Search Results

Search found 9095 results on 364 pages for 'nonlinear functions'.

Page 276/364 | < Previous Page | 272 273 274 275 276 277 278 279 280 281 282 283  | Next Page >

• Things one needs to know while writing a game engine

  - by Joe Barr

  I have been dabbling in game development as a hobby for a while now, and I cannot seam to quite get my games to sparkle at least a bit with some graphics. I have decided to write a simple test game engine that only focuses on the representation of graphics - shapes, textures and surfaces. While I have a few very simple game engines designed for my own games under my belt, I want to create a game engine that I can use to display and play with graphics. I'm going to do this in C++. Since this is my first time with a major engine, the engine in not going to focus on 3D graphics, it's going to be a mixture of isometric and 2D graphics. My previous engines have incorporated (been able to draw) or focused on simple flat (almost 2D) non impressive graphic designs and representations of: the player NPCs objects walls and surfaces textures Also, I had some basic AI and sometimes even sound. They also saved and loaded games. They didn't have a map editor or a level editor. Is this going to be a problem in the future? At this time I have to point out that some of my games didn't get finished because I was to lazy to write the few last levels. My question at this point would be: What are some things one should know if one wants write (develope) a better graphical game engine with all it's functions.

  Read the article

• How do you capture a group with regex?

  - by Sylvain

  Hi, I'm trying to extract a string from another using regex. I'm using the POSIX regex functions (regcomp, regexec ...), and I fail at capturing a group ... For instance, let the pattern be something as simple as "MAIL FROM:<(.*)>" (with REG_EXTENDED cflags) I want to capture everything between '<' and '' My problem is that regmatch_t gives me the boundaries of the whole pattern (MAIL FROM:<...) instead of just what's between the parenthesis ... What am I missing ? Thanks in advance, edit: some code #define SENDER_REGEX "MAIL FROM:<(.*)>" int main(int ac, char **av) { regex_t regex; int status; regmatch_t pmatch[1]; if (regcomp(&regex, SENDER_REGEX, REG_ICASE|REG_EXTENDED) != 0) printf("regcomp error\n"); status = regexec(&regex, av[1], 1, pmatch, 0); regfree(&regex); if (!status) printf( "matched from %d (%c) to %d (%c)\n" , pmatch[0].rm_so , av[1][pmatch[0].rm_so] , pmatch[0].rm_eo , av[1][pmatch[0].rm_eo] ); return (0); } outputs: $./a.out "012345MAIL FROM:<abcd>$" matched from 6 (M) to 22 ($) solution: as RarrRarrRarr said, the indices are indeed in pmatch[1].rm_so and pmatch[1].rm_eo hence regmatch_t pmatch[1]; becomes regmatch_t pmatch[2]; and regexec(&regex, av[1], 1, pmatch, 0); becomes regexec(&regex, av[1], 2, pmatch, 0); Thanks :)

  Read the article

• How do you pass .net objects values around in F#?

  - by Russell

  I am currently learning F# and functional programming in general (from a C# background) and I have a question about using .net CLR objects during my processing. The best way to describe my problem will be to give an example: let xml = new XmlDocument() |> fun doc -> doc.Load("report.xml"); doc let xsl = new XslCompiledTransform() |> fun doc -> doc.Load("report.xsl"); doc let transformedXml = new MemoryStream() |> fun mem -> xsl.Transform(xml.CreateNavigator(), null, mem); mem This code transforms an XML document with an XSLT document using .net objects. Note XslCompiledTransform.Load works on an object, and returns void. Also the XslCompiledTransform.Transform requires a memorystream object and returns void. The above strategy used is to add the object at the end (the ; mem) to return a value and make functional programming work. When we want to do this one after another we have a function on each line with a return value at the end: let myFunc = new XmlDocument("doc") |> fun a -> a.Load("report.xml"); a |> fun a -> a.AppendChild(new XmlElement("Happy")); a Is there a more correct way (in terms of functional programming) to handle .net objects and objects that were created in a more OO environment? The way I returned the value at the end then had inline functions everywhere feels a bit like a hack and not the correct way to do this. Any help is greatly appreciated!

  Read the article

• realloc() & ARC

  - by RynoB

  How would I be able to rewrite the the following utility class to get all the class string values for a specific type - using the objective-c runtime functions as shown below? The ARC documentation specifically states that realloc should be avoided and I also get the following compiler error on this this line: classList = realloc(classList, sizeof(Class) * numClasses); "Implicit conversion of a non-Objective-C pointer type 'void *' to '__unsafe_unretained Class *' is disallowed with ARC" The the below code is a reference to the original article which can be found here. + (NSArray *)classStringsForClassesOfType:(Class)filterType { int numClasses = 0, newNumClasses = objc_getClassList(NULL, 0); Class *classList = NULL; while (numClasses < newNumClasses) { numClasses = newNumClasses; classList = realloc(classList, sizeof(Class) * numClasses); newNumClasses = objc_getClassList(classList, numClasses); } NSMutableArray *classesArray = [NSMutableArray array]; for (int i = 0; i < numClasses; i++) { Class superClass = classList[i]; do { superClass = class_getSuperclass(superClass); if (superClass == filterType) { [classesArray addObject:NSStringFromClass(classList[i])]; break; } } while (superClass); } free(classList); return classesArray; } Your help will be much appreciated. Thanks

  Read the article

• Delegate within a delegate in VB.NET.

  - by Topdown

  I am trying to write a VB.NET alternative to a C# anonymous function. I wish to call Threading.SynchronizationContext.Current.Send which expects a delegate of type Threading.SendOrPostCallback to be passed to it. The background is here, but because I wish to both pass in a string to MessageBox.Show and also capture the DialogResult I need to define another delegate within. I am struggling with the VB.NET syntax, both from the traditional delegate style, and lambda functions. My go at the traditional syntax is below, but I have gut feeling it should be much simpler than this: Private Sub CollectMesssageBoxResultFromUserAsDelegate(ByVal messageToShow As String, ByRef wasCanceled As Boolean) wasCanceled = False If Windows.Forms.MessageBox.Show(String.Format("{0}{1}Please press [OK] to ignore this error and continue, or [Cancel] to stop here.", messageToShow), "Continue", Windows.Forms.MessageBoxButtons.OKCancel, Windows.Forms.MessageBoxIcon.Exclamation) = Windows.Forms.DialogResult.Cancel Then wasCanceled = True End If End Sub Private Delegate Sub ShowMessageBox(ByVal messageToShow As String, ByRef canceled As Boolean) Private Sub AskUserWhetherToCancel(ByVal message As String, ByVal args As CancelEventArgs) If args Is Nothing Then args = New System.ComponentModel.CancelEventArgs With {.Cancel = False} Dim wasCancelClicked As Boolean Dim firstDelegate As New ShowMessageBox(AddressOf CollectMesssageBoxResultFromUserAsDelegate) '…. Now what?? 'I can’t declare SendOrPostCallback as below: 'Dim myDelegate As New Threading.SendOrPostCallback(AddressOf firstDelegate) End Sub

  Read the article

• How can I write reusable Javascript?

  - by RenderIn

  I've started to wrap my functions inside of Objects, e.g.: var Search = { carSearch: function(color) { }, peopleSearch: function(name) { }, ... } This helps a lot with readability, but I continue to have issues with reusabilty. To be more specific, the difficulty is in two areas: Receiving parameters. A lot of times I will have a search screen with multiple input fields and a button that calls the javascript search function. I have to either put a bunch of code in the onclick of the button to retrieve and then martial the values from the input fields into the function call, or I have to hardcode the HTML input field names/IDs so that I can subsequently retrieve them with Javascript. The solution I've settled on for this is to pass the field names/IDs into the function, which it then uses to retrieve the values from the input fields. This is simple but really seems improper. Returning values. The effect of most Javascript calls tends to be one in which some visual on the screen changes directly, or as a result of another action performed in the call. Reusability is toast when I put these screen-altering effects at the end of a function. For example, after a search is completed I need to display the results on the screen. How do others handle these issues? Putting my thinking cap on leads me to believe that I need to have an page-specific layer of Javascript between each use in my application and the generic methods I create which are to be used application-wide. Using the previous example, I would have a search button whose onclick calls a myPageSpecificSearchFunction, in which the search field IDs/names are hardcoded, which marshals the parameters and calls the generic search function. The generic function would return data/objects/variables only, and would not directly read from or make any changes to the DOM. The page-specific search function would then receive this data back and alter the DOM appropriately. Am I on the right path or is there a better pattern to handle the reuse of Javascript objects/methods?

  Read the article

• javascript class calling XMLHttpRequest internally, then handling onreadystatechange

  - by Radu M

  this thing almost works: function myClass(url) { this.source = url; this.rq = null; this.someOtherProperty = "hello"; // open connection to the ajax server this.start = function() { if (window.XMLHttpRequest) { this.rq = new XMLHttpRequest(); if (this.rq.overrideMimeType) this.rq.overrideMimeType("text/xml"); } else this.rq = new ActiveXObject("Microsoft.XMLHTTP"); try { this.rq.onreadystatechange = connectionEvent; this.rq.open("GET", this.source, true); this.rq.send(null); this.state = 1; } catch (err) { // some error handler here } } function connectionEvent() { alert("i'm here"); alert("this doesnt work: " + this.someOtherProperty); } } // myClass so it's nothing more than having the XMLHttpRequest object as a member of my class, instead of globally defined, and invoking it in the traditional way. however, inside my connectionEvent callback function, the meaning of "this" is lost, even though the function itself is scoped inside myClass. i also made sure that the object that i instantiate from myClass is kept alive long enough (declared global in the script). in all the examples of using javascript classes that i saw, "this" was still available inside the inner functions. for me, it is not, even if i take my function outside and make it a myClass.prototype.connectionEvent. what am i doing wrong? thank you.

  Read the article

• Implementing arrays using a stack

  - by Zack

  My programming language has no arrays, no lists, no pointers, no eval and no variable variables. All it has: Ordinary variables like you know them from most programming languages: They all have an exact name and a value. One stack. Functions provided are: push (add element to top), pop (remove element from top, get value) and empty (check if stack is empty) My language is turing-complete. (Basic arithmetics, conditional jumps, etc implemented) That means, it must be possible to implement some sort of list or array, right? But I have no idea how... What I want to achieve: Create a function which can retrieve and/or change an element x of the stack. I could easily add this function in the implementation of my language, in the interpreter, but I want to do it in my programming language. "Solution" one (Accessing an element x, counting from the stack top) Create a loop. Pop off the element from the stack top x times. The last element popped of is element number x. I end up with a destroyed stack. Solution two: Do the same as above, but store all popped off values in a second stack. Then you could move all elements back after you are done. But you know what? I don't have a second stack!

  Read the article

• Adding Table Columns to a Group by clause - Ruby on Rails - Postgresql

  - by bgadoci

  I am trying to use Heroku and apparently Postgresql is a lot more strict than SQL for aggregate functions. When I am pushing to Heroku I am getting an error stating the below. On another question I asked I received some guidance that said I should just add the columns to my group by clause and I am not sure how to do that. See the full error below and the PostsControll#index. SELECT posts.*, count(*) as vote_total FROM "posts" INNER JOIN "votes" ON votes.post_id = posts.id GROUP BY votes.post_id ORDER BY created_at DESC LIMIT 5 OFFSET 0): PostsController def index @tag_counts = Tag.count(:group => :tag_name, :order => 'count_all DESC', :limit => 20) conditions, joins = {}, :votes @ugtag_counts = Ugtag.count(:group => :ugctag_name, :order => 'count_all DESC', :limit => 20) conditions, joins = {}, :votes @vote_counts = Vote.count(:group => :post_title, :order => 'count_all DESC', :limit => 20) conditions, joins = {}, :votes unless(params[:tag_name] || "").empty? conditions = ["tags.tag_name = ? ", params[:tag_name]] joins = [:tags, :votes] end @posts=Post.paginate( :select => "posts.*, count(*) as vote_total", :joins => joins, :conditions=> conditions, :group => "votes.post_id", :order => "created_at DESC", :page => params[:page], :per_page => 5) @popular_posts=Post.paginate( :select => "posts.*, count(*) as vote_total", :joins => joins, :conditions=> conditions, :group => "votes.post_id", :order => "vote_total DESC", :page => params[:page], :per_page => 3) respond_to do |format| format.html # index.html.erb format.xml { render :xml => @posts } format.json { render :json => @posts } format.atom end end

  Read the article

• How can I write classes that don't rely on "global" variables?

  - by Joel

  When I took my first programming course in university, we were taught that global variables were evil & should be avoided at all cost (since you can quickly develop confusing and unmaintainable code). The following year, we were taught object oriented programming, and how to create modular code using classes. I find that whenever I work with OOP, I use my classes' private variables as global variables, i.e., they can be (and are) read and modified by any function within the class. This isn't really sitting right with me, as it seems to introduce the same problems global variables had in languages like C. So I guess my question is, how do I stop writing classes with "global" variables? Would it make more sense to pretend I'm writing in a functional language? By this I mean having all functions take parameters & return values instead of directly modifying class variables. If I need to set any fields, I can just take the output of the function and assign it instead of having the function do it directly. This seems like it might make more maintainable code, at least for larger classes. What's common practice? Thanks!

  Read the article

• jQuery: Multiple animations with a delay on a set of divs

  - by Waleed

  Hey there, I have a group of 4 divs and I'm looking to use jQuery to animate them once, then have a delay using delay(), and then run another set of animations on them, putting the divs back to their original configuration. Here's the code that I have: //only selectors called 'option1' are affected by delay, and not 'option1 img' or 'option2' $("#option1").showOption1().delay(3000).hideOption1(); //if i don't attach to #option1, delay doesn't work, but the animations that need to happen simultaneously work $(document).showOption1().delay(3000).hideOption1(); jQuery.fn.showOption1 = function(){ $("#option2, #option3, #leftColumn").fadeOut(1000); $("#option1").css("zIndex", "5"); $("#option1").animate({ left: "370px", }, 1500); $("#option1 img").animate({ width: "500px", }, 1500, function(){ $("p.optionText").text('hello'); }); return this; } jQuery.fn.hideOption1 = function(){ $("#option1 img").animate({ width: "175px", }, 1500); $("#option1").animate({ left: "743px", }, 1500); $("#option2, #option3, #leftColumn").fadeIn(2000); $("#option1").css("zIndex", "1"); return this; } I've tried two ways of running these two functions, as seen on lines 2 and 5. In the case of line 2, showOption1() will run fine, but then only $("#option1").animate({ left: "743px", }, 1500); will work from hideOption1() after the delay. The rest of hideOption1() is fired immediately after showOption1() finishes, ignoring the delay. On the other hand, if I run line 5, all the code in hideOption1() runs simultaneously as desired, but ignores the delay entirely, running immediately after showOption1() finishes. How can I have all the code in hideOption1() run simultaneously after the delay? Thanks much in advance!

  Read the article

• Best way to be able to pick multiple colors/designs of symbols dynamically from flash

  - by Cyprus106

  Sorry the title's so convoluted... I must've tried for ten minutes to get a good, descriptive title! Basically, here's the scenario. Let's say a user can pick fifty different hat colors and styles to put on an avatar. The avatar can move his head around, so we'd need the same types of movements in the symbol for when that happens. Additionally, it gets which hat should be on the 'avatar' from a database. The problem is that we can't just make 50 different frames with a different hat on each. And each hat symbol will have the same movements, it'll just be different styles, colors and sizes. So how can I make one variable that is the HAT, that way we can just put the appropriate hat symbol into the variable and always be able to call Hat.gotoAndplay('tip_hat') or any other generic functions.... Does that make sense? Hope that's not too confusing. Sorry, I'm not great at the visual Flash stuff, but it's gotta be done! Thanks!

  Read the article

• Haskell Linear Algebra Matrix Library for Arbitrary Element Types

  - by Johannes Weiß

  I'm looking for a Haskell linear algebra library that has the following features: Matrix multiplication Matrix addition Matrix transposition Rank calculation Matrix inversion is a plus and has the following properties: arbitrary element (scalar) types (in particular element types that are not Storable instances). My elements are an instance of Num, additionally the multiplicative inverse can be calculated. The elements mathematically form a finite field (??2256). That should be enough to implement the features mentioned above. arbitrary matrix sizes (I'll probably need something like 100x100, but the matrix sizes will depend on the user's input so it should not be limited by anything else but the memory or the computational power available) as fast as possible, but I'm aware that a library for arbitrary elements will probably not perform like a C/Fortran library that does the work (interfaced via FFI) because of the indirection of arbitrary (non Int, Double or similar) types. At least one pointer gets dereferenced when an element is touched (written in Haskell, this is not a real requirement for me, but since my elements are no Storable instances the library has to be written in Haskell) I already tried very hard and evaluated everything that looked promising (most of the libraries on Hackage directly state that they wont work for me). In particular I wrote test code using: hmatrix, assumes Storable elements Vec, but the documentation states: Low Dimension : Although the dimensionality is limited only by what GHC will handle, the library is meant for 2,3 and 4 dimensions. For general linear algebra, check out the excellent hmatrix library and blas bindings I looked into the code and the documentation of many more libraries but nothing seems to suit my needs :-(. Update Since there seems to be nothing, I started a project on GitHub which aims to develop such a library. The current state is very minimalistic, not optimized for speed at all and only the most basic functions have tests and therefore should work. But should you be interested in using or helping out developing it: Contact me (you'll find my mail address on my web site) or send pull requests.

  Read the article

• Zendx JQuery Autocomplete

  - by emeraldjava

  I've been trying to get the Zend Jquery autocomplete function working, when i noticed this section in the Zend documentation. The following UI widgets are available as form view helpers. Make sure you use the correct version of jQuery UI library to be able to use them. The Google CDN only offers jQuery UI up to version 1.5.2. Some other components are only available from jQuery UI SVN, since they have been removed from the announced 1.6 release. autoComplete($id, $value, $params, $attribs): The AutoComplete View helper will be included in a future jQuery UI version (currently only via jQuery SVN) and creates a text field and registeres it to have auto complete functionality. The completion data source has to be given as jQuery related parameters 'url' or 'data' as described in the jQuery UI manual. Does anybody know which svn url tag or branch i need to download to get a javascript file with the autocomplete functions available in it? At the moment, my Bootstrap.php has $view->addHelperPath('ZendX/JQuery/View/Helper/', 'ZendX_JQuery_View_Helper'); $view->jQuery()->enable(); $view->jQuery()->uiEnable(); Zend_Controller_Action_HelperBroker::addHelper( new ZendX_JQuery_Controller_Action_Helper_AutoComplete() ); // Add it to the ViewRenderer $viewRenderer = new Zend_Controller_Action_Helper_ViewRenderer(); $viewRenderer->setView($view); Zend_Controller_Action_HelperBroker::addHelper($viewRenderer); In my layout, i define the jquery ui version i want <?php echo $this->jQuery() ->setUiVersion('1.7.2');?> Finally my index.phtml has the autocomplete widget <p><?php $data = array('New York', 'Tokyo', 'Berlin', 'London', 'Sydney', 'Bern', 'Boston', 'Baltimore'); ?> <?php echo $this->autocomplete("ac1", "", array('data' => $data));?></p> I'm using Zend 1.8.3 atm.

  Read the article

• C++ Swig Python (Embedded Python in C++) works in Release but not in Debug

  - by sambha

  Platform: Windows 7, 64 bit (x64), Visual Studio 2008 I chose Python & Swig binding as the scripting environment of the application. As a prototype, created a simple VS solution with main() which initializes Python (Py_Initalize, Py_setPyHome, etc) & executes test.py. In the same solution created another project which is a DLL of a simple class. Used SWIG to wrap this class. This DLL is the _MyClasses.pyd. test.py creates the objects of my class & calls its member functions. All this works like a charm in the Release mode. But does not work in Debug mode (even tried banging my head on the laptop ;-) ). Output of my work looks like this (in both release & debug): x64 -debug - _MyClasses.pyd - MyClasses.py - test.exe - test.py - python26.dll - python26_d.dll Note that the debug version is linked against python26_d.lib. Had to build python myself for this! test.py import MyClasses print "ello" m = MyClasses.Male("John Doe", 25) print m.getType() Male is the C++ class. The problem: Traceback (most recent call last): File "test.py", line 6, in <module> import MyClasses File "...\x64\Debug\MyClasses.py", line 25, in <module> _MyClasses = swig_import_helper() File "...\x64\Debug\MyClasses.py", line 17, in swig_imp ort_helper import _MyClasses ImportError: No module named _MyClasses [15454 refs] I am used to Makefiles & am new to Visual Studio. I dont know who the culprit is here: Swig, The debug build of Python, Visual Studio, my stupidity. Thank you in advance. It will be a great help.

  Read the article

• OpenGL bitmap text fails after drawing polygon

  - by kaykun

  I'm using Win32 and OpenGL to to draw text onto a window. I'm using the bitmap font method, with wglUseFontBitmaps. Here is my main rendering function: glClear(GL_COLOR_BUFFER_BIT); glPushMatrix(); glColor3f(1.0f, 0.0f, 1.0f); glBegin(GL_QUADS); glVertex2f(0.0f, 0.0f); glVertex2f(128.0f, 0.0f); glVertex2f(128.0f, 128.0f); glVertex2f(0.0f, 128.0f); glEnd(); glPopMatrix(); glPushMatrix(); glColor3f(1.0f, 1.0f, 1.0f); glRasterPos2i(200, 200); glListBase(fontList); glCallLists(5, GL_UNSIGNED_BYTE, "Test."); glPopMatrix(); SwapBuffers(hDC); As you can see it's very simple and the only thing that it's supposed to do is draw a quadrilateral and draw the text "Test.". But the problem is that drawing a polygon seems to mess up any text operations I try to do after it. If I place the text drawing functions before the polygon, both the text and the polygon draw fine. Is there something I'm missing here? Edit: This problem only happens when the window is run in Fullscreen, by ChangeDisplaySettings. Any reason why this would be??

  Read the article

• Adapting existing HTML/Javascript model to Titanium's latest release (v 0.9)

  - by Alan Neal

  In pre-0.9 versions of Titanium, one could simply specify an .html file (local or remote) in the tiapp.xml file and interact with it in the same manner as one would on a website. As of version 0.9, that is no the longer case. One creates their entire app dynamically. Unfortunately, this broke my previous implementation and, other than an updated Kitchen Sink, much of the new model and API calls are not covered in the documentation (e.g., createLabel). So, my question is this... What are the simplest steps for re-creating the previous effect (knowingly forgoing some of the advantages of the Titanium's latest approach if necessary)? My previous implementation was exactly as it functions on the website. The website has a single index.html file with no content other than links to JavaScript and style files. The document body's onload event called the first JavaScript function (located in the main script) and, from that point forth, the entire content was dynamically created. How can I set up the latest version of Titanium so that I am poised to do the exact same thing? BTW: Whereas I previously had the choice to keep the files local or remote, I don't believe that remote access (e.g., simply using the webView widget to point to the website) is viable. That's because pages displayed via the webView do not have access to most of the API. Since the iPhone and Safari browsers do not support the file input type, the only means for uploading files (something my app requires) is calling Titanium's function. Thanks in advance.

  Read the article

• Shell script to emulate warnings-as-errors?

  - by talkaboutquality

  Some compilers let you set warnings as errors, so that you'll never leave any compiler warnings behind, because if you do, the code won't build. This is a Good Thing. Unfortunately, some compilers don't have a flag for warnings-as-errors. I need to write a shell script or wrapper that provides the feature. Presumably it parses the compilation console output and returns failure if there were any compiler warnings (or errors), and success otherwise. "Failure" also means (I think) that object code should not be produced. What's the shortest, simplest UNIX/Linux shell script you can write that meets the explicit requirements above, as well as the following implicit requirements of otherwise behaving just like the compiler: - accepts all flags, options, arguments - supports redirection of stdout and stderr - produces object code and links as directed Key words: elegant, meets all requirements. Extra credit: easy to incorporate into a GNU make file. Thanks for your help. === Clues === This solution to a different problem, using shell functions (?), Append text to stderr redirects in bash, might figure in. Wonder how to invite litb's friend "who knows bash quite well" to address my question? === Answer status === Thanks to Charlie Martin for the short answer, but that, unfortunately, is what I started out with. A while back I used that, released it for office use, and, within a few hours, had its most severe drawback pointed out to me: it will PASS a compilation with no warnings, but only errors. That's really bad because then we're delivering object code that the compiler is sure won't work. The simple solution also doesn't meet the other requirements listed. Thanks to Adam Rosenfield for the shorthand, and Chris Dodd for introducing pipefail to the solution. Chris' answer looks closest, because I think the pipefail should ensure that if compilation actually fails on error, that we'll get failure as we should. Chris, does pipefail work in all shells? And have any ideas on the rest of the implicit requirements listed above?

  Read the article

• jQuery set selected value in option box once the box has been loaded

  - by Maarten

  I want to preset the value of a selectbox based on a hidden field. I need this after an error has been detected in a form to avoid the user having to set the value themselves again. I do this by setting the value of a hidden field server side. The problem I have seems to be that the select box isn't done yet at the time I try to set the selected value. Anyone know how to solve this (possibly in a very different way?) <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.js"></script> <script type="text/javascript" charset="utf-8"> $(function(){ // this functions loads the state select box with states if a country with states is selected $("select#countries").change(function(){ $.getJSON("/ajax/exhibition/getstates.php?idCountry="+$("select#countries").val(), function(j){ var options = ''; $.each(j, function(key, value){ options += '<option value="' + key + '">' + value + '</option>'; }); $("select#state").html(options); }); }); }); $(document).ready(function(){ // preset the state select box on page ready $('select#countries').change(); // set the selected value of the state select box var foo = $('#statepreset').val(); $("select#state option[value="+foo+"]").attr('selected', 'selected'); }); </script>

  Read the article

• ffmpeg(libavcodec). memory leaks in avcodec_encode_video

  - by gavlig

  I'm trying to transcode a video with help of libavcodec. On transcoding big video files(hour or more) i get huge memory leaks in avcodec_encode_video. I have tried to debug it, but with different video files different functions produce leaks, i have got a little bit confused about that :). [Here] (http://stackoverflow.com/questions/4201481/ffmpeg-with-qt-memory-leak) is the same issue that i have, but i have no idea how did that person solve it. QtFFmpegwrapper seems to do the same i do(or i missed something). my method is lower. I took care about aFrame and aPacket outside with av_free and av_free_packet. int Videocut::encode( AVStream *anOutputStream, AVFrame *aFrame, AVPacket *aPacket ) { AVCodecContext *outputCodec = anOutputStream->codec; if (!anOutputStream || !aFrame || !aPacket) { return 1; /* NOTREACHED */ } uint8_t * buffer = (uint8_t *)malloc( sizeof(uint8_t) * _DefaultEncodeBufferSize ); if (NULL == buffer) { return 2; /* NOTREACHED */ } int packetSize = avcodec_encode_video( outputCodec, buffer, _DefaultEncodeBufferSize, aFrame ); if (packetSize < 0) { free(buffer); return 1; /* NOTREACHED */ } aPacket->data = buffer; aPacket->size = packetSize; return 0; }

  Read the article

• Python API for VirtualBox

  - by jessica

  I have made a command-line interface for virtualbox such that the virtualbox can be controlled from a remote machine. now I am trying to implement the commmand-line interface using python virtualbox api. For that I have downloaded the pyvb package (python api documentation shows functions that can be used for implementing this under pyvb package). but when I give pyvb.vb.VB.startVM(instance of VB class,pyvb.vm.vbVM) SERVER SIDE CODE IS from pyvb.constants import * from pyvb.vm import * from pyvb.vb import * import xpcom import pyvb import os import socket import threading class ClientThread ( threading.Thread ): # Override Thread's init method to accept the parameters needed: def init ( self, channel, details ): self.channel = channel self.details = details threading.Thread.__init__ ( self ) def run ( self ): print 'Received connection:', self.details [ 0 ] while 1: s= self.channel.recv ( 1024 ) if(s!='end'): if(s=='start'): v=VB() pyvb.vb.VB.startVM(v,pyvb.vm.vbVM) else: self.channel.close() break print 'Closed connection:', self.details [ 0 ] server = socket.socket ( socket.AF_INET, socket.SOCK_STREAM ) server.bind ( ( '127.0.0.1', 2897 ) ) server.listen ( 5 ) while True: channel, details = server.accept() ClientThread ( channel, details ).start() it shows an error Exception in thread Thread-1: Traceback (most recent call last): File "/usr/lib/python2.5/threading.py", line 486, in __bootstrap_inner self.run() File "news.py", line 27, in run pyvb.vb.VB.startVM(v,pyvb.vm.vbVM.getUUID(m)) File "/usr/lib/python2.5/site-packages/pyvb-0.0.2-py2.5.egg/pyvb/vb.py", line 65, in startVM cmd='%s %s'%(VB_COMMAND_STARTVM, vm.getUUID()) AttributeError: 'str' object has no attribute 'getUUID'

  Read the article

• Bad linking in Qt unit test -- missing the link to the moc file?

  - by dwj

  I'm trying to unit test a class that inherits QObject; the class itself is located up one level in my directory structure. When I build the unit test I get the standard unresolved errors if a class' MOC file cannot be found: test.obj : error LNK2001: unresolved external symbol "public: virtual void * __thiscall UnitToTest::qt_metacast(char const *)" (?qt_metacast@UnitToTest@@UAEPAXPBD@Z) + 2 missing functions The MOC file is created but appears to not be linking. I've been poking around SO, the web, and Qt's docs for quite a while and have hit a wall. How do I get the unit test to include the MOC file in the link? ==== My project file is dead simple: TEMPLATE = app TARGET = test DESTDIR = . CONFIG += qtestlib INCLUDEPATH += . .. DEPENDPATH += . HEADERS += test.h SOURCES += test.cpp ../UnitToTest.cpp stubs.cpp DEFINES += UNIT_TEST My directory structure and files: C:. | UnitToTest.cpp | UnitToTest.h | \---test | test.cpp (Makefiles removed for clarity) | test.h | test.pro | stubs.cpp | +---debug | UnitToTest.obj | test.obj | test.pdb | moc_test.cpp | moc_test.obj | stubs.obj Edit: Additional information The generated Makefile.Debug shows the moc file missing: SOURCES = test.cpp \ ..\test.cpp \ stubs.cpp debug\moc_test.cpp OBJECTS = debug\test.obj \ debug\UnitToTest.obj \ debug\stubs.obj \ debug\moc_test.obj

  Read the article

• mtl, transformers, monads-fd, monadLib, and the paradox of choice

  - by yairchu

  Hackage has several packages for monad transformers: mtl: Monad transformer library transformers: Concrete functor and monad transformers monads-fd: Monad classes, using functional dependencies monads-tf: Monad classes, using type families monadLib: A collection of monad transformers. mtl-tf: Monad transformer library using type families mmtl: Modular Monad transformer library mtlx: Monad transformer library with type indexes, providing 'free' copies. compose-trans: Composable monad transformers (and maybe I missed some) Which one shall we use? mtl is the one in the Haskell Platform, but I keep hearing on reddit that it's uncool. But what's bad about choice anyway, isn't it just a good thing? Well, I saw how for example the authors of data-accessor had to make all these to cater to just the popular choices: data-accessor-monadLib library: Accessor functions for monadLib's monads data-accessor-monads-fd library: Use Accessor to access state in monads-fd State monad class data-accessor-monads-tf library: Use Accessor to access state in monads-tf State monad type family data-accessor-mtl library: Use Accessor to access state in mtl State monad class data-accessor-transformers library: Use Accessor to access state in transformers State monad I imagine that if this goes on and for example several competing Arrow packages evolve, we might see something like: spoonklink-arrows-transformers, spoonklink-arrows-monadLib, spoonklink-tfArrows-transformers, spoonklink-tfArrows-monadLib, ... And then I worry that if spoonklink gets forked, Hackage will run out of disk space. :) Questions: Why are there so many monad transformer packages? Why is mtl [considered] uncool? What are the key differences? Most of these seemingly competing packages were written by Andy Gill and are maintained by Ross Paterson. Does this mean that these packages are not competing but rather work together in some way? And do Andy and Ross consider any of their own packages as obsolete? Which one should me and you use?

  Read the article

• Implementing the ‘defer’ statement from Go in Objective-C?

  - by zoul

  Hello! Today I read about the defer statement in the Go language: A defer statement pushes a function call onto a list. The list of saved calls is executed after the surrounding function returns. Defer is commonly used to simplify functions that perform various clean-up actions. I thought it would be fun to implement something like this in Objective-C. Do you have some idea how to do it? I thought about dispatch finalizers, autoreleased objects and C++ destructors. Autoreleased objects: @interface Defer : NSObject {} + (id) withCode: (dispatch_block_t) block; @end @implementation Defer - (void) dealloc { block(); [super dealloc]; } @end #define defer(__x) [Defer withCode:^{__x}] - (void) function { defer(NSLog(@"Done")); … } Autoreleased objects seem like the only solution that would last at least to the end of the function, as the other solutions would trigger when the current scope ends. On the other hand they could stay in the memory much longer, which would be asking for trouble. Dispatch finalizers were my first thought, because blocks live on the stack and therefore I could easily make something execute when the stack unrolls. But after a peek in the documentation it doesn’t look like I can attach a simple “destructor” function to a block, can I? C++ destructors are about the same thing, I would create a stack-based object with a block to be executed when the destructor runs. This would have the ugly disadvantage of turning the plain .m files into Objective-C++? I don’t really think about using this stuff in production, I’m just interested in various solutions. Can you come up with something working, without obvious disadvantages? Both scope-based and function-based solutions would be interesting.

  Read the article

• C# - Alternative to System.Time.Timer, to call a function at a specific time.

  - by Fábio Antunes

  Hello everybody. I want to call a specific function on my C# application at a specific time. At first i thought about using a Timer (System.Time.Timer), but that soon became impossible to use. Why? Simple. The Timer Class requires a Interval in milliseconds, but considering that i might want the function to be executed, lets says in a week that would mean: 7 Days = 168 hours; 168 Hours = 10,080 minutes; 10,080 Minutes = 6,048,000 seconds; 6,048,000 Seconds = 6,048,000,000 milliseconds; So the Interval would be 6,048,000,000; Now lets remember that the Interval accepted data type is int, and as we know int range goes from -2,147,483,648 to 2,147,483,647. That makes Timer useless in this case once we cannot set a Interval bigger that 2,147,483,647 milliseconds. So i need a solution where i could specify when the function should be called. Something like this: solution.ExecuteAt = "30-04-2010 15:10:00"; solution.Function = "functionName"; solution.Start(); So when the System Time would reach "30-04-2010 15:10:00" the function would be executed in the application. How can this problem be solved? Thanks just by taking the time to read my question. But if you could provide me with some help i would be most grateful. Additional Info: What these functions will do? Getting climate information and based on that info: Starting / Shutting down other Applications (most of them Console Based); Sending custom Commands to those Console Applications; Power down, Rebooting, Sleep, Hibernate the computer; And if possible schedule the BIOS to Power Up the Computer;

  Read the article

< Previous Page | 272 273 274 275 276 277 278 279 280 281 282 283  | Next Page >