the trouble is, I can't figure out how to style it. I know that QTreeView has a setStyleSheet(QString) member, but I can't seem to get it working. It may be as simple as I'm not styling the correct attribute. Any pointers would be appreciated. Thanks. For clarity, here are my class defs. class SurveyTreeItem : public QStandardItem { public: SurveyTreeItem(); SurveyTreeItem( const QString & text ); ~SurveyTreeItem(); }; class StandardItemModelTreeView : public QTreeView { public: StandardItemModelTreeView(QWidget* parent = 0); ~StandardItemModelTreeView(); QStandardItemModel* getStandardItemModel(); }; I've tried the following StyleSheets: StandardTreeView::Item { font: 87 12pt 'Arial Black'; } StandardTreeView::QStandardItem { font: 87 12pt 'Arial Black'; } QTreeView::QStandardItem { font: 87 12pt 'Arial Black'; } QTreeView::Item { font: 87 12pt 'Arial Black'; } QTreeView::SurveyTreeItem { font: 87 12pt 'Arial Black'; } StandardTreeView::SurveyTreeItem { font: 87 12pt 'Arial Black'; }

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  • Comments in Activity Stream

    - by fesja
    Hi, I'm starting to develop an activity stream. I've read both How to implement the activity stream in a social network and What’s the best manner of implementing a social activity stream?. What I haven't found is the best way to add comments to the activities. As in facebook, each comment can be commented by another person. If each activity comment is saved as another activity, then I would not be able to get the activity of that comment without doing a query. So the solution I'm thinking is to save the comments inside the serialize data field of each activity. If the user wants to delete his comment, I would have to update that activity. Is this the correct solution? Is there a better approach? Thanks!

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  • Implementing the tree with reference to the root for each leaf

    - by AntonAL
    Hi, i implementing a products catalog, that looks, like this: group 1 subgroup 1 subgroup 2 item 1 item 2 ... item n ... subgroup n group 2 subgroup 1 ... subgroup n group 3 ... group n The Models: class CatalogGroup < ActiveRecord::Base has_many: catalog_items has_many :catalog_items_all, :class_name => "CatalogItem", :foreign_key => "catalog_root_group_id" end class CatalogItem < ActiveRecord::Base belongs_to :catalog_group belongs_to :catalog_root_group, :class_name => "CatalogGroup" end Migrations: class CreateCatalogItems < ActiveRecord::Migration def self.up create_table :catalog_items do |t| t.integer :catalog_group_id t.integer :catalog_root_group_id t.string :code t.timestamps end end For convenience, i referenced each CatalogItem to it's top-most CatalogGroup and named this association "catalog_root_group". This will give us the simple implementation of search request, like "show me all items in group 1". We will have a deal only with CatalogModel.catalog_root_group The problem is - this association does't work. I always get "catalog_root_group" equals to nil Also, i have tried to overcome the using of reference to root group ("catalog_root_group"), but i cannot construct appropriate search request in ruby ... Do you know, how to do it ?

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  • Is this a situation where Qt Model/View architecture is not useful?

    - by csmithmaui
    Hi, I am writing a GUI based application where I read a string of values from serial port every few seconds and I need to display most of the values in some type graphical indicator(I was thinking of QprogressBar maybe) that displays the range and the value. Some of the other data that I am parsing from the string are the date and fault codes. Also, the data is hierarchical. I wanted to use the model/view architecture of Qt because I have been interested in MVC stuff for a while but have never quite wrapped my brain around how to implement it very well. As of now, I have subclassed QAbstractItemModel and in the model I read the serial port and wrap the items parsed from the string in a Tree data structure. I can view all of the data in a QtreeView with no issues. I have also began to subclass QAbstractItemView to build my custom view with all of the Graphical Indicators and such. This is where I am getting stuck. It seems to me that in order for me to design a view that knows how to display my custom model the view needs to know exactly how all of the data in the model is organized. Doesn't that defeat the purpose of Model/View? The QTreeView I tested the model with is basically just displaying the model as it is setup in the Tree structure but I don't want to do that because the data is not all of the same type. Is the type of data or the way you would like to present it to the user a determining factor in whether or not you should use this architecture? I always assumed it was just always better to design in an MVC style. It seems to me like it might have been better to just subclass QWidget and then read in from the serial port and update all of subwidgets(graphical indicators, labels, etc...) from the subclass. Essentially, do everything in one class. Does anybody understand this issue that can explain to me either what I am missing or why I shouldn't be doing it this way. As of now I am a little confused. Thanks so much for any help!

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  • GWT, MVP, and UIBinding - How to get the best of all worlds

    - by Stephane Grenier
    With MVP, you normally bind the View (UI) with the Presenter in the Presenter. However with the latest version of GWT, especially with UIBinding, you can do the following in the View: @UiHandler("loginButton") void onAboutClicked(ClickEvent event) { // my login code } Which basically exchanges a lot of anonymous inner class code for some quick annotation code. Very nice!! The problem is that this code is in the view and not the presenter... So I thought maybe: @UiHandler("loginButton") void onAboutClicked(ClickEvent event) { myPresenter.onAboutClicked(...); } But there are several problems with this approach. The most important, you blur the lines between View and Presenter. Who does which binding, in some cases it's the View, in others it's the presenter (binding to events not in your current view but that need to be attached - for example a system wide update event). You still get the benefit of being able to unit test your presenter, but at what cost. The responsibilities are messy now. For example the binding is sometimes in the View and others times in the Presenter level. I can see the code falling into all kinds of chaos with time. I also thought of extending the Presenter to the View, so that you could do this in the View. The problem here is that you lose the Presenter's ability to run standard unit tests! That's a major issue. That and the lines again become blurred. So my question, does anyone have a good method of taking advantage of the annotation from UIBinding within the MVP pattern without blurring the lines and losing the advantages of the MVP pattern?

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  • Nullable<> as TModel for ViewPage

    - by Alexander Prokofyev
    What are the possible reasons what Nullable<> types are disallowed to be passed as TModel parameter of System.Web.Mvc.ViewPage<TModel> generic? This could be handy sometimes. In ASP.NET MVC source defined what TModel should be a class: public class ViewPage<TModel> : ViewPage where TModel : class but Nullable types are value types. Maybe definition could be less restrictive...

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  • Generic list typecasting problem

    - by AJ
    Hello, I'm new to C# and am stuck on the following. I have a Silverlight web service that uses LINQ to query a ADO.NET entity object. e.g.: [OperationContract] public List<Customer> GetData() { using (TestEntities ctx = new TestEntities()) { var data = from rec in ctx.Customer select rec; return data.ToList(); } } This works fine, but what I want to do is to make this more abstract. The first step would be to return a List<EntityObject> but this gives a compiler error, e.g.: [OperationContract] public List<EntityObject> GetData() { using (TestEntities ctx = new TestEntities()) { var data = from rec in ctx.Customer select rec; return data.ToList(); } } The error is: Error 1 Cannot implicitly convert type 'System.Collections.Generic.List<SilverlightTest.Web.Customer>' to 'System.Collections.Generic.IEnumerable<System.Data.Objects.DataClasses.EntityObject>'. An explicit conversion exists (are you missing a cast?) What am i doing wrong? Thanks, AJ

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  • How can i return IEnumarable data from function in GridView with Entity FrameWork?

    - by programmerist
    protected IEnumerable GetPersonalsData() { // List personel; using (FirmaEntities firmactx = new FirmaEntities()) { var personeldata = (from p in firmactx.Personals select new { p.ID, p.Name, p.SurName }); return personeldata.AsEnumerable(); } } i wan to send GetPersonelData() into GridView DataSource. Like That: gwPersonel.DataSource = GetPersonelData(); gwPersonel.DataBind(); it monitored to me on : gwPersonel.DataBind(); this error: "The ObjectContext instance has been disposed and can no longer be used for operations that require a connection."

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  • What does flushing thread local memory to global memory mean?

    - by Jack Griffith
    Hi, I am aware that the purpose of volatile variables in Java is that writes to such variables are immediately visible to other threads. I am also aware that one of the effects of a synchronized block is to flush thread-local memory to global memory. I have never fully understood the references to 'thread-local' memory in this context. I understand that data which only exists on the stack is thread-local, but when talking about objects on the heap my understanding becomes hazy. I was hoping that to get comments on the following points: When executing on a machine with multiple processors, does flushing thread-local memory simply refer to the flushing of the CPU cache into RAM? When executing on a uniprocessor machine, does this mean anything at all? If it is possible for the heap to have the same variable at two different memory locations (each accessed by a different thread), under what circumstances would this arise? What implications does this have to garbage collection? How aggressively do VMs do this kind of thing? Overall, I think am trying to understand whether thread-local means memory that is physically accessible by only one CPU or if there is logical thread-local heap partitioning done by the VM? Any links to presentations or documentation would be immensely helpful. I have spent time researching this, and although I have found lots of nice literature, I haven't been able to satisfy my curiosity regarding the different situations & definitions of thread-local memory. Thanks very much.

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  • How to implement menuitems that depend on current selection in WPF MVVM explorer-like application

    - by Doug
    I am new to WPF and MVVM, and I am working on an application utilizing both. The application is similar to windows explorer, so consider an app with a main window with menu (ShellViewModel), a tree control (TreeViewModel), and a list control (ListViewModel). I want to implement menu items such as Edit - Delete, which deletes the currently selected item (which may be in the tree or in the list). I am using Josh Smith's RelayCommand, and binding the menuitem to a DeleteItemCommand in the ShellViewModel is easy. It seems like implementing the DeleteItemCommand, however, requires some fairly tight coupling between the ShellViewModel and the two child view models (TreeViewModel and ListViewModel) to keep track of the focus/selection and direct the action to the proper child for implementation. That seems wrong to me, and makes me think I'm missing something. Writing a focus manager and/or selection manager to do the bookkeeping does not seem too hard, and could be done without coupling the classes together. The windowing system is already keeping track of which view has the focus, and it seems like I'd be duplicating code. What I'm not sure about is how I would route the command from the ShellViewModel down to either the ListViewModel or the TreeViewModel to do the actual work without making a mess of the code. Some day, the application will be extended to include more than two children, and I want the shell to be as ignorant of the children as possible to make that extension as painless as possible. Looking at some sample WPF/MVVM applications (Karl Shifflett's CipherText, Josh Smith's MVVM Demo, etc.), I haven't seen any code that does this (or I didn't understand it). Regardless of whether you think my approach is way off base or I'm just missing a small nuance, please share your thoughts and help me get back on track. Thanks!

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  • Is this part of MVC in .NET?

    - by 4thSpace
    I have a .NET MVC winform app. I've created an AppDelegate class that handles application startup and shutdown...for now (it might do more later). Winform apps have a Program.cs file that does some app initialization, starts the message pump and creates the first form. In my app, the first form is AppDelegate, which isn't really a form but is forced that way by Application.Run(). AppDelegate does any further app initialization and starts the first Controller, which then initializes any child controllers (these then create their views). I don't consider events occuring in Program.cs and AppDelegate as part of the MVC. Conceptually, what would these be called?

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  • Cyclic References and WCF

    - by Kunal
    I have generated my POCO entities using POCO Generator, I have more than 150+ tables in my database. I am sharing POCO entities all across the application layers including the client. I have disabled both LazyLoading and ProxyCreation in my context.I am using WCF on top of my data access and business layer. Now, When I return a poco entity to my client, I get an error saying "Underlying connection was closed" I enabled WCF tracing and found the exact error : Contains cycles and cannot be serialized if reference tracking is disabled. I Looked at MSDN and found solutions like setting IsReference=true in the DataContract method atttribute but I am not decorating my POCO classes with DataContracts and I assume there is no need of it as well. I won't be calling that as a POCO if I decorate a class with DataContract attribute Then, I found solutions like applying custom attribute [CyclicReferenceAware] over my ServiceContracts.That did work but I wanted to throw this question to community to see how other people managed this and also why Microsoft didn't give built in support for figuring out cyclic references while serializing POCO classes

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  • Entity Relationship Multiple 1:1's

    - by Evan
    I have an application where I have a generic object (table) called Hull. Each hull in the table is unique. I have another object that has three hulls, but they are specifically the Port_Hull, Center_Hull and Starboard_Hull. Rather than create a One to Many relationship, I was trying to create a one to one relationship for each one, but this results in numerous errors unless I make the relationship from Hull to Vessel one to many (which it is not). Any idea how I go about this, or should I abandon the concept and make the vessel to hull relationship one to many and deal with lists that always have three entries? p.s. Using uniqueidentifiers as many users can be adding records while disconnected. Hull Table HullID uniqueidentifier (primary key) plus bunch of hull data fields Vessel Table VesselID uniqueidentifier (primary key) MainHullID uniqueidentifier (tried as key and non-key) PortHullID uniqueidentifier StarboardHullID uniqueidentifier plus bunch of Vessel data fields

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  • How to access the subject of a compose mail item in Outlook

    - by vwfreak034
    In Outlook, I can set the subject for a new message (when composing a new mail message), but I want to prepend text. So I need to get the subject first, and then set it. Outlook.Application application = Globals.ThisAddIn.Application; Outlook.Inspector inspector = application.ActiveInspector(); Outlook.MailItem myMailItem = (Outlook.MailItem)inspector.CurrentItem; if (myMailItem != null && !string.IsNullOrEmpty(myMailItem.Subject)) { myMailItem.Subject = "Following up on your order"; } This code works on replies, but not for new messages, because in that case, myMailItem is null.

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  • In Ruby on Rails, why will story.votes return an empty Array object, but story.votes.create will act

    - by Jian Lin
    In Ruby on Rails, say a Story object can "has_many" Vote objects (a story is voted "hot" by many users). So when we do a s = Story.find(:first) s is a Story object, and say s.votes returns [] and s.votes.class returns Array So clearly, s.votes is an empty Array object. At this time, when s.votes.create is called, it actually invokes a method of the Vote class? How come an Array class object can invoke a Vote class method?

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  • Association not imported in EF4 designer for non-primary key

    - by Rommel Manalo
    The relationship 'FK_EXTERNAL_ISMARKETI_MARKETIN' has columns that are not part of the key of the table on the primary side of the relationship. The relationship was excluded. USE [Instruments.UnitTest] GO ALTER TABLE [Instr].[ExternalIdentification] WITH CHECK ADD CONSTRAINT [FK_EXTERNAL_ISMARKETI_MARKETIN] FOREIGN KEY([InstrumentID], [MarketInstrumentID]) REFERENCES [Instr].[MarketInstrument] ([InstrumentID], [MarketInstrumentID]) GO ALTER TABLE [Instr].[ExternalIdentification] CHECK CONSTRAINT [FK_EXTERNAL_ISMARKETI_MARKETIN] GO I'm using an association for NON-PRIMARY KEY columns, is this possible in the EF4?

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  • What is the best database structure for this scenario?

    - by Ricketts
    I have a database that is holding real estate MLS (Multiple Listing Service) data. Currently, I have a single table that holds all the listing attributes (price, address, sqft, etc.). There are several different property types (residential, commercial, rental, income, land, etc.) and each property type share a majority of the attributes, but there are a few that are unique to that property type. My question is the shared attributes are in excess of 250 fields and this seems like too many fields to have in a single table. My thought is I could break them out into an EAV (Entity-Attribute-Value) format, but I've read many bad things about that and it would make running queries a real pain as any of the 250 fields could be searched on. If I were to go that route, I'd literally have to pull all the data out of the EAV table, grouped by listing id, merge it on the application side, then run my query against the in memory object collection. This also does not seem very efficient. I am looking for some ideas or recommendations on which way to proceed. Perhaps the 250+ field table is the only way to proceed. Just as a note, I'm using SQL Server 2012, .NET 4.5 w/ Entity Framework 5, C# and data is passed to asp.net web application via WCF service. Thanks in advance.

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  • Problem with date_select when using :discard option. (Rails)

    - by MikeH
    I'm using a date_select with the option :discard_year => true If a user selects a date in the date select, and then he comes back and returns the select to the prompt values of Month and Day, Rails automatically sets the select values to January 1. I know this is the intended functionality if a month is selected and a day is left blank, but that's not the case here. In my example, the user sets both the month and day back to the prompt. By Rails forcing January 1, I'm getting bad results. I've tried every parameter available in the api. :default = nil, :include_blank = true. None of those change the behavior I'm describing. I've isolated the root of the problem, which is this: Because I'm discarding the :year parameter, when the user tries to return the month and day to the prompt values, Rails doesn't see an empty prompt select. It perhaps sees a year selected with empty month and day, which it then sets to January 1. This is the case because the :discard_year parameter does in fact set a date in the database, it just removes it from the view. How can I code around this problem?

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  • In Prism (CAL), how can I RegisterPresenterWithRegion instead of RegisterViewWithRegion

    - by Edward Tanguay
    I have a module in a Prism application and in its initialize method I want to register a presenter instead of a view with a region, i.e. I want to do this: PSEUDO-CODE: regionManager.RegisterPresenterWithRegion( "MainRegion", typeof(Presenters.EditCustomerPresenter)); instead of loading a view like this: regionManager.RegisterViewWithRegion( "MainRegion", typeof(Views.EditCustomerView)); The presenter would of course bring along its own view and ultimately register this view in the region, but it would allow me to bind the presenter to the view in the presenter's constructor instead of binding the two together in XAML (which is more of a decoupled MVVM pattern which I want to avoid here). How can I add a Presenter to a Region instead of a view? namespace Client.Modules.CustomerModule { [Module(ModuleName = "CustomerModule")] public class CustomerModule : IModule { private readonly IRegionManager regionManager; public CustomerModule(IRegionManager regionManager) { this.regionManager = regionManager; } public void Initialize() { regionManager.RegisterViewWithRegion("MainRegion", typeof(Views.EditCustomerView)); } } }

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  • How set opacity on QGraphicsItem

    - by La Chamelle
    Hello, i have a inherited from QGraphicsScene and QGraphicsItem to create my own classes. I use Qt 4.6. I want to set a specific opacity on each items of my scene. I use setOpacity : setOpacity method, but its not the result i hope. I want to have for example one item opaque and an other transparent (to see the desktop, or the other application). But if i dont set the opacity of the QGraphicsView to 0.5, i have not the transparancy. And if the QGraphicsView is set to 0.5, the item is not real opaque. What should i do ? Thanks you.

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  • Rails :dependent => :destroy VS :dependent => :delete_all

    - by Sergey
    In rails guides it's described like this: "Objects will be in addition destroyed if they’re associated with :dependent = :destroy, and deleted if they’re associated with :dependent = :delete_all." Right, cool. But what's the difference between being destroyed and being deleted? I tried both and it seems to do the same thing.

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  • MVP - asp.net - passing information via views - confused

    - by ekynox
    Hi, I've just started to play around with MVP in asp.net. One thing I quite cant figure out is how do I pass information, i.e. an integer variable from one view(webform) to another. Let's I have a customerlistView which is mapped to a customerlist.aspx page. From it I select a customer and it's record id. Say I want to display the customer's details in another view (i.e customerDetailView, customerdetail.aspx). How do I achieve that ? Does that mean customerlistView would call the presenter of the customerdetail and cause a page redirect ? Any ideas ? thanks

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