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  • How do I remove (or apply) transparency on a gdk-pixbuf?

    - by Andrew Stacey
    I have a c++ program in which a gdk-pixbuf is created. I want to output it as an image, so I call gdk_pixbuf_save_to_stream(pixbuf,stream,type,NULL,&err,NULL). This works fine when "type" is png or tiff, but with jpeg or bmp it just produces a black square. The original pixbuf consists of black-on-transparent (and gdk_pixbuf_get_has_alpha returns true) so I'm guessing that the problem is with the alpha mask. GdkPixbuf has a function to add an alpha channel, but I can't see one that removes it again, or (which might be as good) to invert it. Is there a simple way to get the jpeg and bmp formats to work properly? (I should say that I'm very new to proper programming like this.)

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  • What language is to binary, as Perl is to text?

    - by ehdr
    I am looking for a scripting (or higher level programming) language (or e.g. modules for Python or similar languages) for effortlessly analyzing and manipulating binary data in files (e.g. core dumps), much like Perl allows manipulating text files very smoothly. Things I want to do include presenting arbitrary chunks of the data in various forms (binary, decimal, hex), convert data from one endianess to another, etc. That is, things you normally would use C or assembly for, but I'm looking for a language which allows for writing tiny pieces of code for highly specific, one-time purposes very quickly. Any suggestions?

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  • Questions every good Java/J2EE Developer should be able to answer?

    - by Rachel
    I was going through Questions every good .Net developer should be able to answer and was highly impressed with the content and approach of this question, and so in the same spirit, I am asking this question for Java/J2EE Developer. What questions do you think should a good Java/J2EE programmer be able to answer? I am marking this question as community wiki as it is not user specific and it aims to serve programming community at large. Looking forward for some amazing responses. EDIT: Please answer questions too, as suggested in the comments, so that people could learn something new regarding the language, too.

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  • Smartest way to draw 100+ images on screen

    - by Henrik
    Hello all, First of all I'm a newbie when it comes to Android programming. So if this question is totally stupid please delete it ASAP :-). Question: I'm going to draw a grid of 10x10 PNG images. Each image is 32x32 px. All of the images are unique. I'm thinking that the easiest way seems to be to put each image in an ImageView. If adding all ImageView's to the layout would this give me some kind of performance hit? Would there be any smarter way to draw these images? Thanks. / Henrik

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  • Controlling the laziest common denominator

    - by bobobobo
    This is a programming-related question in that it has to do with combatting the laziest common denominator in a start-up like team. Some devs are driven. They wanna do stuff. They wanna build feature after feature. They wanna do it all. Others are.. lazy. And in every team there's someone who is the laziest. Some lazy people though have an influence on the others.. by their behavior and words, they actually make other people wanna do less. You can't always get rid of these people. But you need to control it. How?

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  • Referring to the type of an inner class in Scala

    - by saucisson
    The following code tries to mimic Polymorphic Embedding of DSLs: rather than giving the behavior in Inner, it is encoded in the useInner method of its enclosing class. I added the enclosing method so that user has only to keep a reference to Inner instances, but can always get their enclosing instance. By doing this, all Inner instances from a specific Outer instance are bound to only one behavior (but it is wanted here). abstract class Outer { sealed class Inner { def enclosing = Outer.this } def useInner(x:Inner) : Boolean } def toBoolean(x:Outer#Inner) : Boolean = x.enclosing.useInner(x) It does not compile and scala 2.8 complains about: type mismatch; found: sandbox.Outer#Inner required: _81.Inner where val _81:sandbox.Outer From Programming Scala: Nested classes and A Tour of Scala: Inner Classes, it seems to me that the problem is that useInnerexpects as argument an Inner instance from a specific Outer instance. What is the true explanation and how to solve this problem ?

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  • Why isn't wchar_t widely used in code for Linux / related platforms?

    - by Ninefingers
    This intrigues me, so I'm going to ask - for what reason is wchar_t not used so widely on Linux/Linux-like systems as it is on Windows? Specifically, the Windows API uses wchar_t internally whereas I believe Linux does not and this is reflected in a number of open source packages using char types. My understanding is that given a character c which requires multiple bytes to represent it, then in a char[] form c is split over several parts of char* whereas it forms a single unit in wchar_t[]. Is it not easier, then, to use wchar_t always? Have I missed a technical reason that negates this difference? Or is it just an adoption problem?

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  • using bash: write bit representation of integer to file

    - by theseion
    Hullo First, I want to use bash for this and the script should run on as many systems as possible (I don't know if the target system will have python or whatever installed). Here's the problem: I have a file with binary data and I need to replace a few bytes in a certain position. I've come up with the following to direct bash to the offset and show me that it found the place I want: dd bs=1 if=file iseek=24 conv=block cbs=2 | hexdump Now, to use "file" as the output: echo anInteger | dd bs=1 of=hextest.txt oseek=24 conv=block cbs=2 This seems to work just fine, I can review the changes made in a hex editor. Problem is, "anInteger" will be written as the ASCII representation of that integer (which makes sense) but I need to write the binary representation. How do I tell the command to convert the input to binary (possibly from a hex)?

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  • Can a grails controller extend from a base class? How to make it so grails doesn't blow up?

    - by egervari
    I wrote a base class to help build my controllers more quickly and to remove duplication. It provides some helper methods, default actions and some meta programming to make these things easier to build. One of those methods in the base class is like this: def dynamicList(Class clazz) { def model = new LinkedHashMap() model[getMapString(clazz) + "s"] = list(clazz) model[getMapString(clazz) + "sTotal"] = count(clazz) model } The action that calls it, also in the base class, is this: def list = { dynamicList(clazz) } Unfortunately, when I go to list action in the controller subclass that inherits the base class when my application is deployed, I get this exception: groovy.lang.MissingMethodException: No signature of method: groovy.lang.MissingMethodException.dynamicList() is applicable for argument types: (java.lang.Class) values: [class project .user.User] at project.user.UserController$_closure1.doCall(UserController.groovy:18) at project.user.UserController$_closure1.doCall(UserController.groovy) at java.lang.Thread.run(Thread.java:619) How can I hit grails over the head and just tell it do what I want it to do? My controller unit tests run just fine, so grails' run-time is totally at fault :/ Ken

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  • Static libraries, dynamic libraries, DLLs, entry points, headers ... how to get out of this alive?

    - by tunnuz
    Hello, I recently had to program C++ under Windows for an University project, and I'm pretty confused about static and dynamic libraries system, what the compiler needs, what the linker needs, how to build a library ... is there any good document about this out there? I'm pretty confused about the *nix library system as well (so, dylibs, the ar tool, how to compile them ...), can you point a review document about the current library techniques on the various architectures? Note: due to my poor knowledge this message could contain wrong concepts, feel free to edit it. Thank you Feel free to add more reference, I will add them to the summary. References Since most of you posted *nix or Windows specific references I will summarize here the best ones, I will mark as accepted answer the Wikipedia one, because is a good start point (and has references inside too) to get introduced to this stuff. Program Library Howto (Unix) Dynamic-Link Libraries (from MSDN) (Windows) DLL Information (StackOverflow) (Windows) Programming in C (Unix) An Overview of Compiling and Linking (Windows)

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  • Syncing an iPod or iPhone with Cocoa

    - by Koning Baard XIV
    I'm creating an iTunes clone in Cocoa (don't ask why, it's not evil) and I want to be able to sync my iPod with it. This means: music, photos, videos and podcasts. I couldn't really find anything, since Google only shows articles about iPod touch and iPhone programming, but I'm actually creating a desktop application for Mac OS X, and I also want to be able to sync click-wheel iPods. Is there an API or should I read and write directly to the USB port? Can anyone help me? Thanks

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  • GDI fast scroll

    - by genesys
    Hi! I use GDI to create some custom textwidget. I draw directly to the screen, unbuffered. now i'd like to implement some fast scrolling, that simply pixelshifts the respective part of the framebuffer (and only redraws the newly visible lines). I noticed that for example the rich text controls does it like this. If i use some GDI drawing functions to directly draw to the framebuffer, over a rich text control, and then scroll the rich text, it will also scroll my drawing along with the text. so i assume the rich text simply pixelshifts it's part of the framebuffer. I'd like to do the same, but don't know how to do so. Can someone help? (independant of programming language)) thanks!

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  • Python: undefined reference to `_imp __Py_InitModule4'

    - by Mark
    I'm trying to do a debug build of the Rabbyt library using mingw's gcc to run with my MSVC built python26_d.. I got a lot of undefined references which caused me to create libpython26_d.a, however one of the undefined references remains. Googling gives me: http://www.techlists.org/archives/programming/pythonlist/2003-03/msg01035.shtml But -rdynamic doesn't help. e:\MinGW/bin\gcc.exe -mno-cygwin -mdll -O -Wall -g -IE:\code\python\python\py26\ include -IE:\code\python\python\py26\PC -c rabbyt/rabbyt._rabbyt.c -o build\temp .win32-2.6-pydebug\Debug\rabbyt\rabbyt._rabbyt.o -O3 -fno-strict-aliasing rabbyt/rabbyt._rabbyt.c:1351: warning: '__Pyx_SetItemInt' defined but not used writing build\temp.win32-2.6-pydebug\Debug\rabbyt\_rabbyt_d.def e:\MinGW/bin\gcc.exe -mno-cygwin -shared -g build\temp.win32-2.6-pydebug\Debug\r abbyt\rabbyt._rabbyt.o build\temp.win32-2.6-pydebug\Debug\rabbyt\_rabbyt_d.def - LE:\code\python\python\py26\libs -LE:\code\python\python\py26\PCbuild -lopengl32 -lglu32 -lpython26_d -lmsvcr90 -o build\lib.win32-2.6-pydebug\rabbyt\_rabbyt_d. pyd build\temp.win32-2.6-pydebug\Debug\rabbyt\rabbyt._rabbyt.o: In function `init_ra bbyt': E:/code/python/rabbyt/rabbyt/rabbyt._rabbyt.c:1121: undefined reference to `_imp __Py_InitModule4'

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  • What happens with TCP packets between two Socket.BeginReceive calls?

    - by Rodrigo
    I have a doubt about socket programming. I am developing a TCP packet sniffer. I am using Socket.BeginAccept, Socket.BeginReceive to capture every packet, but when a packet is received I have to process something. It is a fast operation, but would take some milliseconds, and then call BeginReceive again. My question is, what would happen if some packets are sent while I am processing, and haven't called BeginReceive? Are packets lost, or are they buffered internally? Is there a limit?

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  • File Access problems with SLES 10 SP2 OES2 SP1

    - by Blackhawk131
    We have identified a couple of repeatable, demonstrable scenarios with unexplained rejected folder access on our servers for Mac users. Hopefully, this can be presented to Novell for a solution. What we did to demonstrate scenario 1; 1. setup a PC and Mac side-by-side 2. login to our server and open up to a central location on both Mac and PC 3. on the PC in that central location create a folder 4. on the Mac in that central location drag the created folder to the Mac desktop, this should work fine, no problem 5. on the PC rename that folder 6. on the Mac drag a file to that renamed folder, this should error with the following message; a. You cannot copy some of these items to the destination because their names are too long for the destination. Do you want to skip copying these items and continue copying the other items? b. Select skip, response is the filename is copied to the location with zero or small byte size. Try opening it and you get file is corrupted error message. What we did to demonstrate scenario 2; 1. setup a PC and Mac side-by-side 2. login to our server and open up to a central location on both Mac and PC 3. on the PC in that central location create a folder then create a subfolder 4. copy some content into the subfolder 5. on the Mac in that central location drag the created top level folder to the Mac desktop, this should work fine, no problem 6. on the PC rename that subfolder 7. on the Mac drag that top level folder to the Mac desktop, this should error on the Mac with the following; a. The operation cannot be completed because you do not have sufficient privileges for b. The operation cannot be completed because you do not have sufficient privileges for 8. on the Mac, if you open that subfolder you can see the file copied in step 4 above but, you can not open that file, you get the following message if you try; a. There was an error opening this document. You do not have permission to open this file. 9. on the PC drag some content into the top level folder 10. on the Mac you can open that file directly from the server or copy it locally, no problem, however-the subfolder is still corrupted or locked, whichever 11. on the PC rename the top level folder 12. on the Mac that same file just opened in step 10 above is now not accessible, get the following message; a. The document could not be opened. I have observed some variances in the above. For instance, a change on the PC side may take a moment before you can observer or act on the Mac side - kind of like the server is slow to respond. Also, the error message may vary. However, the key is once a folder, or subfolder, gets renamed by a PC, Mac problems commence. The solution is to create a new folder from a PC and copy the contents of the corrupted folder to the new folder and not rename the folder name. This has to be done on a PC because the corrupted folder is not accessible by a Mac user. Another problem that dovetails with the above is that we know certain characters are not allowed for PC folder or filenames. If a Mac user creates a folder with a slash in the file name, from the PC the user does not see that slash in the name. As soon as the PC user copies a file to that folder, the Mac user is locked from that folder. Will get the following error message; - Sorry, the operation could not be completed because an unexpected error occurred. - (Error code - 50) In addition to the above mentioned character issue with folders, the problem is more evil with filenames. If, for example, you create a file with a slash in the filename on a Mac and copy it to the server you will get the following error message; - You cannot copy some of these items to the destination because their names are too long for the destination. Do you want to skip copying these items and continue copying the other items? Select either Stop or Skip buttons. It does not matter which button is selected. The file name gets copied to the destination location at a reduced size. Depending on the file type, the icon associated with the file may or may not be present. Furthermore, if you open that file on the server you will get the following message; - Couldnt open the file. It may be corrupt or a file format that doesnt recognize. From the users perspective, if they are not observant of the icon or file size, they may disregard the error message and think their file has copied as intended. Only later do they discover the file is corrupt if they open that file. I want to make a note on this problem. It is the PC causing the issue. You can change folder and file names all day on a MAC and you don't have a problem as long as a character is not the issue. Once you change the file name or folder name from a PC the entire folder structure from that level down is corrupted. But it has to be resolved from a PC by creating a new folder and copying the contents to the new folder like stated above. Is something not configured correctly? SUSE Linux Enterprise Server 10 (x86_64) VERSION = 10 PATCHLEVEL = 2 LSB_VERSION="core-2.0-noarch:core-3.0-noarch:core-2.0-x86_64:core-3.0-x86_64" Novell Open Enterprise Server 2.0.1 (x86_64) VERSION = 2.0.1 PATCHLEVEL = 1 BUILD Note: We use Novell clients on all windows systems to connect to the servers for file access and network storage. We use AFP to allow OSx systems to connect to servers.

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  • Overview of PHP shorthand

    - by James Simpson
    I've been programming in PHP for years now, but I've never learned how to use any shorthand. I come across it from time to time in code and have a hard time reading it, so I'd like to learn the different shorthand that exists for the language sot hat I can read it and start saving time/lines by using it, but I can't seem to find a comprehensive overview of all of the shorthand. A Google search pretty much exclusively shows the shorthand for if/else statements, but I know there must be more than just that. By shorthand, I am talking about stuff like: ($var) ? true : false;

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  • iphone memory leaks and malloc?

    - by Brodie4598
    Okay so im finally to the point where I am testing my iPad App on an actual iPad... One thing that my app does is display a large (2mb) image in a scroll view. This is causing the iPad to get memory warnings. I run the app in the instruments to check for the leak. When I load the image, a leak is detected and i see the following in the allocations: ALl Allocations: 83.9 MB Malloc 48.55 MB: 48.55 MB Malloc 34.63 MB: 34.63 MB What im trying to understand is how to plug the leak obviously, but also why a 2MB image is causing a malloc of 20x that size I am very new to programming in obj-c so im sure this is an obvious thing, but I just cant figure it out. Here is the code:

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  • Ios Parse Login

    - by user3806600
    I am programming an IOS app that will use parse to login a user. Using storyboard I have the login button connected to another view controller with the push segue. Whether the username and password are correct the button selection always goes to the new view controller. I might be doing this all wrong. Any help is appreciated. Here is my code: - (IBAction)signIn:(id)sender { [PFUser logInWithUsernameInBackground:self.emailField.text password:self.passwordField.text block:^(PFUser *user, NSError *error) { if (!error) { [self performSegueWithIdentifier:@"signIn" sender:nil]; } else { // The login failed. Check error to see why. } }]; }

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  • How does memory management in Java and C# differ?

    - by David Johnstone
    I was reading through 2010 CWE/SANS Top 25 Most Dangerous Programming Errors and one of the entries is for Buffer Copy without Checking Size of Input. It suggests using a language with features to prevent or mitigate this problem, and says: For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. I was not aware that Java and C# differed in any meaningful way with regard to memory management. How is it that Java is not subject to buffer overflows, while C# only protects against overflows? And how is it possible to disable this protection in C#?

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  • Noob Rails ? about learning Rails

    - by user271916
    Hi All I have been programming for a while and for the past 3 or 4 months have been learning ruby. I am not an expert by any means but I believe I have the basics down. I decided to start learning RoR and bought the "Agile Web Development with Rails 3rd Edition" and have been dutifully going through the chapters one by one. Currently I am in chapter 8 and have had no problems so far. My question is I know I have learned several things so far and I know that I am starting to get a sense of the Rails framework I have this fear that I am just not learning as much as I should. Some things I get and understand the interconnections while I feel on other things I am just going through the motions and don't fully comprehend the total interconnectivity. Now, there is still a large amount of the book for me to complete. I guess I am just wondering if I complete this book what should I expect to be able to accomplish on my own and what should be my next steps. Thanks

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  • Listing time every second as a Bash script

    - by Caleb
    Hello all, first time here as I've finally started to learn programming. Anyway, I'm just trying to print the time in nanoseconds every second here, and I have this: #!/usr/bin/env bash while true; do date=(date +%N) ; echo $date ; sleep 1 ; done Now, that simply yields a string of date's, which isn't what I want. My learning has been rather messy, so I hope you'll excuse me for this if it's really simple. Also, I did manage to fine this, that worked on the prompt: while true ; do date +%N ; sleep 1 ; done But that obviously doesn't work as a script.

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  • c# resize window over display resolution

    - by Sebastian
    I am total newbie in .Net programming so be patient, please ;-). I have problem with resizing window. I want to resize from my app other app's window and take screenshot of it. I do resizing based on this example: http://blogs.geekdojo.net/richard/archive/2003/09/24/181.aspx. But I have a problem. I work on a laptop with 1024x640 pixels screen resolution but I want to resize my window to 1200x1600 px. I can't do that couse display limitations. Is there any tricky solution to resize window for this resolution and take a screenshot of whole window? I've alos tried Sdesk program witch is suggested here: http://stackoverflow.com/questions/445893/create-window-larger-than-desktop-display-resolution. Any help?

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  • Namespace Autoload works under windows, but not on Linux

    - by EvilChookie
    I have the following php code: index.php <?php spl_autoload_extensions(".php"); spl_autoload_register(); use modules\standard as std; $handler = new std\handler(); $handler->delegate(); ?> modules\standard\handler.php <?php namespace modules\standard { class handler { function delegate(){ echo 'Hello from delegation!'; } } } ?> Under Windows 7, running WAMP, the code produces the message "Hello from Delegation!" however under Linux, I get the following: Fatal error: spl_autoload(): Class modules\standard\handler could not be loaded in /var/www/index.php on line 15 Windows is running PHP 5.3.0 under WAMP, and Linux is running the 5.3.2 dotdeb package under Ubuntu 9.10. Is this a configuration issue on my linux box, or just a difference in the way namespaces and autoloading is handled on the different operating systems

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  • A web framework where AJAX was not an after thought

    - by Pirate for Profit
    AJAX is a pain in the ass because it essentially means you'll have to write two sets of similarish code: one for browsers with JavaScript enabled and those without. Not only this, but you have to connect JavaScript events to hook into your models and display the results. And if all that weren't bad enough, you need to send an address change with the request, otherwise the user won't be able to "click back" correctly (if confused look at what happens to the address bar when you click links in GMail). We're searching for something that had the foresight and design goals with all these concerns in mind. Performance and security are also obvious major concerns. We love config-based systems as well, where you don't have to write a lot of code you just drop it into an easily read config format. It's like asking for the holy grail right?

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  • Advantage of using Thread.Start vs QueueUserWorkItem

    - by Cheeso
    In multithreaded .NET programming, what are the decision criteria for using ThreadPool.QueueUserWorkItem versus starting my own thread via new Thread() and Thread.Start()? In a server app (let's say, an ASP.NET app or a WCF service) I think the ThreadPool is always there and available. What about in a client app, like a WinForms or WPF app? Is there a cost to spin up the thread pool? If I just want 3 or 4 threads to work for a short period on some computation, is it better to QUWI or to Thread.Start().

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