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  • two classes contain objects of each other

    - by Julz
    hi, i hope there's a simple answer to this. without getting too complicated i have two classes. an "Animal" and a "Cell" Cell contains an Animal as a member. Animal has methods that accept Cells in their parameters. i'm just confused as to how i #include each class the others header? i've only ever had to go up a chain of classes and just included the last class header in the next and so on, but this circular situation has me a bit lost. i hope that makes sense, any help greatly appreciated.

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  • Is there any way to retrieve a float from a varargs function's parameters?

    - by Jared P
    If the function was defined with a prototype which explicitly stated the types of the parameters, eg. void somefunc(int arg1, float arg2); but is implemented as void somefunc(int arg1, ...) { ... } is it possible to use va_arg to retrieve a float? It's normally prevented from doing this because varargs functions have implicit type promotions, like float to double, so trying to retrieve an unpromoted type is unsupported, even though the function is being called with the unpromoted type do to the more specific function prototype. The reason for this is to retrieve arguments of different types at runtime, as part of an obj-c interpreter, where one function will be reused for all different types of methods. This would be best as architecture independent (so that if nothing else the same code works on simulator and on device), although if there is no way to do this then device specific fixes will be accepted.

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  • c++: strange syntax in what() method of std::exception

    - by Patrick Oscity
    When i am inheriting from std::exception in order to define my own exception type, i need to override the what() method, which has the following signature: virtual const char* what() const throw(); This definitely looks strange to me, like if there were two method names in the signature. Is this some very specific syntax, like with pure virtual methods, e.g.: virtual int method() const = 0; or is this a feature, that could somehow be used in another context, too? And if so, for what could it be used?

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  • How to find which method makes my iPhone app slow ?

    - by Stewart Hou
    Currently I am working on a production app. One function acts like the settings.app on iPhone. When the user click a cell of a tableView, as shown below http://www.penguintech.net/images/stackoverflow/1.png It will push another view, which includes a textfield to let user input something. However, on both simulator and device, after the app just loaded, the delay between clicking and showing the second view takes around 2 seconds. Then if user get back to previous view and click again, it will be no delay at all. To detect which method makes the delay, I put a NSLog() in every involved methods, but when I was inspecting the console while running the app, all NSLog() message showed in 0.1 seconds, and then still a delay on the app. Is there any other way to trace the performance footage of a app? The Instruments shows only CPU usage in Mac OS not in iPhone.

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  • Acceptable to have spaces before dot?

    - by Rudy
    What is the general opinion on the 2nd indentation method below. // Normal indentation a.Value = "foobar"; ab.Checked = false; foo.Value = "foobar"; foobar.Checked = true; // Spaces before the dot to align the properties/methods a .Value = "foobar"; ab .Checked = false; foo .Value = "foobar"; foobar.Checked = true; This should probably be a wiki, but I either don't have enough privileges or don't know how to change it.

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  • Creating a jQuery Plugin, How do I do Custom Scopes?

    - by viatropos
    I would like to create a jQuery plugin with an API something like this: $("#chart").pluginName().attr("my_attr"); Instead of these: $("#chart").pluginName_attr("my_attr"); $.pluginName.attr("#chart", "my_attr"); Basically, instead of having to namespace every method that acts similar to ones in jQuery, I'd like to "scope" the methods to a custom api, where $("#chart).pluginName() would return an object such that get, attr, find, and a few others would be completely rewritten. I'm sure this is not a well-liked idea as it breaks convention (does it?), but it's easier and more readable, and probably more optimized, than the two options above. What are your thoughts?

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  • How do I change the background image of my iPhone app?

    - by alJaree
    Hello I have looked around and found some code which so called chooses an image from an array of image objects, but cant find an explanation. I would like to make my app have a background image and the user can select next and previous buttons to scroll through some full screen images, setting them as the background image as they scroll. I know how to do this in java, but cant seem to do it for this app. How or what code is linked to a next button to grab the next image in the array and reverse for the back button? Then that needs to be displayed obviously. I have used a layered architecture with a MVC style approach but cant seem to put it together with Objective-C. Would the buttons call the appropriate methods of the so called delegates, which the delegates handle fetching and returning the Images? Would the buttons use the returned images and actually handle the redrawing? I would really appreciate the help. Regards Jarryd

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  • Java: global values inside a class?

    - by HH
    I want less methods. I want a common global TestClass from which I could use any of its value inside the class. import java.util.*; import java.io.*; public class TestClass { TestClass(String hello){ String hallo = hello; String halloSecond = "Saluto!"; } public static void main(String[] args) { TestClass test = new TestClass("Tjena!"); System.out.println("I want "Tjena!": " + test.hallo); TestClass testSecond = new TestClass("1"); System.out.println("I want Saluto!:" + test.halloSecond); System.out.println("I want Saluto!:" + testSecond.halloSecond); } }

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  • what's the difference between DEFAULT_SIZE and PREFERRED_SIZE?

    - by CD1
    hi, I'm using Swing GroupLayout and I'm confused about the values GroupLayout.DEFAULT_SIZE and GroupLayout.PREFERRED_SIZE. I never know when to use each one of them in methods like GroupLayout.addComponent(Component, int, int, int). suppose I have this code: GroupLayout l = ...; l.setHorizontalGroup(l.createSequentialGroup() .addComponent(tf1) .addComponent(tf2)); l.setVerticalGroup(l.createParallelGroup() .addComponent(tf1) .addComponent(tf2)); there are two JTextFields on a single line laid out with GroupLayout (one sequential group horizontally and one parallel group vertically). if I resize the window now, both components get the available space (50% each). but I want only the first text field to grow/shrink horizontally and only the second text field to grow/shrink vertically. what values of min, pref and max should I use to accomplish that? I know I can just try it and see what combination works but I'd like to know the reasoning behind this problem.

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  • Qt: QAbstractItemModel and 'const'

    - by Eye of Hell
    Hello. I'm trying to use a QTreeView for a first time, with a QAbstractItemModel. And instantly it's a problem: QAbstractItemModel interface declares methods as 'const', assuming they will not change data. But i want a result of SQL query displayed, and returning data for a record with specified indeq REQUIRES to use QSqlQuery::seek() that is a non-const. Is it any 'official' guideline to use a QAbstractItemModel with data that MUST be changed in order to get number of items, data per item etc? Or i must hack C++ with const casts?

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  • Java vs C# - AddActionListener vs event subscription

    - by S.O.
    Very simple question from one somewhat new to Java: when adding an event handler (or whatever it is called in Java) to a Control, MUST it be an object? I mean, in C# I can do control.event += System.eventHandler(methodThatHandlesEvent) Sure, that's because we have delegate types in C#, but I was wondering if I can choose which method would be called when an event is raised in Java? I mean, in Java I can have something like control.AddActionListener(objectWhichClassImplementsActionListener) And then I have the stupid actionPerformed method in this class, which is the only method that is called. I know, there are more kinds of listeners, but I can't have a "ActionListenerHandler" class in which I implement several actionPerformed methods that can be assigned to different controls?

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  • How to store data to Excel from DataSet without going cell-by-cell?

    - by Jason Barnwell
    Duplicate of: What’s the simplest way to import a System.Data.DataSet into Excel? Using c# under VS2008, we can create an excel app, workbook, and then worksheet fine by doing this: Application excelApp = new Application(); Workbook excelWb = excelApp.Workbooks.Add(template); Worksheet excelWs = (Worksheet)this.Application.ActiveSheet; Then we can access each cell by "excelWs.Cells[i,j]" and write/save without problems. However with large numbers of rows/columns, we are expecting a loss in efficiency. Is there a way to "data bind" from a DataSet object into the worksheet without using the cell-by-cell approach? Most of the methods we have seen at some point revert to the cell-by-cell approach. Thanks for any suggestions.

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  • How to create GUI as inner class with WindowBuilder

    - by Tim Kemp
    I would like to use WindowBuilder in Eclipse to construct Swing GUIs. The JPanels I need to build will be inner classes in a non-GUI wrapper, like so: public class MyWrapper extends MyBaseClass { ... class MyPanel extends JPanel { ... } } So my question is this: can I construct MyPanel using WindowBuilder? If so, how should I set it up? If anyone is interested, the wrapper is an abstract base class which the plug-ins I am developing for my app must extend; deployment concerns mean that it's not really practical to put the GUIs in a separate JAR either so I pretty much have to do it this way. My current workflow, which is awful, is to build the GUI in NetBeans and paste the entire generated class into Eclipse where I connect it up to the methods in my wrapper. I am very hopeful that WindowBuilder will let me work more reliably and efficiently if I can trick it into generating code in MyPanel, not MyWrapper. Thanks

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  • jQuery mobile 1.1.0 slider: JS-object properties access?

    - by Koniak
    EDIT: This could be seen as a pure javascript objects question. The code can be found here: jquery.mobile-1.1.0.js I need to access properties of a jQuery mobile JS-object but is not sure how that is possible. In the jquery.mobile-1.1.0.js and mobile.slider is the following (see extend on line 5967): $.widget( "mobile.slider", $.mobile.widget, { ... _create: function() { ... $.extend( this, { slider: slider, handle: handle, valuebg: valuebg, dragging: false, beforeStart: null, userModified: false, mouseMoved: false }); Primarily the property I would like to read is the "dragging". I know i can execute the methods using: $("#slider").slider("refresh") Is there a similair way to access the properties? Thanks

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  • Applying transformations to NSBitmapImageRep

    - by Adam
    So ... I have an image loaded into an NSBitmapImageRep object, so I am able to examine the contents of specific pixels via a two dimensional array. Now I want to apply a couple of "transformations" to the image, in preparation for some additional processing. If I was manipulating the image manually, in Photoshop, I would: Rotate the image Crop a portion of it and discard the rest Apply a "threshold" transformation (which essentially converts the image to black and white, based on the threshold value I provide) Resample the image to shrink it down a bit (which, although losing some image quality, will speed up the subsequent processing) (not necessarily in that order) Are there objective C methods available to facilitate these specific image manipulations, with the data in the NSBitmapImageRep object? If so, can someone point me to some good examples?

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  • PHP Store User Data without Sessions

    - by Sev
    Is there anyway to store users data such as userid, email, etc to be accessible from all pages of a website after they have logged in, but without using sessions or cookies? For example: class User { var $userid; var $username; var $email; .. methods.. } after they login at login.php $currentUser = new User($_POST['username']) now, how do I access $currentUser from another page, such as index.php if I shouldn't use sessions or cookies at all? so that I could do the following in index.php: if ($currentUser->userid > -1) { echo "you are logged in as: " . $currentUser->username; } else { echo "click here to login"; } i asked a similar question before, here, but the answers didn't fulfill my needs.

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  • NoMethodError when trying to invoke helper method from Rails controller

    - by John Topley
    I'm getting a NoMethodError when trying to access a method defined in one of my helper modules from one of my controller classes. My Rails application uses the helper class method with the :all symbol as shown below: class ApplicationController < ActionController::Base helper :all . . end My understanding is that this should make all of my controller classes automatically include all of the helper modules within the app/helpers directory, therefore mixing in all of the methods into the controllers. Is this correct? If I explicitly include the helper module within the controller then everything works correctly.

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  • How to load an entity by a key other than primary key?

    - by stacker
    In a customized servlet (seam 2.1.2) this works fine TableNameHome tableNameHome = (TableNameHome) Component.getInstance( "tableNameHome " ); tableName entity = tableNameHome.getInstance(); entity.setXXX(); tableNameHome.persit(); However this one fails: entityManager = tableNameHome .getEntityManager(); Query query = entityManager.createQuery( "SELECT b FROM tablename b WHERE b.box_id = :key2nd" ); query.setParameter( "key2nd", value); List results = query.getResultList(); and leads to this error message: org.hibernate.hql.ast.QuerySyntaxException: tablename is not mapped [SELECT b FROM tablename b WHERE b.key2nd = :key2nd] In EJB 2.1 I could implement other finder-methods. EntityHome.find() searches only by primary key. What do I need to do in order to query by a different criteria than primary key?

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  • Define 2D array with loops in php

    - by Michael
    I have an array $rows where each element is a row of 15 tab-delimited values. I want to explode $rows into a 2D array $rowData where each row is an array element and each tab-delimited value is assigned to a different array element. I've tried these two methods without success. I know the first one has a coding error but I do not know how to correct it. Any help would be amazing. for ($i=0; $i<count($rows); $i++){ for ($j=0; $j<15; $j++){ $rowData = array([$i] => array (explode(" ", $rows[$j]))); } } foreach ($rows as $value){ $rowData = array( array (explode(" ", $rows[$value]))); }

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  • assignment makes pointer from integer without a cast

    - by mrblippy
    hi, i am trying to make a linked list and create some methods. but i am getting the error assignment makes pointer from integer without a cast. #include <stdio.h> #include <stdlib.h> #include "students.h" node_ptr create(void) { node_ptr students = (node_ptr) malloc(sizeof(struct node)); students->ID = 0; students->name = NULL; students->next = NULL; return students; } void insert_in_order(int n, node_ptr list) { node_ptr before = list; node_ptr new_node = (node_ptr) malloc(sizeof(struct node)); new_node->ID = n;//error is here i think while(before->next && (before->next->ID < n)) { before = before->next; } new_node->next = before->next; before->next = new_node; }

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  • Accessing facebook sdk result Object using .NET 3.5 API?

    - by John K
    Consider the following in .NET 3.5 (using the Bin\Net35\Facebook*.dll assemblies): using Facebook; var app = new FacebookApp(); var result = app.Get("me"); // want to access result properties with no dynamic ... in the absence of the C# 4.0 dynamic keyword this provides only generic object members. How best should I access the facebook properties of this result object? Are there helper or utility methods or stronger types in the facebook C# SDK, or should I use standard .NET reflection techniques?

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  • How to write a value validation method for core data?

    - by mystify
    The docs say: you should implement methods of the form validate:error:, as defined by the NSKeyValueCoding protocol so lets say I have an attribute which is an int: friendAge I want to make sure that any friend may not be younger than 30. So how would I make that validation method? -validateFriendAge:error: What am I gonna do in there, exactly? And what shall I do with that NSError I get passed? I think it has an dictionary where I can return a humanly readable string in an arbitrary language (i.e. the one that's used currently), so I can output a reasonable error like: "Friend is not old enough"... how to do that?

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  • Fragment savedInstanceState is always null (Android support lib)

    - by Evgeny Egorov
    I wrote a simple test project, but I cant understand why I always receive savedInstanceState = null in lifecycle methods onCreate, onCreateView and onActivityCreated. I change the screen orientation, see the log, but state not saved. Tell me please where is my mistake. Thanks. The code of fragment class is: public class TestFragment extends Fragment { private String state = "1"; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { if (savedInstanceState != null) { //never works state = savedInstanceState.getString("state"); } //always prints 1 Toast.makeText(getActivity(), state, Toast.LENGTH_SHORT).show(); return inflater.inflate(R.layout.fragment_layout, container, false); } @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); outState.putString("state", "2"); Log.e("", "saved 2"); } }

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  • How do I run modals windows from code with cocoa?

    - by Leandro
    Hi,everybody I`m trying to run a window as modal directly from the code. My program starts and a main NSWindows is showed.A thread still running to see if the user has a valid distribution. if he doesn't I need to run a modal.I mean, I have no buttons clicked in the interface.I've designed a NSWindow on the interface builder for a password set, and I want to call it only when my validation is not successful. I have tested and realized that these methods which are responsible for modal windows running only work in a IBAction environment. //This doesn't work -(void) showPasswordWindow { [NSApp runModalForWindow:[self window]]; } //this works But its not useful for me =( - (IBAction) passwordWindowButton:(id)sender { [NSApp runModalForWindow:[self window]]; } Please, help this newbie =)

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  • When to use try/catch

    - by coffeeaddict
    I'm always finding myself wanting to put a try/catch around the lets say Business Layer methods. But I feel though that I don't need a try/catch if I'm simply rethrowing it up to the Presentation Layer. Is that right? I should not be rethrowing an exception from code that's wrapped in a try/catch in a BL method and should be letting the caller which would be from the Presentation Layer code be using a try/catch to handle it there? The BL method will throw an error without the try/catch anyway..the compiler will. So it wouldn't make sense to use a try/catch in a BL method that's to be consumed by a layer higher up correct?

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