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  • how to display "complex" widgets in a list in pyqt?

    - by Giorgio Gelardi
    I'm quite new to QT and I have to display a list of "panels" like this: My datamodel handles different classes' instances, so having more than one panel layout would be great - but it's not a requirement. Btw I have to catch mouse clicks on the images to execute related actions. I'm thinking about use some html capable widget (QWebPage?) to render the items in a QListView or QListWidget, but as I said, I don't know QTs so much and need a direction (delegates? stylesheets?). Any help will be appreciated.

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  • Difference between var and Class class in object creation

    - by Divine
    Its a silly question, however shocked to see different behaviors. Learning a lot. Lets say I have two classes below Class A { public void Display() { } } Class B : A { public void Display() { } } Class C : B { public void Display() { } } Class Final { static void Main() { var c = new C(); // B c = new C(); //My doubt is, both of the above gives different results. May I know B c = new C() creates object of B or C? What I understood is, it creates object of B. Then why we say "new C()"? I agree with C c = new C(); But I thought, B b = new C(); creates object of B. Where we use this style? Only when utilizing runtime polymorphism? (Overriding methods)? } }

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  • Hibernate Annotation for Entity existing in more than 1 catalog

    - by user286395
    I have a Person entity mapped by Hibernate to a database table in a database catalog "Active". After a period of time, records in this database table in the "Active" catalog are archived/moved to an exact copy of the table in a database Catalog "History". I have the need to retrieve from both the Active and History Catalogs. Is there a better way to model this with Hibernate annotations than making an abstract class that 2 classes extend from. This is what I have now. @MappedSuperclass public abstract class Person { @Id private Integer id; private String name; } @Entity @Table(name="Person", catalog="Active") public class PersonActive extends Person { } @Entity @Table(name="Person", catalog="History") public class PersonHistory extends Person { }

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  • java.lang.NoClassDefFoundError when the file is there

    - by tsOverflow
    I've tried to look around for postings that might help me, cant find any. I am deploying an ear to JBoss4 server, and I started having this problem since I added a new project. this new project is defined as Java project in eclipse, and the EAR project has an EJB project that has the new Java project as one of the projects as its dependent upon - if deployed on JBoss locally through eclipse, there's no problem and everything goes smoothly But when being deployed to JBoss in test environment (outside eclipse), kept getting java.lang.NoClassDefFoundError on one of the classes that are defined in the new Java project. I looked inside the EAR file to get to the jar (EJB project), and then inside the jar, I can see the directory structure and all the class files from the new Java project - ie. The class that it complains about is right there inside the EAR-JAR and matching the exact structure that it's looking for. I am at lost to what else I can look at. Any pointers are greatly appreciated! Thanks

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  • What features of Scala cannot be translated to Java?

    - by Paul
    The Scala compiler compiles direct to Java byte code (or .NET CIL). Some of the features of Scala could be re-done in Java straightforwardly (e.g. simple for comprehensions, classes, translating anonymous/inner functionc etc). What are the features that cannot be translated that way? That is presumably mostly of academic interest. More usefully, perhaps, what are the key features or idioms of Scala that YOU use that cannot be easily represented in Java? Are there any the other way about? Things that can be done straightforwardly in Java that have no straightforward equivalent in Scala? Idioms in Java that don't translate?

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  • How to convert objects in reflection (Linq to XML)

    - by user829174
    I have the following code which is working fine, the code creates plugins in reflection via run time: using System; using System.Collections.Generic; using System.Linq; using System.IO; using System.Xml.Linq; using System.Reflection; using System.Text; namespace WindowsFormsApplication1 { public abstract class Plugin { public string Type { get; set; } public string Message { get; set; } } public class FilePlugin : Plugin { public string Path { get; set; } } public class RegsitryPlugin : Plugin { public string Key { get; set; } public string Name { get; set; } public string Value { get; set; } } static class MyProgram { [STAThread] static void Main(string[] args) { string xmlstr =@" <Client> <Plugin Type=""FilePlugin""> <Message>i am a file plugin</Message> <Path>c:\</Path> </Plugin> <Plugin Type=""RegsitryPlugin""> <Message>i am a registry plugin</Message> <Key>HKLM\Software\Microsoft</Key> <Name>Version</Name> <Value>3.5</Value> </Plugin> </Client> "; Assembly asm = Assembly.GetExecutingAssembly(); XDocument xDoc = XDocument.Load(new StringReader(xmlstr)); Plugin[] plugins = xDoc.Descendants("Plugin") .Select(plugin => { string typeName = plugin.Attribute("Type").Value; var type = asm.GetTypes().Where(t => t.Name == typeName).First(); Plugin p = Activator.CreateInstance(type) as Plugin; p.Type = typeName; foreach (var prop in plugin.Descendants()) { var pi = type.GetProperty(prop.Name.LocalName); object newVal = Convert.ChangeType(prop.Value, pi.PropertyType); pi.SetValue(p, newVal, null); } return p; }).ToArray(); // //"plugins" ready to use // } } } I am trying to modify the code and adding new class named DetailedPlugin so it will be able to read the following xml: string newXml = @" <Client> <Plugin Type=""FilePlugin""> <Message>i am a file plugin</Message> <Path>c:\</Path> <DetailedPlugin Type=""DetailedFilePlugin""> <Message>I am a detailed file plugin</Message> </DetailedPlugin> </Plugin> <Plugin Type=""RegsitryPlugin""> <Message>i am a registry plugin</Message> <Key>HKLM\Software\Microsoft</Key> <Name>Version</Name> <Value>3.5</Value> <DetailedPlugin Type=""DetailedRegsitryPlugin""> <Message>I am a detailed registry plugin</Message> </DetailedPlugin> </Plugin> </Client> "; for this i modified my classes to the following: public abstract class Plugin { public string Type { get; set; } public string Message { get; set; } public DetailedPlugin DetailedPlugin { get; set; } // new } public class FilePlugin : Plugin { public string Path { get; set; } } public class RegsitryPlugin : Plugin { public string Key { get; set; } public string Name { get; set; } public string Value { get; set; } } // new classes: public abstract class DetailedPlugin { public string Type { get; set; } public string Message { get; set; } } public class DetailedFilePlugin : Plugin { public string ExtraField1 { get; set; } } public class DetailedRegsitryPlugin : Plugin { public string ExtraField2{ get; set; } } from here i need some help to accomplish reading the xml and create the plugins with the nested DetailedPlugin

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  • Subsonic foreign key returning collection?

    - by Shaul
    I'm just writing my first "Hello World" program using Subsonic, for which I've thrown together a simple little Customer/Invoice/InvoiceItem/Product database. The connection was successfully made to the DB, and it generated all the right ActiveRecord classes. But for some reason, the Invoice class has a property called Customers, which returns a collection of Customer objects, even though the Invoice table has a CustomerID field which has a foreign key to the Customer table. I would have expected a Customer property returning a single Customer object. I must be doing something wrong - but what?

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  • Why does a Linq Cast<T> operation fail when I have an implicit cast defined?

    - by Ryan Versaw
    I've created two classes, with one of them having an implicit cast between them: public class Class1 { public int Test1; } public class Class2 { public int Test2; public static implicit operator Class1(Class2 item) { return new Class1{Test1 = item.Test2}; } } When I create a new list of one type and try to Cast<T> to the other, it fails with an InvalidCastException: List<Class2> items = new List<Class2>{new Class2{Test2 = 9}}; foreach (Class1 item in items.Cast<Class1>()) { Console.WriteLine(item.Test1); } This, however, works fine: foreach (Class1 item in items) { Console.WriteLine(item.Test1); } Why is the implicit cast not called when using Cast<T>?

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  • How to add libraries in C++?

    - by m00st
    Yea this is a dumb question... However in both of my C++ classes we did not do this at all (except for native libraries: iostream, iomanip, etc.)... My question is can anyone provide a link that gives the general explanation of adding libraries to C++? I do realize what what #include means; it's just I have no clue on the linker/directories in a C++ IDE. So long question short; could I get a general explanation of terms used to link libraries in C++? I'm using c::b w/ MinGW.

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  • Interview Questions that can be asked on TCP/IP, UDP, Socket Programming ?

    - by Shantanu Gupta
    I am going for an interview day after tomorrow where i will be asked vaious questions related to TCP/IP and UDP. As of now i have prepared theoritical knowledge about it. But now I am looking up for gaining some practicle knowledge related to how it works in a network. What all is going in vaious .NET classes. I want to create a very small application like a chat or something that can make me all these concepts very much clear. Could you please suggest some questions related to TCP/IP that you generally ask or that you might have faced. How communication is going from server to client. Right now I am studying TcpClient, TcpListener and UdpClient Class but I want to implement all of them so as to get aware about its working. Is Chat application a Tcp/IP application ? I would appreciate your help.

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  • .NET Micro Edition - Open Multiple Windows

    - by RM
    I've had a look through quite a few tutorials, but cant seem to find how to open multipe windows? I'm not expecting to have them layer etc, I just want to define multiple window classes and say, from a menu, launch the appropriate window class from the menu window. Then when that window is finished, call the close method on it and menu will show again. I have managed to do the same kind of functionality using panels, but think window is really what I should be using? (.NET MF 4.0) I assume you can do this? I think im missing something obvious?

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  • Should downcasting be avoided while using a class hierarchy in C++?

    - by neuviemeporte
    Let's say I'm writing an application which works with projects, and exposes different functionality depending on the type of the project. I have a hierarchy of classes for the different types of projects: class AbstractProject { }; class ProjectA : public AbstractProject { }; class ProjectB : public AbstractProject { }; class ProjectC : public AbstractProject { }; Now, I was planning to have an AbstractProject *_currentProject pointer as a member in the application's main class, pop up a dialog box on startup and based on the selection, do: _currentProject = new ProjectB(); // e.g. Later, I'll have to downcast the pointer to the specific type to utilize the functionality specific to different Project-s. Somehow this makes me feel uneasy. Is there a Better Way of doing this?

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  • ASP.NET MVC2 - usage of LINQ-generated class (validation problem)

    - by ile
    There are few things not clear to me about ASP.NET MV2. In database I have table Contacts with several fields, and there is an additional field XmlFields of which type is xml. In that field are stored additional description fields. There are 4 classes: Contact class which corresponds to Contact table and is defined by default when creating LINQ classes ContactListView class which inherits Contact class and has some additional properties ContactXmlView class that contains fields from XmlFields field ContactDetailsView class which merges ContactListView and ContactXmlView into one class and this one is used to display data in view pages ContactListView class has re-defined some properties from Contact class (so that I can add [Required] filter used for validation) - but I get warning message: 'ObjectTest.Models.Contacts.ContactListView.FirstName' hides inherited member 'SA.Model.Contact.FirstName'. Use the new keyword if hiding was intended. ContactDetailsView class is also used in a form when creating new contact and adding it to database. I am not sure if this is correct way, and the warning message confuses me a bit. Any advise about this? Thanks, Ile EDIT According to Jakob's instructions I tried it from scratch: [MetadataType(typeof(Person_Validation))] public partial class Person { } public class Person_Validation { [Required] string FirstName { get; set; } [Required] string LastName { get; set; } [Required] int Age { get; set; } } In Controller I have this: [HttpPost] public ActionResult Create(Person person, FormCollection collection) { if (ModelState.IsValid) { try { personRepository.Add(person); personRepository.Save(); } catch { return View(person); } } return RedirectToAction("Index"); } View: <%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<Validate.Models.Person>" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server"> Create </asp:Content> <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <h2>Create</h2> <% using (Html.BeginForm()) {%> <%= Html.ValidationSummary(true) %> <fieldset> <legend>Fields</legend> <div class="editor-label"> <%= Html.LabelFor(model => model.FirstName) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.FirstName) %> <%= Html.ValidationMessageFor(model => model.FirstName) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.LastName) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.LastName) %> <%= Html.ValidationMessageFor(model => model.LastName) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Age) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Age) %> <%= Html.ValidationMessageFor(model => model.Age) %> </div> <p> <input type="submit" value="Create" /> </p> </fieldset> <% } %> <div> <%= Html.ActionLink("Back to List", "Index") %> </div> </asp:Content> When posting new person with no values, nothing happens (page is just reloaded). When posting with some values, person is added to db. I have no idea what am I doing wrong.

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  • Is there any free, open source php CMS\framework for described case?

    - by Ole Jak
    I want that cms\framework to create me tables like "Users" "Cameras" and so on and declare classes and simple default methods for them (like paged sql relults and so on). I mean I say to it: I want Users to have ID, SpecialNumber and Name Flilds. and I want to get from it class for table generation (to call it once) and class containing methods such as Search by ID, SpecialNumber and Name, Create User, Delit User and so on functions. Is there any framework/cms like this for working with CODE not ui's and so on... so to say PHP generator or something... The result should be as that framework free as possible. So Is there any free, open source php CMS\framework for described case?

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  • Casting to specific asp.net page type

    - by DEH
    I have an asp.net page with a code-behind class definition as follows: public partial class examplepage : System.Web.UI.Page I'd like to set a public property within the page that I can reference from other classes. My understanding is that if I cast to examplepage then I should be able to get at the public property that is specific to example page, as in: string test=((examplepage)HttpContext.Current.Handler).propertyX; However, when I try casting as above the compiler does not recognise examplepage. Can anyone tell me how I can cast? I have no specific namespaces defined. Thanks

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  • Real-world examples of populating a GWT CellTable using a clean MVP pattern?

    - by piehole
    We are using the GWT-Presenter framework and attempting to use CellTable to put together an updateable grid. It seems as though several of the GWT constructs for CellTable don't lend themselves to easily breaking up the logic into clean view and presenter code. Examples: 1) Within the View's constructor, the CellTable is defined and each column is created by anonymous inner classes that extend the Column class to provide the onValue() method. 2) The FieldUpdater interface must be implemented to provide logic to execute when a user alters data in a cell. This seems like it would best fit in the Presenter's onBind() method, but FieldUpdaters often need access to the Cell or Column which belong in the view. CellTable does not have accessor methods to get hold of the Columns or Cells, so it seems the only way for the Presenter to get them is for me to create a multitude of member variables on the View and accessors on my Display interface. Can anyone provide good examples for dealing with CellTable in GWT-Presenter or a comparable MVP

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  • Use DataContext to create schema in an existing blank database file?

    - by jdk
    With a DataContext and a blank file-based database that already exists, is it possible to write the Data Context classes (i.e. the ones I added to the designer) to create the db schema? With a data context I only see the abilities to either: create a new database file and have its structure created at the same time, or to populate data into an existing database having preexisting schema. I'm looking for a hybrid solution between those two worlds. Update 1: My proof that a preexisting db is not compatible with the Data Context CreateDatabase() operation is this error Database 'C:...\App_Data\IntermediateData.mdf' already exists. Choose a different database name. based on this code using (IntermediateClassesDataContext intermediateContext = new IntermediateClassesDataContext(_getIntermediateConn())) { intermediateContext.CreateDatabase(); }

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  • how to implement this observer pattern?

    - by lethal
    Hello. I have 4 classes, that describe state diagram. Node, Edge, ComponentOfNode, ComponentOfEdge. ComponentOfEdge compounds from ComponentsOfNode. Node can have 0..n outgoing edges. Edge can have only 2 nodes. Edge should be able to offer ComponentOfNode, but only from nodes that Edge has, in form ComponentOfEdge. The user can change ComponentsOfNode. I need this change spreads to all Edge. Hw to do it? I expect the observer should be used. Can you give me example in pseudocode please?

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  • how to call a function to refresh GUI

    - by SWKK
    Hi Guys, I am refactoring some code to decouple GUI from some state. #include <StateObject> Class GUI{ ... StateObject A; void doSomething() { A->hullaballoo();} **void ReFreshMyGui() { //take state A and redraw }** }; State object is being shared by multiple classes to update the state but this Gui Object specializes in displaying the state. So I would like to call the Refresh function via StateObject whenever its modified. I am not sure how or if signals will provide the solution. Any hints?

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  • Inheritance and Implicit Type Casting

    - by Josué Molina
    Suppose I have the following three classes: class Animal {}; class Human : public Animal {}; class Dog : public Animal { public: void setOwner(Animal* owner) { this->owner = owner; } private: Animal* owner; }; Why is the following allowed, and what exactly is happening? Dog d; Human h; d.setOwner(&h); // ? At first, I tried to cast it like this d.setOwner(&(Animal)h), but the compiler gave me a warning, and I hit a run-time error. Edit: the warning the compiler gave me was "taking address of temporary". Why is this so?

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  • How to add Ads for my android app using eclipse?

    - by user3896367
    I am trying to add ads to my app but I don't know how I followed the instructions from this site: https://developer.android.com/google/play-services/ads.html I did step 1 and 2 in the getting started column, I imported the google-play-services_libs to my workspace then I referenced it in my app and I added this code in my mainfest: <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" /> I opened the sample ad and copied this code to my xml: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:ads="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@android:color/black" android:gravity="center" android:orientation="vertical" > <com.google.android.gms.ads.AdView android:id="@+id/adView" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_alignParentLeft="true" ads:adUnitId="@string/ad_unit_id"/> but I am getting this error: The following classes could not be instantiated: - com.google.android.gms.ads.AdView so do you know how to fix this problem and can you tell me what should i write in the java to make in work thanks

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  • [Java6] Same source code, Eclipse build success but Maven (javac) fails

    - by EnToutCas
    Keep getting this error when compiling using Maven: type parameters of <X>X cannot be determined; no unique maximal instance exists for type variable X with upper bounds int,java.lang.Object Generics type interference cannot be applied to primitive types. But I thought since Java5, boxing/unboxing mechanism works seamlessly between primitive types and wrapper classes. In any case, the strange thing is Eclipse doesn't report any errors and happily compiles. I'm using JDK1.6.0_12. What could possibly be the problem here?

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  • In Ruby, is there are better way of selecting a constant (or avoiding the constant altogether) based

    - by Vertis
    Not sure the title fully describes the problem/question I'm trying to ask, sorry. I'm One of my fellow developers has created classes as such: class Widget attr_accessor :model_type ... end and: class ModelType MODEL1 = "model1" MODEL2 = "model2" MODEL3 = "model3" end Now he wants me to convert a retrieved string "MODEL1" to the constant. So that when he is referencing that model elsewhere he can use ModelType::MODEL1. Obviously I've got to convert from the string I'm being given with something like the following: case model_type when 'MODEL1' @model_type = ModelType::MODEL1 ... end I feel like this is clunky, so I'd like to know if there is a better DRYer way of providing this kind of functionality.

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  • IPhone: Controllers, Delagates, DataSources, etc all in one class?

    - by MLS
    Hi All, I am learning iPhone programming. I am starting with a simple example of displaying recently used documents in a UITableView. What I am confused about is why do I need to have several classes and why cant I just use one? Example, My class is called RecentFileList. I need to implement controller, delegate and datasource as well as the actual table view. Can't I just do this all in my RecentFileList Class versus having to create a RecentFileListDelegate RecentFileListController, RecentFileListDataSource class, etc, etc. Related to this can one define a class like: @interface FileListView : NSObject <UITableViewDelegate> <UITableViewController> <UITableViewDataSource { // code } @end or would I just do the work to make my class a delegate and controller in init()?

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  • Should the include guards be unique even between namespaces?

    - by Arun
    I am using same class name in two namespaces, say A and B. Should the include guards be unique while declaring the classes with different namespaces too? I mean can't there be two files names AFile.h (in different directories) with same include guards and declaring different namespaces? File 1: #ifndef AFILE_H #define AFILE_H namespace A { class CAFile {... }; }; #endif File 2: #ifndef AFILE_H #define AFILE_H namespace B { class CAFile {... }; }; #endif

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