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  • Why is my GreaseMonkey function unexpectedly being called multiple times?

    - by Ryan Fisher
    I am missing something, I'm not sure why the function 'addIcon()' is being called multiple times. Given: <div class="ticketpostcontainer">Some text</div> <div class="ticketpostcontainer">Some text</div> <div class="ticketpostcontainer">Some text</div> Using the utility function waitForKeyElements, the result is that each div element receives my "collapse icon" three times: // ==UserScript== // @name Collapse Kayako Response // @grant Sandbox // @namespace http://my.chiromatrixbase.com/fisher.chiromatrix.com/collaps_div.js // @include http://imatrixsupport.com/* // @require http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js // ==/UserScript== /*jslint plusplus: true, undef: true, sloppy: true, vars: true, white: true, indent: 2, maxerr: 30 */ //Enable or disable GreaseMonkey function, GM_log var GM_Debug = 1; if (!GM_Debug) { var GM_log = function () {}; } //If FireBig is active, send GM log events to FB. if (unsafeWindow.console && GM_Debug) { var GM_log = unsafeWindow.console.log; } GM_log("Running collapse kayako response script"); //Don't run on frames or iframes. if (window.top !== window.self) { return; } waitForKeyElements(".ticketpostcontainer", addIcon); function addIcon() { var i, toCollapse = document.getElementsByClassName('ticketpostcontainer'), j = toCollapse.length; GM_log("Number of elements to collapse: " + toCollapse.length); for (i = 0; i < j; i++) { var curElement = toCollapse[i]; var p = document.createElement('p'); var a = document.createElement('a'); var span = document.createElement('span'); styleLink(a); styleParagraph(p); styleSpan(span); p.appendChild(a); p.appendChild(span); a.appendChild(document.createTextNode('-')); span.appendChild(document.createTextNode(' Some text')); a.addEventListener("click", toggle, false); curElement.parentNode.insertBefore(p, curElement); } function toggle(e) { if (this.firstChild.nodeValue === '-') { this.parentNode.nextSibling.style.display = 'none'; this.firstChild.nodeValue = '+'; this.nextSibling.style.display = 'inline'; } else { this.parentNode.nextSibling.style.display = 'block'; this.firstChild.nodeValue = '-'; this.nextSibling.style.display = 'none'; } e.preventDefault(); } function styleLink(a) { a.href = '#'; a.style.fontWeight = 'bold'; a.style.background = '#F6F1E7'; a.style.border = '1px solid #cccccc'; a.style.color = '#B24C58'; a.style.textDecoration = 'none'; a.style.width = '15px'; a.style.height = '15px'; a.style.textAlign = 'center'; a.style.fontSize = '100%'; a.style.margin = '0 5px 5px 8px'; a.style.cssFloat = 'left'; a.style.display = 'block'; a.style.lineHeight = '13px'; } function styleParagraph(p) { p.style.margin = '0 0 0 0'; p.style.lineHeight = '16px'; p.style.clear = 'both'; p.style.height = '15px'; } function styleSpan(span) { span.style.display = 'none'; } }

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  • how to pull href link

    - by user1751494
    I am trying to pull a link from a page that is in a formal I can't seem to find by simply googling... it might be simple but xpath is not my area of expertise I am using c# and trying to pull the link and just write it to the console to figure out how to get the link here is my C# code var document = webGet.Load("http://classifieds.castanet.net/cat/vehicles/cars/0_-_4_years_old/"); var browser = document.DocumentNode.SelectSingleNode("//a[starts-with(@href,'/details/')]"); if (browser != null) { string htmlbody = browser.OuterHtml; Console.WriteLine(htmlbody); } the html code section is <div class="last">&hellip;</div><a href="/cat/vehicles/cars/0_-_4_years_old/?p=13">13</a><a href="/cat/vehicles/cars/0_-_4_years_old/?p=2">&raquo;</a> <select name="sortby" class="sortby" onchange="doSort(this);"> <option value="">Most Recent</option> <option value="of" >Oldest First</option> <option value="mw" >Most Views</option> <option value="lw" >Fewest Views</option> <option value="lp" >Lowest Price</option> <option value="hp" >Highest Price</option> </select><div style="clear:both"></div> </div> <br /><br /><br /> <a href="/details/2008_vw_gti/1454282/" class="prod_container" > <h2>2008 VW GTi</h2> <div style="float:left; width:122px; z-index:1000"> <div class="thumb"><img src="http://c.castanet.net/img/28/thumbs/1454282-1-1.jpg" border="0"/></div> <div class="clear"></div> mls </div> <div class="descr"> The most fun car I have owned. Dolphin Grey, 4 door, Dual Climate control, DRG Transmission with paddle shift. Leather... </div> <div class="pdate"> <p class="price">$19,000.00</p> <p class="date">Kelowna<br />Posted: Oct 15, 2:54 PM<br />Views: 349</p> </div> <div style="clear:both" ></div> <div class="seal"><img src="/images/bookmark.png" /></div> </a> <a href="/details/price_drop_gorgeous_rare_white_2009_honda_accord_ex-l_coupe/1447341/" class="prod_container" > <h2>PRICE DROP!!! Gorgeous Rare White 2009 Honda Accord EX-L Coupe </h2> <div style="float:left; width:122px; z-index:1000"> <div class="thumb"><img src="http://c.castanet.net/img/28/thumbs/1447341-1-1.jpg" border="0"/></div> <div class="clear"></div> sun2010 </div> <div class="descr"> the link I'm trying to get is the "/details/2008_vw_gti/1454282/" part. THanks

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  • Not sure why I'm getting a NullPointerException when creating a Swing component

    - by Alex
    The error occurs when creating the Box object. public void drawBoard(Board board){ for(int row = 0; row < 8; row++){ for(int col = 0; col < 8; col++){ Box box = new Box(board.getSquare(col, row).getColour(), col, row); squarePanel[col][row].add(box); } } Board is given from the Game constructor here (another class): public Game() throws Throwable{ View graphics = new View(); board = new Board(); board.setDefault(); graphics.drawBoard(board); } The Board constructor looks like this: public Board(){ grid = new Square[COLUMNS][ROWS]; for(int row = 0; row < 8; row++){ for(int col = 0; col < 8; col++){ grid[col][row] = new Square(this); } } for(int row = 0; row < 8; row++){ for(int col = 0; col < 4; col++){ int odd = 2*col + 1; int even = 2*col; getSquare(odd, row).setColour(Color.BLACK); getSquare(even, row).setColour(Color.WHITE); } } } And finally the Box class: class Box extends JComponent{ Color boxColour; int col, row; public Box(Color boxColour, int col, int row){ this.boxColour = boxColour; this.col = col; this.row = row; repaint(); } public void paint(Graphics drawBox){ drawBox.setColor(boxColour); drawBox.drawRect(50*col, 50*row, 50, 50); drawBox.fillRect(50*col, 50*row, 50, 50); } } So while looping through the array, it uses the two integers as coordinates to create the Box. The coordinates are referenced and then repaint() is run. The box also gets the colour, using the two integers, from the Square in the Board class. Since the colour is already set, before the drawBoard(board) method is run, that shouldn't be a problem, right? Exception in thread "main" java.lang.NullPointerException at View.drawBoard(View.java:38) at Game.<init>(Game.java:21) at Game.main(Game.java:14) The relevant part of Square import java.awt.Color; public class Square { private Piece piece; private Board board; private Color squareColour; public Square(Board board){ this.board = board; } public void setColour(Color squareColour){ this.squareColour = squareColour; } public Color getColour(){ return squareColour; }

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  • How to determine edges in an image optimally?

    - by SorinA.
    I recently was put in front of the problem of cropping and resizing images. I needed to crop the 'main content' of an image for example if i had an image similar to this: the result should be an image with the msn content without the white margins(left& right). I search on the X axis for the first and last color change and on the Y axis the same thing. The problem is that traversing the image line by line takes a while..for an image that is 2000x1600px it takes up to 2 seconds to return the CropRect = x1,y1,x2,y2 data. I tried to make for each coordinate a traversal and stop on the first value found but it didn't work in all test cases..sometimes the returned data wasn't the expected one and the duration of the operations was similar.. Any idea how to cut down the traversal time and discovery of the rectangle round the 'main content'? public static CropRect EdgeDetection(Bitmap Image, float Threshold) { CropRect cropRectangle = new CropRect(); int lowestX = 0; int lowestY = 0; int largestX = 0; int largestY = 0; lowestX = Image.Width; lowestY = Image.Height; //find the lowest X bound; for (int y = 0; y < Image.Height - 1; ++y) { for (int x = 0; x < Image.Width - 1; ++x) { Color currentColor = Image.GetPixel(x, y); Color tempXcolor = Image.GetPixel(x + 1, y); Color tempYColor = Image.GetPixel(x, y + 1); if ((Math.Sqrt(((currentColor.R - tempXcolor.R) * (currentColor.R - tempXcolor.R)) + ((currentColor.G - tempXcolor.G) * (currentColor.G - tempXcolor.G)) + ((currentColor.B - tempXcolor.B) * (currentColor.B - tempXcolor.B))) > Threshold)) { if (lowestX > x) lowestX = x; if (largestX < x) largestX = x; } if ((Math.Sqrt(((currentColor.R - tempYColor.R) * (currentColor.R - tempYColor.R)) + ((currentColor.G - tempYColor.G) * (currentColor.G - tempYColor.G)) + ((currentColor.B - tempYColor.B) * (currentColor.B - tempYColor.B))) > Threshold)) { if (lowestY > y) lowestY = y; if (largestY < y) largestY = y; } } } if (lowestX < Image.Width / 4) cropRectangle.X = lowestX - 3 > 0 ? lowestX - 3 : 0; else cropRectangle.X = 0; if (lowestY < Image.Height / 4) cropRectangle.Y = lowestY - 3 > 0 ? lowestY - 3 : 0; else cropRectangle.Y = 0; cropRectangle.Width = largestX - lowestX + 8 > Image.Width ? Image.Width : largestX - lowestX + 8; cropRectangle.Height = largestY + 8 > Image.Height ? Image.Height - lowestY : largestY - lowestY + 8; return cropRectangle; } }

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  • using JQuery and Ajax to post a form

    - by hopes
    Hi there, I want to use ajax to post my form I want radiobuttons to do this(there is no submit buton) so clicking a radiobutton will cause a form to be submitted or be post my php page needs to know the name of the radio button clicked is my code correct? cuz it doesn't work and I don't know why? <div id="Q1"> <form id="Question1" method='post'> <br /> <P> The sky color is.. </P><img border="0" src="images/wonder.png" width="94" height="134"/><br /><br /><br /> <input type="radio" id="option1" name="answer[1]" value="correct!"/> blue <br /> <input type="radio" id="option1" name="answer[1]" value="false!"/> red <br /> <input type="radio" id="option1" name="answer[1]" value="false!"/> green <br /> <input type="radio" id="option1" name="answer[1]" value="false!"/> white <br /> <br /> </Form> <!-- <p id="greatp" style="display: none;"> GREAT !!<br /><br /><br /><br /><br /><br /><br /></p> --> <img border="0" src="images/welldone3.png" width="230" height="182" id="greatp" style="display: none;"/> <!-- <p id="sorryp" style="display: none;"> Sorry !!<br /><br /><br /><br /><br /><br /><br /></p> --> <img border="0" src="images/failed3.png" width="230" height="182" id="sorryp" style="display: none;"/> <img src="images/false2.png"id="myImage1"style="display: none;"/> <img src="images/correct2.png"id="myImage2"style="display: none;"/> <!-- <input type= "submit" onclick="Next1()" value="Next"/> --> <input type="image" src="images/next.png" name="image" width="80" height="30" onclick="Next1()"> </div> jquery cod: <script> $(document).ready(function(){ $("#option1").click(function() { var answer= $("#option1").value; var fff= $("#option1").name; $.ajax({ type: "POST", url: "page2.php", data: fff, success: function(){ if(answer=='correct!') { $('#greatp').show(); $('#myImage2').show(); $('#Question1').hide(); } else { $('#sorryp').show(); $('#myImage1').show(); $('#Question1').hide(); } } }); return false; }); }); </script>

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  • WCF service is not getting called

    - by Cheranga
    I have a web solution and I have a WCF service project inside it. We need to support "cookieless". so in the web.config, it's set as <sessionState mode="SQLServer" sqlConnectionString="Data Source=ds;Initial Catalog=db;User Id=uid;Password=pwd" allowCustomSqlDatabase="true" cookieless="true" timeout="720" regenerateExpiredSessionId="false"/> The WCF service will be supporting sessions, so we have also set "aspNetCompatibilityEnabled" to true in web.config. <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true"/> The service and interfaces are as follows, [ServiceContract(SessionMode=SessionMode.Allowed)] public interface ICDOCService { } [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] public class CDOCService : ICDOCService { } The problem we are facing is we cannot access the service from any client application. (web app, WCF test client) The following error is showing, when we access it via WCF Test client, Failed to invoke the service. Possible causes: The service is offline or inaccessible; the client-side configuration does not match the proxy; the existing proxy is invalid. Refer to the stack trace for more detail. You can try to recover by starting a new proxy, restoring to default configuration, or refreshing the service. The content type text/html; charset=UTF-8 of the response message does not match the content type of the binding (multipart/related; type="application/xop+xml"). If using a custom encoder, be sure that the IsContentTypeSupported method is implemented properly. The first 1024 bytes of the response were: <HTML> <HEAD> <link rel="alternate" type="text/xml" href="http://localhost:53721/Services/CDOCService.svc?disco"/> <STYLE type="text/css">#content{ FONT-SIZE: 0.7em; PADDING-BOTTOM: 2em; MARGIN-LEFT: 30px}BODY{MARGIN-TOP: 0px; MARGIN-LEFT: 0px; COLOR: #000000; FONT-FAMILY: Verdana; BACKGROUND-COLOR: white}P{MARGIN-TOP: 0px; MARGIN-BOTTOM: 12px; COLOR: #000000; FONT-FAMILY: Verdana}PRE{BORDER-RIGHT: #f0f0e0 1px solid; PADDING-RIGHT: 5px; BORDER-TOP: #f0f0e0 1px solid; MARGIN-TOP: -5px; PADDING-LEFT: 5px; FONT-SIZE: 1.2em; PADDING-BOTTOM: 5px; BORDER-LEFT: #f0f0e0 1px solid; PADDING-TOP: 5px; BORDER-BOTTOM: #f0f0e0 1px solid; FONT-FAMILY: Courier New; BACKGROUND-COLOR: #e5e5cc}.heading1{MARGIN-TOP: 0px; PADDING-LEFT: 15px; FONT-WEIGHT: normal; FONT-SIZE: 26px; MARGIN-BOTTOM: 0px; PADDING-BOTTOM: 3px; MARGIN-LEFT: -30px; WIDTH: 100%; COLOR: #ffffff; PADDING-TOP: 10px; FONT-FAMILY: Tahoma; BACKGROUND-COLOR: #003366}.intro{MARGIN-LEFT: -15px} </STYLE> <TITLE>CDOCService Service</TITLE></HEAD><BODY><DIV id="content"><P '. Server stack trace: at System.ServiceModel.Channels.HttpChannelUtilities.ValidateRequestReplyResponse(HttpWebRequest request, HttpWebResponse response, HttpChannelFactory factory, WebException responseException, ChannelBinding channelBinding) at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout) at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout) at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message message, TimeSpan timeout) at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout) at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs) at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation) at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message) Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg) at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type) at ICDOCService.GetCDOCCount(String institutionID, String mrnID, String userID, String callingSystemID, String securityToken) at CDOCServiceClient.GetCDOCCount(String institutionID, String mrnID, String userID, String callingSystemID, String securityToken)

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  • Window's content disappears when minimized

    - by Carmen Cojocaru
    I have a simple class that draws a line when mouse dragging or a dot when mouse pressing(releasing). When I minimize the application and then restore it, the content of the window disappears except the last dot (pixel). I understand that the method super.paint(g) repaints the background every time the window changes, but the result seems to be the same whether I use it or not. The difference between the two of them is that when I don't use it there's more than a pixel painted on the window, but not all my painting. How can I fix this? Here is the class. package painting; import java.awt.*; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseMotionAdapter; import javax.swing.JFrame; import javax.swing.JPanel; class CustomCanvas extends Canvas{ Point oldLocation= new Point(10, 10); Point location= new Point(10, 10); Dimension dimension = new Dimension(2, 2); CustomCanvas(Dimension dimension){ this.dimension = dimension; this.init(); addListeners(); } private void init(){ oldLocation= new Point(0, 0); location= new Point(0, 0); } public void paintLine(){ if ((location.x!=oldLocation.x) || (location.y!=oldLocation.y)) { repaint(location.x,location.y,1,1); } } private void addListeners(){ addMouseListener(new MouseAdapter(){ @Override public void mousePressed(MouseEvent me){ oldLocation = location; location = new Point(me.getX(), me.getY()); paintLine(); } @Override public void mouseReleased(MouseEvent me){ oldLocation = location; location = new Point(me.getX(), me.getY()); paintLine(); } }); addMouseMotionListener(new MouseMotionAdapter() { @Override public void mouseDragged(MouseEvent me){ oldLocation = location; location = new Point(me.getX(), me.getY()); paintLine(); } }); } @Override public void paint(Graphics g){ super.paint(g); g.setColor(Color.red); g.drawLine(location.x, location.y, oldLocation.x, oldLocation.y); } @Override public Dimension getMinimumSize() { return dimension; } @Override public Dimension getPreferredSize() { return dimension; } } class CustomFrame extends JPanel { JPanel displayPanel = new JPanel(new BorderLayout()); CustomCanvas canvas = new CustomCanvas(new Dimension(200, 200)); public CustomFrame(String titlu) { canvas.setBackground(Color.white); displayPanel.add(canvas, BorderLayout.CENTER); this.add(displayPanel); } } public class CustomCanvasFrame { public static void main(String args[]) { CustomFrame panel = new CustomFrame("Test Paint"); JFrame f = new JFrame(); f.add(panel); f.pack(); SwingConsole.run(f, 700, 700); } }

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  • How to find if a Item in a ListBox has the focus?

    - by eitan barazani
    I have a List box defined like this: <ListBox x:Name="EmailList" ItemsSource="{Binding MailBoxManager.Inbox.EmailList}" SelectedItem="{Binding SelectedMessage, Mode=TwoWay}" Grid.Row="1"> <ListBox.ItemTemplate> <DataTemplate> <usrctrls:MessageSummary /> </DataTemplate> </ListBox.ItemTemplate> </ListBox> The UserControl is defined like this: <UserControl x:Class="UserControls.MessageSummary" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="600"> <UserControl.Resources> </UserControl.Resources> <Grid HorizontalAlignment="Left"> <Grid.ColumnDefinitions> <ColumnDefinition Width="50" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <CheckBox Grid.Column="0" VerticalAlignment="Center" /> <Grid Grid.Column="1" Margin="0,0,12,0"> <Grid.RowDefinitions> <RowDefinition /> <RowDefinition /> <RowDefinition /> </Grid.RowDefinitions> <Grid Grid.Row="0" Grid.Column="0" HorizontalAlignment="Stretch"> <Grid.ColumnDefinitions> <ColumnDefinition Width="30" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="80" /> <ColumnDefinition Width="80" /> </Grid.ColumnDefinitions> <Image x:Name="FlaggedImage" Grid.Column="0" Width="20" Height="10" Margin="0" VerticalAlignment="Center" HorizontalAlignment="Center" Source="/Assets/ico_flagged_white.png" /> <TextBlock x:Name="Sender" Grid.Column="1" Text="{Binding EmailProperties.DisplayFrom}" Style="{StaticResource TextBlock_SenderRowTitle}" HorizontalAlignment="Left" VerticalAlignment="Center" /> <Grid x:Name="ImagesContainer" Grid.Column="2" VerticalAlignment="Center"> <Grid.ColumnDefinitions> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <Image x:Name="ImgImportant" Grid.Column="0" Width="20" Height="20" VerticalAlignment="Center" HorizontalAlignment="Center" Source="ms-appx:///Assets/ico_important_red.png" /> <Image x:Name="ImgFolders" Grid.Column="1" Width="20" Height="20" VerticalAlignment="Center" HorizontalAlignment="Center" Source="ms-appx:///Assets/ico_ico_addtofolder.png" /> <Image x:Name="ImgAttachment" Grid.Column="2" Width="20" Height="20" VerticalAlignment="Center" HorizontalAlignment="Center" Source="ms-appx:///Assets/ico_attachment_lightgray.png" /> <Image x:Name="ImgFlag" Grid.Column="3" Width="20" Height="20" VerticalAlignment="Center" HorizontalAlignment="Center" Source="ms-appx:///Assets/ico_flag.png" /> </Grid> <TextBlock x:Name="Time" Grid.Column="3" Text="{Binding EmailProperties.DateReceived, Converter={StaticResource EmailHeaderTimeConverter}}" TextAlignment="Center" FontSize="16" VerticalAlignment="Center" Margin="0" /> </Grid> <TextBlock Grid.Row="1" Text="{Binding EmailProperties.Subject}" TextTrimming="WordEllipsis" Margin="0,10" /> <TextBlock Grid.Row="2" Text="{Binding EmailProperties.Preview}" TextTrimming="WordEllipsis" /> </Grid> </Grid> The MessageSummary is a UserControl. I would like to bind the foreground color of the Items of the ListBox to whether the item is the one selected in the list box, i.e. I would like the Item's foreground color to be Black if not selected and White if the item is selected. How can it be done? Thanks,

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  • Lines don't overlap when they should Java Swing

    - by Sven
    I'm drawing lines in a JFrame on a self made gridPanel. Problem is, I draw the lines between 2 points. When I have a line that is between point 1 and point 2 and a line between point 2 and point 3, the lines should connect. This however isn,t the case, there is a small gap in between, no idea why. But it isn't drawing till the end of the specified point. (start point is correct.) Here is the code of the JFrame: public void initialize(){ this.setLayout(new BorderLayout()); this.setPreferredSize(new Dimension(500, 400)); gridPane = new GridPane(); gridPane.setBackground(Color.WHITE); gridPane.setSize(this.getPreferredSize()); gridPane.setLocation(0, 0); this.add(gridPane,BorderLayout.CENTER); //createSampleLabyrinth(); drawWall(0,5,40,5); //These are the 2 lines that don't connect. drawWall(40,5,80,5); this.pack(); } drawWall calls a method that calls a method in GridPane. The relevant code in gridPane: /** * Draws a wall on this pane. With the starting point being x1, y1 and its end x2,y2. * @param x1 * @param y1 * @param x2 * @param y2 */ public void drawWall(int x1, int y1, int x2, int y2) { Wall wall = new Wall(x1,y1,x2,y2, true); wall.drawGraphic(); wall.setLocation(x1, y1); wall.setSize(10000,10000); this.add(wall, JLayeredPane.DEFAULT_LAYER); this.repaint(); } This method creates a wall and puts it in the Jframe. The relevant code of the wall: public class Wall extends JPanel { private int x1; private int x2; private int y1; private int y2; private boolean black; /** * x1,y1 is the start point of the wall (line) end is x2,y2 * * @param x1 * @param y1 * @param x2 * @param y2 */ public Wall(int x1, int y1, int x2, int y2, boolean black) { this.x1 = x1; this.x2 = x2; this.y1 = y1; this.y2 = y2; this.black = black; setOpaque(false); } private static final long serialVersionUID = 1L; public void drawGraphic() { repaint(); } public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D) g; if(black){ g2.setColor(Color.BLACK); g2.setStroke(new BasicStroke(8)); } else { g2.setColor(Color.YELLOW); g2.setStroke(new BasicStroke(3)); } g2.drawLine(x1, y1, x2, y2); } } So, where am I going wrong? The true/false is to determine if the wall should be black or yellow, nothing to be concerned about.

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  • texture colours opengl

    - by user1324894
    Hi I am making a simple 2D game in c++ and for the map I am doing texture mapping by using tiles and assigning textures to those tiles. However, when I run the programme the textures become black and white when I want them to be the colour they are in the .png image. This is my code: int worldMap[10][10] = { {0,0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0,0}, }; void background() { glClearColor(0.0,0.0,0.0,0.0); /**********************************************************************************************/ // Texture loading object nv::Image img; // Return true on success if(img.loadImageFromFile("Image_Loading/field.png")) { glGenTextures(1, &myTexture); glBindTexture(GL_TEXTURE_2D, myTexture); glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE); glTexImage2D(GL_TEXTURE_2D, 0, img.getInternalFormat(), img.getWidth(), img.getHeight(), 0, img.getFormat(), img.getType(), img.getLevel(0)); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT ); glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT ); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 16.0f); } else MessageBox(NULL, "Failed to load texture", "End of the world", MB_OK | MB_ICONINFORMATION); /**********************************************************************************************/ } void drawTiles (void) { //our function to draw the tiles for (int i = 0; i < 10; i++) //loop through the height of the map { for (int j = 0; j < 10; j++) //loop through the width of the map { if (worldMap[i][j] == 0) //if the map at this position contains a 0 { glBindTexture( GL_TEXTURE_2D, myTexture ); //bind our grass texture to our shape } glPushMatrix(); //push the matrix so that our translations only affect this tile glTranslatef(j, -i, 0); //translate the tile to where it should belong glBegin (GL_QUADS); //begin drawing our quads glTexCoord2d(10, 0); glVertex2f((-10 + mapX),(-10 + mapY)); //with our vertices we have to assign a texcoord glTexCoord2d(10, 0); glVertex2f((10 + mapX),(-10 + mapY)); //so that our texture has some points to draw to glTexCoord2d(10, 10); glVertex2f((10 + mapX),(10 + mapY)); glTexCoord2d(0, 10); glVertex2f((-10 + mapX),(10 + mapY)); glEnd(); glPopMatrix(); //pop the matrix } //end first loop } //end second loop } void display() { glClearColor (0.0,0.0,0.0,1.0); glClear(GL_COLOR_BUFFER_BIT); /**********************************************************************************************/ glMatrixMode( GL_PROJECTION ); glLoadIdentity(); gluOrtho2D( -5, 5, -5, 5); glMatrixMode( GL_MODELVIEW ); glEnable(GL_TEXTURE_2D); glBindTexture(GL_TEXTURE_2D, myTexture); glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); drawTiles(); glDisable(GL_TEXTURE_2D); glDisable(GL_BLEND); /**********************************************************************************************/ } void character () { glBegin(GL_POLYGON); glVertex2f((-0.5+characterX),(-0.5 +characterY)); glVertex2f((-0.5+characterX),(0.5+characterY)); glVertex2f((0.5+characterX),(0.5+characterY)); glVertex2f((0.5+characterX),(-0.5+characterY)); glTranslatef(characterX, characterY, 0.0f); glEnd(); } Can anybody help please?

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  • How to make a character jump, both on objects and just normal jump.

    - by haxerflaxer
    Hi, I'm kind of a beginner when it comes to java programming, and I have a project in school where I'm going to create a game much like Icy Tower. And my question is, how am I going to write to make the character stand on the ground and be able to jump up on objects? Here's my code so far: Part one package Sprites; import java.awt.Image; import java.awt.event.KeyEvent; import javax.swing.ImageIcon; public class jumper { private String jump = "oka.png"; private int dx; private int dy; private int x; private int y; private Image image; public jumper() { ImageIcon ii = new ImageIcon(this.getClass().getResource(jump)); image = ii.getImage(); x = 50; y = 100; } public void move() { x += dx; y += dy; } public int getX() { return x; } public int getY() { return y; } public Image getImage() { return image; } public void keyPressed(KeyEvent e) { int key = e.getKeyCode(); if (key == KeyEvent.VK_LEFT) { dx = -5; ImageIcon ii = new ImageIcon(this.getClass().getResource("oki.png")); image = ii.getImage(); } if (key == KeyEvent.VK_RIGHT){ dx = 5; ImageIcon ii = new ImageIcon(this.getClass().getResource("oka.png")); image = ii.getImage(); } if (key == KeyEvent.VK_SPACE) { dy = -5; } if (key == KeyEvent.VK_DOWN) { dy = 5; } } public void keyReleased(KeyEvent e) { int key = e.getKeyCode(); if (key == KeyEvent.VK_LEFT) { dx = 0; } if (key == KeyEvent.VK_RIGHT){ dx = 0; } if (key == KeyEvent.VK_SPACE) { dy = 0; } if (key == KeyEvent.VK_DOWN) { dy = 0; } } } Part two package Sprites; import java.awt.Color; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Toolkit; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyAdapter; import java.awt.event.KeyEvent; import javax.swing.JPanel; import javax.swing.Timer; public class board extends JPanel implements ActionListener { private Timer klocka; private jumper jumper; public board() { addKeyListener(new TAdapter()); setFocusable(true); setBackground(Color.WHITE); setDoubleBuffered(true); jumper = new jumper(); klocka = new Timer(5, this); klocka.start(); } public void paint(Graphics g) { super.paint(g); Graphics2D g2d = (Graphics2D)g; g2d.drawImage(jumper.getImage(), jumper.getX(), jumper.getY(), this); Toolkit.getDefaultToolkit().sync(); g.dispose(); } public void actionPerformed(ActionEvent e) { jumper.move(); repaint(); } private class TAdapter extends KeyAdapter { public void keyReleased(KeyEvent e) { jumper.keyReleased(e); } public void keyPressed(KeyEvent e) { jumper.keyPressed(e); } } } Part three package Sprites; import javax.swing.JFrame; public class RType extends JFrame { public RType() { add(new board()); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setSize(800, 600); setLocationRelativeTo(null); setTitle("R - type"); setResizable(false); setVisible(true); } public static void main(String[] args) { new RType(); } } I really appreciate all the help I can get!

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  • How do you make a character jump, both on objects and just normal jump?

    - by haxerflaxer
    Hi, I'm kind of a beginner when it comes to java programming, and I have a project in school where I'm going to create a game much like Icy Tower. And my question is, how am I going to write to make the character stand on the ground and be able to jump up on objects? Here's my code so far: Part one package Sprites; import java.awt.Image; import java.awt.event.KeyEvent; import javax.swing.ImageIcon; public class jumper { private String jump = "oka.png"; private int dx; private int dy; private int x; private int y; private Image image; public jumper() { ImageIcon ii = new ImageIcon(this.getClass().getResource(jump)); image = ii.getImage(); x = 50; y = 100; } public void move() { x += dx; y += dy; } public int getX() { return x; } public int getY() { return y; } public Image getImage() { return image; } public void keyPressed(KeyEvent e) { int key = e.getKeyCode(); if (key == KeyEvent.VK_LEFT) { dx = -5; ImageIcon ii = new ImageIcon(this.getClass().getResource("oki.png")); image = ii.getImage(); } if (key == KeyEvent.VK_RIGHT){ dx = 5; ImageIcon ii = new ImageIcon(this.getClass().getResource("oka.png")); image = ii.getImage(); } if (key == KeyEvent.VK_SPACE) { dy = -5; } if (key == KeyEvent.VK_DOWN) { dy = 5; } } public void keyReleased(KeyEvent e) { int key = e.getKeyCode(); if (key == KeyEvent.VK_LEFT) { dx = 0; } if (key == KeyEvent.VK_RIGHT){ dx = 0; } if (key == KeyEvent.VK_SPACE) { dy = 0; } if (key == KeyEvent.VK_DOWN) { dy = 0; } } } Part two package Sprites; import java.awt.Color; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Toolkit; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyAdapter; import java.awt.event.KeyEvent; import javax.swing.JPanel; import javax.swing.Timer; public class board extends JPanel implements ActionListener { private Timer klocka; private jumper jumper; public board() { addKeyListener(new TAdapter()); setFocusable(true); setBackground(Color.WHITE); setDoubleBuffered(true); jumper = new jumper(); klocka = new Timer(5, this); klocka.start(); } public void paint(Graphics g) { super.paint(g); Graphics2D g2d = (Graphics2D)g; g2d.drawImage(jumper.getImage(), jumper.getX(), jumper.getY(), this); Toolkit.getDefaultToolkit().sync(); g.dispose(); } public void actionPerformed(ActionEvent e) { jumper.move(); repaint(); } private class TAdapter extends KeyAdapter { public void keyReleased(KeyEvent e) { jumper.keyReleased(e); } public void keyPressed(KeyEvent e) { jumper.keyPressed(e); } } } Part three package Sprites; import javax.swing.JFrame; public class RType extends JFrame { public RType() { add(new board()); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setSize(800, 600); setLocationRelativeTo(null); setTitle("R - type"); setResizable(false); setVisible(true); } public static void main(String[] args) { new RType(); } } I really appreciate all the help I can get!

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  • Can draw on only half of UIView

    - by ydlee777
    Hello. I am trying to draw grid on a UIView on a UIScrollView. The width of UIView is about 1000 pixels. However, I can draw lines only about first 340 pixels of the UIView. Can anyone help me on this? The drawGrid function is - (void)drawRect:(CGRect)rect { NSInteger width = 25 * 5 * 10; NSInteger height = (10 * 2 + 10) * 12; NSInteger i; //Get the CGContext from this view CGContextRef context = UIGraphicsGetCurrentContext(); // Draw rectangle with a blue stroke color and white fill color CGContextSetRGBStrokeColor(context, 0.0, 0.0, 1.0, 1.0); CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1.0); CGContextSetLineWidth(context, 2.0); CGContextAddRect(context, CGRectMake(0.0, 0.0, width, height)); CGContextFillPath(context); // Draw grid with red color CGContextSetStrokeColorWithColor(context, [UIColor redColor].CGColor); // Set the width of the pen mark CGContextSetLineWidth(context, 0.2); for (i = 0; i < height; i += 5) { if (i % 25 == 0) { CGContextSetLineWidth(context, 0.4); // Draw a line CGContextMoveToPoint(context, i, 0.0); CGContextAddLineToPoint(context, i, width); CGContextStrokePath(context); CGContextSetLineWidth(context, 0.2); } else { // Draw a line CGContextMoveToPoint(context, i, 0.0); CGContextAddLineToPoint(context, i, width); CGContextStrokePath(context); } } for (i = 0; i < width; i += 5) { if (i % 25 == 0) { CGContextSetLineWidth(context, 0.4); // Draw a line CGContextMoveToPoint(context, 0.0, i); CGContextAddLineToPoint(context, height, i); CGContextStrokePath(context); CGContextSetLineWidth(context, 0.2); } else { // Draw a line CGContextMoveToPoint(context, 0.0, i); CGContextAddLineToPoint(context, height, i); CGContextStrokePath(context); } } } I am also setting up the UIScrollView and UIView as follows: - (void)viewDidLoad { [super viewDidLoad]; CGRect frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height); waveScrollView = [[WaveScrollView alloc] initWithFrame:frame]; CGRect waveframe = CGRectMake(0, 0, 25 * 5 * 10, (10 * 2 + 10) * 12); EKGWaveView *ekgWaveView = [[EKGWaveView alloc] initWithFrame:waveframe]; waveScrollView.contentSize = CGSizeMake(waveframe.size.width, waveframe.size.height); waveScrollView.maximumZoomScale = 4.0; waveScrollView.minimumZoomScale = 0.75; waveScrollView.clipsToBounds = YES; waveScrollView.aView = ekgWaveView; [waveScrollView addSubview:ekgWaveView]; waveScrollView.delegate = self; [self.view addSubview:waveScrollView]; } I appreciate any help. Thanks.

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  • how to change php functions send result to jquery ajax

    - by OpenCode
    I have many codes for user notifications, it do many mysql works, so it needs waiting times. jquery ajax works for php files. how can i use jquery for send php result to web page? current code : <? echo db_cache("main_top_naver_cache", 300, "naver_popular('naver_popular', 4)"))?> wanted code : but it shows errors... <div id='a'> <div id='b'> <script type="text/javascript"> $("#test1").html( " <? echo htmlspecialchars(db_cache("main_top_naver_cache", 300, "naver_popular('naver_popular', 4)"))?> " ); </script> IE debuger shows error ... SCRIPT1015:... <script type="text/javascript"> $("#test1").html( " &lt;style&gt; /* http://html.nhncorp.com/uio_factory/ui_pattern/list/3 */ .section_ol3{position:relative;border:1px solid #ddd;background:#fff;font-size:12px;font-family:Tahoma, Geneva, sans-serif;line-height:normal;*zoom:1} .section_ol3 a{color:#666;text-decoration:none} .section_ol3 a:hover, .section_ol3 a:active, .section_ol3 a:focus{text-decoration:underline} .section_ol3 em{font-style:normal} .section_ol3 h2{margin:0;padding:10px 0 8px 13px;border-bottom:1px solid #ddd;font-size:12px;color:#333} .section_ol3 h2 em{color:#cf3292} .section_ol3 ol{margin:13px;padding:0;list-style:none} .section_ol3 li{position:relative;margin:0 0 10px 0;*zoom:1} .section_ol3 li:after{display:block;clear:both;content:&quot;&quot;} .section_ol3 li .ranking{display:inline-block;width:14px;height:11px;margin:0 5px 0 0;border-top:1px solid #fff;border-bottom:1px solid #d1d1d1;background:#d1d1d1;text-align:center;vertical-align:top;font:bold 10px Tahoma;color:#fff} .section_ol3 li.best .ranking{border-bottom:1px solid #6e87a5;background:#6e87a5} .section_ol3 li.best a{color:#7189a7} .section_ol3 li .num{position:absolute;top:0;right:0;font-size:11px;color:#a8a8a8;white-space:nowrap} .section_ol3 li.best .num{font-weight:bold;color:#7189a7} .section_ol3 .more{position:absolute;top:10px;right:13px;font:11px Dotum, ??;text-decoration:none !important} .section_ol3 .more span{margin:0 2px 0 0;font-weight:bold;font-size:16px;color:#d76ea9;vertical-align:middle} &lt;/style&gt; &lt;div class=&quot;section_ol3&quot;&gt; &lt;ol style='text-align:left;'&gt; &lt;li class='best'&gt;&lt;span class='ranking'&gt;1&lt;/span&gt;&lt;a href='http://search.naver.com/search.naver?where=nexearch&amp;query=%B9%AB%C7%D1%B5%B5%C0%FC&amp;sm=top_lve' onfocus='this.blur()' title='????' target=new&gt;????&lt;/a&gt;&lt;span class='num'&gt;+42&lt;/span&gt;&lt;/li&gt;&lt;li class='best'&gt;&lt;span class='ranking'&gt;2&lt;/span&gt;&lt;a href='http://search.naver.com/search.naver?where=nexearch&amp;query=%B1%E8%C0%E7%BF%AC&amp;sm=top_lve' onfocus='this.blur()' title='???' target=new&gt;???&lt;/a&gt;&lt;span class='num'&gt;+123&lt;/span&gt;&lt;/li&gt;&lt;li class='best'&gt;&lt;span class='ranking'&gt;3&lt;/span&gt;&lt;a href='http://search.naver.com/search.naver?where=nexearch&amp;query=%C0%CC%C7%CF%C0%CC&amp;sm=top_lve' onfocus='this.blur()' title='???' target=new&gt;???&lt;/a&gt;&lt;span class='num'&gt;+90&lt;/span&gt;&lt;/li&gt;&lt;li &gt;&lt;span class='ranking'&gt;4&lt;/span&gt;&lt;a href='http://search.naver.com/search.naver?where=nexearch&amp;query=%BA%D2%C8%C4%C0%C7%B8%ED%B0%EE2&amp;sm=top_lve' onfocus='this.blur()' title='?????2' target=new&gt;?????2&lt;/a&gt;&lt;span class='num'&gt;+87&lt;/span&gt;&lt;/li&gt; &lt;/ol&gt; </div> " );

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  • Is this a SEO SAFE anchor link

    - by Mayhem
    so... Is this a safe way to use internal links on your site.. By doing this i have the index page generating the usual php content section and handing it to the div element. THE MAIN QUESTION: Will google still index the pages using this method? Common sense tells me it does.. But just double checking and leaving this here as a base example as well if it is. As in. EXAMPLE ONLY PEOPLE The Server Side if (isset($_REQUEST['page'])) {$pageID=$_REQUEST['page'];} else {$pageID="home";} if (isset($_REQUEST['pageMode']) && $_REQUEST['pageMode']=="js") { require "content/".$pageID.".php"; exit; } // ELSE - REST OF WEBSITE WILL BE GENERATED USING THE page VARIABLE The Links <a class='btnMenu' href='?page=home'>Home Page</a> <a class='btnMenu' href='?page=about'>About</a> <a class='btnMenu' href='?page=Services'>Services</a> <a class='btnMenu' href='?page=contact'>Contact</a> The Javascript $(function() { $(".btnMenu").click(function(){return doNav(this);}); }); function doNav(objCaller) { var sPage = $(objCaller).attr("href").substring(6,255); $.get("index.php", { page: sPage, pageMode: 'js'}, function(data) { ("#siteContent").html(data).scrollTop(0); }); return false; } Forgive me if there are any errors, as just copied and pasted from my script then removed a bunch of junk to simplify it as still prototyping/white boarding the project its in. So yes it does look a little nasty at the moment. REASONS WHY: The main reason is bandwidth and speed, This will allow other scripts to run and control the site/application a little better and yes it will need to be locked down with some coding. -- FURTHER EXAMPLE-- INSERT PHP AT TOP <?php // PHP CODE HERE ?> <html> <head> <link rel="stylesheet" type="text/css" href="style.css" /> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript" src="scripts.js"></script> </head> <body> <div class='siteBody'> <div class='siteHeader'> <?php foreach ($pageList as $key => $value) { if ($pageID == $key) {$btnClass="btnMenuSel";} else {$btnClass="btnMenu";} echo "<a class='$btnClass' href='?page=".$key."'>".$pageList[$key]."</a>"; } ?> </div><div id="siteContent" style='margin-top:10px;'> <?php require "content/".$pageID.".php"; ?> </div><div class='siteFooter'> </div> </div> </body> </html>

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  • Can someone explain this color wheel code to me?

    - by user1869438
    I just started doing java and i need some help with understanding this code. I got it from a this website. This is supposed to be code for a color wheel but i don't really understand how it works, especially the final ints STEPS and SLICES. import java.awt.Color; import objectdraw.*; public class ColorWheel extends WindowController { private double brightness; private Text text; private FilledRect swatch; private Location center; private int size; private FilledRect brightnessOverlay; private static final int SLICES = 96; private static final int STEPS = 16; public void begin() { canvas.setBackground(Color.BLACK); brightness = 1.; size = Math.min(canvas.getWidth(), canvas.getHeight() - 20); center = new Location(canvas.getWidth() / 2, size / 2); for(int j = STEPS; j >= 1; j--) { int arcSize = size * j / STEPS; int x = center.getX() - arcSize / 2; int y = center.getY() - arcSize / 2; for(int i = 0; i < SLICES; i++) { Color c = Color.getHSBColor((float)i / SLICES, (float)j / STEPS, (float)brightness); new FilledArc(x, y, arcSize, arcSize, i * 360. / SLICES, 360. / SLICES + .5, c, canvas); } } swatch = new FilledRect(0, canvas.getHeight() - 20, canvas.getWidth(), 20, Color.BLACK, canvas); brightnessOverlay = new FilledRect(0, 0, canvas.getWidth(), canvas.getHeight() - 20, new Color(0, 0, 0, 0), canvas); text = new Text("", canvas.getWidth() / 2, canvas.getHeight() - 18, canvas); text.setAlignment(Text.CENTER, Text.TOP); text.setBold(true); } public void onMouseDrag(Location point) { brightness = (canvas.getHeight() - point.getY()) / (double)(canvas.getHeight()); if(brightness < 0) { brightness = 0; } else if(brightness > 1) { brightness = 1; } if(brightness < .5) { text.setColor(Color.WHITE); } else { text.setColor(Color.BLACK); } brightnessOverlay.setColor(new Color(0f, 0f, 0f, (float)(1 - brightness))); } public void onMouseMove(Location point) { double saturation = 2 * center.distanceTo(point) / size; if(saturation > 1) { text.setText(""); swatch.setColor(Color.BLACK); return; } double hue = -Math.atan2(point.getY() - center.getY(), point.getX() - center.getX()) / (2 * Math.PI); if(hue < 0) { hue += 1; } swatch.setColor(Color.getHSBColor((float)hue, (float)saturation, (float)brightness)); text.setText("Color.getHSBColor(" + Text.formatDecimal(hue, 2) + "f, " + Text.formatDecimal(saturation, 2) + "f, " + Text.formatDecimal(brightness, 2) + "f)"); } }

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  • "assignment makes integer from pointer without a cast " warning in c

    - by mekasperasky
    #include<stdio.h> /* this is a lexer which recognizes constants , variables ,symbols, identifiers , functions , comments and also header files . It stores the lexemes in 3 different files . One file contains all the headers and the comments . Another file will contain all the variables , another will contain all the symbols. */ int main() { int i=0,j; char a,b[20],c[30]; FILE *fp1,*fp2; c[0]='"if"; c[1]="then"; c[2]="else"; c[3]="switch"; c[4]="printf"; c[5]="scanf"; c[6]="NULL"; c[7]="int"; c[8]="char"; c[9]="float"; c[10]="long"; c[11]="double"; c[12]="char"; c[13]="const"; c[14]="continue"; c[15]="break"; c[16]="for"; c[17]="size of"; c[18]="register"; c[19]="short"; c[20]="auto"; c[21]="while"; c[22]="do"; c[23]="case"; fp1=fopen("source.txt","r"); //the source file is opened in read only mode which will passed through the lexer fp2=fopen("lext.txt","w"); //now lets remove all the white spaces and store the rest of the words in a file if(fp1==NULL) { perror("failed to open source.txt"); //return EXIT_FAILURE; } i=0; while(!feof(fp1)) { a=fgetc(fp1); if(a!=' ') { b[i]=a; } else { for (j=0;j<23;j++) { if(c[j]==b) { fprintf(fp2, "%.20s\n", c[j]); continue ; } b[i]='\0'; fprintf(fp2, "%.20s\n", b); i=0; continue; } //else if //{ i=i+1; /*Switch(a) { case EOF :return eof; case '+':sym=sym+1; case '-':sym=sym+1; case '*':sym=sym+1; case '/':sym=sym+1; case '%':sym=sym+1; case ' */ } fclose(fp1); fclose(fp2); return 0; } This is my c code for lexical analysis .. its giving warnings and also not writing anything into the lext file ..

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  • Using my custom colormap in Java for images

    - by John
    Hi everyone! I've got a question concering a colormapping via index. I tried this code found on http://www.podgoretsky.pri.ee/ftp/Docs/Java/Tricks%20of%20the%20Java%20Programming%20Gurus/ch12.htm // Gradient.java // Imports import java.applet.Applet; import java.awt.; import java.awt.image.; public class Gradient extends Applet { final int colors = 32; final int width = 200; final int height = 200; Image img; public void init() { // Create the color map byte[] rbmap = new byte[colors]; byte[] gmap = new byte[colors]; for (int i = 0; i < colors; i++) gmap[i] = (byte)((i * 255) / (colors - 1)); // Create the color model int bits = (int)Math.ceil(Math.log(colors) / Math.log(2)); IndexColorModel model = new IndexColorModel(bits, colors, rbmap, gmap, rbmap); // Create the pixels int pixels[] = new int[width * height]; int index = 0; for (int y = 0; y < height; y++) for (int x = 0; x < width; x++) pixels[index++] = (x * colors) / width; // Create the image img = createImage(new MemoryImageSource(width, height, model, pixels, 0, width)); } public void paint(Graphics g) { g.drawImage(img, 0, 0, this); } } It worked great but I tried to load a custom image jpeg mapped on my own colormap but it didnt work right. I saw only a bunch of green and blue pixels drawn on a white background. My custom color map method here: public void inintByteArrays() { double[][] c = // basic color map { { 0.0000, 0.0000, 0.5625 }, { 0.0000, 0.0000, 0.6250 }, { 0.0000, 0.0000, 0.6875 }, { 0.0000, 0.0000, 0.6875 }, { 0.0000, 0.0000, 0.7500 }, { 0.0000, 0.0000, 0.8125 }, { 0.0000, 0.0000, 0.8750 }, { 0.0000, 0.0000, 0.9375 }, { 0.0000, 0.0000, 1.0000 }, { 0.0000, 0.0625, 1.0000 }, { 0.0000, 0.1250, 1.0000 }, { 0.0000, 0.1875, 1.0000 }, { 0.0000, 0.2500, 1.0000 }, { 0.0000, 0.3125, 1.0000 }, { 0.0000, 0.3750, 1.0000 }, { 0.0000, 0.4375, 1.0000 }, { 0.0000, 0.5000, 1.0000 }, { 0.0000, 0.5625, 1.0000 }, { 0.0000, 0.6250, 1.0000 }, { 0.0000, 0.6875, 1.0000 }, { 0.0000, 0.7500, 1.0000 }, { 0.0000, 0.8125, 1.0000 }, { 0.0000, 0.8750, 1.0000 }, { 0.0000, 0.9375, 1.0000 }, { 0.0000, 1.0000, 1.0000 }, { 0.0625, 1.0000, 0.9375 }, { 0.1250, 1.0000, 0.8750 }, { 0.1875, 1.0000, 0.8125 }, { 0.2500, 1.0000, 0.7500 }, { 0.3125, 1.0000, 0.6875 }, { 0.3750, 1.0000, 0.6250 }, { 0.4375, 1.0000, 0.5625 }, { 0.5000, 1.0000, 0.5000 }, { 0.5625, 1.0000, 0.4375 }, { 0.6250, 1.0000, 0.3750 }, { 0.6875, 1.0000, 0.3125 }, { 0.7500, 1.0000, 0.2500 }, { 0.8125, 1.0000, 0.1875 }, { 0.8750, 1.0000, 0.1250 }, { 0.9375, 1.0000, 0.0625 }, { 1.0000, 1.0000, 0.0000 }, { 1.0000, 0.9375, 0.0000 }, { 1.0000, 0.8750, 0.0000 }, { 1.0000, 0.8125, 0.0000 }, { 1.0000, 0.7500, 0.0000 }, { 1.0000, 0.6875, 0.0000 }, { 1.0000, 0.6250, 0.0000 }, { 1.0000, 0.5625, 0.0000 }, { 1.0000, 0.5000, 0.0000 }, { 1.0000, 0.4375, 0.0000 }, { 1.0000, 0.3750, 0.0000 }, { 1.0000, 0.3125, 0.0000 }, { 1.0000, 0.2500, 0.0000 }, { 1.0000, 0.1875, 0.0000 }, { 1.0000, 0.1250, 0.0000 }, { 1.0000, 0.0625, 0.0000 }, { 1.0000, 0.0000, 0.0000 }, { 0.9375, 0.0000, 0.0000 }, { 0.8750, 0.0000, 0.0000 }, { 0.8125, 0.0000, 0.0000 }, { 0.7500, 0.0000, 0.0000 }, { 0.6875, 0.0000, 0.0000 }, { 0.6250, 0.0000, 0.0000 }, { 0.5625, 0.0000, 0.0000 }, { 0.5000, 0.0000, 0.0000 } }; for (int i = 0; i < c.length; i++) { for (int j = 0; j < c[i].length; j++) { if (j == 0) r[i] = (byte) ((byte) c[i][j]*255); if (j == 1) g[i] = (byte) ((byte) c[i][j]*255); if (j == 2) b[i] = (byte) ((byte) c[i][j]*255); } } My question is how I can use my colormap for any image I want to load and map in the right way. Thank you very much! Greetings, protein1.

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  • won't repaint a different Month after pressing button in my calendar

    - by DarkStar123
    I'm trying to build a Calendar in Java as a little project I thought of, But I can't seem to change the name of the Month every time I click the Next button. here's my code! package drawing; import javax.swing.*; import java.awt.*; import java.awt.event.*; public class Drawing_something extends JPanel{ int[] calender_squares = {1, 2, 3, 4, 5, 6, 7}; String[] Month = {"January", "February", "March", "April","May","June","July", "August","September","October","November","December"}; int i = 0; Graphics c; @Override public void paintComponent(Graphics c){ super.paintComponent(c); this.setBackground(Color.WHITE); int WIDTH = 55, HEIGHT = 65; for (int in: calender_squares) { for (int counter = 0; counter < 7; counter++){ c.drawRect(50, 50, 100, 100); c.drawRect(50, 50, 700, 500); c.copyArea(50, 50, 600, 500, 100, 0); c.copyArea(50, 50, 600, 400, 0, 100); } } for (int date = 1; date <= 30; date++) { String s = String.valueOf(date); c.drawString(s, WIDTH, HEIGHT); if (date <= 6){ WIDTH += 100; } else if (date == 7){ WIDTH = 55; HEIGHT = 165; }else if (date <= 13){ WIDTH += 100; }else if (date == 14){ WIDTH = 55; HEIGHT = 265; }else if (date <= 20){ WIDTH += 100; }else if (date == 21){ WIDTH = 55; HEIGHT = 365; }else if (date <= 27){ WIDTH += 100; }else if (date == 28){ WIDTH = 55; HEIGHT = 465; }else if (date <= 30){ WIDTH += 100; } } c.setFont(new Font("default", Font.BOLD, 40)); c.drawString(Month[i], 320, 45); } public Drawing_something(){ setLayout(new BorderLayout()); JButton N = new JButton("NEXT"); JButton B = new JButton("BACK"); JPanel P = new JPanel(); P.add(B); P.add(N); add(P, BorderLayout.SOUTH); B.addActionListener(new HandlerClass()); N.addActionListener(new NextClass()); } public class HandlerClass implements ActionListener{ public void actionPerformed(ActionEvent e){ } } public class NextClass implements ActionListener{ public void actionPerformed(ActionEvent e){ if (i == 11){ i = 0; } i = i + 1; c.drawString(Month[i], 320, 45); } } public static void main(String[] args){ JFrame mainFrame = new JFrame("Calender"); mainFrame.add(new Drawing_something()); mainFrame.setSize(850, 650); mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); mainFrame.setVisible(true); } } if anyone could help that would be much appreciated!! Thanks in advance!!

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  • Making CSS Render in a simialr way on FireFox 3.0.15/IE 6.0 & 7.0

    - by R.R
    Following css renders differently depends on the browser (mainly with Firefox) Firefox: the border-left-style:dashed does not seem to take effect as desired and black lines are shown instead. Also font seems to be another issue using em as they respond relatively better in cross browser. When i used pixel its a mess but not sure em is better or not. I am not a CSS expert and working with CSS makes me feel worse than dealing with a second hand car dealer. .Main { font-family: Arial, "Trebuchet MS", Sans-Serif; font-size: 0.8em; border:0px; } .Header { font-family: Arial, "Trebuchet MS", Sans-Serif; font-size: 1.2em; color:#666; background : url("../images/header.jpg") repeat-x top left; padding-left: 10px; padding:4px; text-transform:uppercase; border:1px; border-left-style:dashed; border-bottom-width:thin; border-collapse:collapse } .Footer { color:#666; font-family: Arial, "Trebuchet MS", Sans-Serif; font-size: 0.7em; } .Footer td { border-style:none; text-align:center; } .Footer span { color:#666; font-family: Arial, "Trebuchet MS", Sans-Serif; font-size: 0.7em; font-weight:bold; text-decoration:underline; border-style:none; } .Footer a { font-family: Arial, "Trebuchet MS", Sans-Serif; font-size: 0.7em; color:#666; } .Results-Item td { margin-left: 10px; vertical-align:middle; color:#666; background-color: white; font-size: 1.2em; padding:4px; font-family: Arial, "Trebuchet MS", Sans-Serif; padding-left: 10px; line-height: 20px; border:1px; border-left-style:dashed; border-bottom-width:thin; border-collapse:collapse; } .Results-AltItem td { margin-left: 10px; vertical-align:middle; color:#666; font-size: 1.2em; /* _font-size: 1.2em; /* IE6 hack */ padding:4px; font-family: Arial, "Trebuchet MS", Sans-Serif; background-color: #ccc; padding-left: 10px; line-height: 20px; border:1px; border:1px; border-left-style:dashed; border-bottom-width:thin; border-collapse:collapse; } Amount { text-align:right; }

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  • Cant center dropdown menu

    - by sonicboom
    I have a dropdown below ive creaeted, but im having troulbe centering the the menu. Ive tried to put <center> tags around it and also set the ul to margin auto 0 but its not working. Is there anything im missing? <style type="text/css"> ul { font-family: Arial, Verdana; font-size: 14px; margin: 0; padding: 0; list-style: none; } ul li { display: block; position: relative; float: left; } li ul { display: none; } ul li a { display: block; text-decoration: none; color: #ffffff; border-top: 1px solid #ffffff; padding: 5px 15px 5px 15px; background: #1e7c9a; margin-left: 1px; white-space: nowrap; } ul li a:hover { background: #3b3b3b; } li:hover ul { display: block; position: absolute; } li:hover li { float: none; font-size: 11px; } li:hover a { background: #3b3b3b; } li:hover li a:hover { background: #1e7c9a; } </style> </head> <body> <ul id="menu"> <li><a href="#">Home</a></li> <li><a href="#">Portfolio</a> <ul> <li><a href="#">Web Design</a></li> <li><a href="#">Graphic Design</a></li> <li><a href="#">Logo Design</a></li> <li><a href="#">Blog Design</a></li> </ul> </li> <li><a href="#">Projects</a> <ul> <li><a href="#">This is a project</a></li> <li><a href="#">So is this</a></li> <li><a href="#">and this</a></li> <li><a href="#">don't forget this too</a></li> </ul> </li> <li><a href="#">Contact</a> <ul> <li><a href="#">Support</a></li> <li><a href="#">Quote</a></li> <li><a href="#">General Enquiry</a></li> </ul> </li> </ul> I went ahead and put it on jsfiddle Here

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  • change value upon select

    - by Link
    what i'm aiming is to show the other div when it selects one of the two options Full time and Part Time and if possible compute a different value for each When the user selects Part time the value of PrcA will change to PrcB this is the code i used <!====================================================================================> <script language="javascript"> <!--// function dm(amount) { string = "" + amount; dec = string.length - string.indexOf('.'); if (string.indexOf('.') == -1) return string + '.00'; if (dec == 1) return string + '00'; if (dec == 2) return string + '0'; if (dec > 3) return string.substring(0,string.length-dec+3); return string; } function calculate() { QtyA = 0; TotA = 0; PrcA = 1280; PrcB = 640; if (document.form1.qtyA.value > "") { QtyA = document.form1.qtyA.value }; document.form1.qtyA.value = eval(QtyA); TotA = QtyA * PrcA; document.form1.totalA.value = dm(eval(TotA)); Totamt = eval(TotA) ; document.form1.GrandTotal.value = dm(eval(Totamt)); } //--> </script> <!====================================================================================> <p> <label for="acct" style="margin-right:90px;"><strong>Account Type<strong><font color=red size=3> * </font></strong></label> <select name="acct" style="background-color:white;" class="validate[custom[serv]] select-input" id="acct" value=""> <option value="Full Time">Full-Time</option> <option value="Part Time">Part-Time</option> <option selected="selected" value=""></option> </select></p> <!====================================================================================> <script> $(document).ready(function() { $("input[name$='acct']").select(function() { var test = $(this).val(); $("div.desc").hide(); $("#acct" + test).show(); }); }); </script> <!====================================================================================> <p> <table><tr><td> <lable style="margin-right:91px;"># of Agent(s)<font color=red size=3> * </font></lable> </td><td> <input style="width:25px; margin-left:5px;" type="text" class="validate[custom[agnt]] text-input" name="qtyA" id="qtyA" onchange="calculate()" /> </td><td> <div id="acctFull Time" class="desc"> x 1280 = </div> <div id="acctPart Time" class="desc" style="display:none"> x 640 = </div> </td><td> $<input style="width:80px; margin-left:5px;" type="text" readonly="readonly" name="totalA" id="totalA" onchange="calculate()" /> </p> </td></tr></table> is there any way for me to achieve this?

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  • JQuery works on JsFiddle but not in project

    - by DanielNova
    Here is the JsFiddle I created: http://jsfiddle.net/ShHVy/ Everything works fine - different data is displayed in the column row to the right as I wish.. However, even having this exact code in my Project won't make it work The page in question is a popup view and it looks like this: <style type="text/css"> .highlighted { background-color: Orange; color: White; } </style> <script> var chosen = []; $("td").click(function () { var idx = $(this).index() + 1; $("td:nth-child(" + idx + ")").removeClass("highlighted"); $(this).addClass("highlighted"); chosen[idx] = $(this).parent("tr").index(); }); var data = { "Differdange": ["Differdange 1", "Differdange 2", "Differdange 3", "Differdange 4"], "Dippach": ["Dippach 1", "Dippach 2", "Dippach 3", "Dippach 4", ] }; function pushData(id, col) { $("#datachange table td:nth-child(" + 2 + ")").each(function (i, v) { $(this).html(data[id][i]) }); } $(function () { $("#datachange td").click(function () { var idx = $(this).index() + 1; $("td:nth-child(" + idx + ")").removeClass("highlighted"); $(this).addClass("highlighted"); pushData($(".highlighted").html(), 2); }); }); </script> <html> <head><title>Table Data Change</title></head> <body id="datachange" class="demo"> <table> <thead> <tr> <th>ID</th> <th>DATA</th> </tr> </thead> <tbody> <tr> <td>Differdange</td> <td></td> </tr> <tr> <td>Dippach</td> <td></td> </tr> <tr> <td>Dippach</td> <td></td> </tr> <tr> <td>Differdange</td> <td></td> </tr> </tbody> </table> </body> </html> Can anyone tell me why this small piece of JQuery doesn't work on mine (it's nothing to do with libraries as the top "td" function works 100% fine)

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  • Parallelism in .NET – Part 3, Imperative Data Parallelism: Early Termination

    - by Reed
    Although simple data parallelism allows us to easily parallelize many of our iteration statements, there are cases that it does not handle well.  In my previous discussion, I focused on data parallelism with no shared state, and where every element is being processed exactly the same. Unfortunately, there are many common cases where this does not happen.  If we are dealing with a loop that requires early termination, extra care is required when parallelizing. Often, while processing in a loop, once a certain condition is met, it is no longer necessary to continue processing.  This may be a matter of finding a specific element within the collection, or reaching some error case.  The important distinction here is that, it is often impossible to know until runtime, what set of elements needs to be processed. In my initial discussion of data parallelism, I mentioned that this technique is a candidate when you can decompose the problem based on the data involved, and you wish to apply a single operation concurrently on all of the elements of a collection.  This covers many of the potential cases, but sometimes, after processing some of the elements, we need to stop processing. As an example, lets go back to our previous Parallel.ForEach example with contacting a customer.  However, this time, we’ll change the requirements slightly.  In this case, we’ll add an extra condition – if the store is unable to email the customer, we will exit gracefully.  The thinking here, of course, is that if the store is currently unable to email, the next time this operation runs, it will handle the same situation, so we can just skip our processing entirely.  The original, serial case, with this extra condition, might look something like the following: foreach(var customer in customers) { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { // Exit gracefully if we fail to email, since this // entire process can be repeated later without issue. if (theStore.EmailCustomer(customer) == false) break; customer.LastEmailContact = DateTime.Now; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, we’re processing our loop, but at any point, if we fail to send our email successfully, we just abandon this process, and assume that it will get handled correctly the next time our routine is run.  If we try to parallelize this using Parallel.ForEach, as we did previously, we’ll run into an error almost immediately: the break statement we’re using is only valid when enclosed within an iteration statement, such as foreach.  When we switch to Parallel.ForEach, we’re no longer within an iteration statement – we’re a delegate running in a method. This needs to be handled slightly differently when parallelized.  Instead of using the break statement, we need to utilize a new class in the Task Parallel Library: ParallelLoopState.  The ParallelLoopState class is intended to allow concurrently running loop bodies a way to interact with each other, and provides us with a way to break out of a loop.  In order to use this, we will use a different overload of Parallel.ForEach which takes an IEnumerable<T> and an Action<T, ParallelLoopState> instead of an Action<T>.  Using this, we can parallelize the above operation by doing: Parallel.ForEach(customers, (customer, parallelLoopState) => { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { // Exit gracefully if we fail to email, since this // entire process can be repeated later without issue. if (theStore.EmailCustomer(customer) == false) parallelLoopState.Break(); else customer.LastEmailContact = DateTime.Now; } }); There are a couple of important points here.  First, we didn’t actually instantiate the ParallelLoopState instance.  It was provided directly to us via the Parallel class.  All we needed to do was change our lambda expression to reflect that we want to use the loop state, and the Parallel class creates an instance for our use.  We also needed to change our logic slightly when we call Break().  Since Break() doesn’t stop the program flow within our block, we needed to add an else case to only set the property in customer when we succeeded.  This same technique can be used to break out of a Parallel.For loop. That being said, there is a huge difference between using ParallelLoopState to cause early termination and to use break in a standard iteration statement.  When dealing with a loop serially, break will immediately terminate the processing within the closest enclosing loop statement.  Calling ParallelLoopState.Break(), however, has a very different behavior. The issue is that, now, we’re no longer processing one element at a time.  If we break in one of our threads, there are other threads that will likely still be executing.  This leads to an important observation about termination of parallel code: Early termination in parallel routines is not immediate.  Code will continue to run after you request a termination. This may seem problematic at first, but it is something you just need to keep in mind while designing your routine.  ParallelLoopState.Break() should be thought of as a request.  We are telling the runtime that no elements that were in the collection past the element we’re currently processing need to be processed, and leaving it up to the runtime to decide how to handle this as gracefully as possible.  Although this may seem problematic at first, it is a good thing.  If the runtime tried to immediately stop processing, many of our elements would be partially processed.  It would be like putting a return statement in a random location throughout our loop body – which could have horrific consequences to our code’s maintainability. In order to understand and effectively write parallel routines, we, as developers, need a subtle, but profound shift in our thinking.  We can no longer think in terms of sequential processes, but rather need to think in terms of requests to the system that may be handled differently than we’d first expect.  This is more natural to developers who have dealt with asynchronous models previously, but is an important distinction when moving to concurrent programming models. As an example, I’ll discuss the Break() method.  ParallelLoopState.Break() functions in a way that may be unexpected at first.  When you call Break() from a loop body, the runtime will continue to process all elements of the collection that were found prior to the element that was being processed when the Break() method was called.  This is done to keep the behavior of the Break() method as close to the behavior of the break statement as possible. We can see the behavior in this simple code: var collection = Enumerable.Range(0, 20); var pResult = Parallel.ForEach(collection, (element, state) => { if (element > 10) { Console.WriteLine("Breaking on {0}", element); state.Break(); } Console.WriteLine(element); }); If we run this, we get a result that may seem unexpected at first: 0 2 1 5 6 3 4 10 Breaking on 11 11 Breaking on 12 12 9 Breaking on 13 13 7 8 Breaking on 15 15 What is occurring here is that we loop until we find the first element where the element is greater than 10.  In this case, this was found, the first time, when one of our threads reached element 11.  It requested that the loop stop by calling Break() at this point.  However, the loop continued processing until all of the elements less than 11 were completed, then terminated.  This means that it will guarantee that elements 9, 7, and 8 are completed before it stops processing.  You can see our other threads that were running each tried to break as well, but since Break() was called on the element with a value of 11, it decides which elements (0-10) must be processed. If this behavior is not desirable, there is another option.  Instead of calling ParallelLoopState.Break(), you can call ParallelLoopState.Stop().  The Stop() method requests that the runtime terminate as soon as possible , without guaranteeing that any other elements are processed.  Stop() will not stop the processing within an element, so elements already being processed will continue to be processed.  It will prevent new elements, even ones found earlier in the collection, from being processed.  Also, when Stop() is called, the ParallelLoopState’s IsStopped property will return true.  This lets longer running processes poll for this value, and return after performing any necessary cleanup. The basic rule of thumb for choosing between Break() and Stop() is the following. Use ParallelLoopState.Stop() when possible, since it terminates more quickly.  This is particularly useful in situations where you are searching for an element or a condition in the collection.  Once you’ve found it, you do not need to do any other processing, so Stop() is more appropriate. Use ParallelLoopState.Break() if you need to more closely match the behavior of the C# break statement. Both methods behave differently than our C# break statement.  Unfortunately, when parallelizing a routine, more thought and care needs to be put into every aspect of your routine than you may otherwise expect.  This is due to my second observation: Parallelizing a routine will almost always change its behavior. This sounds crazy at first, but it’s a concept that’s so simple its easy to forget.  We’re purposely telling the system to process more than one thing at the same time, which means that the sequence in which things get processed is no longer deterministic.  It is easy to change the behavior of your routine in very subtle ways by introducing parallelism.  Often, the changes are not avoidable, even if they don’t have any adverse side effects.  This leads to my final observation for this post: Parallelization is something that should be handled with care and forethought, added by design, and not just introduced casually.

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  • Parallelism in .NET – Part 7, Some Differences between PLINQ and LINQ to Objects

    - by Reed
    In my previous post on Declarative Data Parallelism, I mentioned that PLINQ extends LINQ to Objects to support parallel operations.  Although nearly all of the same operations are supported, there are some differences between PLINQ and LINQ to Objects.  By introducing Parallelism to our declarative model, we add some extra complexity.  This, in turn, adds some extra requirements that must be addressed. In order to illustrate the main differences, and why they exist, let’s begin by discussing some differences in how the two technologies operate, and look at the underlying types involved in LINQ to Objects and PLINQ . LINQ to Objects is mainly built upon a single class: Enumerable.  The Enumerable class is a static class that defines a large set of extension methods, nearly all of which work upon an IEnumerable<T>.  Many of these methods return a new IEnumerable<T>, allowing the methods to be chained together into a fluent style interface.  This is what allows us to write statements that chain together, and lead to the nice declarative programming model of LINQ: double min = collection .Where(item => item.SomeProperty > 6 && item.SomeProperty < 24) .Min(item => item.PerformComputation()); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Other LINQ variants work in a similar fashion.  For example, most data-oriented LINQ providers are built upon an implementation of IQueryable<T>, which allows the database provider to turn a LINQ statement into an underlying SQL query, to be performed directly on the remote database. PLINQ is similar, but instead of being built upon the Enumerable class, most of PLINQ is built upon a new static class: ParallelEnumerable.  When using PLINQ, you typically begin with any collection which implements IEnumerable<T>, and convert it to a new type using an extension method defined on ParallelEnumerable: AsParallel().  This method takes any IEnumerable<T>, and converts it into a ParallelQuery<T>, the core class for PLINQ.  There is a similar ParallelQuery class for working with non-generic IEnumerable implementations. This brings us to our first subtle, but important difference between PLINQ and LINQ – PLINQ always works upon specific types, which must be explicitly created. Typically, the type you’ll use with PLINQ is ParallelQuery<T>, but it can sometimes be a ParallelQuery or an OrderedParallelQuery<T>.  Instead of dealing with an interface, implemented by an unknown class, we’re dealing with a specific class type.  This works seamlessly from a usage standpoint – ParallelQuery<T> implements IEnumerable<T>, so you can always “switch back” to an IEnumerable<T>.  The difference only arises at the beginning of our parallelization.  When we’re using LINQ, and we want to process a normal collection via PLINQ, we need to explicitly convert the collection into a ParallelQuery<T> by calling AsParallel().  There is an important consideration here – AsParallel() does not need to be called on your specific collection, but rather any IEnumerable<T>.  This allows you to place it anywhere in the chain of methods involved in a LINQ statement, not just at the beginning.  This can be useful if you have an operation which will not parallelize well or is not thread safe.  For example, the following is perfectly valid, and similar to our previous examples: double min = collection .AsParallel() .Select(item => item.SomeOperation()) .Where(item => item.SomeProperty > 6 && item.SomeProperty < 24) .Min(item => item.PerformComputation()); However, if SomeOperation() is not thread safe, we could just as easily do: double min = collection .Select(item => item.SomeOperation()) .AsParallel() .Where(item => item.SomeProperty > 6 && item.SomeProperty < 24) .Min(item => item.PerformComputation()); In this case, we’re using standard LINQ to Objects for the Select(…) method, then converting the results of that map routine to a ParallelQuery<T>, and processing our filter (the Where method) and our aggregation (the Min method) in parallel. PLINQ also provides us with a way to convert a ParallelQuery<T> back into a standard IEnumerable<T>, forcing sequential processing via standard LINQ to Objects.  If SomeOperation() was thread-safe, but PerformComputation() was not thread-safe, we would need to handle this by using the AsEnumerable() method: double min = collection .AsParallel() .Select(item => item.SomeOperation()) .Where(item => item.SomeProperty > 6 && item.SomeProperty < 24) .AsEnumerable() .Min(item => item.PerformComputation()); Here, we’re converting our collection into a ParallelQuery<T>, doing our map operation (the Select(…) method) and our filtering in parallel, then converting the collection back into a standard IEnumerable<T>, which causes our aggregation via Min() to be performed sequentially. This could also be written as two statements, as well, which would allow us to use the language integrated syntax for the first portion: var tempCollection = from item in collection.AsParallel() let e = item.SomeOperation() where (e.SomeProperty > 6 && e.SomeProperty < 24) select e; double min = tempCollection.AsEnumerable().Min(item => item.PerformComputation()); This allows us to use the standard LINQ style language integrated query syntax, but control whether it’s performed in parallel or serial by adding AsParallel() and AsEnumerable() appropriately. The second important difference between PLINQ and LINQ deals with order preservation.  PLINQ, by default, does not preserve the order of of source collection. This is by design.  In order to process a collection in parallel, the system needs to naturally deal with multiple elements at the same time.  Maintaining the original ordering of the sequence adds overhead, which is, in many cases, unnecessary.  Therefore, by default, the system is allowed to completely change the order of your sequence during processing.  If you are doing a standard query operation, this is usually not an issue.  However, there are times when keeping a specific ordering in place is important.  If this is required, you can explicitly request the ordering be preserved throughout all operations done on a ParallelQuery<T> by using the AsOrdered() extension method.  This will cause our sequence ordering to be preserved. For example, suppose we wanted to take a collection, perform an expensive operation which converts it to a new type, and display the first 100 elements.  In LINQ to Objects, our code might look something like: // Using IEnumerable<SourceClass> collection IEnumerable<ResultClass> results = collection .Select(e => e.CreateResult()) .Take(100); If we just converted this to a parallel query naively, like so: IEnumerable<ResultClass> results = collection .AsParallel() .Select(e => e.CreateResult()) .Take(100); We could very easily get a very different, and non-reproducable, set of results, since the ordering of elements in the input collection is not preserved.  To get the same results as our original query, we need to use: IEnumerable<ResultClass> results = collection .AsParallel() .AsOrdered() .Select(e => e.CreateResult()) .Take(100); This requests that PLINQ process our sequence in a way that verifies that our resulting collection is ordered as if it were processed serially.  This will cause our query to run slower, since there is overhead involved in maintaining the ordering.  However, in this case, it is required, since the ordering is required for correctness. PLINQ is incredibly useful.  It allows us to easily take nearly any LINQ to Objects query and run it in parallel, using the same methods and syntax we’ve used previously.  There are some important differences in operation that must be considered, however – it is not a free pass to parallelize everything.  When using PLINQ in order to parallelize your routines declaratively, the same guideline I mentioned before still applies: Parallelization is something that should be handled with care and forethought, added by design, and not just introduced casually.

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