Search Results

Search found 14034 results on 562 pages for 'interface inheritance'.

Page 177/562 | < Previous Page | 173 174 175 176 177 178 179 180 181 182 183 184  | Next Page >

  • C++ Namespaces & templates question

    - by Kotti
    Hi! I have some functions that can be grouped together, but don't belong to some object / entity and therefore can't be treated as methods. So, basically in this situation I would create a new namespace and put the definitions in a header file, the implementation in cpp file. Also (if needed) I would create an anonymous namespace in that cpp file and put all additional functions that don't have to be exposed / included to my namespace's interface there. See the code below (probably not the best example and could be done better with another program architecture, but I just can't think of a better sample...) Sample code (header) namespace algorithm { void HandleCollision(Object* object1, Object* object2); } Sample code (cpp) #include "header" // Anonymous namespace that wraps // routines that are used inside 'algorithm' methods // but don't have to be exposed namespace { void RefractObject(Object* object1) { // Do something with that object // (...) } } namespace algorithm { void HandleCollision(Object* object1, Object* object2) { if (...) RefractObject(object1); } } So far so good. I guess this is a good way to manage my code, but I don't know what should I do if I have some template-based functions and want to do basically the same. If I'm using templates, I have to put all my code in the header file. Ok, but how should I conceal some implementation details then? Like, I want to hide RefractObject function from my interface, but I can't simply remove it's declaration (just because I have all my code in a header file)... The only approach I came up with was something like: Sample code (header) namespace algorithm { // Is still exposed as a part of interface! namespace impl { template <typename T> void RefractObject(T* object1) { // Do something with that object // (...) } } template <typename T, typename Y> void HandleCollision(T* object1, Y* object2) { impl::RefractObject(object1); // Another stuff } } Any ideas how to make this better in terms of code designing?

    Read the article

  • Link compatibility between C++ and D

    - by Caspin
    D easily interfaces with C. D just as easily interfaces with C++, but (and it's a big but) the C++ needs to be extremely trivial. The code cannot use: namespaces templates multiple inheritance mix virtual with non-virtual methods more? I completely understand the inheritance restriction. The rest however, feel like artificial limitations. Now I don't want to be able to use std::vector<T> directly, but I would really like to be able to link with std::vector<int> as an externed template. The C++ interfacing page has this particularly depressing comment. D templates have little in common with C++ templates, and it is very unlikely that any sort of reasonable method could be found to express C++ templates in a link-compatible way with D. This means that the C++ STL, and C++ Boost, likely will never be accessible from D. Admittedly I'll probably never need std::vector while coding in D, but I'd love to use QT or boost. So what's the deal. Why is it so hard to express non-trivial C++ classes in D? Would it not be worth it to add some special annotations or something to express at least namespaces?

    Read the article

  • Is is possible to do an end-run around generics covariance in C# < 4 in this hypothetical situation?

    - by John Feminella
    Suppose I have a small inheritance hierarchy of Animals: public interface IAnimal { string Speak(); } public class Animal : IAnimal { public Animal() {} public string Speak() { return "[Animal] Growl!"; } } public class Ape : IAnimal { public string Speak() { return "[Ape] Rawrrrrrrr!"; } } public class Bat : IAnimal { public string Speak() { return "[Bat] Screeeeeee!"; } } Next, here's an interface offering a way to turn strings into IAnimals. public interface ITransmogrifier<T> where T : IAnimal { T Transmogrify(string s); } And finally, here's one strategy for doing that: public class Transmogrifier<T> : ITransmogrifier<T> where T : IAnimal, new() { public T Transmogrify(string s) { T t = default(T); if (typeof(T).Name == s) t = new T(); return t; } } Now, the question. Is it possible to replace the sections marked [1], [2], and [3] such that this program will compile and run correctly? If you can't do it without touching parts other than [1], [2], and [3], can you still get an IAnimal out of each instance of a Transmogrifier in a collection containing arbitrary implementations of an IAnimal? Can you even form such a collection to begin with? static void Main(string[] args) { var t = new Transmogrifier<Ape>(); Ape a = t.Transmogrify("Ape"); Console.WriteLine(a.Speak()); // Works! // But can we make an arbitrary collection of such animals? var list = new List<Transmogrifier< [1] >>() { // [2] }; // And how about we call Transmogrify() on each one? foreach (/* [3] */ transmogrifier in list) { IAnimal ia = transmogrifier.Transmogrify("Bat"); } } }

    Read the article

  • Generic Constraints And Type Parameters Mess

    - by Dummy01
    Hi everyone, I have the following base abstract class defined as: public abstract class BaseObject<T> : IComparable, IComparable<T>, IEquatable<T> {} I also have an interface defined as: public interface ICode<T> where T : struct { T Code { get; } } Now I want to derive a class that is inherited from BaseObject<T> and includes interface ICode<T>. I tried to define it like that: public class DerivedObject<T, U> : BaseObject<T>, ICode<U> where T : DerivedObject<T, U> where U : struct { public DerivedObject(U code) { Code = code; } // From BaseObject protected override int InstanceCompareTo(T obj) { return Code.CompareTo(obj.Code); } // From BaseObject protected override bool InstanceEquals(T obj) { return Code.Equals(obj.Code); } // From ICode U _Code; public U Code { get { return _Code; } protected set { _Code = value; } } } The only error that comes from the compiler is for Code.CompareTo(obj.Code) with the message: 'U' does not contain a definition for 'CompareTo' and no extension method 'CompareTo' accepting a first argument of type 'U' could be found. But U is a value type and should know CompareTo. Have you any idea what I am doing wrong, or if I do all wrong? My final aim is to derive classes such these: public class Account : DerivedObject<Account, int> public class ItemGroup : DerivedObject<ItemGroup, string> Big Thanks In Advance!

    Read the article

  • Can JMX operations take interfaces as parameters?

    - by Thor84no
    I'm having problems with an MBean that takes a Map<String, Object> as a parameter. If I try to execute it via JMX using a proxy object, I get an Exception: Caused by: javax.management.ReflectionException at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:231) at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:668) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) Caused by: java.lang.IllegalArgumentException: Unable to find operation updateProperties(java.util.HashMap) It appears that it attempts to use the actual implementation class rather than the interface, and doesn't check if this is a child of the required interface. The same thing happens for extended classes (for example declare HashMap, pass in LinkedHashMap). Does this mean it's impossible to use an interface for such methods? At the moment I'm getting around it by changing the method signature to accept a HashMap, but it seems odd that I wouldn't be able to use interfaces (or extended classes) in my MBeans. Edit: The proxy object is being created by an in-house utility class called JmxInvocationHandler. The (hopefully) relevant parts of it are as follows: public class JmxInvocationHandler implements InvocationHandler { ... public static <T> T createMBean(final Class<T> iface, SFSTestProperties properties, String mbean, int shHostID) { T newProxyInstance = (T) Proxy.newProxyInstance(iface.getClassLoader(), new Class[] { iface }, (InvocationHandler) new JmxInvocationHandler(properties, mbean, shHostID)); return newProxyInstance; } ... private JmxInvocationHandler(SFSTestProperties properties, String mbean, int shHostID) { this.mbeanName = mbean + MBEAN_SUFFIX + shHostID; msConfig = new MsConfiguration(properties.getHost(0), properties.getMSAdminPort(), properties.getMSUser(), properties.getMSPassword()); } ... public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { if (management == null) { management = ManagementClientStore.getInstance().getManagementClient(msConfig.getHost(), msConfig.getAdminPort(), msConfig.getUser(), msConfig.getPassword(), false); } final Object result = management.methodCall(mbeanName, method.getName(), args == null? new Object[] {} : args); return result; } }

    Read the article

  • WCF: get generic type object (e.g. MyObject<T>) from remote machine

    - by Aaron
    I have two applications that are communicating through WCF. On the server the following object exists: public class MyObject<T> { ... public Entry<T> GetValue() } Where Entry<T> is another object with T Data as a public property. T could be any number of types (string, double, etc) On the client I have ClientObject<T> that needs to get the value of Data from the server (same type). Since I'm using WCF, I have to define my ServiceContract as an interface, and I can't have ClientObject<T> call Entry<T> GetMyObjectValue (string Name) which calls GetValue on the correct MyObject<T> because my interface isn't aware of the type information. I've tried implementing separate GetValue functions (GetMyObjectValueDouble, GetMyObjectValueString) in the interface and then have ClientObject determine the correct one to call. However, Entry<T> val = (Entry<T>)GetMyObjectValueDouble(...); doesn't work because it's not sure about the type information. How can I go about getting a generic object over WCF with the correct type information? Let me know if there are other details I can provide. Thanks!

    Read the article

  • Loading GWT Messages from a Database

    - by Lars Tackmann
    In GWT one typically loads i18n strings using a interface like this: public interface StatusMessage extends Messages { String error(String username); : } which then loads the actual strings from a StatusMessage.property file: error=User: {0} does not have access to resource This is a great solution, however my client is unbendable in his demand for putting the i18n strings in a database so they can be changed at runtime (though its not a requirement that they be changed realtime). One solution is to create a async service which takes a message ID and user locale and returns a string. I have implemented this and find it terribly ugly (and it introduces a huge amount of extra communication with the server, plus it makes property placeholder replacement rather complicated). So my question is this, can I in some nice way implement a custom message provider that loads the messages from the backend in one big swoop (for the current user session). If it can also hook into the default GWT message mechanism, then I would be completely happy (i.e. so I can create a interface like above and keep using the the nice {0}, {1}... property replacement format). Other suggestions for clean database driven messages in GWT are also welcome.

    Read the article

  • Repository Pattern Standardization of methods

    - by Nix
    All I am trying to find out the correct definition of the repository pattern. My original understanding was this (extremely dubmed down) Separate your Business Objects from your Data Objects Standardize access methods in data access layer. I have really seen 2 different implementations. Implementation 1 : public Interface IRepository<T>{ List<T> GetAll(); void Create(T p); void Update(T p); } public interface IProductRepository: IRepository<Product> { //Extension methods if needed List<Product> GetProductsByCustomerID(); } Implementation 2 : public interface IProductRepository { List<Product> GetAllProducts(); void CreateProduct(Product p); void UpdateProduct(Product p); List<Product> GetProductsByCustomerID(); } Notice the first is generic Get/Update/GetAll, etc, the second is more of what I would define "DAO" like. Both share an extraction from your data entities. Which I like, but i can do the same with a simple DAO. However the second piece standardize access operations I see value in, if you implement this enterprise wide people would easily know the set of access methods for your repository. Am I wrong to assume that the standardization of access to data is an integral piece of this pattern ? Rhino has a good article on implementation 1, and of course MS has a vague definition and an example of implementation 2 is here.

    Read the article

  • C++ and Dependency Injection in unit testing

    - by lhumongous
    Suppose I have a C++ class like so: class A { public: A() { } void SetNewB( const B& _b ) { m_B = _b; } private: B m_B; } In order to unit test something like this, I would have to break A's dependency on B. Since class A holds onto an actual object and not a pointer, I would have to refactor this code to take a pointer. Additionally, I would need to create a parent interface class for B so I can pass in my own fake of B when I test SetNewB. In this case, doesn't unit testing with dependency injection further complicate the existing code? If I make B a pointer, I'm now introducing heap allocation, and some piece of code is now responsible for cleaning it up (unless I use ref counted pointers). Additionally, if B is a rather trivial class with only a couple of member variables and functions, why introduce a whole new interface for it instead of just testing with an instance of B? I suppose you could make the argument that it would be easier to refactor A by using an interface. But are there some cases where two classes might need to be tightly coupled?

    Read the article

  • How to understand other people's CSS architectures?

    - by John
    I am reasonably good with CSS. However, when working with someone else's CSS, it's difficult for me to see the "bigger picture" in their architecture (but i have no problem when working with a CSS sheet I wrote myself). For example, I have no problems using Firebug to isolate and fix cross browser compatibility issues, or fixing a floating issue, or changing the height on a particular element. But if I'm asked to do something drastic such as, "I want the right sidebars of pages A, B, C and D to have a red border. I want the right side bars of pages E, F and G to have a blue border if and only if the user mouses over", then it takes me time a long time to map out all the CSS inheritance rules to see the "bigger picture". For some reason, I don't encounter the same difficulty with backend code. After a quick debriefing of how a feature works, and a quick inspection of the controller and model code, I will feel comfortable with the architecture. I will think, "it's reasonable to assume that there will be an Employee class that inherits from the Person Class that's used by a Department controller". If I discover inconvenient details that aren't consistent with overall architectural style, I am confident that I can hammer things back in place. With someone else's CSS work, it's much harder for me to see the "relationships" between different classes, and when and how the classes are used. When there are many inheritance rules, I feel overwhelmed. I'm having trouble articulating my question and issues... All I want to know is, why is it so much harder for me to see the bigger picture in someone else's CSS architecture than compared to someone else's business logic layer? **Does it have any thing to do with CSS being a relatively new technology, and there aren't many popular design patterns?

    Read the article

  • Complicated API issue with calling assemblies dynamically?

    - by Stefanos Tses
    I have an interesting challenge that I'm wondering if anyone here can give me some direction. I'm writing a .Net windows forms application that runs on a network and uses an SQL Server to save and pull data. I want to offer a mini "plugin" API, where developers can build their own assemblies and implement a specific interface (IDataManipulate). These assemblies then can be used by my application to call the interface functions and do something. I can create assemblies using my API, copy the file to a folder in my local hard drive and configure my application to use Reflection to call a specific function from the implemented interface (IDataManipulate.Execute). The problem: Since the application will be installed in multiple workstations in the network, is impossible to copy the plugin dlls the users will create to each machine. Solutions I tried: Solution 1 Copy the API dll to a network share. Problem: Requires AllowPartiallyTrustedCallersAttribute, which requires .Net singing, which I can't force from my users. Solution 2 (preferred) Serialize the dll object, save it to the database, deserialize it and call IDataManipulate.Execute. Problem: After deserialization, I try cast it to a IDataManipulate object but returns an error looking for the actual dll file. Solution 3 Save the dll bytes as byte[] to the database and recreate the dll at the local PC every time the user starts my application. Problem: Dll may have dependencies, which I don't know if I can detect. Any suggestions will be greatly appreciated. Thanks

    Read the article

  • File write not getting updated in Qt 4.5.3

    - by user249490
    Hi, I have an XML file. My application requires manipulation into that XML file. I will be writing the values into the XML value. I also have interface to display the read contents of the file. The user might add values into that XML (through an interface). Without closing the application he may decide to display the File contents also. Now the problem is, after i write the XML contents into the file, when i view the file through the interface , the values are not getting updated. After i close the application and open it the updated values are available.I am using the following code to achieve this. For writing QXmlStreamWriter and for reading QDomDocument, QDomNodeList. After i complete the writing, I flush and close the file too. lFile.flush(); lFile.close(); After reading also i closed the file. Can someone tell me what am doing wrong??

    Read the article

  • Intelligent search and generation of Java code, preferrably using Python?

    - by Ipsquiggle
    Basically, I do lots of one-off code generation, large-scale refactorings, etc. etc. in Java. My tool language of choice is Python, but I'll take whatever solutions you can offer. Here is a simplified illustration of what I would like, in a pseudocode Generating an implementation for an interface search within my project: for each Interface as iName: write class(name=iName+"Impl", implements=iName) search within the body of iName: for each Method as mName: write method(name=mName, body="// TODO implement this...") Basically, the tool I'm searching for would allow me to: parse files according to their Java structure ("search for interfaces") search for words contextualized by language elements and types ("variables of type SomeClass", "doStuff() method calls on SomeClass instances") to run searches with structural context ("within the body of the current result") easily replace or generate code (with helpers to generate, as above, or functions for replacing, "rename the interface to Foo", "insert the line Blah.Blah()", etc.) The point is, I don't want to spend a lot of time writing these things, as they are usually throwaway. But sometimes I need something just a little smarter than what grep offers. It wouldn't be too hard to write up a simplistic version of this, but if I'm going to use something like this at all, I'd expect it to be robust. Any suggestions of a tool/library that will help me accomplish this?

    Read the article

  • Writing my own implementation of stl-like Iterator in C++.

    - by Negai
    Good evening everybody, I'm currently trying to understand the intrinsics of iterators in various languages i.e. the way they are implemented. For example, there is the following class exposing the list interface. template<class T> class List { public: virtual void Insert( int beforeIndex, const T item ) throw( ListException ) =0 ; virtual void Append( const T item ) =0; virtual T Get( int position ) const throw( ListException ) =0; virtual int GetLength() const =0; virtual void Remove( int position ) throw( ListException ) =0; virtual ~List() =0 {}; }; According to GoF, the best way to implement an iterator that can support different kinds of traversal is to create the base Iterator class (friend of List) with protected methods that can access List's members. The concrete implementations of Iterator will handle the job in different ways and access List's private and protected data through the base interface. From here forth things are getting confusing. Say, I have class LinkedList and ArrayList, both derived from List, and there are also corresponding iterators, each of the classes returns. How can I implement LinkedListIterator? I'm absolutely out of ideas. And what kind of data can the base iterator class retrieve from the List (which is a mere interface, while the implementations of all the derived classes differ significantly) ? Sorry for so much clutter. Thanks.

    Read the article

  • C#: Determine Type for (De-)Serialization

    - by dbemerlin
    Hi, i have a little problem implementing some serialization/deserialization logic. I have several classes that each take a different type of Request object, all implementing a common interface and inheriting from a default implementation: This is how i think it should be: Requests interface IRequest { public String Action {get;set;} } class DefaultRequest : IRequest { public String Action {get;set;} } class LoginRequest : DefaultRequest { public String User {get;set;} public String Pass {get;set;} } Handlers interface IHandler<T> { public Type GetRequestType(); public IResponse HandleRequest(IModel model, T request); } class DefaultHandler<T> : IHandler<T> // Used as fallback if the handler cannot be determined { public Type GetRequestType() { return /* ....... how to get the Type of T? ((new T()).GetType()) ? .......... */ } public IResponse HandleRequest(IModel model, T request) { /* ... */ } } class LoginHandler : DefaultHandler<LoginRequest> { public IResponse HandleRequest(IModel mode, LoginRequest request) { } } Calling class Controller { public ProcessRequest(String action, String serializedRequest) { IHandler handler = GetHandlerForAction(action); IRequest request = serializer.Deserialize<handler.GetRequestType()>(serializedRequest); handler(this.Model, request); } } Is what i think of even possible? My current Solution is that each handler gets the serialized String and is itself responsible for deserialization. This is not a good solution as it contains duplicate code, the beginning of each HandleRequest method looks the same (FooRequest request = Deserialize(serializedRequest); + try/catch and other Error Handling on failed deserialization). Embedding type information into the serialized Data is not possible and not intended. Thanks for any Hints.

    Read the article

  • Common methods/implementation across multiple WCF Services

    - by Rob
    I'm looking at implementing some WCF Services as part of an API for 3rd parties to access data within a product I work on. There are currently a set of services exposed as "classic" .net Web Services and I need to emulate the behaviour of these, at least in part. The existing services all have an AcquireAuthenticationToken method that takes a set of parameters (username, password, etc) and return a session token (represented as a GUID), which is then passed in on calls to any other method (There's also a ReleaseAuthenticationToken method, no guesses needed as to what that does!). What I want to do is implement multiple WCF services, such as: ProductData UserData and have both of these services share a common implementation of Acquire/Release. From the base project that is created by VS2k8, it would appear I will start with, per service: public class ServiceName : IServiceName { } public interface IServiceName { } Therefore my questions would be: Will WCF tolerate me adding a base class to this, public class ServiceName : ServiceBase, IServiceName, or does the fact that there's an interface involved mean that won't work? If "No it won't work" to Question 1, could I change IServiceName so it extends another interface, IServiceBase, thus forcing the presence of Acquire/Release methods, but then having to supply the implementation in each service. Are 1 and 2 both really bad ideas and there's actually a much better solution that, knowing next to nothing about WCF, I just haven't thought of?

    Read the article

  • How can I use CssResources in UiBinder a generated Cell?

    - by confile
    I want to generate a Cell for a CellWidget with the UiBinder (UiRenderer). What I did to generate the cell is in MyCell.java: public class MyCell implements AbstractCell<MyDto> { public interface Resources extends ClientBundle { @Source({Css.DEFAULT_CSS }) Css css(); } public interface Css extends CssResource { String DEFAULT_CSS = "test/MyStyle.css"; String test(); } interface MyUiRenderer extends UiRenderer { void render(SafeHtmlBuilder sb, String name, SafeStyles styles); } private static MyUiRenderer renderer = GWT.create(MyUiRenderer.class); Resources resources = GWT.create(Resources.class); @Override public void render(SafeHtmlBuilder safeHtmlBuilder, MyDto model) { SafeStyles style = SafeStylesUtils.fromTrustedString(resources.css().test().toString()); renderer.render(safeHtmlBuilder, model.getName(), style); } } My MyCell.ui.xml file looks like this: <!DOCTYPE ui:UiBinder SYSTEM "http://dl.google.com/gwt/DTD/xhtml.ent"> <ui:UiBinder xmlns:ui='urn:ui:com.google.gwt.uibinder'> <ui:with field="name" type="java.lang.String" /> <ui:with field='styles' type='com.google.gwt.safecss.shared.SafeStyles'/> <div style="{styles}"><ui:text from="{name}" /></div> </ui:UiBinder> MyStyle.css: .test { background-color: red; font-size: 20px; display: flex; ... } When I run my code I get the following error: [DEBUG] [mobile] - Rebinding test.client.app.MyCell.MyUiRenderer [DEBUG] [mobile] - Invoking generator com.google.gwt.uibinder.rebind.UiBinderGenerator [ERROR] [mobile] - java.lang.String required, but {styles} returns com.google.gwt.safecss.shared.SafeStyles: <div style='{styles}'> (:9) [ERROR] [mobile] - Deferred binding failed for 'test.client.app.MyCell.MyUiRenderer'; expect subsequent failures [ERROR] [mobile] - (GWT.java:72) 2014-06-08 17:15:05,214 [FATAL] Uncaught Exception: Then I tried to this: in my UiBinder but it does not work. How can I use css style from a CssResource in my UiRenderer?

    Read the article

  • Implementations details of drag and drop of file path in cocoa.

    - by foo
    Hi, I'm trying to get a part of my window to react to drag and drop. In this case to copy the file path to the file being dropped on the view. I have looked over some documentation but I still have some problems to see exactly where I should implement my methods for drag and drop. I have seen some examples but almost all of them assumes that I want to drop an image on the view. I'm pretty new to cocoa and Xcode so, I have some problems with seeing the exact relation between interface builder and the generated code. I have created a subclass to NSView, called drop zone like this: #import <Cocoa/Cocoa.h> @interface dropZone : NSView { } @end I then use an NSRect to color it grey like this: #import "dropZone.h" @implementation dropZone - (void)drawRect:(NSRect)rect { NSRect bounds = [self bounds]; [[NSColor grayColor] set]; [NSBezierPath fillRect:bounds]; } @end I then drag this class to my window in interface builder. But I will need to implement the registerForDraggingTypes method, but where? I have also seen a convenience method in the Apple docs for file paths like this: dragFile:fromRect:slideBack:event: that might work.

    Read the article

  • eliminating duplicate Enum code

    - by Don
    Hi, I have a large number of Enums that implement this interface: /** * Interface for an enumeration, each element of which can be uniquely identified by it's code */ public interface CodableEnum { /** * Get the element with a particular code * @param code * @return */ public CodableEnum getByCode(String code); /** * Get the code that identifies an element of the enum * @return */ public String getCode(); } A typical example is: public enum IMType implements CodableEnum { MSN_MESSENGER("msn_messenger"), GOOGLE_TALK("google_talk"), SKYPE("skype"), YAHOO_MESSENGER("yahoo_messenger"); private final String code; IMType (String code) { this.code = code; } public String getCode() { return code; } public IMType getByCode(String code) { for (IMType e : IMType.values()) { if (e.getCode().equalsIgnoreCase(code)) { return e; } } } } As you can imagine these methods are virtually identical in all implementations of CodableEnum. I would like to eliminate this duplication, but frankly don't know how. I tried using a class such as the following: public abstract class DefaultCodableEnum implements CodableEnum { private final String code; DefaultCodableEnum(String code) { this.code = code; } public String getCode() { return this.code; } public abstract CodableEnum getByCode(String code); } But this turns out to be fairly useless because: An enum cannot extend a class Elements of an enum (SKYPE, GOOGLE_TALK, etc.) cannot extend a class I cannot provide a default implementation of getByCode(), because DefaultCodableEnum is not itself an Enum. I tried changing DefaultCodableEnum to extend java.lang.Enum, but this doesn't appear to be allowed. Any suggestions that do not rely on reflection? Thanks, Don

    Read the article

  • Javascript OOP - accessing the inherited property or function from a closure within a subclass

    - by Ali
    Hi All, I am using the javascript inheritance helper provided here: http://ejohn.org/blog/simple-javascript-inheritance/ I have the following code, and I have problem accessing the inherited property or function from a closure within a subclass as illustrated below. I am new to OOP javascript code and I appreciate your advice. I suppose within the closure, the context changes to JQuery (this variable) hence the problem. I appreciate your comments. Thanks, -A PS - Using JQuery 1.5 var Users = Class.extend({ init: function(names){this.names = names;} }); var HomeUsers = Users.extend({ work:function(){ // alert(this.names.length); // PRINTS A // var names = this.names; // If I make a local alias it works $.map([1,2,3],function(){ var newName = this.names.length; //error this.names is not defined. alert(newName); }); } }); var users = new HomeUsers(["A"]); users.work();

    Read the article

  • Operator overloading in generic struct: can I create overloads for specific kinds(?) of generic?

    - by Carson Myers
    I'm defining physical units in C#, using generic structs, and it was going okay until I got the error: One of the parameters of a binary operator must be the containing type when trying to overload the mathematical operators so that they convert between different units. So, I have something like this: public interface ScalarUnit { } public class Duration : ScalarUnit { } public struct Scalar<T> where T : ScalarUnit { public readonly double Value; public Scalar(double Value) { this.Value = Value; } public static implicit operator double(Scalar<T> Value) { return Value.Value; } } public interface VectorUnit { } public class Displacement : VectorUnit { } public class Velocity : VectorUnit { } public struct Vector<T> where T : VectorUnit { #... public static Vector<Velocity> operator /(Vector<Displacement> v1, Scalar<Duration> v2) { return new Vector<Velocity>(v1.Magnitude / v2, v1.Direction); } } There aren't any errors for the + and - operators, where I'm just working on a Vector<T>, but when I substitute a unit for T, suddenly it doesn't like it. Is there a way to make this work? I figured it would work, since Displacement implements the VectorUnit interface, and I have where T : VectorUnit in the struct header. Am I at least on the right track here? I'm new to C# so I have difficulty understanding what's going on sometimes.

    Read the article

  • How to import properties of an external API into Script#

    - by AndrewDotHay
    I'm using Script# inside Visual Studio 2010 to import the API for the HTML5 Canvas element. Its working great for things like FillRect(), MoveTo(), LineTo() and so on. I've declared the following interface and then I can code against it in C#. Then, Script# converts it to JavaScript nicely. public interface CanvasContext { void FillRect(int x, int y, int width, int height); void BeginPath(); void MoveTo(int x, int y); void LineTo(int x, int y); void Stroke(); void FillText(string text, int x, int y); } I want to include the StrokeStyle property that takes a simple string. The following interface definition produces a prefix in the JavaScript, which causes it to fail. string StrokeStyle { get; set; } string Font { get; set; } The previous property will create this JavaScript: ctx.set_strokeStyle('#FF0'); How can I get Script# to generate the simple assignment properties of the canvas context without the get_/set_ prefix?

    Read the article

  • Can you explain this generics behavior and if I have a workaround?

    - by insta
    Sample program below: using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace GenericsTest { class Program { static void Main(string[] args) { IRetrievable<int, User> repo = new FakeRepository(); Console.WriteLine(repo.Retrieve(35)); } } class User { public int Id { get; set; } public string Name { get; set; } } class FakeRepository : BaseRepository<User>, ICreatable<User>, IDeletable<User>, IRetrievable<int, User> { // why do I have to implement this here, instead of letting the // TKey generics implementation in the baseclass handle it? //public User Retrieve(int input) //{ // throw new NotImplementedException(); //} } class BaseRepository<TPoco> where TPoco : class,new() { public virtual TPoco Create() { return new TPoco(); } public virtual bool Delete(TPoco item) { return true; } public virtual TPoco Retrieve<TKey>(TKey input) { return null; } } interface ICreatable<TPoco> { TPoco Create(); } interface IDeletable<TPoco> { bool Delete(TPoco item); } interface IRetrievable<TKey, TPoco> { TPoco Retrieve(TKey input); } } This sample program represents the interfaces my actual program uses, and demonstrates the problem I'm having (commented out in FakeRepository). I would like for this method call to be generically handled by the base class (which in my real example is able to handle 95% of the cases given to it), allowing for overrides in the child classes by specifying the type of TKey explicitly. It doesn't seem to matter what parameter constraints I use for the IRetrievable, I can never get the method call to fall through to the base class. Also, if anyone can see an alternate way to implement this kind of behavior and get the result I'm ultimately looking for, I would be very interested to see it. Thoughts?

    Read the article

  • Obj-C Sending Messages Between Classes

    - by user544359
    I'm a newbie in iPhone Programming. I'm trying to send a message from one view controller to another. The idea is that viewControllerA takes information from the user and sends it to viewControllerB. viewControllerB is then supposed to display the information in a label. viewControllerA.h #import <UIKit/UIKit.h> @interface viewControllerA : UIViewController { int num; } -(IBAction)do; @end viewControllerA.m #import "viewControllerA.h" #import "viewControllerB.h" @implementation viewControllerA - (IBAction)do { //initializing int for example num = 2; viewControllerB *viewB = [[viewControllerB alloc] init]; [viewB display:num]; [viewB release]; //viewA is presented as a ModalViewController, so it dismisses itself to return to the //original view, i know it is not efficient [self dismissModalViewControllerAnimated:YES]; } - (void)dealloc { [super dealloc]; } @end viewControllerB.h #import <UIKit/UIKit.h> @interface viewControllerB : UIViewController { IBOutlet UILabel *label; } - (IBAction)openA; - (void)display:(NSInteger)myNum; @end viewControllerB.m #import "viewControllerB.h" #import "viewControllerA.h" @implementation viewControllerB - (IBAction)openA { //presents viewControllerA when a button is pressed viewControllerA *viewA = [[viewControllerA alloc] init]; [self presentModalViewController:viewA animated:YES]; } - (void)display:(NSInteger)myNum { NSLog(@"YES"); [label setText:[NSString stringWithFormat:@"%d", myNum]]; } @end YES is logged successfully, but the label's text does not change. I have made sure that all of my connections in Interface Builder are correct, in fact there are other (IBAction) methods in my program that change the text of this very label, and all of those other methods work perfectly... Any ideas, guys? You don't need to give me a full solution, any bits of information will help. Thanks.

    Read the article

  • License For (Mostly) Open Source Website / Service

    - by Ryan Sullivan
    I have an interesting setup and am not sure how to license a website. I know this is not legal advice, and I am not asking for any. There are so many different Open Source Licenses and I do not have the time to read every last one to see which best fits my situation. Really, I am looking for suggestions and a nudge in the right direction. My setup is: I give away for free version of my web service with a clean website interface. The implementation I use in the actual web site is (almost) identical to what I give away. The main service works the exactly the same way, but the website interface to manage features in the service is fairly different. Really the web interfaces have the same exact backend, and the front ends accomplish the same tasks, but the service I offer on my site is very rich and uses a good deal of javascript, where I kept the interface in the version I give away as simple and javascript-less as possible. Mostly so it is easy to understand and integrate into other sites. I am not entirely sure how I should license this. It is more like I develop an open source service but have a separate site built upon it. I like the GPLv3 but I am not sure if I can use it in this case especially since I am making some money off of google ad's on the site and plan on using amazon affiliates as well. Any help would be greatly appreciated. I do want to open it up as much as possible. But I still want to be able to continue with my own implementation. Thanks in advance for any information or help anyone can provide.

    Read the article

< Previous Page | 173 174 175 176 177 178 179 180 181 182 183 184  | Next Page >