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• How to force calling of QWidget::paintEvent() when its hovered by other window?

  - by Pie_Jesu

  Hi there. I have occured a problem: I'm writing a widget, which displays current date's day number. It's like a button, but it's not derived from QPushButton class. Just from QWidget. So I reimplemented enterEvent(), leaveEvent(), mousePressEvent(), mouseReleaseEvent(). I call update() inside these methods and widget has realistic button behavior (paintEvent() is reimplemented too). But when I change system date and hover that widget with other window, my widget doesn't calls paintEvent() and displays old date. Only when I place mouse over it, widget repaints it's contents. I guess there is an option, which paints old contents on hover event to avoid unnecessary paint events. But I need to disable it. Tried to set many attributes (Qt::WidgetAttribute enum). But it doesn't helps. Please, help me (and sorry for my bad english).

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• Usage examples of binary search

  - by python dude

  I just realized that in my 4+ years of Java programming (mostly desktop apps) I never used the binary search methods in the Arrays class for anything practical. Not even once. Some reasons I can think of: 100% of the time you can get away with linear search, maps or something else that isn't binary search. The incoming data is almost never sorted, and making it sorted requires an extra sorting step. So I wonder if it's just me, or do a lot of people never use binary search? And what are some good, practical usage examples of binary search?

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• How to find out where my memory is going

  - by the_mandrill

  I've got the situation where the cycle of loading and then closing a document eats up a few Mb of RAM. This memory isn't being leaked as something owns it and cleans it up when the app exits (Visual Leak Detector and the Mac Leaks tool show agreement on this). However, I'd like to find out where it's going. I'm assuming it's some sort of cache in the application that gets populated when the document loads but not freed when the document is closed. Which methods or tools could I use to find out where these allocations are being made?

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• data loading - app launching on tableview

  - by wallou

  hi, i encounter an issue with my application. On one hand when my app launches, the first view displayed is a tableview within a tableviewcontroller. On the other hand my app calls a web service to collect data. These methods are in MyAppDelegate\applicationDidFinishLaunching. The thing is that my tableview is made of custom cells that need data from the web service. I noticed that the view (with the tableview) is launched first and then MyAppDelegate\applicationDidFinishLaunchin is executed. As a result the labels of my custom cells are all equal to null as my arrays aren't filled yet by the web service. I would like to know the proper way to make it. If anyone has an idea please tell me. Wallou

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• Extendable accessing of sqlite database on android platform

  - by mscriven

  Hi, I am fairly new to the android sdk and databases and have been searching for an answer to this quite some time. I am trying to build an app which has multiple tables within a database. e.g. one for weapons, armours etc. However, my DatabaseManager class which handles all of my table creating, DatabaseHelper inner class and populating of data is creating for an extremely large class requiring high maintenance. Every time I would like to add or remove a table column I need to change quite a few areas of code, - Every reference to the addition of a row in that table with data - The method that the above calls - The method returning all of the database rows - The code in the helper class creating the table - Any specific update methods My question is this: Surely there must be some better way of coding this system, maybe using a database isn't the best way to go, or am i just not used to such large classes having only learned java at university and my largest class consisting of a mere 400-600 lines of code. Thanks for any help!

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• I'm maintaining a java class that's 40K lines long.. problem?

  - by Billworth Vandory

  This may be a subjective question leading to deletion but I would really like some feedback. Recently, I moved to another very large enterprise project where I work as a C++ developer. I was aghast to find most classes in the project are anywhere from 8K to 50K lines long with methods that are 1K to 8K lines long. It's mostly business logic dealing with DB tables and data management, full of conditional statements to handle the use cases. Are classes this large common in large enterprise systems? I realize without looking at the code it's hard to make a determination, but have you ever worked on a system with classes this large?

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• Are there alternative ways to implementing an "active link" navigation without using server side languages?

  - by Mel

  By "active" I mean to have the link pointing to the current page classed as "active." This way the link's appearance can be modified using css. Is it possible to implement an active link navigation without using a server side language? I would like to only use CSS/HTML/jQuery if possible. If there are, what are those methods? Assuming you want to create the following structure: <ul id="nav"> <li class="active">Home</li> <li>About</li> <li>Contact</li> </ul>

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• What constitutes a private API in an iPhone app?

  - by tweened

  I'm fairly new to Objective-C and am confused on what falls under the unbrella of a "private API" that could cause Apple to reject my app. Does this include adding methods to existing classes? For example, I found some code on stackoverflow to recolor the tab bar icons for UITabBars with this extension to the UITabBarItem class. Is this considered a "private API"? If not, what does? @interface UITabBar (ColorExtensions) - (void)recolorItemsWithImage:(UIImage *)image shadowColor:(UIColor *)shadowColor shadowOffset:(CGSize)shadowOffset shadowBlur:(CGFloat)shadowBlur; @end

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• pointer and malloc [closed]

  - by gcc

  How many methods/ways are there taking input by using with pointer and dynamic memory? Input: 3 1 2 n k l 2 1 2 p 4 55 62 * # x (x is stop value, first input always integer) Example code: p=malloc(sizeof(int)); scanf("%d",&num_arrays); while(1) { scanf("%c",&(*(p+i))); if(*(p+i)=='x') break; ++i; } "3" is stored in num_arrays. The other input values are stored in pointer[array].

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• Waiting on threads

  - by Paul Reiners

  I have a method that contains the following (Java) code: doSomeThings(); doSomeOtherThings(); doSomeThings() creates some threads, each of which will run for only a finite amount of time. The problem is that I don't want doSomeOtherThings() to be called until all the threads launched by doSomeThings() are finished. (Also doSomeThings() will call methods that may launch new threads and so on. I don't want to execute doSomeOtherThings() until all these threads have finished.) This is because doSomeThings(), among other things will set myObject to null, while doSomeOtherThings() calls myObject.myMethod() and I do not want myObject to be null at that time. Is there some standard way of doing this kind of thing (in Java)?

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• login with users, groups and permissions

  - by Dan Bemowski

  OK, I have a set of tables that I want to use for my user logins. I am guessing that I need a separate model for each table in the database. My tables are as follows: Users - user information such as first and last name, groups_id, status, etc... groups - defines the user groups with id, name, description permissions - defines a list of permissions that a group can have permission_assignments - groups_id and permissions_id. many to many relationship table I am not sure how to go about populating an array that would contain the list of permissions that a user would have based on the group they are in after a successful login. Basically, a user belongs to a group, and the group gets assigned permissions. I want to then be able to validate functions/methods based on weather the logged in user has certain permissions. Any help is appreciated

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• .NET project: unified wrapper for object databases.

  - by Steve

  I am considering doing a project which would provide unified API and tools (import/export, etc.) for object databases (e.g. Caché, Objectivity) for .NET. It would provide: schema generation from CLR classes, generation of C# classes from given OODBMs schema, API for deleting, creating and updating objects, Linq provider, API for calling object's methods on DB server, some of OODBMs provide some kind of SQL support, so API for this, providers for Caché and Objectivity in first phase. Does any project which implements any of above exist? Can this be achieved with NHibernate dialects? or are OODBMs so different than RDBMs that it worth doing separate framework for them?

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• How to create and add a custom made component to a Dialog based app (MFC)?

  - by kobac

  I want to make a custom made component (a line chart), that would be used in other applications. I don't know 2 things: 1) Where should I use (within component class!) the methods for drawing, like FillRect or PolyLine? In OnPaint handler that I should define and map it in MESSAGE MAP? Will it (OnPaint handler) be called from OnPaint handler of the dialog of the application or where from? 2)How to connect the component, once it is made, to the test application, which will for example be dialog based? Where should I instantiate that component? From an OnCreate method of the MyAppDialog.cpp? I started coding in MFC few days ago and I'm so confused about it. Thanks in advance, Cheers.

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• Write a tree class in Java where each level has a unique object type

  - by user479576

  I need to write a tree class in Java where each level has a unique object type. The way it is written below does not take advantage of generics and causes alot of duplicate code. Is there a way to write this with Generics ? public class NodeB { private String nodeValue; //private List<NodeB> childNodes; // constructors // getters/setters } public class NodeA { private String value; private List<NodeB> childNodes; // constructors // getters/setters } public class Tree { private String value; private List<NodeA> childNodes; // constructors // tree methods }

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• How do I create a dynamic method in PHP?

  - by sandelius

  I'm trying to extend my ActiveRecord class with some dynamic methods. I would like to be able to run this from my controller $user = User::find_by_username(param); $user = User::find_by_email(param); I've read a little about overloading and think that's the key. I'v got a static $_attributes in my AR class and I get the table name by pluralizing my model (User = users) in this case. How do I do this? All models extends the ActiveRecord class.

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• Where and why JVM checks that the return type of entry method main(String args[]) is void and not an

  - by akjain

  I will try to answer both, please correct me if I am wrong: Where: If a static method is being called using Classname.method() or using reflection then it doesn’t matter even if you change the return type of the calling method, the same method will still be called. So JVM probably checks this in one of the native methods of jvm.cpp methodHandle m (THREAD, init_klass-find_method(vmSymbols::object_initializer_name(), vmSymbols::void_method_signature())); if (m.is_null()) { ------ THROW_MSG_0 ……….. Why: Although it’s of useless to return a value from main, as java does not do anything with it but if we try to change the return type of main to int for example, JVM throws public static int main(String[] args) { return 1; } java.lang.NoSuchMethodError: main Exception in thread "main" So may be Java mandates the use of same signature for entry method main() to maintain a symmetry in all Java programs written.

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• I want to make a wrapped acces type for certain internals of one of classes and I have some performa

  - by Alex

  I am writing an abstract matrix class (and some concrete subclasses) for use on very differing hardwares/architectures, etc. and I want to write a row and column type that provides a transparent reference to the rows and columns of the matrix. However, I want to tune for performance, so I'd like this class to be essentially a compiler construct. In other words, I'm willing to sacrifice some dev time to making the overhead of these classes as small as possible. I assume all (small) methods would want to be virtual? Keep the structure small? Any other suggestions?

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• What are the differences in performance between synchronous and asynchronous JavaScript script loading?

  - by jasdeepkhalsa

  My question is simply: what are the differences in performance between synchronous and asynchronous JavaScript script loading? From what I've gathered synchronous code blocks the loading of a page and/or rest of the code from executing. This happens at two levels. First, at the level of the script actually loading, and secondly, within the JavaScript code itself. For example, on the page: Synchronous: <script src="demo_async.js" type="text/javascript"></script> Asynchronous: <script async src="demo_async.js" type="text/javascript"></script> And within a script: Synchronous: function a() {alert("a"); function b() {alert("b");}} Asynchronous (and self-executing): (function(a, function(b){ alert(b); }) { alert(a); }))(); So what really is the difference in performance from using these different loading methods and JavaScript patterns?

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• How can I get class, property, and method data from files without executing their code, similar to R

  - by Chris

  I have a bunch of PHP files with classes, in them (although I can't be 100% sure that they won't have code outside of classes in them too), and I need to parse these files to get information about the classes, such as the names of the classes, the methods, the properties, whether they are private/public/static, etc. I looked at PHP's reflection classes and this is very close to what I want but the reflection doesn't seem to use external files and it appears to need to define the classes first. I need to make sure that none of the code is executed and I will be editing the files so I can't guarantee that they will even be error-free. Any suggestions? Thanks.

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• Ojective C Class or struct?

  - by Scott Pendleton

  I have a class Song with properties Title, Key, Artist, etc. There are no methods. I loop through a database of song information and create a Song object for each, populating the properties, and then store the Song objects in an NSArray. Then I thought, why not just have a struct Song with all those same properties instead of a class Song. Doing so would eliminate the class files, the #import Song line in the using class's .m file, and the need to alloc, init, release. On the other hand, I'd have to put the struct definition in every class that might need it. (Unless there's some globally accessible location -- is there?) Also, can a struct be stored in an NSArray?

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• C# Possible to partial class "program" class for a console application?

  - by JL

  I was wondering if its possible to change the default "program" class that gets created for any console application to a partial class. I want to do this because I want better organisation rather than have all methods in 1 file categorized by region. It would make more sense for me to have certain method categories sitting in separate files. My understanding of a partial class is that it is a class definition in multiple files that during a compile merges the class files into 1 class unit. I could be wrong, or there could be a better way for me to achieve better organisational structure. Any suggestions would help, and thanks

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• Generic type parameter naming convention for Java (with multiple chars)?

  - by chaper29

  In some interfaces i wrote I'd like to name generic type parameter with more than one character to make the code more readable. Something like.... Map<Key,Value> Instead of this... Map<K,V> But when it comes to methods, the type-parameters look like java-classes which is also confusing. public void put(Key key, Value value) This seems like Key and Value are classes. I found or thought of some notations, but nothing like a convention from sun or a general best-practice. Alternatives i guesed of or found... Map<KEY,VALUE> Map<TKey,TValue>

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• The pImpl idiom and Testability

  - by Rimo

  The pImpl idiom in c++ aims to hide the implementation details (=private members) of a class from the users of that class. However it also hides some of the dependencies of that class which is usually regarded bad from a testing point of view. For example if class A hides its implementation details in Class AImpl which is only accessible from A.cpp and AImpl depends on a lot of other classes, it becomes very difficult to unit test class A since the testing framework has no access to the methods of AImpl and also no way to inject dependency into AImpl. This has been a problem for me lately and I am beginning to think that the pImpl idiom and writing testable code don't mix well. Has anyone come across this problem before? and have you found a solution?

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• Understanding behaviour of read() and write()

  - by neo730

  hi i am a student and just start learning low level c programming.i tried to understand read() and write() methods with this program. #include <unistd.h> #include <stdlib.h> main() { char *st; st=calloc(sizeof(char),2);//allocate memory for 2 char read(0,st,2); write(1,st,2); } i was expecting that it would give segmentation fault when i would try to input more than 2 input characters.but when i execute program and enter " asdf " after giving " as " as output it executes "df" command. i want to know why it doesn't give segmentation fault when we assign more than 2 char to a string of size 2.and why is it executing rest(after 2 char)of input as command instead of giving it as output only? also reading man page of read() i found read() should give EFAULT error,but it doesn't. I am using linux.

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• MediaType of REST

  - by user357243

  Hi, I am beginner in REST web services. I wrote a program of REST to display the HTML or XML. The @Path annotation's value is @Path("{typeDocument}"). There are two methods for GET : @GET @Produces(MediaType.TEXT_XML) public String getXml(@PathParam("typeDocument") String typeDocument) to display XML file, and @GET @Produces(MediaType.TEXT_HTML) public String getHtml(@PathParam("typeDocument") String typeDocument) to display HTML. The browser Firefox always excutes getHtml() when URL is either http://localhost:8080/sources/html or localhost:8080/sources/xml But IE always excutes getXml(). How to excute the correct method, as defined by URL, in different browser ? Thanks a lot.

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