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  • In Android GUI flickers when reading the properties file

    - by ManojValiveti
    Hi, I am getting the GUI flicker when reading a file properties and accordingly enabling/disabling checkbox and List value in listbox. when i remove this file reading code the GUI doesnt have flicker. I am reading the properties before creating the Preferences in OnCreate(). Attached the file write code below for reference.Please let us know is there any other way to read and update the preference staus. private void SetExtendConf(String key, String strValue) { mProperties = new Properties(); try { File file = new File(FILE_EXT); if(!file.exists()) file.createNewFile(); file.setWritable(true,false); FileInputStream fis = new FileInputStream(file); mProperties.load(fis); fis.close(); FileOutputStream stream = new FileOutputStream(file); Log.d(TAG, "Setting Values " + key + ":"+ strValue); mProperties.setProperty(key, strValue); mProperties.store(stream,"ext.conf"); stream.close(); } catch (IOException e) { Log.d(TAG, "Could not open properties file: " + GPS_FILE_EXT); } } -Manoj

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  • StackPanel loded is not getting fired in.cs page

    - by prince23
    <sdk:DataGridTemplateColumn> <sdk:DataGridTemplateColumn.CellTemplate> <DataTemplate> <StackPanel Loaded ="SPImage_Loaded" Orientation="Horizontal" Background="Transparent" > <Button x:Name="myButton" Click="Btn_Click"> <Image x:Name="imgMarks" " Stretch="None"/> </Button> </StackPanel> </DataTemplate> </sdk:DataGridTemplateColumn.CellTemplate> </sdk:DataGridTemplateColumn> in .cs i have defined the event for stack panel private void SPImage_Loaded(object sender, RoutedEventArgs e) { try { var TargetMarks = sender as StackPanel; Image imgMarks= (Image)TargetScore.FindName("imgMarks"); Marks obj = (Marks )TargetMarks.DataContext; // here marks oject would be containg the details // here if marks.score object value is 1 then bind the image //else // dnt bind the image . that is logic i am trying to do. imgMarks.Source = new BitmapImage(new Uri("/Images/a1.png", UriKind.Relative)); } catch (Exception) { throw; } } any solution on this would be great. is there any better solution to achive this. plz help me out. thank you.

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  • Lightweight HTTP application/server for static content

    - by PartlyCloudy
    Hi, I am in need of a scalable and performant HTTP application/server that will be used for static file serving/uploading. So I only need support for GET and PUT operations. However, there are a few extra features that I need: Custom authentication: I need to check credentials against a database for each request. Thus I must be able to integrate propietary database interaction. Support for signed access keys: The access to resources via PUT should be signed using a key like http://uri/?key=foo The key then contains information about the request like md5(user + path + secret) which allows me to block unwanted requests. The application/server should allow me to check for this. Performance: I'd like to avoid piping content as much as possible. Otherwise the whole application could be implemented in Perl/etc. in a few lines as CGI. Perlbal (in webserver mode) looks nice, however the single-threaded model does not fit with my database lookup and it does also not support query strings. Lighttp/Nginx/… have some modules for these tasks, however it is not feasible putting everything together without ending up writing own extensions/modules. So how would you solve this? Are there other leightweight webservers available for this? Should I implement an application inside of a webserver (i.e. CGI). How can I avoid/speed up piping content between the webserver and my application. Thanks in advance!

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  • AngularJS - $routeParams Empty on $locationChangeSuccess

    - by Marc M.
    I configure my app in the following run block. Basically I want to preform an action that requires me to know the $routeParams every $locationChangeSuccess. However $routeParams is empty at this point! Are there any work rounds? What's going on? app.run(['$routeParams', function ($routeParams) { $rootScope.$on("$locationChangeSuccess", function () { console.log($routeParams); }); }]); UPDATE function configureApp(app, user) { app.config(['$routeProvider', function ($routeProvider) { $routeProvider. when('/rentroll', { templateUrl: 'rent-roll/rent-roll.html', controller: 'pwRentRollCtrl' }). when('/bill', { templateUrl: 'bill/bill/bill.html', controller: 'pwBillCtrl' }). when('/fileroom', { templateUrl: 'file-room/file-room/file-room.html', controller: 'pwFileRoomCtrl' }). when('/estate-creator', { templateUrl: 'estate/creator.html' }). when('/estate-manager', { templateUrl: 'estate/manager.html', controller: 'pwEstateManagerCtrl' }). when('/welcomepage', { templateURL: 'welcome-page/welcome-page.html', controller: 'welcomePageCtrl' }). otherwise({ redirectTo: '/welcomepage' }); }]); app.run(['$rootScope', '$routeParams', 'pwCurrentEstate','pwToolbar', function ($rootScope, $routeParams, pwCurrentEstate, pwToolbar) { $rootScope.user = user; $rootScope.$on("$locationChangeSuccess", function () { pwToolbar.reset(); console.log($routeParams); }); }]); } Accessing URL: http://localhost:8080/landlord/#/rentroll?landlord-account-id=ahlwcm9wZXJ0eS1tYW5hZ2VtZW50LXN1aXRlchwLEg9MYW5kbG9yZEFjY291bnQYgICAgICAgAoM&billing-month=2014-06

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  • Problem with thumbnails after newly added - PHP on-the-fly method

    - by Wayne
    Hey again... to those that may have read my previous question that got solved a couple minutes ago .< The on-the-fly php script works perfectly, but when I went to upload new images into a gallery which I made myself, the images are resized to 150 x 150 for what I wanted... however, when it comes to new images being added it is all black... As you can see the three black images that were uploaded to the folder and the directory added to the database. What is causing this? If I view the source, the code is fine... the while loop in the PHP generates an output like this: <div class="view-wrap" id="photo-10"> <div class="view-icon"> <div class="img-label"> <a href="#" id="10" class="delete"><img src="img/small-delete.png" /> Delete</a> </div> <a href="img/events/Paintballing/24251_1395408043148_1170626626_1204038_5382765_n.jpg"> <img src="image.php?dir=img/events/Paintballing/24251_1395408043148_1170626626_1204038_5382765_n.jpg" alt="" width="110" height="110" /> </a> </div> </div> An example of one block. If I view the source (in Firefox) and click on the image.php?dir=img/events/Paintballing/24251_1395408043148_1170626626_1204038_5382765_n.jpg by exmaple, I can see the thumbnail at it's 150 x 150 size but in the layout, it shows a black thumbnail... Does anyone know why this is happening?

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  • jQuery preventing RedirectToAction from working?

    - by DaveDev
    I'm trying to redirect the user if they login successfully but the code I have on my page seems to be preventing the redirection from working. If I remove the jQuery below the redirection works. Can somebody tell me tell me if there's something I'm doing wrong? Thanks I have the following Action: [AcceptVerbs(HttpVerbs.Post)] public ActionResult Login(User user) { var myErrors = new Dictionary<string, string>(); try { if (ModelState.IsValid) { if (userRepository.ValidUser(user)) { return RedirectToAction("Index", "Group", new {page = (int?)null}); } else { return Json("Username or password seems to be incorrect"); } } else { foreach (KeyValuePair<string, ModelState> keyValuePair in ViewData.ModelState) { if (keyValuePair.Value.Errors.Count > 0) { List<string> errors = new List<string>(); myErrors.Add(keyValuePair.Key, keyValuePair.Value.Errors[0].ErrorMessage); } } return Json(myErrors); } } catch (Exception) { return Json("Invalid"); } } and the following code on my page: <script language="javascript" type="text/javascript"> $(document).ready(function() { $("#SaveSuccess").hide(); $("#btnLogin").click(function() { $("form").submit(function(event) { var formData = $(this).serialize(); $.post($(this).attr("action"), formData, function(res) { ShowErrors(res); if (res == true) { $("#SaveSuccess").text("Saved"); } else { $("#divError").html(res); } $("#SaveSuccess").fadeIn(100); }, "json"); return false; }); }); }); </script>

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  • MVC2 Json request not actually hitting the controller

    - by SlackerCoder
    I have a JSON request, but it seems that it is not hitting the controller. Here's the jQuery code: $("#ddlAdminLogsSelectLog").change(function() { globalLogSelection = $("#ddlAdminLogsSelectLog").val(); alert(globalLogSelection); $.getJSON("/Administrative/AdminLogsChangeLogSelection", { NewSelection: globalLogSelection }, function(data) { if (data.Message == "Success") { globalCurrentPage = 1; } else if (data.Message == "Error") { //Do Something } }); }); The alert is there to show me if it actually fired the change event, which it does. Heres the method in the controller: public ActionResult AdminLogsChangeLogSelection(String NewSelection) { String sMessage = String.Empty; StringBuilder sbDataReturn = new StringBuilder(); try { if (NewSelection.Equals("Application Log")) { int i = 0; } else if (NewSelection.Equals("Email Log")) { int l = 0; } } catch (Exception e) { //Do Something sMessage = "Error"; } return Json(new { Message = sMessage, DataReturn = sbDataReturn.ToString() }, JsonRequestBehavior.AllowGet); } I have a bunch of Json requests in my application, and it seems to only happen in this area. This is a separate area (I have 6 "areas" in the app, 5 of which work fine with JSON requests). This controller is named "AdministrativeController", if that matters. Does anything jump out anyone as being incorrect or why the request would not pass to the server side?

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  • When should EntityManagerFactory instance be created/opened ?

    - by masato-san
    Ok, I read bunch of articles/examples how to write Entity Manager Factory in singleton. One of them easiest for me to understand a bit: http://javanotepad.blogspot.com/2007/05/jpa-entitymanagerfactory-in-web.html I learned that EntityManagerFactory (EMF) should only be created once preferably in application scope. And also make sure to close the EMF once it's used (?) So I wrote EMF helper class for business methods to use: public class EmProvider { private static final String DB_PU = "KogaAlphaPU"; public static final boolean DEBUG = true; private static final EmProvider singleton = new EmProvider(); private EntityManagerFactory emf; private EmProvider() {} public static EmProvider getInstance() { return singleton; } public EntityManagerFactory getEntityManagerFactory() { if(emf == null) { emf = Persistence.createEntityManagerFactory(DB_PU); } if(DEBUG) { System.out.println("factory created on: " + new Date()); } return emf; } public void closeEmf() { if(emf.isOpen() || emf != null) { emf.close(); } emf = null; if(DEBUG) { System.out.println("EMF closed at: " + new Date()); } } }//end class And my method using EmProvider: public String foo() { EntityManager em = null; List<Object[]> out = null; try { em = EmProvider.getInstance().getEntityManagerFactory().createEntityManager(); Query query = em.createNativeQuery(JPQL_JOIN); //just some random query out = query.getResultList(); } catch(Exception e) { //handle error.... } finally { if(em != null) { em.close(); //make sure to close EntityManager } } I made sure to close EntityManager (em) within method level as suggested. But when should EntityManagerFactory be closed then? And why EMF has to be singleton so bad??? I read about concurrency issues but as I am not experienced multi-thread-grammer, I can't really be clear on this idea.

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  • Initializing Disqus comments in hidden element causes issue in FF 14.0.1

    - by Bazze
    This issue appears only in Firefox 14.0.1 (well I couldn't reproduce it in any other browser). If you put the code for Disqus comments inside an element that is hidden and wait until everything is fully loaded and then display the element using JavaScript, the comment box nor comments will show up. However if you resize the window, it'll show up immediately. It's working fine in latest version of Google Chrome and Safari though. What's causing this and how to fix it? Sample code to reproduce: <div id="test" style="display:none;"> <div id="disqus_thread"></div> <script type="text/javascript"> /* * * CONFIGURATION VARIABLES: EDIT BEFORE PASTING INTO YOUR WEBPAGE * * */ var disqus_shortname = 'onlinefunctions'; // required: replace example with your forum shortname /* * * DON'T EDIT BELOW THIS LINE * * */ (function() { var dsq = document.createElement('script'); dsq.type = 'text/javascript'; dsq.async = true; dsq.src = 'http://' + disqus_shortname + '.disqus.com/embed.js'; (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq); })(); </script> <noscript>Please enable JavaScript to view the <a href="http://disqus.com/?ref_noscript">comments powered by Disqus.</a></noscript> <a href="http://disqus.com" class="dsq-brlink">comments powered by <span class="logo-disqus">Disqus</span></a> </div> <a href="#" onclick="document.getElementById('test').style.display = 'block'">show</a> I could post a link to a live example but I'm not sure about the policy of posting links here on Stack Overflow.

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  • Why is this Javascript that writes out a Google Ad not displaying properly on the iPhone?

    - by Dave M G
    I have this Javacsript code that checks to see if there is a DIV named "google-ad", and if there is, it writes in a the necessary code to display the Google Ad. This works great in browsers like Firefox, Chrome, Safari on Mac, and Android. However, when I bundle this code with Adobe's Phonegap Build, and deploy it to iPhones, it behaves strangely. It launches a browser window displaying just the Google Ad alone. In order to keep using my app, every time I change a page and a new Google Ad is loaded, I have to close the browser window to get back to the app. Why is this code launching browser windows outside of my Phonegap app on iPhone? if(document.getElementById("google-ad") && document.getElementById("google-ad") !== null && document.getElementById("google-ad") !== "undefined") { if(userStatus.status == 0) { document.getElementById("centre").style.padding = "137px 0 12px 0"; document.getElementById("header-container").style.margin = "-138px 0 0 0"; document.getElementById("header-container").style.height = "132px"; document.getElementById("header-username").style.top = "52px"; document.getElementById("google-ad").style.height = "50px"; document.getElementById("google-ad").style.width = "320px"; document.getElementById("google-ad").style.backgroundColor = "#f0ebff"; document.getElementById("google-ad").style.display = "block"; window["google_ad_client"] = 'ca-pub-0000000000000000'; window["google_ad_slot"] = "00000000"; window["google_ad_width"] = 320; window["google_ad_height"] = 50; window.adcontainer = document.getElementById('google-ad'); window.adhtml = ''; function mywrite(html) { adhtml += html; adcontainer.innerHTML = adhtml; }; document.write_ = document.write; document.write = mywrite; script = document.createElement('script'); script.src='http://pagead2.googlesyndication.com/pagead/show_ads.js'; script.type='text/javascript'; document.body.appendChild(script); }

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  • Flash - can't access classes in another SWF

    - by Ashley Muller
    Hi, I'm trying to load a local SWF file and use the classes in that SWF (its a code only SWF, nothing in library). Here's the code that loads the library: var AD:ApplicationDomain = ApplicationDomain.currentDomain; var context:LoaderContext = new LoaderContext(false, AD); SA_gamecore_loader = new Loader(); SA_gamecore_loader.contentLoaderInfo.addEventListener(Event.COMPLETE, onGameCoreLibraryDataComplete); SA_gamecore_loader.load(new URLRequest("GameCore.swf"), context); Here's the code that tries to instantiate a class from GameCore.swf: var test:Class = GetClassFromDefinition("MenuArt") as Class; var testInstance:Object = new test(); public function GetClassFromDefinition(theStr:String):Object { var theClass:Object; try { theClass = GameCoreLibraryData.applicationDomain.getDefinition(theStr); } catch(e:ReferenceError) { trace(e); return null; } return theClass; } And this is the message that's traced: ReferenceError: Error #1065: Variable MenuArt is not defined. The GameCore.swf is in the same location as the parent swf. I'm using Flash Develop if that helps. Anyone able to point out what I'm doing wrong?

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  • Am I encrypting my passwords correctly in ASP.NET

    - by Nick
    I have a security class: public class security { private static string createSalt(int size) { //Generate a random cryptographic number RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider(); byte[] b = new byte[size]; rng.GetBytes(b); //Convert to Base64 return Convert.ToBase64String(b); } /// <summary> /// Generate a hashed password for comparison or create a new one /// </summary> /// <param name="pwd">Users password</param> /// <returns></returns> public static string createPasswordHash(string pwd) { string salt = "(removed)"; string saltAndPwd = string.Concat(pwd, salt); string hashedPwd = FormsAuthentication.HashPasswordForStoringInConfigFile( saltAndPwd, "sha1"); return hashedPwd; } } This works fine, but I am wondering if it is sufficient enough. Also, is this next block of code better? Overkill? static byte[] encrInitVector = new byte[] { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF }; static string encrKey = "(removed)"; public static string EncryptString(string s) { byte[] key; try { key = Encoding.UTF8.GetBytes(encrKey.Substring(0, 8)); DESCryptoServiceProvider des = new DESCryptoServiceProvider(); byte[] inputByteArray = Encoding.UTF8.GetBytes(s); MemoryStream ms = new MemoryStream(); CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(key, encrInitVector), CryptoStreamMode.Write); cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); return Convert.ToBase64String(ms.ToArray()); } catch (Exception e) { throw e; }

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  • unknown exception error in php

    - by fayer
    i wanna catch all exceptions thrown in a script and then check if they have a error code 23000. if they don't i want to rethrow the exception. here is my code: function myException($exception) { /*** If it is a Doctrine Connection Mysql Duplication Exception ***/ if(get_class($exception) === 'Doctrine_Connection_Mysql_Exception' && $exception->getCode() === 23000) { echo "Duplicate entry"; } else { throw $exception; } } set_exception_handler('myException'); $contact = new Contact(); $contact->email = 'peter'; $contact->save(); but i get this error message and i dont know what it means: Fatal error: Exception thrown without a stack frame in Unknown on line 0 i want to be able to rethrow the original error message if it has not the error code 23000. even when i deleted the check errorcode i still get the same message: function myException($exception) { throw $exception; } set_exception_handler('myException'); $contact = new Contact(); $contact->email = 'peter'; $contact->save(); how could i solve this? thanks

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  • How to properly handle signals when using the worker thread pattern?

    - by ipartola
    I have a simple server that looks something like this: void *run_thread(void *arg) { // Communicate via a blocking socket } int main() { // Initialization happens here... // Main event loop while (1) { new_client = accept(socket, ...); pthread_create(&thread, NULL, &run_thread, *thread_data*); pthread_detach(thread); } // Do cleanup stuff: close(socket); // Wait for existing threads to finish exit(0); ) Thus when a SIGINT or SIGTERM is received I need to break out of the main event loop to get to the clean up code. Moreover most likely the master thread is waiting on the accept() call so it's not able to check some other variable to see if it should break;. Most of the advice I found was along the lines of this: http://devcry.blogspot.com/2009/05/pthreads-and-unix-signals.html (creating a special signal handling thread to catch all the signals and do processing on those). However, it's the processing portion that I can't really wrap my head around: how can I possibly tell the main thread to return from the accept() call and check on an external variable to see if it should break;?

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  • How do I create and send appointments to Microsoft Outlook calender?

    - by Shyju
    I am trying to create an appointment in the Microsoft Outlook (2003) calender of another person using the below code.While running this program, The Appointment is getting saved in my calender.But not being sent to the recipient. try { Microsoft.Office.Interop.Outlook.Application app = null; Microsoft.Office.Interop.Outlook.AppointmentItem appt = null; app = new Microsoft.Office.Interop.Outlook.Application(); appt = (Microsoft.Office.Interop.Outlook.AppointmentItem)app .CreateItem(Microsoft.Office.Interop.Outlook.OlItemType.olAppointmentItem); appt.Subject = "Meeting "; appt.Body = "Test Appointment body"; appt.Location = "TBD"; appt.Start = Convert.ToDateTime("12/23/2009 05:00:00 PM"); appt.Recipients.Add("[email protected]"); appt.End = Convert.ToDateTime("12/23/2009 6:00:00 PM"); appt.ReminderSet = true; appt.ReminderMinutesBeforeStart = 15; appt.Importance = Microsoft.Office.Interop.Outlook.OlImportance.olImportanceHigh; appt.BusyStatus = Microsoft.Office.Interop.Outlook.OlBusyStatus.olBusy; appt.Save(); appt.Send(); } catch (COMException ex) { Response.Write(ex.ToString()); } Am i missing anything? Can any one help me out to solve this issue?

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  • Center big image in smaller div

    - by larin555
    I'm trying to align images in the center of a slider div. I'm adjusting FlexSlider css by the way. Here's my CSS code : .flexslider {margin: 0; padding: 0; width: 600px; height:480px; overflow:hidden;margin-left:auto;margin-right:auto;} .flexslider .slides > li {display: none; -webkit-backface-visibility: hidden;} /* Hide the slides before the JS is loaded. Avoids image jumping */ .flexslider .slides img {width:auto;height:100%; display: inline-block; text-align:center;} Everything is working like I want, except that I want wider image to be centered in the div. Right now it is left-aligned. I cannot use background-image by the way. Any ideas? I also tried applying to the .flexslider .slides img : margin-left:-50%...not working margin-left:auto and margin-right:auto...not working left:50% and right:50%...not working either

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  • Ruby: counters, counting and incrementing

    - by Shyam
    Hi, If you have seen my previous questions, you'd already know I am a big nuby when it comes to Ruby. So, I discovered this website which is intended for C programming, but I thought whatever one can do in C, must be possible in Ruby (and more readable too). The challenge is to print out a bunch of numbers. I discovered this nifty method .upto() and I used a block (and actually understanding its purpose). However, in IRb, I got some unexpected behavior. class MyCounter def run 1.upto(10) { |x| print x.to_s + " " } end end irb(main):033:0> q = MyCounter.new => #<MyCounter:0x5dca0> irb(main):034:0> q.run 1 2 3 4 5 6 7 8 9 10 => 1 I have no idea where the = 1 comes from :S Should I do this otherwise? I am expecting to have this result: 1 2 3 4 5 6 7 8 9 10 Thank you for your answers, comments and feedback!

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  • Convert a image to a monochrome byte array

    - by Scott Chamberlain
    I am writing a library to interface C# with the EPL2 printer language. One feature I would like to try to implement is printing images, the specification doc says p1 = Width of graphic Width of graphic in bytes. Eight (8) dots = one (1) byte of data. p2 = Length of graphic Length of graphic in dots (or print lines) Data = Raw binary data without graphic file formatting. Data must be in bytes. Multiply the width in bytes (p1) by the number of print lines (p2) for the total amount of graphic data. The printer automatically calculates the exact size of the data block based upon this formula. I plan on my source image being a 1 bit per pixel bmp file, already scaled to size. I just don't know how to get it from that format in to a byte[] for me to send off to the printer. I tried ImageConverter.ConvertTo(Object, Type) it succeeds but the array it outputs is not the correct size and the documentation is very lacking on how the output is formatted. My current test code. Bitmap i = (Bitmap)Bitmap.FromFile("test.bmp"); ImageConverter ic = new ImageConverter(); byte[] b = (byte[])ic.ConvertTo(i, typeof(byte[])); Any help is greatly appreciated even if it is in a totally different direction.

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  • Display one div if nothing is selected

    - by Levani
    I use this javascript to display different div classes upon selection. I need to display one div class if nothing is selected, for example when page is loaded, and that replace it with one of the divs according to the selection... <script type="text/javascript"><!-- var lastDiv = ""; function showDiv(divName) { // hide last div if (lastDiv) { document.getElementById(lastDiv).className = "hiddenDiv"; } //if value of the box is not nothing and an object with that name exists, then change the class if (divName && document.getElementById(divName)) { document.getElementById(divName).className = "visibleDiv"; lastDiv = divName; } } //--> </script> css: <style type="text/css" media="screen"><!-- .hiddenDiv { display: none; } .visibleDiv { display: block; border: 1px grey solid; } --></style> HTML: <form id="FormName" action="blah.php" method="get" name="FormName"> <select name="selectName" size="1" onChange="showDiv(this.value);"> <option value="">Choose One...</option> <option value="one">first</option> <option value="two">second</option> <option value="three">third</option> </select> </form> <p id="one" class="hiddenDiv">This is paragraph 1.</p> <p id="two" class="hiddenDiv">This is paragraph 2.</p> <p id="three" class="hiddenDiv">This is paragraph 3.</p> Can anyone please help?

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  • ZeroMQ REQ/REP on ipc:// and concurrency

    - by Metiu
    I implemented a JSON-RPC server using a REQ/REP 0MQ ipc:// socket and I'm experiencing strange behavior which I suspect is due to the fact that the ipc:// underlying unix socket is not a real socket, but rather a single pipe. From the documentation, one has to enforce strict zmq_send()/zmq_recv() alternation, otherwise the out-of-order zmq_send() will return an error. However, I expected the enforcement to be per-client, not per-socket. Of course with a Unix socket there is just one pipeline from multiple clients to the server, so the server won't know who it is talking with. Two clients could zmq_send() simultaneously and the server would see this as an alternation violation. The sequence could be: ClientA: zmq_send() ClientB: zmq_send() : will it block until the other send/receive completes? will it return -1? (I suspect it will with ipc:// due to inherent low-level problems, but with TCP it could distinguish the two clients) ClientA: zmq_recv() ClientB: zmq_recv() so what about tcp:// sockets? Will it work concurrently? Should I use some other locking mechanism to work around this?

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  • tiemout for a function that waits indefiinitely (like listen())

    - by Fantastic Fourier
    Hello, I'm not quite sure if it's possible to do what I'm about to ask so I thought I'd ask. I have a multi-threaded program where threads share a memory block to communicate necessary information. One of the information is termination of threads where threads constantly check for this value and when the value is changed, they know it's time for pthread_exit(). One of the threads contains listen() function and it seems to wait indefinitely. This can be problematic if there are nobody who wants to make connection and the thread needs to exit but it can't check the value whether thread needs to terminate or not since it's stuck on listen() and can't move beyond. while(1) { listen(); ... if(value == 1) pthread_exit(NULL); } My logic is something like that if it helps illustrate my point better. What I thought would solve the problem is to allow listen() to wait for a duration of time and if nothing happens, it moves on to next statement. Unfortunately, none of two args of listen() involves time limit. I'm not even sure if I'm going about the right way with multi-threaded programming, I'm not much experienced at all. So is this a good approach? Perhaps there is a better way to go about it? Thanks for any insightful comments.

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  • Terminal-based snake game: input thread manipulates output

    - by enlightened
    I'm writing a snake game for the terminal, i.e. output via print. The following works just fine: while status[snake_monad] do print to_string draw canvas, compose_all([ frame, specs, snake_to_hash(snake[snake_monad]) ]) turn! snake_monad, get_dir move! snake_monad, specs sleep 0.25 end But I don't want the turn!ing to block, of course. So I put it into a new Thread and let it loop: Thread.new do loop do turn! snake_monad, get_dir end end while status[snake_monad] do ... # no turn! here ... end Which also works logically (the snake is turning), but the output is somehow interspersed with newlines. As soon as I kill the input thread (^C) it looks normal again. So why and how does the thread have any effect on my output? And how do I work around this issue? (I don't know much about threads, even less about them in ruby. Input and output concurrently on the same terminal make the matter worse, I guess...) Also (not really important): Wanting my program as pure as possible, would it be somewhat easily possible to get the input non-blockingly while passing everything around? Thank you!

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  • When to use @Singleton in a Jersey resource

    - by dexter
    I have a Jersey resource that access the database. Basically it opens a database connection in the initialization of the resource. Performs queries on the resource's methods. I have observed that when I do not use @Singleton, the database is being open at each request. And we know opening a connection is really expensive right? So my question is, should I specify that the resource be singleton or is it really better to keep it at per request especially when the resource is connecting to the database? My resource code looks like this: //Use @Singleton here or not? @Path(/myservice/) public class MyResource { private ResponseGenerator responser; private Log logger = LogFactory.getLog(MyResource.class); public MyResource() { responser = new ResponseGenerator(); } @GET @Path("/clients") public String getClients() { logger.info("GETTING LIST OF CLIENTS"); return responser.returnClients(); } ... // some more methods ... } And I connect to the database using a code similar to this: public class ResponseGenerator { private Connection conn; private PreparedStatement prepStmt; private ResultSet rs; public ResponseGenerator(){ Class.forName("org.h2.Driver"); conn = DriverManager.getConnection("jdbc:h2:testdb"); } public String returnClients(){ String result; try{ prepStmt = conn.prepareStatement("SELECT * FROM hosts"); rs = prepStmt.executeQuery(); ... //do some processing here ... } catch (SQLException se){ logger.warn("Some message"); } finally { rs.close(); prepStmt.close(); // should I also close the connection here (in every method) if I stick to per request // and add getting of connection at the start of every method // conn.close(); } return result } ... // some more methods ... } Some comments on best practices for the code will also be helpful.

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  • Need help with threads in a client/server

    - by nunos
    For college, I am developing a local relay chat. I have to program a chat server and client that will only work on sending messages on different terminal windows on the same computer with threads and fifos. The fifos part I am having no trouble, the threads part is the one that is giving me some headaches. The server has one thread for receiving commands from a fifo (used by all clients) and another thread for each client that is connected. For each client that is connected I need to know a certain information. Firstly, I was using global variables, which worked as longs as there was only one client connected, which is much of a chat, to chat alone. So, ideally I would have some data like: -nickname -name -email -etc... per client that is connected. However, I don't know how to do that. I could create a client_data[MAX_NUMBER_OF_THREADS] where client_data was a struct with everything I needed to have access to, but this would require to, in every communication between server and client to ask for the id of the client in the array client_data and that does not seem very pratical I could also instantiate a client_data immediately after creating the thread but it would only be available in that block, and that is not very pratical either. As you can see I am in need of a little guidance here. Any comment, piece of code or link to any relevant information is greatly appreciated. Thanks.

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  • Error Reading Image

    - by javawarrior
    When I tried to open a simple smile.png image using package com.java3d.java3d.graphics; import java.awt.Color; import java.awt.image.BufferedImage; import java.io.File; import javax.imageio.ImageIO; public class Texture { public static Render floor = loadBitMap("smile.png"); public Texture(){} public static Render loadBitMap(String fileName) { try { BufferedImage image = ImageIO.read(Thread.currentThread().getContextClassLoader().getResource(fileName)); System.out.print(image==null); int width = image.getWidth(); System.out.println(width); int height = image.getHeight(); System.out.println(height); System.out.println(image.getRGB(4, 4)); Render result = new Render(width, height); image.getRGB(0, 0, width, height, result.pixels, 0, width); return result; } catch (Exception e) { System.out.println("CRASH!"); throw new RuntimeException(e); } } } it returns every pixel as -1; what could be causing this problem? Here is the image:

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