Search Results

Search found 13862 results on 555 pages for 'questions'.

Page 544/555 | < Previous Page | 540 541 542 543 544 545 546 547 548 549 550 551  | Next Page >

  • Why is parsing a jSON response to a jQUERY ajax request not working

    - by Ankur
    I know there are several similar questions on SO, I have used some of them to get this far. I am trying to list a set of urls that match my input values. I have a servlet which takes some input e.g. "aus" in the example below and returns some output using out.print() e.g. the two urls I have shown below. EXAMPLE Input: "aus" Output: [{"url":"http://dbpedia.org/resource/Stifel_Nicolaus"},{"url":"http://sempedia.org/ontology/object/Australia"}] Which is exactly what I want. I have seen that firebug doesn't seem to have anything in the response section despite having called out.print(jsonString); and it seems that out.print(jsonString); is working as expected which suggests that the variable 'jsonString' contains the expected values. However I am not exactly sure what is wrong. -------- The jQuery --------- $(document).ready(function() { $("#input").keyup(function() { var input = $("#input").val(); //$("#output").html(input); ajaxCall(input); }); }); function ajaxCall(input) { // alert(input); $.ajax({ url: "InstantSearchServlet", data: "property="+input, beforeSend: function(x) { if(x && x.overrideMimeType) { x.overrideMimeType("application/j-son;charset=UTF-8"); } }, dataType: "json", success: function(data) { for (var i = 0, len = datalength; i < len; ++i) { var urlData = data[i]; $("#output").html(urlData.url); } } }); } ------ The Servlet that calls the DAO class - and returns the results ------- public class InstantSearchServlet extends HttpServlet{ private static final long serialVersionUID = 1L; public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { System.out.println("You called?"); response.setContentType("application/json"); PrintWriter out = response.getWriter(); InstantSearch is = new InstantSearch(); String input = (String)request.getParameter("property"); System.out.println(input); try { ArrayList<String> urllist; urllist = is.getUrls(input); String jsonString = convertToJSON(urllist); out.print(jsonString); System.out.println(jsonString); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } private String convertToJSON(ArrayList<String> urllist) { Iterator<String> itr = urllist.iterator(); JSONArray jArray = new JSONArray(); int i = 0; while (itr.hasNext()) { i++; JSONObject json = new JSONObject(); String url = itr.next(); try { json.put("url",url); } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); } jArray.put(json); } String results = jArray.toString(); return results; } }

    Read the article

  • Slow Javascript touch events on Android

    - by oneself
    I'm trying to write a simple html based drawing application (standalone simplified code attached bellow). I've tested this on the following devices: iPad 1 and 2: Works great ASUS T101 running Windows: Works great Samsung Galaxy Tab: Extremely slow and patchy -- unusable. Lenovo IdeaPad K1: Extremely slow and patchy -- unusable. Asus Transformer Prime: Noticeable lag compare with the iPad -- close to usable. The Asus tablet is running ICS, the other android tablets are running 3.1 and 3.2. I tested using the stock Android browser. I also tried the Android Chrome Beta, but that was even worse. My questions is why are the Android tablets so slow? Am I doing something wrong or is it an inherit problem with Android OS or browser, or is there anything I can do about it in my code? multi.html: <html> <body> <style media="screen"> canvas { border: 1px solid #CCC; } </style> <canvas style="" id="draw" height="450" width="922"></canvas> <script class="jsbin" src="jquery.js"></script> <script src="multi.js"></script> </body> </html> multi.js: var CanvasDrawr = function(options) { // grab canvas element var canvas = document.getElementById(options.id), ctxt = canvas.getContext("2d"); canvas.style.width = '100%' canvas.width = canvas.offsetWidth; canvas.style.width = ''; // set props from options, but the defaults are for the cool kids ctxt.lineWidth = options.size || Math.ceil(Math.random() * 35); ctxt.lineCap = options.lineCap || "round"; ctxt.pX = undefined; ctxt.pY = undefined; var lines = [,,]; var offset = $(canvas).offset(); var eventCount = 0; var self = { // Bind click events init: function() { // Set pX and pY from first click canvas.addEventListener('touchstart', self.preDraw, false); canvas.addEventListener('touchmove', self.draw, false); }, preDraw: function(event) { $.each(event.touches, function(i, touch) { var id = touch.identifier; lines[id] = { x : this.pageX - offset.left, y : this.pageY - offset.top, color : 'black' }; }); event.preventDefault(); }, draw: function(event) { var e = event, hmm = {}; eventCount += 1; $.each(event.touches, function(i, touch) { var id = touch.identifier, moveX = this.pageX - offset.left - lines[id].x, moveY = this.pageY - offset.top - lines[id].y; var ret = self.move(id, moveX, moveY); lines[id].x = ret.x; lines[id].y = ret.y; }); event.preventDefault(); }, move: function(i, changeX, changeY) { ctxt.strokeStyle = lines[i].color; ctxt.beginPath(); ctxt.moveTo(lines[i].x, lines[i].y); ctxt.lineTo(lines[i].x + changeX, lines[i].y + changeY); ctxt.stroke(); ctxt.closePath(); return { x: lines[i].x + changeX, y: lines[i].y + changeY }; }, }; return self.init(); }; $(function(){ var drawr = new CanvasDrawr({ id: "draw", size: 5 }); });

    Read the article

  • how to pass a string value from one controller to another

    - by shreedevi
    I have a login controller ,and after the successful login i want to pass some string value to the menu page.however it does not work.the application crashes. I have tried possible suggesstion of Ihuk and SAM from the link below http://stackoverflow.com/questions/1685964/how-to-pass-a-string-value-from-one-view-controller-to-another-view-controller loginController.h: #import <UIKit/UIKit.h> @class RootViewController; @class Menu; @interface LoginController : UIViewController { UIButton *login_Button; UITextField *username_TextField; UITextField *password_TextField; RootViewController *mc1; UINavigationController *navigationController; Menu *mv1; } @property(nonatomic,retain) IBOutlet UIButton *login_Button; @property(nonatomic,retain) IBOutlet UITextField *username_TextField; @property(nonatomic,retain) IBOutlet UITextField *password_TextField; @property(nonatomic,retain) RootViewController *mc1; @property (nonatomic, retain) IBOutlet UINavigationController *navigationController; @property(nonatomic,retain)Menu *mv1; - (IBAction)Login_Method:(id)sender; -(id)initWithUserName:(NSString *)name ; @end loginController.m #import "LoginController.h" #import "Menu.h" #import "ViewController.h" #import "RootViewController.h" @implementation LoginController @synthesize mc1,mv1; @synthesize login_Button,username_TextField,password_TextField; @synthesize navigationController; // Implement viewDidLoad to do additional setup after // loading the view, typically from a nib. - (void)viewDidLoad { if (![self.navigationController isNavigationBarHidden]) [self.navigationController setNavigationBarHidden:YES animated:NO]; //[self presentModalViewController:navigationController animated:YES]; } - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Release any cached data, images, etc that aren't in use. } - (void)viewDidUnload { // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } - (IBAction)Login_Method:(id)sender { Menu *mv2 = [[Menu alloc] initWithUserName:@"Menu" bundle:nil]; //mv2.l1.text=@"aa"; //i tried this, but not work,so created initWithUserName self.mv1=mv2; [self presentModalViewController:mv1 animated:YES]; // [RootViewController release]; } -(id)initWithUserName:(NSString *)name { self = [super init]; if (nil == self) { return nil; } // display or store login info somewhere [mv1.l1 setText:name]; return self; } -(BOOL)textFieldShouldReturn:(UITextField *)theTextField { [theTextField resignFirstResponder]; return YES; } - (void)dealloc { [username_TextField release]; [password_TextField release]; [super dealloc]; } @end Menu.h #import <UIKit/UIKit.h> @class Menu; @interface Menu : UIViewController { UILabel *l1; UIButton *AccountSummary_Button; UIButton *PayOffQuote_Button; UIButton *PayBill_Button; UIButton *Logout_Button; UINavigationController *nv1; } @property(nonatomic,retain) IBOutlet UILabel *l1; @property(nonatomic,retain) IBOutlet UIButton *AccountSummary_Button; @property(nonatomic,retain) IBOutlet UIButton *PayOffQuote_Button; @property(nonatomic,retain) IBOutlet UIButton *PayBill_Button; @property(nonatomic,retain) IBOutlet UIButton *Logout_Button; @property (nonatomic, retain) IBOutlet UINavigationController *nv1; -(IBAction)ViewAccountSummary_method:(id)sender; -(IBAction)ViewPayOffQuote_method:(id)sender; -(IBAction)ViewPayBill_method:(id)sender; -(IBAction)Logout_method:(id)sender; @end Menu.m

    Read the article

  • how to user ajax with json in ruby on rails

    - by fenec
    I am implemeting a facebook application in rails using facebooker plugin, therefore it is very important to use this architecture if i want to update multiple DOM in my page. if my code works in a regular rails application it would work in my facebook application. i am trying to use ajax to let the user know that the comment was sent, and update the comments bloc. migration: class CreateComments < ActiveRecord::Migration def self.up create_table :comments do |t| t.string :body t.timestamps end end def self.down drop_table :comments end end controller: class CommentsController < ApplicationController def index @comments=Comment.all end def create @comment=Comment.create(params[:comment]) if request.xhr? @comments=Comment.all render :json=>{:ids_to_update=>[:all_comments,:form_message], :all_comments=>render_to_string(:partial=>"comments" ), :form_message=>"Your comment has been added." } else redirect_to comments_url end end end view: <script> function update_count(str,message_id) { len=str.length; if (len < 200) { $(message_id).innerHTML="<span style='color: green'>"+ (200-len)+" remaining</span>"; } else { $(message_id).innerHTML="<span style='color: red'>"+ "Comment too long. Only 200 characters allowed.</span>"; } } function update_multiple(json) { for( var i=0; i<json["ids_to_update"].length; i++ ) { id=json["ids_to_update"][i]; $(id).innerHTML=json[id]; } } </script> <div id="all_comments" > <%= render :partial=>"comments/comments" %> </div> Talk some trash: <br /> <% remote_form_for Comment.new, :url=>comments_url, :success=>"update_multiple(request)" do |f|%> <%= f.text_area :body, :onchange=>"update_count(this.getValue(),'remaining');" , :onkeyup=>"update_count(this.getValue(),'remaining');" %> <br /> <%= f.submit 'Post'%> <% end %> <p id="remaining" >&nbsp;</p> <p id="form_message" >&nbsp;</p> <br><br> <br> if i try to do alert(json) in the first line of the update_multiple function , i got an [object Object]. if i try to do alert(json["ids_to_update"][0]) in the first line of the update_multiple function , there is no dialog box displayed. however the comment got saved but nothing is updated. questions: 1.how can javascript and rails know that i am dealing with json objects? 2.how can i debug this problem? 3.how can i get it to work?

    Read the article

  • trie reg exp parse step over char and continue

    - by forest.peterson
    Setup: 1) a string trie database formed from linked nodes and a vector array linking to the next node terminating in a leaf, 2) a recursive regular expression function that if A) char '*' continues down all paths until string length limit is reached, then continues down remaining string paths if valid, and B) char '?' continues down all paths for 1 char and then continues down remaining string paths if valid. 3) after reg expression the candidate strings are measured for edit distance against the 'try' string. Problem: the reg expression works fine for adding chars or swapping ? for a char but if the remaining string has an error then there is not a valid path to a terminating leaf; making the matching function redundant. I tried adding a 'step-over' ? char if the end of the node vector was reached and then followed every path of that node - allowing this step-over only once; resulted in a memory exception; I cannot find logically why it is accessing the vector out of range - bactracking? Questions: 1) how can the regular expression step over an invalid char and continue with the path? 2) why is swapping the 'sticking' char for '?' resulting in an overflow? Function: void Ontology::matchRegExpHelper(nodeT *w, string inWild, Set<string> &matchSet, string out, int level, int pos, int stepover) { if (inWild=="") { matchSet.add(out); } else { if (w->alpha.size() == pos) { int testLength = out.length() + inWild.length(); if (stepover == 0 && matchSet.size() == 0 && out.length() > 8 && testLength == tokenLength) {//candidate generator inWild[0] = '?'; matchRegExpHelper(w, inWild, matchSet, out, level, 0, stepover+1); } else return; //giveup on this path } if (inWild[0] == '?' || (inWild[0] == '*' && (out.length() + inWild.length() ) == level ) ) { //wild matchRegExpHelper(w->alpha[pos].next, inWild.substr(1), matchSet, out+w->alpha[pos].letter, level, 0, stepover);//follow path -> if ontology is full, treat '*' like a '?' } else if (inWild[0] == '*') matchRegExpHelper(w->alpha[pos].next, '*'+inWild.substr(1), matchSet, out+w->alpha[pos].letter, level, 0, stepover); //keep adding chars if (inWild[0] == w->alpha[pos].letter) //follow self matchRegExpHelper(w->alpha[pos].next, inWild.substr(1), matchSet, out+w->alpha[pos].letter, level, 0, stepover); //follow char matchRegExpHelper(w, inWild, matchSet, out, level, pos+1, stepover);//check next path } } Error Message: +str "Attempt to access index 1 in a vector of size 1." std::basic_string<char,std::char_traits<char>,std::allocator<char> > +err {msg="Attempt to access index 1 in a vector of size 1." } ErrorException Note: this function works fine for hundreds of test strings with '*' wilds if the extra stepover gate is not used Semi-Solved: I place a pos < w->alpha.size() condition on each path that calls w->alpha[pos]... - this prevented the backtrack calls from attempting to access the vector with an out of bounds index value. Still have other issues to work out - it loops infinitely adding the ? and backtracking to remove it, then repeat. But, moving forward now. Revised question: why during backtracking is the position index accumulating and/or not deincrementing - so at somepoint it calls w->alpha[pos]... with an invalid position that is either remaining from the next node or somehow incremented pos+1 when passing upward?

    Read the article

  • GUI Freezes and Output to JTextField from user input

    - by user2929005
    I am having I hope only two issues currently. I have had help on this on a previous question that I have asked but now I am running into different issues. My current issues now is that I need to print out into a JTextField a sorted array. I do not have questions about how to sort the array I just would like help on how to get the array to print to the JTextField when the Bubble Sort button is pressed. Currently when I press the button it freezes. It freezes at this line. list.add(Integer.valueOf(input.nextInt())); please help Thank you. import java.awt.EventQueue; import javax.swing.*; import java.awt.event.*; import java.util.*; public class Sorting { private JFrame frame; private JTextArea inputArea; private JTextField outputArea; ArrayList<Integer> list = new ArrayList<Integer>(); Scanner input = new Scanner(System.in); /** * Launch the application. */ public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { public void run() { try { Sorting window = new Sorting(); window.frame.setVisible(true); } catch (Exception e) { e.printStackTrace(); } } }); } /** * Create the application. */ public Sorting() { initialize(); } /** * Initialize the contents of the frame. */ private void initialize() { frame = new JFrame(); frame.setBounds(100, 100, 450, 300); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setTitle("Sorting"); frame.getContentPane().setLayout(null); JButton bubbleButton = new JButton("Bubble Sort"); bubbleButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent arg0) { list.add(Integer.valueOf(input.nextInt())); // for(int i = 0; i < list.size(); i++){ // // } } }); bubbleButton.setBounds(10, 211, 114, 23); frame.getContentPane().add(bubbleButton); JButton mergeButton = new JButton("Merge Sort"); mergeButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { } }); mergeButton.setBounds(305, 211, 114, 23); frame.getContentPane().add(mergeButton); JButton quickButton = new JButton("Quick Sort"); quickButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { } }); quickButton.setBounds(163, 211, 114, 23); frame.getContentPane().add(quickButton); inputArea = new JTextArea(); inputArea.setBounds(10, 36, 414, 51); frame.getContentPane().add(inputArea); outputArea = new JTextField(); outputArea.setEditable(false); outputArea.setBounds(10, 98, 414, 59); frame.getContentPane().add(outputArea); outputArea.setColumns(10); JLabel label = new JLabel("Please Enter 5 Numbers"); label.setHorizontalAlignment(SwingConstants.CENTER); label.setBounds(10, 11, 414, 14); frame.getContentPane().add(label); } }

    Read the article

  • Loading multiple copies of a group of DLLs in the same process

    - by george
    Background I'm maintaining a plugin for an application. I'm Using Visual C++ 2003. The plugin is composed of several DLLs - there's the main DLL, that's the one that the application loads using LoadLibrary, and there are several utility DLLs that are used by the main DLL and by each other. Dependencies generally look like this: plugin.dll - utilA.dll, utilB.dll utilA.dll - utilB.dll utilB.dll - utilA.dll, utilC.dll You get the picture. Some of the dependencies between the DLLs are load-time and some run-time. All the DLL files are stored in the executable's directory (not a requirement, just how it works now). The problem There's a new requirement - running multiple instances of the plugin within the application. The application runs each instance of a plugin in its own thread, i.e. each thread calls The plugin's code, however, is nothing but thread-safe - lots of global variables etc.. Unfortunately, fixing the whole thing isn't currently an option, so I need a way to load multiple (at most 3) copies of the plugin's DLLs in the same process. Option 1: The distinct names approach Creating 3 copies of each DLL file, so that each file has a distinct name. e.g. plugin1.dll, plugin2.dll, plugin3.dll, utilA1.dll, utilA2.dll, utilA3.dll, utilB1.dll, etc.. The application will load plugin1.dll, plugin2.dll and plugin3.dll. The files will be in the executable's directory. For each group of DLLs to know each other by name (so the inter-dependencies work), the names need to be known at compilation time - meaning the DLLs need to be compiled multiple times, only each time with different output file names. Not very complicated, but I'd hate having 3 copies of the VS project files, and don't like having to compile the same files over and over. Option 2: The side-by-side assemblies approach Creating 3 copies of the DLL files, each group in its own directory, and defining each group as an assembly by putting an assembly manifest file in the directory, listing the plugin's DLLs. Each DLL will have an application manifest pointing to the assembly, so that the loader finds the copies of the utility DLLs that reside in the same directory. The manifest needs to be embedded for it to be found when a DLL is loaded using LoadLibrary. I'll use mt.exe from a later VS version for the job, since VS2003 has no built-in manifest embedding support. I've tried this approach with partial success - dependencies are found during load-time of the DLLs, but not when a DLL function is called that loads another DLL. This seems to be the expected behavior according to this article - A DLL's activation context is only used at the DLL's load-time, and afterwards it's deactivated and the process's activation context is used. I haven't yet tried working around this using ISOLATION_AWARE_ENABLED. Questions Got any other options? Any quick & dirty solution will do. :-) Will ISOLATION_AWARE_ENABLED even work with VS2003? Comments will be greatly appreciated. Thanks!

    Read the article

  • Migrate Spring JPA DAO unit testing to google app engine

    - by twingocerise
    I'm trying to put together a simple environment where I can get Spring, Maven, JPA, Google App Engine and DAO unit testing working happily all together. The goal is to be able to run a simple DAO unit test creating an entity and then load it again with a simple find to check it's been created properly - all of this from my maven build. My dao is making use of the JPA entity manager (query(), persist(), etc.) I've got it working no problem with hsqldb and a datasource, etc. but I'm struggling to get it working with appengine. My questions are: 1) I'm using an entity manager, injecting my persistence unit as followed. Is it OK? Is there any need for a datasource or something special? I thought not but correct me if I'm wrong. applicationContext.xml <bean id='entityManagerFactory' class='org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean'> <property name="persistenceUnitName" value="transactions-optional" /> </bean> Persistence.xml <persistence-unit name="transactions-optional"> <provider>org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider</provider> <properties> <property name="datanucleus.NontransactionalRead" value="true"/> <property name="datanucleus.NontransactionalWrite" value="true"/> <property name="datanucleus.ConnectionURL" value="appengine"/> </properties> </persistence-unit> 2) what are the dependencies I need to add to my pom file to be able to run the unit test making use of the entityManager? What about versions ? I found loads of things about appengine-api-labs/stubs/testing but none them got it working i.e. I'm getting jdo dependency missing while I'm using JPA... I also get loads of conflicts when I try to add some jars (datanucleus and stuff). So far I'm trying appengine-api-1.0-sdk v1.7.0 - ASM-all v3.3 - datanucleus core/api-jpa/enhancer v3.1.0 - datanucleus-appengine v2.0.1.1 and all the gae testing jars v1.7.0 3) Is there anything I need to add to my surefire plugin (test runner) to make sure it picks up all the dependencies? I'm getting an exhausting ClassNotFound on DatastorePersistenceProvider while it is in my classpath (I checked the jars and the mvn dependency:tree) I had a look at this but it doesn't seem to be working at all: http://www.vertigrated.com/blog/2011/02/working-maven-3-google-app-engine-plugin-with-gwt-support/ 4) Do I need to use any sot of localhelper to test my DAOs? Ideally I'd want to test my dao layer "as is" with the entity manager... what's your opinion ? Has anyone managed to run a unit test using JPA on google app engine ? 5) Do I need to set up any sort of gae.home somewhere in my pom file? Would anyone make use of it (a plugin or something) ? 6) Is the gwt-maven plugin any helpful if I don't use gwt - I'm writing a simple webservice making use of appengine, not a GWT app... Any help would be much appreciated as I've been struggling for 2 days now... Cheers, V.

    Read the article

  • Reconciling a new BindingList into a master BindingList using LINQ

    - by Neo
    I have a seemingly simple problem whereby I wish to reconcile two lists so that an 'old' master list is updated by a 'new' list containing updated elements. Elements are denoted by a key property. These are my requirements: All elements in either list that have the same key results in an assignment of that element from the 'new' list over the original element in the 'old' list only if any properties have changed. Any elements in the 'new' list that have keys not in the 'old' list will be added to the 'old' list. Any elements in the 'old' list that have keys not in the 'new' list will be removed from the 'old' list. I found an equivalent problem here - http://stackoverflow.com/questions/161432/ - but it hasn't really been answered properly. So, I came up with an algorithm to iterate through the old and new lists and perform the reconciliation as per the above. Before anyone asks why I'm not just replacing the old list object with the new list object in its entirety, it's for presentation purposes - this is a BindingList bound to a grid on a GUI and I need to prevent refresh artifacts such as blinking, scrollbars moving, etc. So the list object must remain the same, only its updated elements changed. Another thing to note is that the objects in the 'new' list, even if the key is the same and all the properties are the same, are completely different instances to the equivalent objects in the 'old' list, so copying references is not an option. Below is what I've come up with so far - it's a generic extension method for a BindingList. I've put comments in to demonstrate what I'm trying to do. public static class BindingListExtension { public static void Reconcile<T>(this BindingList<T> left, BindingList<T> right, string key) { PropertyInfo piKey = typeof(T).GetProperty(key); // Go through each item in the new list in order to find all updated and new elements foreach (T newObj in right) { // First, find an object in the new list that shares its key with an object in the old list T oldObj = left.First(call => piKey.GetValue(call, null).Equals(piKey.GetValue(newObj, null))); if (oldObj != null) { // An object in each list was found with the same key, so now check to see if any properties have changed and // if any have, then assign the object from the new list over the top of the equivalent element in the old list foreach (PropertyInfo pi in typeof(T).GetProperties()) { if (!pi.GetValue(oldObj, null).Equals(pi.GetValue(newObj, null))) { left[left.IndexOf(oldObj)] = newObj; break; } } } else { // The object in the new list is brand new (has a new key), so add it to the old list left.Add(newObj); } } // Now, go through each item in the old list to find all elements with keys no longer in the new list foreach (T oldObj in left) { // Look for an element in the new list with a key matching an element in the old list if (right.First(call => piKey.GetValue(call, null).Equals(piKey.GetValue(oldObj, null))) == null) { // A matching element cannot be found in the new list, so remove the item from the old list left.Remove(oldObj); } } } } It can be called like this: _oldBindingList.Reconcile(newBindingList, "MyKey") However, I'm looking for perhaps a method of doing the same using LINQ type methods such as GroupJoin<, Join<, Select<, SelectMany<, Intersect<, etc. So far, the problem I've had is that each of these LINQ type methods result in brand new intermediary lists (as a return value) and really, I only want to modify the existing list for all the above reasons. If anyone can help with this, would be most appreciated. If not, no worries, the above method (as it were) will suffice for now. Thanks, Jason

    Read the article

  • Java algorithm for normalizing audio

    - by Marty Pitt
    I'm trying to normalize an audio file of speech. Specifically, where an audio file contains peaks in volume, I'm trying to level it out, so the quiet sections are louder, and the peaks are quieter. I know very little about audio manipulation, beyond what I've learnt from working on this task. Also, my math is embarrassingly weak. I've done some research, and the Xuggle site provides a sample which shows reducing the volume using the following code: (full version here) @Override public void onAudioSamples(IAudioSamplesEvent event) { // get the raw audio byes and adjust it's value ShortBuffer buffer = event.getAudioSamples().getByteBuffer().asShortBuffer(); for (int i = 0; i < buffer.limit(); ++i) buffer.put(i, (short)(buffer.get(i) * mVolume)); super.onAudioSamples(event); } Here, they modify the bytes in getAudioSamples() by a constant of mVolume. Building on this approach, I've attempted a normalisation modifies the bytes in getAudioSamples() to a normalised value, considering the max/min in the file. (See below for details). I have a simple filter to leave "silence" alone (ie., anything below a value). I'm finding that the output file is very noisy (ie., the quality is seriously degraded). I assume that the error is either in my normalisation algorithim, or the way I manipulate the bytes. However, I'm unsure of where to go next. Here's an abridged version of what I'm currently doing. Step 1: Find peaks in file: Reads the full audio file, and finds this highest and lowest values of buffer.get() for all AudioSamples @Override public void onAudioSamples(IAudioSamplesEvent event) { IAudioSamples audioSamples = event.getAudioSamples(); ShortBuffer buffer = audioSamples.getByteBuffer().asShortBuffer(); short min = Short.MAX_VALUE; short max = Short.MIN_VALUE; for (int i = 0; i < buffer.limit(); ++i) { short value = buffer.get(i); min = (short) Math.min(min, value); max = (short) Math.max(max, value); } // assign of min/max ommitted for brevity. super.onAudioSamples(event); } Step 2: Normalize all values: In a loop similar to step1, replace the buffer with normalized values, calling: buffer.put(i, normalize(buffer.get(i)); public short normalize(short value) { if (isBackgroundNoise(value)) return value; short rawMin = // min from step1 short rawMax = // max from step1 short targetRangeMin = 1000; short targetRangeMax = 8000; int abs = Math.abs(value); double a = (abs - rawMin) * (targetRangeMax - targetRangeMin); double b = (rawMax - rawMin); double result = targetRangeMin + ( a/b ); // Copy the sign of value to result. result = Math.copySign(result,value); return (short) result; } Questions: Is this a valid approach for attempting to normalize an audio file? Is my math in normalize() valid? Why would this cause the file to become noisy, where a similar approach in the demo code doesn't?

    Read the article

  • retrieving value from database in java

    - by Akcire Atienza
    I am making AGAIN another program that retrieves the inputted data/values of fields from the database I created. but this time, my inputted value will be coming from the JtextField I created. I wonder what's wrong in here bec when I'm running it the output is always null. in this program i will convert the inputted value of my JTextField into int. here it is: public class ButtonHandler implements ActionListener { public void actionPerformed(ActionEvent e) { if(e.getSource() == extendB) { ExtensionForm extend = new ExtensionForm(); extend.setVisible(true); } else if(e.getSource()== searchB) { //get text from the textField String guest = guestIDTF.getText(); //parse the string to integer for retrieving of data int id = Integer.parseInt(guest); GuestsInfo guestInfo = new GuestsInfo(id); Room roomInfo = new Room(id); String labels[] = {guestInfo.getFirstName()+" "+guestInfo.getLastName(),""+roomInfo.getRoomNo(),roomInfo.getRoomType(),guestInfo.getTime(),"11:00"}; for(int z = 0; z<labels.length; z++) { labelDisplay[z].setText(labels[z]); } in my second class it retrieves the inputted values of fields from the database I created here's the code: import java.sql.*; public class Room { private String roomType; private int guestID, roomNo; private Connection con; private PreparedStatement statement; public Room(){ try { Class.forName("com.mysql.jdbc.Driver"); con = DriverManager.getConnection( "jdbc:mysql://localhost:3306/3moronsdb","root",""); } catch (Exception e) { e.printStackTrace(); } } public Room(int guestsID) { this(); try{ statement = con.prepareStatement("SELECT * FROM guest WHERE guestID=?"); statement.setInt(1, guestID); ResultSet rs = statement.executeQuery(); while(rs.next()){ this.guestID = rs.getInt(1); this.roomType = rs.getString(2); this.roomNo = rs.getInt(3); } }catch(Exception e){ System.out.print(e); } } //Constructor for setting rate public Room(String roomType, int roomNo) { this(); try { statement = con.prepareStatement("Insert into room(roomType, roomNo) values(?,?)"); statement.setString(1, roomType); statement.setInt(2, roomNo); statement.executeUpdate(); } catch(Exception e) { e.printStackTrace(); return; } } //getting roomType public String getRoomType(){ return roomType; } //getting roomNo public int getRoomNo(){ return roomNo; } //getting guestID public int getGuestId(){ return guestID; } } i already insert some values in my 3moronsdb which are ( 1, Classic , 103). here's my TEST main class: public class TestMain { public static void main(String [] a){ GuestsInfo guest = new GuestsInfo(1); //note that this instantiation is the other class which i just ask the other day.. (http://stackoverflow.com/questions/12762835/retrieving-values-from-database-in-java) Room rum = new Room(1); System.out.print(rum.getRoomType()+" "+ guest.getFirstName()); } } when i'm running it it only gives me null output for the Room class but i am getting the output of the GuestsInfo class which is 'Ericka'. Can you help me guys? I know I ask this kind of problem yesterday but i really don't know what's wrong in here now..

    Read the article

  • Getter/Setter (composition, Java, HW)

    - by Crystal
    I have one class called Person that basically looks like: public class Person { String firstName; String lastName; String telephone; String email; public Person() { firstName = ""; lastName = ""; telephone = ""; email = ""; } public Person(String firstName, String lastName, String telephone, String email) { this.firstName = firstName; this.lastName = lastName; this.telephone = telephone; this.email = email; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } .... Using that class, I setup an abstract class called Loan that looks like: public abstract class Loan { public void setClient(Person client) { this.client = client; } public Person getClient() { return client; } public void setLoanId(int nextId) { loanId = nextId; nextId++; } public int getLoanId() { return loanId; } public void setInterestRate(double interestRate) { this.interestRate = interestRate; } public double getInterestRate() { return interestRate; } public void setLoanLength(int loanLength) { this.loanLength = loanLength; } public int getLoanLength() { return loanLength; } public void setLoanAmount(double loanAmount) { this.loanAmount = loanAmount; } public double getLoanAmount(double loanAmount) { return loanAmount; } private Person client; private int loanId; private double interestRate; private int loanLength; private double loanAmount; private static int nextId = 1; } I have to extend the Loan class with CarLoan and it looks like: public class CarLoan extends Loan { public CarLoan(Person client, double vehiclePrice, double downPayment, double salesTax, double interestRate, CAR_LOAN_TERMS length) { super.setClient(client); super.setInterestRate(interestRate); this.client = client; this.vehiclePrice = vehiclePrice; this.downPayment = downPayment; this.salesTax = salesTax; this.length = length; } public void setVehiclePrice(double vehiclePrice) { this.vehiclePrice = vehiclePrice; } public double getVehiclePrice() { return vehiclePrice; } public void setDownPayment(double downPayment) { this.downPayment = downPayment; } public double getDownPayment() { return downPayment; } public void setSalesTax(double salesTax) { this.salesTax = salesTax; } public double getSalesTax() { return salesTax; } public String toString() { return getClass().getName() + "[vehiclePrice = " + vehiclePrice + '\n' + "downPayment = " + downPayment + '\n' + "salesTax = " + salesTax + "]"; } public enum CAR_LOAN_TERMS {TWO_YEAR, THREE_YEAR, SIX_YEAR}; private double vehiclePrice; private double downPayment; private double salesTax; Few questions. (a) Is what I did in the Loan class to setClient correct given what I have in the Person class? (e.g.this.client = client) (b) Can I call super twice in a method? I have to set two attributes from the Loan class from the constructor in the CarLoan class and I thought that would be a way to do it. (c) Do you have to set attributes for enumeration types differently in a constructor or getter/setter methods? I get an error for (this.length = length) in my CarLoan class and I was unsure of how enumeration values should be set. Thanks!

    Read the article

  • Problems re-populating select options in Rails when form returned with errors

    - by Rick
    I have a form with 2 select options in it -- frequency and duration. When there are errors with the form, and it is returned to the browser, the select options are not re-populated with the selections the user made even though the returned values for those fields match the values of options in the selects. Also, when the form is returned, these fields are not marked as having errors even though their values are blank. Here's the frequency and duration fields in Rails <%= frequency_select c, :frequency %> <%= duration_select c, :duration %> The method for frequency_select is def frequency_select(f, method) options = [["day", 1.day], ["other day", 2.days], ["week", 1.week]] f.select method, options, :include_blank => true end And the method for duration_select is def duration_select(f, method, unit="day" ) values, units = *case unit when "day" : [[[5, 5], [15, 15], [30, 29]], "days"] when "other day" : [[[15, 15], [30, 29], [45,45]], "days"] when "week" : [[[4, 29], [6, 43], [8, 57]], "weeks"] end f.select method, values.map {|(label, i)| ["#{label} #{units}", i.days]}, :include_blank => true end If you enter a value into one or both of these fields and submit the form without completing part of it (any part of it), the form is returned to the user (as would be expected), but the duration and frequency fields are not re-populated with the user's selection. If I add this bit of code to the form <p><%= @challenge.attributes.inspect %></p> I see that this for duration and frequency when the form is returned to the browser: "duration"=>3888000, "frequency"=>172800 These values match values on the options in the select fields. Is there anything special in Rails that needs to be done so that the select fields are re-populated with the user's selections? Any thoughts on what the problem could be or what I should try next? Help is greatly appreciated! -Rick PS If you look at some of the other questions, you'll notice I've asked about this in the past. At one point, I thought the form was returning values for frequency and duration in days rather than seconds, but that's not the case. PPS Here's one other bit of information that might matter, but my tests indicate that it probably does not. (Though, I'm a bit of a newbie to this, so don't take my word for it.) These two fields are chained together using the cascade jquery plugin. The javascript is included on the page (not in a separate file) and some of the js is being created by Rails. First, here are the scripts as they appear in the browser. The first is the script to generate the options for the duration select and the second is the script required by the Cascade plugin to trigger the field chaining. <script type="text/javascript"> var list1 = [ {'When':'86400','Value':' ','Text':' '}, {'When':'172800','Value':' ','Text':' '}, {'When':'604800','Value':' ','Text':' '}, {'When':'86400','Value':'432000','Text':'5 days'}, {'When':'86400','Value':'1296000','Text':'15 days'}, {'When':'86400','Value':'2505600','Text':'30 days'}, {'When':'172800','Value':'1296000','Text':'15 days'}, {'When':'172800','Value':'2505600','Text':'30 days'}, {'When':'172800','Value':'3888000','Text':'45 days'}, {'When':'604800','Value':'2505600','Text':'4 weeks'}, {'When':'604800','Value':'3715200','Text':'6 weeks'}, {'When':'604800','Value':'4924800','Text':'8 weeks'} ]; function commonTemplate(item) { return "<option value='" + item.Value + "'>" + item.Text + "</option>"; }; function commonMatch(selectedValue) { return this.When == selectedValue; }; </script> <script type="text/javascript"> jQuery(document).ready(function(){ jQuery("#challenge_duration, #user_challenge_duration").cascade("#challenge_frequency, #user_challenge_frequency",{ list: list1, template: commonTemplate, match: commonMatch }) }); </script> And here's a bit of the the first script as it is in the erb file -- you see that some of the script is being generated by Rails <%= [ [1.day, [[5, 5], [15,15], [30, 29]], "days"], [2.days, [[15, 15], [30, 29], [45, 45]], "days"], [1.week, [[4, 29], [6, 43], [8, 57]], "weeks"]].map do |(frequency, durations, unit)| durations.map do |(label, value)| "{'When':'#{frequency}','Value':'#{value.days}','Text':'#{label} #{unit}'}" end end.join(",\n") -%> Now, the reason I don't think that it matters whether the duration is being generated with JS is the problem still exists if I remove all the JS the problem also affects the frequency field, whose options are not being generated by the JS

    Read the article

  • PHP and XPath Loop

    - by user1794852
    Thank you all in advance. I've got some great answers to my sometimes stupid questions, so thank you again. I'm trying to parse a SOAP response using PHP, Xpath (namespaces) and SimpleXML. Down below is a snippet of the Response. What I need to do is loop through each <ns1:file></ns1:file> and add it to a DB. But I'm not sure how to do that. Please help! Namespace Stuff $x = simplexml_load_string($response); $x->registerXPathNamespace('ns1', 'http://ws.icontent.idefense.com/V3/2'); Here's the response: <ns1:mal_files> <ns1:file> <ns1:id>2895144</ns1:id> <ns1:md5>2189c3d3857ba0cabd19c8aa031d63cd</ns1:md5> <ns1:sha1>c20b26148caa059ecf85e9b29df4e28e8354d655</ns1:sha1> <ns1:path>%WINDIR%\Temp\Temporary Internet Files\Content.IE5\K9ANOPQB\1219831[1].htm</ns1:path> <ns1:size>110</ns1:size> <ns1:code_available>true</ns1:code_available> <ns1:len_char>fixed</ns1:len_char> </ns1:file> <ns1:file> <ns1:id>2895147</ns1:id> <ns1:md5>a533825ef1752630a300125b3eef6825</ns1:md5> <ns1:sha1>ec7feb1414b3c2e720f6c06e2750421b73634f87</ns1:sha1> <ns1:path>%WINDIR%\Temp\Temporary Internet Files\Content.IE5\4PMB8T67\bg[1].jpg</ns1:path> <ns1:size>707</ns1:size> <ns1:code_available>true</ns1:code_available> <ns1:len_char>fixed</ns1:len_char> </ns1:file> <ns1:file> <ns1:id>2895155</ns1:id> <ns1:md5>c88724e985efcc82173c0d3aa0b77dfd</ns1:md5> <ns1:sha1>ecc042ca06aac988cd4593bb2b25fa39c4b2a819</ns1:sha1> <ns1:path>%WINDIR%\Prefetch\24604775.EXE-3ADEC0C2.pf</ns1:path> <ns1:size>44940</ns1:size> <ns1:code_available>true</ns1:code_available> <ns1:len_char>fixed</ns1:len_char> </ns1:file> <ns1:file> <ns1:id>2895158</ns1:id> <ns1:md5>422a011793af6195ea517c2c4a26bdbc</ns1:md5> <ns1:sha1>f449240c091c27e2531342d6b291d6a7e4655834</ns1:sha1> <ns1:path>%WINDIR%\Temp\Temporary Internet Files\Content.IE5\KPYV0TM7\gamesleap[1].png</ns1:path> <ns1:size>2676</ns1:size> <ns1:code_available>true</ns1:code_available> <ns1:len_char>fixed</ns1:len_char> </ns1:file> </ns1:mal_files> PHP Code $md5 = $x->xpath('//ns1:mal_files/ns1:file/ns1:md5'); // Returns array :( The PHP code returns an Array of all MD5 for every <ns1:file></ns1:file> and that's not what I need. What I need is to loop through each of the (nodes?) for each of the <ns1:file> keying on the <ns1:id> and add all their associated elements (id, md5, sha1, etc) as a record, then move onto the next <ns1:file> and repeat. And obviously the PHP I'm using returns an array, which doesn't work here. Hopefully I've made my question clear... I appreciate any help. Thanks!

    Read the article

  • How can I pipe two Perl CORE::system commands in a cross-platform way?

    - by Pedro Silva
    I'm writing a System::Wrapper module to abstract away from CORE::system and the qx operator. I have a serial method that attempts to connect command1's output to command2's input. I've made some progress using named pipes, but POSIX::mkfifo is not cross-platform. Here's part of what I have so far (the run method at the bottom basically calls system): package main; my $obj1 = System::Wrapper->new( interpreter => 'perl', arguments => [-pe => q{''}], input => ['input.txt'], description => 'Concatenate input.txt to STDOUT', ); my $obj2 = System::Wrapper->new( interpreter => 'perl', arguments => [-pe => q{'$_ = reverse $_}'}], description => 'Reverse lines of input input', output => { '>' => 'output' }, ); $obj1->serial( $obj2 ); package System::Wrapper; #... sub serial { my ($self, @commands) = @_; eval { require POSIX; POSIX->import(); require threads; }; my $tmp_dir = File::Spec->tmpdir(); my $last = $self; my @threads; push @commands, $self; for my $command (@commands) { croak sprintf "%s::serial: type of args to serial must be '%s', not '%s'", ref $self, ref $self, ref $command || $command unless ref $command eq ref $self; my $named_pipe = File::Spec->catfile( $tmp_dir, int \$command ); POSIX::mkfifo( $named_pipe, 0777 ) or croak sprintf "%s::serial: couldn't create named pipe %s: %s", ref $self, $named_pipe, $!; $last->output( { '>' => $named_pipe } ); $command->input( $named_pipe ); push @threads, threads->new( sub{ $last->run } ); $last = $command; } $_->join for @threads; } #... My specific questions: Is there an alternative to POSIX::mkfifo that is cross-platform? Win32 named pipes don't work, as you can't open those as regular files, neither do sockets, for the same reasons. 2. The above doesn't quite work; the two threads get spawned correctly, but nothing flows across the pipe. I suppose that might have something to do with pipe deadlocking or output buffering. What throws me off is that when I run those two commands in the actual shell, everything works as expected. Point 2 is solved; a -p fifo file test was not testing the correct file.

    Read the article

  • many-to-many-to-many, incl alignment of data from diff sources

    - by JefeCoon
    Re-factoring dbase to support many:many:many. At the second and third levels we need to preserve end-user 'mapping' or aligning of data from different sources, e.g. Order 17 FirstpartyOrderID => aha LineItem_for_BigShinyThingy => AA-1 # maps to 77-a LineItem_for_BigShinyThingy => AA-2 # maps to 77-b, 77-c LineItem_for_LittleWidget => AA-x # maps to 77-zulu, 77-alpha, 99-foxtrot LineItem_for_LittleWidget => AA-y # maps to 77-zulu, 99-foxtrot LineItem_for_LittleWidget => AA-z # maps to 77-alpha ThirdpartyOrderID => foo LineItem_for_BigShinyThingy => 77-a LineItem_for_BigShinyThingy => 77-b LineItem_for_BigShinyThingy => 77-c LineItem_for_LittleWidget => 77-zulu LineItem_for_LittleWidget => 77-alpha ThirdpartyOrderID => bar LineItem_for_LittleWidget => 99-foxtrot Each LineItem has daily datapoints reported from its own source (Firstparty|Thirdparty). In our UI & app we provide tools to align these, then we'd like to save them into the cleanest possible schema for querying, enabling us to diff the reported daily datapoints, and perform other daily calculations (which we'll store in the dbase also, fortunately that should be cake once we've nailed this). We need to map related [firstparty|thirdparty]line_items which have their own respective datapoints. We'll be using the association to pull each line_items collection of datapoints for summary and discrepancy calculations. I'm considering two options, std has_many,through x2 --or-- possibly (scary) ubermasterjoin table OptionA: order<<-->> order_join_table[id,order_id,firstparty_order_id,thirdparty_order_id] <<-->>line_item order_join_table[firstparty_order_id]-->raw_order[id] order_join_table[thirdparty_order_id]-->raw_order[id] raw_order-->raw_line_items[raw_order_id] line_item<<-->> line_item_join[id,LI_join_id,firstparty_LI,thirdparty_LI <<-->>raw_line_items line_item_join[firstparty_LI]-->raw_line_item[id] line_item_join[thirdparty_LI]-->raw_line_item[id] raw_line_item<<-->>datapoints = we rely upon join to store all mappings of first|third orders & line_items = keys to raw_* enable lookup of these order & line_item details = concerns about circular references and/or lack of correct mapping logic, e.g order--line_item--raw_line_items vs. order--raw_order--raw_line_items OptionB: order<<-->> join_master[id,order_id,FP_order_id,TP_order_id,FP_line_item_id,TP_line_item_id] join_master[FP_order_id & TP_order_id]-->raw_order[id] join_master[FP_line_item_id & TP_line_item_id]-->raw_line_item[id] = every combo of FP_line_item + TP_line_item writes a record into the join_master table = "theoretically" queries easy/fast/flexible/sexy At long last, my questions: a) any learnings from painful firsthand experience about how best to implement/tune/optimize many-to-many-to-many relationships b) in rails? c) any painful gotchas (circular references, slow queries, spaghetti-monsters) to watch out for? d) any joy & goodness in Rails3 that makes this magically easy & joyful? e) anyone written the "how to do many-to-many-to-many schema in Rails and make it fast & sexy?" tutorial that I somehow haven't found? If not, I'll follow up with our learnings in the hope it's helpful.. Thanks in advance- --Jeff

    Read the article

  • How to develop an english .com domain value rating algorithm?

    - by Tom
    I've been thinking about an algorithm that should rougly be able to guess the value of an english .com domain in most cases. For this to work I want to perform tests that consider the strengths and weaknesses of an english .com domain. A simple point based system is what I had in mind, where each domain property can be given a certain weight to factor it's importance in. I had these properties in mind: domain character length Eg. initially 20 points are added. If the domain has 4 or less characters, no points are substracted. For each extra character, one or more points are substracted on an exponential basis (the more characters, the higher the penalty). domain characters Eg. initially 20 points are added. If the domain is only alphabetic, no points are substracted. For each non-alhabetic character, X points are substracted (exponential increase again). domain name words Scans through a big offline english database, including non-formal speech, eg. words like "tweet" should be recognized. Question 1 : where can I get a modern list of english words for use in such application? Are these lists available for free? Are there lists like these with non-formal words? The more words are found per character, the more points are added. So, a domain with a lot of characters will still not get a lot of points. words hype-level I believe this is a tricky one, but this should be the cause to differentiate perfect but boring domains from perfect and interesting domains. For example, the following domain is probably not that valueable: www.peanutgalaxy.com The algorithm should identify that peanuts and galaxies are not very popular topics on the web. This is just an example. On the other side, a domain like www.shopdeals.com should ring a bell to the hype test, as shops and deals are quite popular on the web. My initial thought would be to see how often these keywords are references to on the web, preferably with some database. Question 2: is this logic flawed, or does this hype level test have merit? Question 3: are such "hype databases" available? Or is there anything else that could work offline? The problem with eg. a query to google is that it requires a lot of requests due to the many domains to be tested. domain name spelling mistakes Domains like "freemoneyz.com" etc. are generally (notice I am making a lot of assumptions in this post but that's necessary I believe) not valueable due to the spelling mistakes. Question 4: are there any offline APIs available to check for spelling mistakes, preferably in javascript or some database that I can use interact with myself. Or should a word list help here as well? use of consonants, vowels etc. A domain that is easy to pronounce (eg. Google) is usually much more valueable than one that is not (eg. Gkyld). Question 5: how does one test for such pronuncability? Do you check for consonants, vowels, etc.? What does a valueable domain have? Has there been any work in this field, where should I look? That is what I came up with, which leads me to my final two questions. Question 6: can you think of any more english .com domain strengths or weaknesses? Which? How would you implement these? Question 7: do you believe this idea has any merit or all, or am I too naive? Anything I should know, read or hear about? Suggestions/comments? Thanks!

    Read the article

  • Question about unions and heap allocated memory

    - by Dennis Miller
    I was trying to use a union to so I could update the fields in one thread and then read allfields in another thread. In the actual system, I have mutexes to make sure everything is safe. The problem is with fieldB, before I had to change it fieldB was declared like field A and C. However, due to a third party driver, fieldB must be alligned with page boundary. When I changed field B to be allocated with valloc, I run into problems. Questions: 1) Is there a way to statically declare fieldB alligned on page boundary. Basically do the same thing as valloc, but on the stack? 2) Is it possible to do a union when field B, or any field is being allocated on the heap?. Not sure if that is even legal. Here's a simple Test program I was experimenting with. This doesn't work unless you declare fieldB like field A and C, and make the obvious changes in the public methods. #include <iostream> #include <stdlib.h> #include <string.h> #include <stdio.h> class Test { public: Test(void) { // field B must be alligned to page boundary // Is there a way to do this on the stack??? this->field.fieldB = (unsigned char*) valloc(10); }; //I know this is bad, this class is being treated like //a global structure. Its self contained in another class. unsigned char* PointerToFieldA(void) { return &this->field.fieldA[0]; } unsigned char* PointerToFieldB(void) { return this->field.fieldB; } unsigned char* PointerToFieldC(void) { return &this->field.fieldC[0]; } unsigned char* PointerToAllFields(void) { return &this->allFields[0]; } private: // Is this union possible with field B being // allocated on the heap? union { struct { unsigned char fieldA[10]; //This field has to be alligned to page boundary //Is there way to be declared on the stack unsigned char* fieldB; unsigned char fieldC[10]; } field; unsigned char allFields[30]; }; }; int main() { Test test; strncpy((char*) test.PointerToFieldA(), "0123456789", 10); strncpy((char*) test.PointerToFieldB(), "1234567890", 10); strncpy((char*) test.PointerToFieldC(), "2345678901", 10); char dummy[11]; dummy[10] = '\0'; strncpy(dummy, (char*) test.PointerToFieldA(), 10); printf("%s\n", dummy); strncpy(dummy, (char*) test.PointerToFieldB(), 10); printf("%s\n", dummy); strncpy(dummy, (char*) test.PointerToFieldC(), 10); printf("%s\n", dummy); char allFields[31]; allFields[30] = '\0'; strncpy(allFields, (char*) test.PointerToAllFields(), 30); printf("%s\n", allFields); return 0; }

    Read the article

  • Faulty to use memcache together with a php web-browser-game in this way?

    - by Crowye
    Background We are currently working on a strategy web-browser game based on php, html and javascript. The plan is to have 10,000+ users playing within the same world. Currently we are using memcached to: store json static data, language files store changeable serialized php class objects (such as armies, inventorys, unit-containers, buildings, etc) In the back we have a mysql server running and holding all the game data aswell. When a object is loaded through our ObjectLoader it loads in this order: checks a static hashmap in the script for the object checks memcache if it has already been loaded into it otherwise loads from database, and saves it into memcache and the static temp hashmap We have built the whole game using a class-object-oriented approach where functionality is always made between objects. Beause of this we think we have managed to get a nice structure, and with the help of memcached we have received good request times from client-server when interacting with the game. I'm aware that memcache is not synchronized, and also is not commonly used for holding a full game in memory. In the beginning after a server's startup the load times when loading objects into memcache for the first time will be high, but after the server's been online for a while and most loads are from memcache, the loads will be well reduced. Currently we are saving changed objects into memcache and database at the same time. Earlier we had an idea to save objects into db only after a certain time or at intervals, but due to risk inconsistency if the memcache/server went down, we skipped it for now. Client requests to server often return object's status simple json-format without changing the object, which in turn is represented in the browser visually with images and javascript. But from time to time depending on when an object was last updated, it updates them with new information (e.g. a build-queue holding planned buildings time-progress is increased, and/or planned-queue-items-array has changed). Questions: Do you see how this could work or are we walking in blindness here? Do you expect us to have a lot of inconsistency issues if someone loads and updates the a memcache objects while someone else does the same? Is it even doable to do it in the way he have done it? Seems to be working fine atm, but so far we have only been 4 people online at the same time.. Is some other cache program more fit for this class-object approach than memcached? Is there any other tips you have for this situation? UPDATE Since it is simply a "normal webpage" (no applet, flash, etc), we are implementing the game so that the server is the only one holding a "real game-state".. the state of the different javascript-objects on the client is more like a approximative version of the server's game state. From time to time and before you do certain things important things, the client's visual state is updated to the server's state (e.g. the client things he can afford a barracks, asks the server to build a barracks, server updates current resources according to income-data on server and then tries to build a barracks or casts an error-message, and then sends the current server-state on resources, buildings back to the client).. It is not a fast-paced game lika real strategy game. More like a quite slow 3-4 months playtime game, where buildings can take +1 minute up to several days to complete.

    Read the article

  • WPF: Binding to ListBoxItem.IsSelected doesn't work for off-screen items

    - by Qwertie
    In my program I have a set of view-model objects to represent items in a ListBox (multi-select is allowed). The viewmodel has an IsSelected property that I would like to bind to the ListBox so that selection state is managed in the viewmodel rather than in the listbox itself. However, apparently the ListBox doesn't maintain bindings for most of the off-screen items, so in general the IsSelected property is not synchronized correctly. Here is some code that demonstrates the problem. First XAML: <StackPanel> <StackPanel Orientation="Horizontal"> <TextBlock>Number of selected items: </TextBlock> <TextBlock Text="{Binding NumItemsSelected}"/> </StackPanel> <ListBox ItemsSource="{Binding Items}" Height="200" SelectionMode="Extended"> <ListBox.ItemContainerStyle> <Style TargetType="{x:Type ListBoxItem}"> <Setter Property="IsSelected" Value="{Binding IsSelected}"/> </Style> </ListBox.ItemContainerStyle> </ListBox> <Button Name="TestSelectAll" Click="TestSelectAll_Click">Select all</Button> </StackPanel> C# Select All handler: private void TestSelectAll_Click(object sender, RoutedEventArgs e) { foreach (var item in _dataContext.Items) item.IsSelected = true; } C# viewmodel: public class TestItem : NPCHelper { TestDataContext _c; string _text; public TestItem(TestDataContext c, string text) { _c = c; _text = text; } public override string ToString() { return _text; } bool _isSelected; public bool IsSelected { get { return _isSelected; } set { _isSelected = value; FirePropertyChanged("IsSelected"); _c.FirePropertyChanged("NumItemsSelected"); } } } public class TestDataContext : NPCHelper { public TestDataContext() { for (int i = 0; i < 200; i++) _items.Add(new TestItem(this, i.ToString())); } ObservableCollection<TestItem> _items = new ObservableCollection<TestItem>(); public ObservableCollection<TestItem> Items { get { return _items; } } public int NumItemsSelected { get { return _items.Where(it => it.IsSelected).Count(); } } } public class NPCHelper : INotifyPropertyChanged { public event PropertyChangedEventHandler PropertyChanged; public void FirePropertyChanged(string prop) { if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs(prop)); } } Two separate problems can be observed. If you click the first item and then press Shift+End, all 200 items should be selected; however, the heading reports that only 21 items are selected. If you click "Select all" then all items are indeed selected. If you then click an item in the ListBox you would expect the other 199 items to be deselected, but this does not happen. Instead, only the items that are on the screen (and a few others) are deselected. All 199 items will not be deselected unless you first scroll through the list from beginning to end (and even then, oddly enough, it doesn't work if you perform scrolling with the little scroll box). My questions are: Can someone explain precisely why this occurs? Can I avoid or work around the problem?

    Read the article

  • hosting simple python scripts in a container to handle concurrency, configuration, caching, etc.

    - by Justin Grant
    My first real-world Python project is to write a simple framework (or re-use/adapt an existing one) which can wrap small python scripts (which are used to gather custom data for a monitoring tool) with a "container" to handle boilerplate tasks like: fetching a script's configuration from a file (and keeping that info up to date if the file changes and handle decryption of sensitive config data) running multiple instances of the same script in different threads instead of spinning up a new process for each one expose an API for caching expensive data and storing persistent state from one script invocation to the next Today, script authors must handle the issues above, which usually means that most script authors don't handle them correctly, causing bugs and performance problems. In addition to avoiding bugs, we want a solution which lowers the bar to create and maintain scripts, especially given that many script authors may not be trained programmers. Below are examples of the API I've been thinking of, and which I'm looking to get your feedback about. A scripter would need to build a single method which takes (as input) the configuration that the script needs to do its job, and either returns a python object or calls a method to stream back data in chunks. Optionally, a scripter could supply methods to handle startup and/or shutdown tasks. HTTP-fetching script example (in pseudocode, omitting the actual data-fetching details to focus on the container's API): def run (config, context, cache) : results = http_library_call (config.url, config.http_method, config.username, config.password, ...) return { html : results.html, status_code : results.status, headers : results.response_headers } def init(config, context, cache) : config.max_threads = 20 # up to 20 URLs at one time (per process) config.max_processes = 3 # launch up to 3 concurrent processes config.keepalive = 1200 # keep process alive for 10 mins without another call config.process_recycle.requests = 1000 # restart the process every 1000 requests (to avoid leaks) config.kill_timeout = 600 # kill the process if any call lasts longer than 10 minutes Database-data fetching script example might look like this (in pseudocode): def run (config, context, cache) : expensive = context.cache["something_expensive"] for record in db_library_call (expensive, context.checkpoint, config.connection_string) : context.log (record, "logDate") # log all properties, optionally specify name of timestamp property last_date = record["logDate"] context.checkpoint = last_date # persistent checkpoint, used next time through def init(config, context, cache) : cache["something_expensive"] = get_expensive_thing() def shutdown(config, context, cache) : expensive = cache["something_expensive"] expensive.release_me() Is this API appropriately "pythonic", or are there things I should do to make this more natural to the Python scripter? (I'm more familiar with building C++/C#/Java APIs so I suspect I'm missing useful Python idioms.) Specific questions: is it natural to pass a "config" object into a method and ask the callee to set various configuration options? Or is there another preferred way to do this? when a callee needs to stream data back to its caller, is a method like context.log() (see above) appropriate, or should I be using yield instead? (yeild seems natural, but I worry it'd be over the head of most scripters) My approach requires scripts to define functions with predefined names (e.g. "run", "init", "shutdown"). Is this a good way to do it? If not, what other mechanism would be more natural? I'm passing the same config, context, cache parameters into every method. Would it be better to use a single "context" parameter instead? Would it be better to use global variables instead? Finally, are there existing libraries you'd recommend to make this kind of simple "script-running container" easier to write?

    Read the article

  • "Warning reaching end of non-void fuction" with Multiple Sections that pull in multiple CustomCells

    - by Newbyman
    I'm getting "Reaching end of non-void function" warning, but don't have anything else to return for the compiler. How do I get around the warning?? I'm using customCells to display a table with 3 Sections. Each CustomCell is different, linked with another viewcontroller's tableview within the App, and is getting its data from its individual model. Everything works great in the Simulator and Devices, but I would like to get rid of the warning that I have. It is the only one I have, and it is pending me from uploading to App Store!! Within the - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {, I have used 3 separate If() statements-(i.e.==0,==1,==2) to control which customCells are displayed within each section throughout the tableview's cells. Each of the customCells were created in IB, pull there data from different models, and are used with other ViewController tableViews. At the end of the function, I don't have a "cell" or anything else to return, because I already specified which CustomCell to return within each of the If() statements. Because each of the CustomCells are referenced through the AppDelegate, I can not set up an empty cell at the start of the function and just set the empty cell equal to the desired CustomCell within each of the If() statements, as you can for text, labels, etc... My question is not a matter of fixing code within the If() statements, unless it is required. My Questions is in "How to remove the warning for reaching end of non-void function-(cellForRowAtIndexPath:) when I have already returned a value for every possible case: if(section == 0); if(section == 1); and if(section == 2). *Code-Reference: The actual file names were knocked down for simplicity, (section 0 refers to M's, section 1 refers to D's, and section 2 refers to B's). Here is a sample Layout of the code: //CELL FOR ROW AT INDEX PATH: -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { //Reference to the AppDelegate: MyAppDelegate *appDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate]; //Section 0: if(indexPath.section == 0) { static NSString *CustomMCellIdentifier = @"CustomMCellIdentifier"; MCustomCell *mCell = (MCustomCell *)[tableView dequeueReusableCellWithIdentifier:CustomMCellIdentifier]; if (mCell == nil) { NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"MCustomCell" owner:tableView options:nil]; for (id oneObject in nib) if ([oneObject isKindOfClass:[MCustomCell class]]) mCell = (MCustomCell *)oneObject; } //Grab the Data for this item: M *mM = [appDelegate.mms objectAtIndex:indexPath.row]; //Set the Cell [mCell setM:mM]; mCell.selectionStyle =UITableViewCellSelectionStyleNone; mCell.root = tableView; return mCell; } //Section 1: if(indexPath.section == 1) { static NSString *CustomDCellIdentifier = @"CustomDCellIdentifier"; DCustomCell *dCell = (DCustomCell *)[tableView dequeueReusableCellWithIdentifier:CustomDaddyCellIdentifier]; if (dCell == nil) { NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"DCustomCell" owner:tableView options:nil]; for (id oneObject in nib) if ([oneObject isKindOfClass:[DCustomCell class]]) dCell = (DCustomCell *)oneObject; } //Grab the Data for this item: D *dD = [appDelegate.dds objectAtIndex:indexPath.row]; //Set the Cell [dCell setD:dD]; //Turns the Cell's SelectionStyle Blue Highlighting off, but still permits the code to run! dCell.selectionStyle =UITableViewCellSelectionStyleNone; dCell.root = tableView; return dCell; } //Section 2: if(indexPath.section == 2) { static NSString *CustomBCellIdentifier = @"CustomBCellIdentifier"; BCustomCell *bCell = (BCustomCell *)[tableView dequeueReusableCellWithIdentifier:CustomBCellIdentifier]; if (bCell == nil) { NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"BCustomCell" owner:tableView options:nil]; for (id oneObject in nib) if ([oneObject isKindOfClass:[BCustomCell class]]) bCell = (BCustomCell *)oneObject; } //Grab the Data for this item: B *bB = [appDelegate.bbs objectAtIndex:indexPath.row]; //Set the Cell [bCell setB:bB]; bCell.selectionStyle =UITableViewCellSelectionStyleNone; bCell.root = tableView; return bCell; } //** Getting Warning "Control reaches end of non-void function" //Not sure what else to "return ???" all CustomCells were specified within the If() statements above for their corresponding IndexPath.Sections. } Any Suggestions ??

    Read the article

  • Const-correctness semantics in C++

    - by thirtythreeforty
    For fun and profit™, I'm writing a trie class in C++ (using the C++11 standard.) My trie<T> has an iterator, trie<T>::iterator. (They're all actually functionally const_iterators, because you cannot modify a trie's value_type.) The iterator's class declaration looks partially like this: template<typename T> class trie<T>::iterator : public std::iterator<std::bidirectional_iterator_tag, T> { friend class trie<T>; struct state { state(const trie<T>* const node, const typename std::vector<std::pair<typename T::value_type, std::unique_ptr<trie<T>>>>::const_iterator& node_map_it ) : node{node}, node_map_it{node_map_it} {} // This pointer is to const data: const trie<T>* node; typename std::vector<std::pair<typename T::value_type, std::unique_ptr<trie<T>>>>::const_iterator node_map_it; }; public: typedef const T value_type; iterator() =default; iterator(const trie<T>* node) { parents.emplace(node, node->children.cbegin()); // ... } // ... private: std::stack<state> parents; // ... }; Notice that the node pointer is declared const. This is because (in my mind) the iterator should not be modifying the node that it points to; it is just an iterator. Now, elsewhere in my main trie<T> class, I have an erase function that has a common STL signature--it takes an iterator to data to erase (and returns an iterator to the next object). template<typename T> typename trie<T>::iterator trie<T>::erase(const_iterator it) { // ... // Cannot modify a const object! it.parents.top().node->is_leaf = false; // ... } The compiler complains because the node pointer is read-only! The erase function definitely should modify the trie that the iterator points to, even though the iterator shouldn't. So, I have two questions: Should iterator's constructors be public? trie<T> has the necessary begin() and end() members, and of course trie<T>::iterator and trie<T> are mutual friends, but I don't know what the convention is. Making them private would solve a lot of the angst I'm having about removing the const "promise" from the iterator's constructor. What are the correct const semantics/conventions regarding the iterator and its node pointer here? Nobody has ever explained this to me, and I can't find any tutorials or articles on the Web. This is probably the more important question, but it does require a good deal of planning and proper implementation. I suppose it could be circumvented by just implementing 1, but it's the principle of the thing!

    Read the article

  • Accessing Layout Items from inside Widget AppWidgetProvider

    - by cam4mav
    I am starting to go insane trying to figure this out. It seems like it should be very easy, I'm starting to wonder if it's possible. What I am trying to do is create a home screen widget, that only contains an ImageButton. When it is pressed, the idea is to change some setting (like the wi-fi toggle) and then change the Buttons image. I have the ImageButton declared like this in my main.xml <ImageButton android:id="@+id/buttonOne" android:src="@drawable/button_normal_ringer" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" /> my AppWidgetProvider class, named ButtonWidget * note that the RemoteViews class is a locally stored variable. this allowed me to get access to the RViews layout elements... or so I thought. @Override public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) { remoteViews = new RemoteViews(context.getPackageName(), R.layout.main); Intent active = new Intent(context, ButtonWidget.class); active.setAction(VIBRATE_UPDATE); active.putExtra("msg","TESTING"); PendingIntent actionPendingIntent = PendingIntent.getBroadcast(context, 0, active, 0); remoteViews.setOnClickPendingIntent(R.id.buttonOne, actionPendingIntent); appWidgetManager.updateAppWidget(appWidgetIds, remoteViews); } @Override public void onReceive(Context context, Intent intent) { // v1.5 fix that doesn't call onDelete Action final String action = intent.getAction(); Log.d("onReceive",action); if (AppWidgetManager.ACTION_APPWIDGET_DELETED.equals(action)) { final int appWidgetId = intent.getExtras().getInt( AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID); if (appWidgetId != AppWidgetManager.INVALID_APPWIDGET_ID) { this.onDeleted(context, new int[] { appWidgetId }); } } else { // check, if our Action was called if (intent.getAction().equals(VIBRATE_UPDATE)) { String msg = "null"; try { msg = intent.getStringExtra("msg"); } catch (NullPointerException e) { Log.e("Error", "msg = null"); } Log.d("onReceive",msg); if(remoteViews != null){ Log.d("onReceive",""+remoteViews.getLayoutId()); remoteViews.setImageViewResource(R.id.buttonOne, R.drawable.button_pressed_ringer); Log.d("onReceive", "tried to switch"); } else{ Log.d("F!", "--naughty language used here!!!--"); } } super.onReceive(context, intent); } } so, I've been testing this and the onReceive method works great, I'm able to send notifications and all sorts of stuff (removed from code for ease of reading) the one thing I can't do is change any properties of the view elements. To try and fix this, I made RemoteViews a local and static private variable. Using log's I was able to see that When multiple instances of the app are on screen, they all refer to the one instance of RemoteViews. perfect for what I'm trying to do The trouble is in trying to change the image of the ImageButton. I can do this from within the onUpdate method using this. remoteViews.setImageViewResource(R.id.buttonOne, R.drawable.button_pressed_ringer); that doesn't do me any good though once the widget is created. For some reason, even though its inside the same class, being inside the onReceive method makes that line not work. That line used to throw a Null pointer as a matter of fact, until I changed the variable to static. now it passes the null test, refers to the same layoutId as it did at the start, reads the line, but it does nothing. Its like the code isn't even there, just keeps chugging along. SO...... Is there any way to modify layout elements from within a widget after the widget has been created!? I want to do this based on the environment, not with a configuration activity launch. I've been looking at various questions and this seems to be an issue that really hasn't been solved, such as link text and link text oh and for anyone who finds this and wants a good starting tutorial for widgets, this is easy to follow (though a bit old, it gets you comfortable with widgets) .pdf link text hopefully someone can help here. I kinda have the feeling that this is illegal and there is a different way to go about this. I would LOVE to be told another approach!!!! Thanks

    Read the article

  • How can I make the storage of C++ lambda objects more efficient?

    - by Peter Ruderman
    I've been thinking about storing C++ lambda's lately. The standard advice you see on the Internet is to store the lambda in a std::function object. However, none of this advice ever considers the storage implications. It occurred to me that there must be some seriously black voodoo going on behind the scenes to make this work. Consider the following class that stores an integer value: class Simple { public: Simple( int value ) { puts( "Constructing simple!" ); this->value = value; } Simple( const Simple& rhs ) { puts( "Copying simple!" ); this->value = rhs.value; } Simple( Simple&& rhs ) { puts( "Moving simple!" ); this->value = rhs.value; } ~Simple() { puts( "Destroying simple!" ); } int Get() const { return this->value; } private: int value; }; Now, consider this simple program: int main() { Simple test( 5 ); std::function<int ()> f = [test] () { return test.Get(); }; printf( "%d\n", f() ); } This is the output I would hope to see from this program: Constructing simple! Copying simple! Moving simple! Destroying simple! 5 Destroying simple! Destroying simple! First, we create the value test. We create a local copy on the stack for the temporary lambda object. We then move the temporary lambda object into memory allocated by std::function. We destroy the temporary lambda. We print our output. We destroy the std::function. And finally, we destroy the test object. Needless to say, this is not what I see. When I compile this on Visual C++ 2010 (release or debug mode), I get this output: Constructing simple! Copying simple! Copying simple! Copying simple! Copying simple! Destroying simple! Destroying simple! Destroying simple! 5 Destroying simple! Destroying simple! Holy crap that's inefficient! Not only did the compiler fail to use my move constructor, but it generated and destroyed two apparently superfluous copies of the lambda during the assignment. So, here finally are the questions: (1) Is all this copying really necessary? (2) Is there some way to coerce the compiler into generating better code? Thanks for reading!

    Read the article

< Previous Page | 540 541 542 543 544 545 546 547 548 549 550 551  | Next Page >