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

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  • Static methods and their overriding

    - by abson
    Java doesn't allow overriding of static methods but, class stat13 { static void show() { System.out.println("Static in base"); } public static void main(String[] ar) { new next().show(); } } class next extends stat13 { static void show() { System.out.println("Static in derived"); } } is not overriding done here?

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  • Ndepend CQL to find methods of certain types using particular framework assembly

    - by icelava
    In order to check if types not derived from certain base classes are using a low-level framework assembly, the following query can be used. SELECT TYPES WHERE IsDirectlyUsing "ASSEMBLY:Framework.Data" AND !(DeriveFrom "App.BaseTypes.BusinessFacadeBase" OR DeriveFrom "App.BaseTypes.BusinessComponentBase" OR DeriveFrom "App.BaseTypes.DataAccessComponentBase") Now I wish to drill down further to see which methods from those classes are actually doing so. But the thing is if I change the query target from TYPES to METHODS then DeriveFrom is not going to apply. How can these criteria be preserved?

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  • Optimizing multiple dispatch notification algorithm in C#?

    - by Robert Fraser
    Sorry about the title, I couldn't think of a better way to describe the problem. Basically, I'm trying to implement a collision system in a game. I want to be able to register a "collision handler" that handles any collision of two objects (given in either order) that can be cast to particular types. So if Player : Ship : Entity and Laser : Particle : Entity, and handlers for (Ship, Particle) and (Laser, Entity) are registered than for a collision of (Laser, Player), both handlers should be notified, with the arguments in the correct order, and a collision of (Laser, Laser) should notify only the second handler. A code snippet says a thousand words, so here's what I'm doing right now (naieve method): public IObservable<Collision<T1, T2>> onCollisionsOf<T1, T2>() where T1 : Entity where T2 : Entity { Type t1 = typeof(T1); Type t2 = typeof(T2); Subject<Collision<T1, T2>> obs = new Subject<Collision<T1, T2>>(); _onCollisionInternal += delegate(Entity obj1, Entity obj2) { if (t1.IsAssignableFrom(obj1.GetType()) && t2.IsAssignableFrom(obj2.GetType())) obs.OnNext(new Collision<T1, T2>((T1) obj1, (T2) obj2)); else if (t1.IsAssignableFrom(obj2.GetType()) && t2.IsAssignableFrom(obj1.GetType())) obs.OnNext(new Collision<T1, T2>((T1) obj2, (T2) obj1)); }; return obs; } However, this method is quite slow (measurable; I lost ~2 FPS after implementing this), so I'm looking for a way to shave a couple cycles/allocation off this. I thought about (as in, spent an hour implementing then slammed my head against a wall for being such an idiot) a method that put the types in an order based on their hash code, then put them into a dictionary, with each entry being a linked list of handlers for pairs of that type with a boolean indication whether the handler wanted the order of arguments reversed. Unfortunately, this doesn't work for derived types, since if a derived type is passed in, it won't notify a subscriber for the base type. Can anyone think of a way better than checking every type pair (twice) to see if it matches? Thanks, Robert

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  • In ASP.NET MVC, why wouldn't I tack on HandleError on a base controller and be done with it?

    - by Jiho Han
    Since HandleError is inherited by the derived Controllers, why wouldn't I just create (or have) a base controller, and apply HandleError on it so that any controllers that inherits from the base controller will automatically be handled as well? And then I would tack on overriding HandleError on controllers and individual actions. Can anyone think of any reason why I wouldn't want to apply HandleError to the base controller?

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  • What are the best practices for avoid xss attacks in a PHP site

    - by rikh
    I have PHP configured so that magic quotes are on and register globals are off. I do my best to always call htmlentities() for anything I am outputing that is derived from user input. I also occasionally seach my database for common things used in xss attached such as... <script What else should I be doing and how can I make sure that the things I am trying to do are always done.

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  • C# Drag and Drop - e.Data.GetData using a base class

    - by Dustin Brooks
    C# Winforms 3.5 I have a list of user controls all derived from one base class. These controls can be added to various panels and I'm trying to implement the drag-drop functionality, the problem I'm running in to is on the DragDrop event. The DragEventArgs: e.Data.GetData(typeof(baseClass)) doesn't work. It wants: e.Data.GetData(typeof(derivedClass1)) e.Data.GetData(typeof(derivedClass2)) etc... Is there a way I can get around this, or a better way to architect it?

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  • How to change colors for ListView, alternating row color?

    - by Gerry
    I have a couple of list views, one uses TextViews laid out with xml, the other uses a custom class derived from View. The default halloween color scheme is pretty ugly. How can I change the background and selection colors for the list elements. Ideally, I'd like to be able to do this in code not xml, to handle the custom view. Thanks, Gerry

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  • Abstract class reference

    - by AlgoMan
    Can i have a class Class Room{ ~Room(); virtual cost() =0; } Class Hotel{ map rooms; /* */ }; will my hotel become abstract ? Can it hold the list of concrete Room objects that are derived from Room ?

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  • What does slicing mean in C++?

    - by George2
    Hello everyone, It is mentioned in C++ FAQ site -- "larger derived class objects get sliced when passed by value as a base class object", what does slicing mean? Any sample to demonstrate? http://www.parashift.com/c++-faq-lite/value-vs-ref-semantics.html#faq-31.8 I am using VSTS 2008 + native C++ as my development environment. thanks in advance, George

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  • What means slicing in C++?

    - by George2
    Hello everyone, It is mentioned in C++ FAQ site -- "larger derived class objects get sliced when passed by value as a base class object", what does slicing mean? Any sample to demonstrate? http://www.parashift.com/c++-faq-lite/value-vs-ref-semantics.html#faq-31.8 I am using VSTS 2008 + native C++ as my development environment. thanks in advance, George

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  • Style guide for database metadata naming

    - by Nulldevice
    We want to establish some database metadata naming rules in our new project. For example: tables are named as nouns in a plural form (courses, books, lessons) if present, an adjective goes before a noun in a table name and is separated by an underscore (red_books, new_lessons) table index column is always named "id" foreign key names are derived from a table name with suffix _id (book_id, red_book_id) so on Does someone know any guide like this?

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  • Crazy interview question

    - by benjamin button
    I was asked this crazy question. I was out of my wits. Can a method in base class which is declared as virtual be called using the base class pointer which is pointing to a derived class object? Is this possible?

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  • Servlet Exception + Class Cast Exception + Glassfish + Netbeans + JPA Entities + Vaadin

    - by Random Joe
    Hi all, I get this error: StandardWrapperValve[Vaadin Servlet]: PWC1406: Servlet.service() for servlet Vaadin Servlet threw exception java.lang.ClassCastException: com.delhi.entities.Category cannot be cast to com.delhi.entities.Category when I try to run my webapps on glassfish v2. Category is a JPA entity object the offending code according to the server log is: for (Category c : categories) { mymethod(); } categories is derived from: List<Category> categories = q.getResultList(); Any idea what went wrong?

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  • C++ type-checking at compile-time

    - by Masterofpsi
    Hi, all. I'm pretty new to C++, and I'm writing a small library (mostly for my own projects) in C++. In the process of designing a type hierarchy, I've run into the problem of defining the assignment operator. I've taken the basic approach that was eventually reached in this article, which is that for every class MyClass in a hierarchy derived from a class Base you define two assignment operators like so: class MyClass: public Base { public: MyClass& operator =(MyClass const& rhs); virtual MyClass& operator =(Base const& rhs); }; // automatically gets defined, so we make it call the virtual function below MyClass& MyClass::operator =(MyClass const& rhs); { return (*this = static_cast<Base const&>(rhs)); } MyClass& MyClass::operator =(Base const& rhs); { assert(typeid(rhs) == typeid(*this)); // assigning to different types is a logical error MyClass const& casted_rhs = dynamic_cast<MyClass const&>(rhs); try { // allocate new variables Base::operator =(rhs); } catch(...) { // delete the allocated variables throw; } // assign to member variables } The part I'm concerned with is the assertion for type equality. Since I'm writing a library, where assertions will presumably be compiled out of the final result, this has led me to go with a scheme that looks more like this: class MyClass: public Base { public: operator =(MyClass const& rhs); // etc virtual inline MyClass& operator =(Base const& rhs) { assert(typeid(rhs) == typeid(*this)); return this->set(static_cast<Base const&>(rhs)); } private: MyClass& set(Base const& rhs); // same basic thing }; But I've been wondering if I could check the types at compile-time. I looked into Boost.TypeTraits, and I came close by doing BOOST_MPL_ASSERT((boost::is_same<BOOST_TYPEOF(*this), BOOST_TYPEOF(rhs)>));, but since rhs is declared as a reference to the parent class and not the derived class, it choked. Now that I think about it, my reasoning seems silly -- I was hoping that since the function was inline, it would be able to check the actual parameters themselves, but of course the preprocessor always gets run before the compiler. But I was wondering if anyone knew of any other way I could enforce this kind of check at compile-time.

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  • How can we set authorization for a whole area in ASP.NET MVC?

    - by CodingTales
    I've an Admin area and I want only Admins to enter the area. I considered adding the Authorized attribute to every controller in the Admin area. Isn't there an elegant solution or is this feature not there in the framework itself? EDIT: I'm sorry, I should to have mentioned this before. I'm using a custom AuthorizedAttribute derived from AuthorizeAttribute.

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  • Is this not downcasting?

    - by cambr
    If I do double d = 34.56; int i = (int)d; Am I not "downcasting"? OR Is this term only used in terms of classes and objects? I am confused because in this case we are "downcasting" from a bigger double to a smaller int, but in case of classes, we "downcast" from a smaller base class to a bigger derived class. Aren't these two conventions, in some sense, opposite?

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  • Printing contents of a div

    - by Hulk
    The contents of the following div re derived dynamically. i.e, A table is added dynamically to this div with some button .My question is how to print the content of this div(window.print) and not other things in the page <div id="newdiv" name="newdiv"></div> Thanks..............

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  • Getting all the fields and properties of a custom attribute from a specific instance

    - by Gbps
    I have a custom attribute PackerAttrib which takes no data, simply marking a field or property, which will be used to mark a property or field of a class inherited from Panel in order to serialize it later on. How would I take an instance of any object derived from Panel and get a Directory<string s, object o> where s is the name of the field or property and o is the current value of said field or property from the instance. Thank you, don't be afraid to ask me to clarify!

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  • Adding NavigationControl to a TabBar Application containing UITableViews

    - by kungfuslippers
    Hi, I'm new to iPhone dev and wanted to get advice on the general design pattern / guide for putting a certain kind of app together. I'm trying to build a TabBar type application. One of the tabs needs to display a TableView and selecting a cell from within the table view will do something else - maybe show another table view or a web page. I need a Navigation Bar to be able to take me back from the table view/web page. The approach I've taken so far is to: Create an app based around UITabBarController as the rootcontroller i.e. @interface MyAppDelegate : NSObject <UIApplicationDelegate> { IBOutlet UIWindow *window; IBOutlet UITabBarController *rootController; } Create a load of UIViewController derived classes and associated NIBs and wire everything up in IB so when I run the app I get the basic tabs working. I then take the UIViewController derived class and modify it to the following: @interface MyViewController : UIViewController<UITableViewDataSource, UITableViewDelegate> { } and I add the delegate methods to the implementation of MyViewController - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 2; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } if (indexPath.row == 0) { cell.textLabel.text = @"Mummy"; } else { cell.textLabel.text = @"Daddy"; } return cell; } Go back to IB , open MyViewController.xib and drop a UITableView onto it. Set the Files Owner to be MyViewController and then set the delegate and datasource of the UITableView to be MyViewController. If I run the app now, I get the table view appearing with mummy and daddy working nicely. So far so good. The question is how do I go about incorporating a Navigation Bar into my current code for when I implement: - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath() { // get row selected NSUInteger row = [indexPath row]; if (row == 0) { // Show another table } else if (row == 1) { // Show a web view } } Do I drop a NavigationBar UI control onto MyControllerView.xib ? Should I create it programmatically? Should I be using a UINavigationController somewhere ? I've tried dropping a NavigationBar onto my MyControllerView.xib in IB but its not shown when I run the app, only the TableView is displayed.

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