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• Testing background audio in the simulator

  - by Cactuar

  I'm experimenting with the new background audio service in iPhone OS 4.0 but I can't get it to work in the simulator. According to this page: iPhone Application Programming Guide: Executing Code in the Background it seems that all I have to do is add the a UIBackgroundModes key with an array containing audio to my Info.plist file and the audio my application plays should automatically continue when I switch to another app. I have done this but the audio still pauses as I switch to another app, when I switch back it continues where it left off. This is the code I'm using to play the sound: NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/audio.mp3", [[NSBundle mainBundle] resourcePath]]]; NSError *error; audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error]; audioPlayer.numberOfLoops = -1; if (audioPlayer == nil) NSLog(@"%@", [error userInfo]); else [audioPlayer play]; Has anyone gotten this to work? Could it be that it would work on an actual device and it's just a problem with the simulator? I'm a bit hesitant to install 4.0 on my phone since I've heard it's still very buggy. Wish I had another device to use only for development.

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• MSN Messenger API

  - by MarceloRamires

  back when I was not working with programming (using skills from courses and school) I started developing a simple program that is supposed to get the Artwork of the album to which the song you're currently listening in iTunes to and set it as you Display Picture in MSN Messenger (everything had to be open at the same time). I was so excited about it, made it as nicely as I could back then (now I consider it a design and usability complete fail), and it surprisingly worked. Now, a couple of versions ahead (MSN from 8.5 to 9.0, iTunes from 8 to 9, and windows from Vista to 7) I am getting some incompatibility issues. Where I work, I use Windows 7, Windows Live Messenger 2009 and iTunes 9 - it works just just like before, but at home I have the same exact setup, but something weird happens: When I open the program (having my itunes AND msn open) it doesn't use the active MSN instance, instead it opens a new one, and doesn't work even on this opened one. I've tried it with a couple of libraries: Interop.Messenger.dll - workis like described above Interop.MessengerAPI.dll - works like described above Interop.MessengerPrivate.dll - never worked MSNMessenger.dll - the one I used before - doesn't work anymore at all What could I do ? Info: Visual Studio 2008, .NET 3.5, C#, WinForms application. I'll watch this question and add any information if requested

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• Best Practice for Uploading Many (2000+) Images to A Server

  - by bob

  Hello, I have a general question about this. When you have a gallery, sometimes people need to upload 1000's of images at once. Most likely, it would be done through a .zip file. What is the best way to go about uploading this sort of thing to a server. Many times, server have timeouts etc. that need to be accounted for. I am wondering what kinds of things should I be looking out for and what is the best way to handle a large amount of images being uploaded. I'm guessing that you would allow a user to upload a zip file (assuming the timeout does not effect you), and this zip file is uploaded to a specific directory, lets assume in this case a directory is created for each user in the system. You would then unzip the directory on the server and scan the user's folder for any directories containing .jpg or .png or .gif files (etc.) and then import them into a table accordingly. I'm guessing labeled by folder name. What kind of server side troubles could I run into? I'm aware that there may be many issues. Even general ideas would be could so I can then research further. Thanks! Also, I would be programming in Ruby on Rails but I think this question applies accross any language.

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• one page has more than one url. search engines give penalty please help me out.

  - by Ali Demirtas

  Hi I am using prestashop as the cart for my website. I have a problem; the website used to be in dynamic urls. I enabled friendly url writing. The problem is that one page has more than one url. You can access a same page from the dynamic url and static url. In fact a single page has 9 different urls. This obviously creates problems for seo as search engiones penalize my website for this. What can I do to solve this problem? I have no knowledge of programming. Here is the htaccess for the website. Any sample code or help is really appreciated. URL rewriting module activation RewriteEngine on URL rewriting rules RewriteRule ^([a-z0-9]+)-([a-z0-9]+)(-[_a-zA-Z0-9-]*)/([_a-zA-Z0-9-]*).jpg$ /img/p/$1-$2$3.jpg [L,E] RewriteRule ^([0-9]+)-([0-9]+)/([_a-zA-Z0-9-]*).jpg$ /img/p/$1-$2.jpg [L,E] RewriteRule ^([0-9]+)(-[_a-zA-Z0-9-]*)/([_a-zA-Z0-9-]).jpg$ /img/c/$1$2.jpg [L,E] RewriteRule ^lang-([a-z]{2})/([a-zA-Z0-9-])/([0-9]+)-([a-zA-Z0-9-]).html(.)$ /product.php?id_product=$3&isolang=$1$5 [L,E] RewriteRule ^lang-([a-z]{2})/([0-9]+)-([a-zA-Z0-9-]).html(.)$ /product.php?id_product=$2&isolang=$1$4 [L,E] RewriteRule ^lang-([a-z]{2})/([0-9]+)-([a-zA-Z0-9-])(.)$ /category.php?id_category=$2&isolang=$1 [QSA,L,E] RewriteRule ^([a-zA-Z0-9-])/([0-9]+)-([a-zA-Z0-9-]).html(.*)$ /product.php?id_product=$2$4 [L,E] RewriteRule ^([0-9]+)-([a-zA-Z0-9-]).html(.)$ /product.php?id_product=$1$3 [L,E] RewriteRule ^([0-9]+)-([a-zA-Z0-9-])(.)$ /category.php?id_category=$1 [QSA,L,E] RewriteRule ^content/([0-9]+)-([a-zA-Z0-9-])(.)$ /cms.php?id_cms=$1 [QSA,L,E] RewriteRule ^([0-9]+)__([a-zA-Z0-9-])(.)$ /supplier.php?id_supplier=$1$3 [QSA,L,E] RewriteRule ^([0-9]+)_([a-zA-Z0-9-])(.)$ /manufacturer.php?id_manufacturer=$1$3 [QSA,L,E] RewriteRule ^lang-([a-z]{2})/(.*)$ /$2?isolang=$1 [QSA,L,E] Catch 404 errors ErrorDocument 404 /404.php Options +FollowSymLinks RewriteEngine on RewriteCond %{HTTP_HOST} ^.com [NC] RewriteRule ^(.)$ http://www.*.com/$1 [L,R=301] Options +FollowSymLinks RewriteEngine on index.php to / RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.index.php\ HTTP/ RewriteRule ^(.)index.php$ /$1 [R=301,L] Header set Cache-Control: "no-store, no-cache, must-revalidate, pre-check=0, post-check=0, max-age=0"

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• The Coolest Parts of Windows API

  - by Andreas Rejbrand

  I have noticed that there are quite a few community wikis about "Tips & Tricks" or "Hidden Features" in programming languages and APIs here at Stack Overflow. But I could not find any about my own personal favourites: Win32 API and Delphi. Therefore I start my "own" CW about Win32 API. There are (at least) two kinds of Win API users: those that have been brought up using Windows API in C/C++, and those that have been brought up using some level of abstraction above the Windows API. I belong to the latter category, being brought up using Delphi's VCL. But over the last five years, I have become increasingly interested in the underlaying API of the Windows operating system, and today I work a lot with it. Depending on which category a programmer belongs to, he (or possibly she) will think that different things are "cool" in the Windows API. For instance, whereas a VCL-brought up developer might think it it very cool to var errIcon: HICON; begin errIcon := LoadIcon(0, IDI_ERROR); DrawIcon(Canvas.Handle, 10, 10, errIcon), a programmer brought up using Windows API in C will not be as impressed. But no matter how you are "brought up": what are the coolest "tricks" in Windows API? I start by listing a few of my own favourites, some of which are more "cool" than "useful", though: LoadIcon and MessageBeep can load/play system default icons and sounds. Open the CD tray: mciSendString('Set cdaudio door open wait', nil, 0, 0); Fade out the screen (Windows Vista and later) and turn of the monitor: SendMessage(Application.Handle, WM_SYSCOMMAND, SC_MONITORPOWER, 2); GetWindowDC(GetDesktopWindow) returns the DC of the desktop.

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• Determining failing sectors on portable flash memory

  - by Faxwell Mingleton

  I'm trying to write a program that will detect signs of failure for portable flash memory devices (thumb drives, etc). I have seen tools in the past that are able to detect failing sectors and other kinds of trouble on conventional mechanical hard drives, but I fear that flash memory does not have the same kind of predictable low-level access to the hardware due to the internal workings of the storage. Things like wear-leveling and other block-remapping techniques (to skip over 'dead' sectors?) lead me to believe that determining if a flash drive is failing will be difficult at best, if not impossible (short of having constant read failures and device unmounts). Flash drives at their end-of-life should be easy to detect (constant CRC discrepancies during reads and all-out failure). But what about drives that might be failing early? Are there any tell-tale signs like slower throughput speeds that might indicate a flash drive is going to fail much sooner than normal? Along the lines of detecting potentially bad blocks, I had considered attempting random reads/writes to a file close to or exactly the size of the entire volume, but even then is it possible that the drive might report sizes under its maximum capacity to account for 'dead' blocks? In short, is there any way to circumvent or at least detect (algorithmically or otherwise) the use of block-remapping or other life extension techniques for flash memory? Let me end this question by expressing my uncertainty as to whether or not this belongs on serverfault.com . This is definitely a hardware-related question, but I also desire a software solution - preferably one that I can program myself. If this question is misplaced, I will be happy to migrate it to serverfault - but I do need a programming solution. Please let me know if you need clarification :) Thanks!

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• Java's Scanner class: using left- and right buttons with Bash

  - by Bart K.

  I'm not too familiar with Linux/Bash, so I can't really find the right terms to search for. Take the snippet: public class Main { public static void main(String[] args) { java.util.Scanner keyboard = new java.util.Scanner(System.in); while(true) { System.out.print("$ "); String in = keyboard.nextLine(); if(in.equals("q")) break; System.out.println(" "+in); } } } If I run it on my Linux box using Bash, I can't use any of the arrow buttons (I'm only interested in the left- and right button, btw). For example, if I type "test" and then try to go back by pressing the left button, ^[[D appears instead of my cursor going back one place: $ test^[[D I've tried the newer Console class as well, but the end result is the same. On Windows' cmd.exe shell, I don't have this problem. So, the question is: is there a way to change my Java code so that I can use the arrow keys without Bash transforming them in sequences like ^[[D but actually move the cursor instead? I'm hoping that I can solve this on a "programming level". If this is not possible, then I guess I'd better try my luck on Superuser to see if there's something I need to change on my Bash console. Thanks in advance.

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• Adding database results to array

  - by Jason

  Hi all, I am having a mental blank here and cannot for the life of me figure out a solution. My scenario is that I am programming in PHP and MySQL. I have a database table returning the results for a specific orderid. The query can return a maximum of 4 rows per order and a minimum of 1 row. Here is an image of how I want to return the results. I have all the orderdetails (Name, address) ect stored in a table named "orders". I have all the packages for that order stored in a table named "packages". What I need to do is using a loop I need to have access to each specific element of the database results (IE package1, itemstype1, package2, itemtype2) ect I am using a query like this to try and get hold of just the "number of items: $sql = "SELECT * FROM bookings_onetime_packages WHERE orderid = '".$orderid."' ORDER BY packageid DESC"; $total = $db-database_num_rows($db-database_query($sql)); $query = $db-database_query($sql); $noitems = ''; while($info = $db-database_fetch_assoc($query)){ $numberitems = $info['numberofitems']; for($i=0; $i $noitems .= $numberitems[$i]; } } print $noitems; I need to have access to each specific element because I them need to create fill out a pdf template using "fpdf". I hope this makes sense. Any direction would be greatly appreciated.

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• How can I do batch image processing with ImageJ in Java or clojure?

  - by Robert McIntyre

  I want to use ImageJ to do some processing of several thousand images. Is there a way to take any general imageJ plugin and apply it to hundreds of images automatically? For example, say I want to take my thousand images and apply a polar transformation to each--- A polar transformation plugin for ImageJ can be found here: http://rsbweb.nih.gov/ij/plugins/polar-transformer.html Great! Let's use it. From: [http://albert.rierol.net/imagej_programming_tutorials.html#How%20to%20automate%20an%20ImageJ%20dialog] I find that I can apply a plugin using the following: (defn x-polar [imageP] (let [thread (Thread/currentThread) options ""] (.setName thread "Run$_polar-transform") (Macro/setOptions thread options) (IJ/runPlugIn imageP "Polar_Transformer" ""))) This is good because it suppresses the dialog which would otherwise pop up for every image. But running this always brings up a window containing the transformed image, when what I want is to simply return the transformed image. The stupidest way to do what I want is to just close the window that comes up and return the image which it was displaying. Does what I want but is absolutely retarded: (defn x-polar [imageP] (let [thread (Thread/currentThread) options ""] (.setName thread "Run$_polar-transform") (Macro/setOptions thread options) (IJ/runPlugIn imageP "Polar_Transformer" "") (let [return-image (IJ/getImage)] (.hide return-image) return-image))) I'm obviously missing something about how to use imageJ plugins in a programming context. Does anyone know the right way to do this? Thanks, --Robert McIntyre

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• Do ruby on rails programmers refactor?

  - by JoaoHornburg

  I'm a Java programmer who started programming Ruby on Rails one year ago. I like the language, rails itself and the principles behind them. But something that bothers me is that Ruby programmers don't seem to refactor. I noticed that there is a big lack of tools for refactoring in Ruby / Rails. Some IDE's, like Aptana and RubyMine seem to offer some very basic refactoring, but nothing really big compared to Eclipse's Java refactorings. Then there is another fact: most railers (even the pros) prefer some lightweight editors, like VIM or TextMate, instead of IDEs. Well, with these tools you just get zero refactoring (only regex with find/replace). This leaves me this impression that rails programmers don't refactor. It might be just a false impression, of course, but I would like to hear the opinion of people who work professionally with ruby on rails. Do you refactor? If you do, how do you do it,with which tools? If not, why not?

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• 3n+1 problem at UVa

  - by ShahradR

  Hello, I am having trouble with the first question in the Programming Challenges book by Skiena and Revilla. I keep getting a "Wrong Answer" error message, and I don't know why. I've ran my code against the sample input, and I keep getting the right answer. Anyways, if anyone could help me, I would really appreciate it :) Here is the problem URL: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=29&page=show_problem&problem=36 And here is the code:` import java.util.Scanner; public class Main { static Scanner kb = new Scanner(System.in); public static void main(String[] args) { while (kb.hasNext()) { long[] numericalInput = {0, 0}; long i = kb.nextLong(); long j = kb.nextLong(); if (i > j) { numericalInput[0] = i; numericalInput[1] = j; } else { numericalInput[0] = j; numericalInput[1] = i; } long maxIterations = 0; for (long n = numericalInput[0]; n <= numericalInput[1]; n += 1) { if (maxIterations < returnIterations(n)) maxIterations = returnIterations(n); } System.out.println(i + " " + j + " " + maxIterations); } System.exit(0); } public static long returnIterations(long num) { long iterations = 0; while (num != 1) { if (num % 2 == 0) num = num / 2; else num = 3 * num + 1; iterations += 1; } iterations += 1; return iterations; } } ` EDIT: I think the problem is with the output. I tried to make it accept all the input first and then display all the answers at once, but I didn't know the terminating condition. I resorted to this method, but I'm not sure that's what the judge wants...

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• ASP.NET MVC 2: How to write this Linq SQL as a Dynamic Query (using strings)?

  - by Dr. Zim

  Skip to the "specific question" as needed. Some background: The scenario: I have a set of products with a "drill down" filter (Query Object) populated with DDLs. Each progressive DDL selection will further limit the product list as well as what options are left for the DDLs. For example, selecting a hammer out of tools limits the Product Sizes to only show hammer sizes. Current setup: I created a query object, sent it to a repository, and fed each option to a SQL "table valued function" where null values represent "get all products". I consider this a good effort, but far from DDD acceptable. I want to avoid any "programming" in SQL, hopefully doing everything with a repository. Comments on this topic would be appreciated. Specific question: How would I rewrite this query as a Dynamic Query? A link to something like 101 Linq Examples would be fantastic, but with a Dynamic Query scope. I really want to pass to this method the field in quotes "" for which I want a list of options and how many products have that option. (from p in db.Products group p by p.ProductSize into g select new Category { PropertyType = g.Key, Count = g.Count() }).Distinct(); Each DDL option will have "The selection (21)" where the (21) is the quantity of products that have that attribute. Upon selecting an option, all other remaining DDLs will update with the remaining options and counts.

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• Where to find algorithms for standard math functions?

  - by dsimcha

  I'm looking to submit a patch to the D programming language standard library that will allow much of std.math to be evaluated at compile time using the compile-time function evaluation facilities of the language. Compile-time function evaluation has several limitations, the most important ones being: You can't use assembly language. You can't call C code or code for which the source is otherwise unavailable. Several std.math functions violate these and compile-time versions need to be written. Where can I get information on good algorithms for computing things such as logarithms, exponents, powers, and trig functions? I prefer just high level descriptions of algorithms to actual code, for two reasons: To avoid legal ambiguity and the need to make my code look "different enough" from the source to make sure I own the copyright. I want simple, portable algorithms. I don't care about micro-optimization as long as they're at least asymptotically efficient. Edit: D's compile time function evaluation model allows floating point results computed at compile time to differ from those computed at runtime anyhow, so I don't care if my compile-time algorithms don't give exactly the same result as the runtime version as long as they aren't less accurate to a practically significant extent.

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• manipulating textbox value

  - by chameios

  hello All, I am new to the programming world of dojo and web applications. I am trying to acomplish a task where I want to manipulate the textbox value with some text. I tried everything including some code from dojocampus, but even this code doesnot do anything. I have also tried to create an instance , with dojo.widget.byId and dijit.byId and then tried the instance.value = 'newtext' and everything that I could find but for some reason , the textbox is not updating. Please help me. <html> <head> <title>Dojo example</title> <style type="text/css"> @import "pathtodojo/dijit/themes/nihilo/nihilo.css"; </style> <style type="text/css"> </style> <script type="text/javascript" src="pathtodojo/dojo/dojo.js" djConfig="parseOnLoad:true, isDebug: true"></script> <script> dojo.require("dijit.form.TextBox"); function init() { var box0 = dijit.byId("value0Box"); var box1 = dijit.byId("value1Box"); box1.attr("value", box0.attr("value") + " modified"); dojo.connect(box0, "onChange", function(){ box1.attr("value", box0.attr("value") + " modified"); }); } dojo.addOnLoad(init); </script> <body class="nihilo"> A textbox with a value: <input id="value0Box" dojoType="dijit.form.TextBox" value="Some value" intermediateChanges="true"></input> <br> A textbox set with a value from the above textbox: <input id="value1Box" dojoType="dijit.form.TextBox"></input> <br> </body> </html> regards C

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• Export SWC from Flash and Access Child from Flex

  - by php html

  I'm creating an actionscript project in Flex Builder. I succeed to export from Flash a SWC file, and to use it succesfully in Flex. I have a good programming background and Flex looks very simple for me, but I have difficult times in flash. I'm trying to achieve something that might be very simple(not for me of course): I create a simple shape in Flash, convert it to symbol. Then I create a TextField. The I select both the elements and convert them to another symbol, and Export it as a movieclip in swc. In flex I want to change the value from the textfield. How should I do? I'm trying to do: var t:ExportedMC = new ExportedMC(); t....(what should I write here) As I mentioned when I open flash I feel like an elephant in a porcelain store. I have 2 questions here: - how to assign a name to the textfield in flash? I'm using CS4. - how to access it as a child in flex?

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• Rails : fighting long http response times with ajax. Is it a good idea? Please, help with implementa

  - by baranov

  Hi, everybody! I've googled some tutorials, browsed some SO answers, and was unable to find a recipe for my problem. I'm writing a web site which is supposed to display almost realtime stock chart. Data is stored in constantly updating MySQL database, I wrote a find_by_sql query code which fetches all the data I need to get my chart drawn. Everything is ok, except performance - it takes from one second to one minute for different queries to fetch all the data from the database, this time includes necessary (My)SQL-server side calculations. This is simply unacceptable. I got the following idea: if the data is queried from the MySQL server one point a time instead of entire dataset, it takes only about 1-100ms to get an individual point. I imagine the data fetch process might be browser-driven. After the user presses the button in order to get a chart drawn, controller makes one request to the database and renders, say, a progress bar, say 1% ready. When the browser gets the response, it immediately makes an (ajax) request, and the server fetches the next piece of data and renders "2%". And so on, until all the data is ready and the server displays the requested chart. Could this be implemented in rails+js, is there a tutorial for solving a similar problem on the Web? I suppose if the thing is feasible at all, somebody should have already done this before. I have read several articles about ajax, I believe I do understand general principles, but never did nontrivial ajax programming myself. Thanks for your time!

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• use of assertions for type checking in php?

  - by user151841

  I do some checking of arguments in my classes in php using exception-throwing functions. I have functions that do a basic check ( ===, in_array etc ) and throw an exception on false. So I can do assertNumeric($argument, "\$argument is not numeric."); instead of if ( ! is_numeric($argument) ) { throw new Exception("\$argument is not numeric."); } Saves some typing I was reading in the comments of the php manual page on assert() that As noted on Wikipedia - "assertions are primarily a development tool, they are often disabled when a program is released to the public." and "Assertions should be used to document logically impossible situations and discover programming errors— if the 'impossible' occurs, then something fundamental is clearly wrong. This is distinct from error handling: most error conditions are possible, although some may be extremely unlikely to occur in practice. Using assertions as a general-purpose error handling mechanism is usually unwise: assertions do not allow for graceful recovery from errors, and an assertion failure will often halt the program's execution abruptly. Assertions also do not display a user-friendly error message." This means that the advice given by "gk at proliberty dot com" to force assertions to be enabled, even when they have been disabled manually, goes against best practices of only using them as a development tool So, am I 'doing it wrong'? What other/better ways of doing this are there?

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• Programmatically Add Controls to WPF Form

  - by user210757

  I am trying to add controls to a UserControl dynamically (programatically). I get a generic List of objects from my Business Layer (retrieved from the database), and for each object, I want to add a Label, and a TextBox to the WPF UserControl and set the Position and widths to make look nice, and hopefully take advantage of the WPF Validation capabilities. This is something that would be easy in Windows Forms programming but I'm new to WPF. How do I do this (see comments for questions) Say this is my object: public class Field { public string Name { get; set; } public int Length { get; set; } public bool Required { get; set; } } Then in my WPF UserControl, I'm trying to create a Label and TextBox for each object: public void createControls() { List<Field> fields = businessObj.getFields(); Label label = null; TextBox textbox = null; foreach (Field field in fields) { label = new TextBox(); // HOW TO set text, x and y (margin), width, validation based upon object? // i have tried this without luck: // Binding b = new Binding("Name"); // BindingOperations.SetBinding(label, Label.ContentProperty, b); MyGrid.Children.Add(label); textbox = new TextBox(); // ??? MyGrid.Children.Add(textbox); } // databind? this.DataContext = fields; }

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• How can I create my own form designer?

  - by Carson Myers

  I'm starting my first C# project, and I want to make a "form designer" (like the one in VS). The idea is, there will be a visual form designer with a limited toolbox, which will generate Python code (later more) to create the same form. Problem is, I have no idea how to even get started. First of all, I have the form designer in VS: how do I make a "form-within-a-form?" Next... I have no idea how complicated this is going to be. I suppose I could just make little boxes appear beside each control created on the form when it is clicked, for resizing, and make a textbox appear on it when double clicked or something, to change the text in it... Things like this. So another thing I would like to know is this: I do have programming experience in C and C++, I've done PHP for a number of years and am starting with Python as of recently. I've generated forms dynamically in VB6. Given this experience, am I in way over my head with this project?

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• Which languages support *recursive* function literals / anonymous functions?

  - by Hugh Allen

  It seems quite a few mainstream languages support function literals these days. They are also called anonymous functions, but I don't care if they have a name. The important thing is that a function literal is an expression which yields a function which hasn't already been defined elsewhere, so for example in C, &printf doesn't count. EDIT to add: if you have a genuine function literal expression <exp>, you should be able to pass it to a function f(<exp>) or immediately apply it to an argument, ie. <exp>(5). I'm curious which languages let you write function literals which are recursive. Wikipedia's "anonymous recursion" article doesn't give any programming examples. Let's use the recursive factorial function as the example. Here are the ones I know: JavaScript / ECMAScript can do it with callee: function(n){if (n<2) {return 1;} else {return n * arguments.callee(n-1);}} it's easy in languages with letrec, eg Haskell (which calls it let): let fac x = if x<2 then 1 else fac (x-1) * x in fac and there are equivalents in Lisp and Scheme. Note that the binding of fac is local to the expression, so the whole expression is in fact an anonymous function. Are there any others?

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• SQL View with Data from two tables

  - by Alex

  Hello! I can't seem to crack this - I have two tables (Persons and Companies), and I'm trying to create a view that: 1) shows all persons 2) also returns companies by themselves once, regardless of how many persons are related to it 3) orders by name across both tables To clarify, some sample data: (Table: Companies) Id Name 1 Banana 2 ABC Inc. 3 Microsoft 4 Bigwig (Table: Persons) Id Name RelatedCompanyId 1 Joe Smith 3 2 Justin 3 Paul Rudd 4 4 Anjolie 5 Dustin 4 The output I'm looking for is something like this: Name PersonName CompanyName RelatedCompanyId ABC Inc. NULL ABC Inc. NULL Anjolie Anjolie NULL NULL Banana NULL Banana NULL Bigwig NULL Bigwig NULL Dustin Dustin Bigwig 4 Joe Smith Joe Smith Microsoft 3 Justin Justin NULL NULL Microsoft NULL Microsoft NULL Paul Rudd Paul Rudd Bigwig 4 As you can see, the new "Name" column is ordered across both tables (the company names appear correctly in between the person names), and each company appears exactly once, regardless of how many people are related to it. Can this even be done in SQL?! P.S. I'm trying to create a view so I can use this later for easy data retrieval, fulltext indexing and make the programming side simpler by just querying the view.

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• Windows console

  - by b-gen-jack-o-neill

  Hello. Well, I have a simple question, at least I hope its simple. I was interested in win32 console for a while. Our teacher told us, that windows console is just for DOS and real mode emulation purposes. Well, I know it is not true, becouse DOS applications are runned by emulator which only uses console to display output. Another thing I learned is that console is built into Windows since NT. Well. But what I could not find is, how actually are console programs written to use console. I use Visual C++ for programming (well, for learning). So, the only thing I need to do for using console is select console project. I first thought that windows decides wheather it run app in console or tries to run app in window mode. So I created win32 program and tried printf(). Well, I could not compile it. I know that by definition printf() prints text or variables to stdout. I also found that stdout is the console interface for output. But, I could not find what actually stdout is. So, basicly what I want to ask is, where is the difference between console app and win32 app. I thought that windows starts console when it gets command from "console-family" functions. But obvisously it does not, so there must be some code that actually commands windows to create console interface. And the second question is, when the console is created, how does windows recognize which console terminal is used for what app? I mean, what actually is stdout? Is it a area in memory , or some windows routine that is called? Thanks.

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• Solving problems involving more complex data structures with CUDA

  - by Nils

  So I read a bit about CUDA and GPU programming. I noticed a few things such that access to global memory is slow (therefore shared memory should be used) and that the execution path of threads in a warp should not diverge. I also looked at the (dense) matrix multiplication example, described in the programmers manual and the nbody problem. And the trick with the implementation seems to be the same: Arrange the calculation in a grid (which it already is in case of the matrix mul); then subdivide the grid into smaller tiles; fetch the tiles into shared memory and let the threads calculate as long as possible, until it needs to reload data from the global memory into shared memory. In case of the nbody problem the calculation for each body-body interaction is exactly the same (page 682): bodyBodyInteraction(float4 bi, float4 bj, float3 ai) It takes two bodies and an acceleration vectors. The body vector has four components it's position and the weight. When reading the paper, the calculation is understood easily. But what is if we have a more complex object, with a dynamic data structure? For now just assume that we have an object (similar to the body object presented in the paper) which has a list of other objects attached and the number of objects attached is different in each thread. How could I implement that without having the execution paths of the threads to diverge? I'm also looking for literature which explains how different algorithms involving more complex data structures can be effectively implemented in CUDA.

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• Returning from dll (Asynchronous sockets)

  - by Juha

  I am trying to do a simple http-server in (c++) dll-file that I can use from managed (C#) application with P/Invoke. I was trying to do this with asynchronous functions (WSAAsyncSelect() and stuff), so that I could manage server by calling functions inside dll whenever needed and after that it would return to my main program. Now I'm not sure if that is even possible. It seems that "main function" in dll, the function that starts the server, has to include message loop or something and since it's a loop, it doesn't return from dll ever. Could I somehow do this message stuff in my managed application and call some function in dll when there is something to do? Or is it even possible to do this stuff in one thred? I would really like to avoid all concurrency stuff. The dll looks now basicly the same as here, main function is the one that I call from managed C# program and would like to return to there after calling the function. http://www.winsocketdotnetworkprogramming.com/winsock2programming/winsock2advancediomethod5b.html I'm quite noob in windows programming, and never even heard of this message-queue or message-loop.

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• Redirect C++ std::clog to syslog on Unix

  - by kriss

  I work on Unix on a C++ program that send messages to syslog. The current code uses the syslog system call that works like printf. Now I would prefer to use a stream for that purpose instead, typically the built-in std::clog. But clog merely redirect output to stderr, not to syslog and that is useless for me as I also use stderr and stdout for other purposes. I've seen in another answer that it's quite easy to redirect it to a file using rdbuf() but I see no way to apply that method to call syslog as openlog does not return a file handler I could use to tie a stream on it. Is there another method to do that ? (looks pretty basic for unix programming) ? Edit: I'm looking for a solution that does not use external library. What @Chris is proposing could be a good start but is still a bit vague to become the accepted answer. Edit: using Boost.IOStreams is OK as my project already use Boost anyway. Linking with external library is possible but is also a concern as it's GPL code. Dependencies are also a burden as they may conflict with other components, not be available on my Linux distribution, introduce third-party bugs, etc. If this is the only solution I may consider completely avoiding streams... (a pity).

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