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  • JPanel.addComponentListener does not work when the listener is a class variable

    - by Coder
    I have a public class which has the following method and instance variable: public void setImagePanel(JPanel value) { imagePanel = value; if (imagePanel != null) { //method 1 : works imagePanel.addComponentListener(new ComponentAdapter() { public void componentResized(ComponentEvent evt) { System.out.println("Here 1"); } }); //method 2 : does not work panelResizeListener = new ResizeListener(); imagePanel.addComponentListener(panelResizeListener); //method 3 : works //ResizeListener listener = new ResizeListener(); //imagePanel.addComponentListener(listener); //method 4 : works //imagePanel.addComponentListener(new ResizeListener()); //method 5 : does not work -- THIS IS THE DESIRED CODE I WANT TO USE imagePanel.addComponentListener(panelResizeListener); } } public class ResizeListener extends ComponentAdapter { @Override public void componentResized(ComponentEvent evt) { System.out.println("RESIZE 3"); } } private ResizeListener panelResizeListener = new ResizeListener(); Each of the methods above correspond the to code immediately below until the next //method comment. What i don't understand is why i can't use the class instance variable and add that to the JPanel as a component listener. What happens in the cases above where i say that the method does not work is that i don't get the "RESIZE 3" log messages. In all cases where i list that it works, then i get the "RESIZE 3" messages. The outer class is public with no other modification except that it implements an interface that i created (which has no methods or variables in common with the methods and variables listed above). If anyone can help me i would greatly appreciate it. This problem makes no sense to me, the code should be identical.

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  • Why & When should I use SPARSE COLUMN? (SQL SERVER 2008)

    - by priyanka.sarkar
    After going thru some tutorials on SQL SERVER 2008's new feature SPARSE COLUMN, I have found that it doesn't take any space if the column value is 0 or null but when there is a value, it takes 4 times the space a regular(non sparse) column holds. If my understanding is correct, then why I will go for that at the time of database design? And if I use that, then at what situation so I be? Also out of curiosity, how come no space get's reserve when a column is defined as sparse column(I mean to say, what is the internal implementation for that) Thanks in advance

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  • What kind of icon should I deploy with my Android 1.x and 2.x application?

    - by licorna
    The thing is this, in Android 1.5 and 1.6 we had the Icon Design Guidelines. In this guide there are specifications for application icons. Every application should conform to this. However, in recent Android versions (2.0 and 2.1) icons have changed from the old to this new flat 2D style. Every icon in Nexus One has this style, so not even Google is conforming to the guideline. To see the differences between high and low density icons see this image and compare Evernote icon with the rest. I've been able to use different icons by using two directories with different icons: drawables-hdpi/icon.png and drawables/icon.png, BUT not every Android 2.x is going to be HDPI and not every 1.x Android device is going to be low pixel density. So the question is: Should I deploy different icons for different Android platform version within my apk file? and if I should, How do I do it?

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  • Saving data to server with user accounts.

    - by AKRamkumar
    Ok, so for an app I am making, I want the user to be able to save data online. On my website, I will provide a web server with tables of UserName/Password/SaveData. How can I do this without crashing the server load? How can I guarantee security ? Is there a Design Pattern for this?Is there a better way of doing this? This is going to be a free application, available to the public and I would like for their settings to be available, no matter the computer they are using. Is there a better way of doing this? I am using MEF for plugins so is there a way I can save plugin data as well?

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  • Shouldn't ObjectInputStream extend FilterInputStream?

    - by Vaibhav Bajpai
    The block quotes are from the Java Docs - A FilterInputStream contains some other input stream, which it uses as its basic source of data, possibly transforming the data along the way or providing additional functionality. A DataInputStream lets an application read primitive Java data types from an underlying input stream in a machine-independent way. The DataInputStream therefore extends FilterInputStream An ObjectInputStream deserializes primitive data and objects previously written using an ObjectOutputStream. However, for some reason the ObjectInputStream does NOT extend FilterInputStream even though it is also reading objects (this time and not primitive types) from the underlying input stream. Here is the branching of the concerned classes. Is there is a design reasoning for the same?

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  • need to get the context value in top of page, where the context value will be set only at the bottom

    - by Mahadevan Alagar
    <script runat="server"> protected void Page_Load(object sender, EventArgs e) { Response.Write("Page Load:"); } public string setContext(string sName, string sVal) { HttpContext.Current.Items[sName] = sVal; return sVal; } public string getContext(string sName) { string sVal = "default"; if (HttpContext.Current.Items[sName] != null) sVal = HttpContext.Current.Items[sName].ToString(); else sVal = "empty"; return sVal; } </script> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Get Context in TOP ???</title> </head> <body> <div> <div id="divDest" name="divDest"> Top Content: Get1 :<%= getContext("topcontent") %> // returns "empty", BUT I Need "value to set" </div> <br /> Set1 : <%= setContext("topcontent", "value to set")%> <br /> // set the value <br /> Get2 : <%= getContext("topcontent") %><br /> // returns "value to set" <br /> <script language="javascript"> var elval = getElementVal("divTest"); document.getElementById("divDest").innerHTML = elval; //alert(elval); function getElementVal(elemid) { var elemval = document.getElementById(elemid); return elemval.innerHTML; } </script> </body> </html> I need to get the context value in top of page, where the context value will be set at the bottom of the page. Get context value == "empty", BUT need "something" Set context value to "something" Get context value == "something" I may use JS/AJAX, where the page source the value won't be present. BUT I need the TEXT in the View Source of the page too. Is there a way to wait for the context to set and then get, I have tried with User Control, prerender and render methods too. But I can't able to get it right. Any idea?

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  • Can Internet Explorer bind events to absolute positioned elements ?

    - by mark
    Can Internet Explorer bind events to absolute positioned elements ? I can't bind a "click" to an element that is overlapping another. Have tried loads of different ways, here a few tests that don't work in IE: //version 1: $(".classHolder").click(function(){ alert( $(this).html() ); }); //version 2: $(".classHolder").each(function(){ $(this).click(function(){ alert( $(this).html() ); }); }); //version 3: $("#id3").click(function(){ alert( $(this).html() ); }); //version 4: $("#id3").click(function(){ alert( $(this).html() ); }); $("#id3").trigger("click"); // in all trials I tested with and without: // $("img").unbind(); // $("div").unbind(); // just to make sure no "ghost" events were bind into the elements but no success. // replace all [ for < , and all ] for [html] [head] [script src="http://code.jquery.com/jquery-latest.js"][/script] [script type="application/javascript"] $(document).ready(function(){ $("#id3").click(function(){ alert( $(this).html() ); }); $("#id3").trigger("click"); }); [/script] [/head] [body] [div id="id1" style="position:relative;"] [img id="id2" src="http://www.google.co.uk/intl/en_com/images/srpr/logo1w.png" style=";z-index:-1;"/] [div id="id3" class="classHolder" style="position:absolute;border:2px solid red;left:0px;top:0px;width:70px;height:70px;z-index:1002;"]G[/div] [div id="id4" class="classHolder" style="position:absolute;border:2px solid red;left:210px;top:0px;width:25px;height:70px;z-index:1001;"]L[/div] asd asdf asdfg [/div] [/body] [/html]

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  • How to implement an EventHandler to update controls

    - by Bill
    May I ask for help with the following? I am attempting to connect and control three pieces of household electronic equipment by computer through a GlobalCache GC-100 and iTach. As you will see in the following code, I created a class-instance of GlobalCacheAdapter that communicates with each piece of equipment. Although the code seems to work well in controlling the equipment, I am having trouble updating controls with the feedback from the equipment. The procedure "ReaderThreadProc" captures the feedback; however I don't know how to update the associated TextBox with the feedback. I believe that I need to create an EventHandler to notify the TextBox of the available update; however I am uncertain as to how an EventHandler like this would be implemented. Any help wold be greatly appreciated. using System; using System.IO; using System.Net; using System.Net.Sockets; using System.Threading; using System.Windows.Forms; namespace WindowsFormsApplication1 { public partial class Form1 : Form { // Create three new instances of GlobalCacheAdaptor and connect. // GC-100 (Elan) 192.168.1.70 4998 // GC-100 (TuneSuite) 192.168.1.70 5000 // GC iTach (Lighting) 192.168.1.71 4999 private GlobalCacheAdaptor elanGlobalCacheAdaptor; private GlobalCacheAdaptor tuneSuiteGlobalCacheAdaptor; private GlobalCacheAdaptor lutronGlobalCacheAdaptor; public Form1() { InitializeComponent(); elanGlobalCacheAdaptor = new GlobalCacheAdaptor(); elanGlobalCacheAdaptor.ConnectToDevice(IPAddress.Parse("192.168.1.70"), 4998); tuneSuiteGlobalCacheAdaptor = new GlobalCacheAdaptor(); tuneSuiteGlobalCacheAdaptor.ConnectToDevice(IPAddress.Parse("192.168.1.70"), 5000); lutronGlobalCacheAdaptor = new GlobalCacheAdaptor(); lutronGlobalCacheAdaptor.ConnectToDevice(IPAddress.Parse("192.168.1.71"), 4999); elanTextBox.Text = elanGlobalCacheAdaptor._line; tuneSuiteTextBox.Text = tuneSuiteGlobalCacheAdaptor._line; lutronTextBox.Text = lutronGlobalCacheAdaptor._line; } private void btnZoneOnOff_Click(object sender, EventArgs e) { elanGlobalCacheAdaptor.SendMessage("sendir,4:3,1,40000,4,1,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,800" + Environment.NewLine); } private void btnSourceInput1_Click(object sender, EventArgs e) { elanGlobalCacheAdaptor.SendMessage("sendir,4:3,1,40000,1,1,20,179,20,179,20,179,20,179,20,179,20,179,20,179,20,278,20,179,20,179,20,179,20,780" + Environment.NewLine); } private void btnSystemOff_Click(object sender, EventArgs e) { elanGlobalCacheAdaptor.SendMessage("sendir,4:3,1,40000,1,1,20,184,20,184,20,184,20,184,20,184,20,286,20,286,20,286,20,184,20,184,20,184,20,820" + Environment.NewLine); } private void btnLightOff_Click(object sender, EventArgs e) { lutronGlobalCacheAdaptor.SendMessage("sdl,14,0,0,S2\x0d"); } private void btnLightOn_Click(object sender, EventArgs e) { lutronGlobalCacheAdaptor.SendMessage("sdl,14,100,0,S2\x0d"); } private void btnChannel31_Click(object sender, EventArgs e) { tuneSuiteGlobalCacheAdaptor.SendMessage("\xB8\x4D\xB5\x33\x31\x00\x30\x21\xB8\x0D"); } private void btnChannel30_Click(object sender, EventArgs e) { tuneSuiteGlobalCacheAdaptor.SendMessage("\xB8\x4D\xB5\x33\x30\x00\x30\x21\xB8\x0D"); } } } public class GlobalCacheAdaptor { public Socket _multicastListener; public string _preferredDeviceID; public IPAddress _deviceAddress; public Socket _deviceSocket; public StreamWriter _deviceWriter; public bool _isConnected; public int _port; public IPAddress _address; public string _line; public GlobalCacheAdaptor() { } public static readonly GlobalCacheAdaptor Instance = new GlobalCacheAdaptor(); public bool IsListening { get { return _multicastListener != null; } } public GlobalCacheAdaptor ConnectToDevice(IPAddress address, int port) { if (_deviceSocket != null) _deviceSocket.Close(); try { _port = port; _address = address; _deviceSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); _deviceSocket.Connect(new IPEndPoint(address, port)); ; _deviceAddress = address; var stream = new NetworkStream(_deviceSocket); var reader = new StreamReader(stream); var writer = new StreamWriter(stream) { NewLine = "\r", AutoFlush = true }; _deviceWriter = writer; writer.WriteLine("getdevices"); var readerThread = new Thread(ReaderThreadProc) { IsBackground = true }; readerThread.Start(reader); _isConnected = true; return Instance; } catch { DisconnectFromDevice(); MessageBox.Show("ConnectToDevice Error."); throw; } } public void SendMessage(string message) { try { var stream = new NetworkStream(_deviceSocket); var reader = new StreamReader(stream); var writer = new StreamWriter(stream) { NewLine = "\r", AutoFlush = true }; _deviceWriter = writer; writer.WriteLine(message); var readerThread = new Thread(ReaderThreadProc) { IsBackground = true }; readerThread.Start(reader); } catch { MessageBox.Show("SendMessage() Error."); } } public void DisconnectFromDevice() { if (_deviceSocket != null) { try { _deviceSocket.Close(); _isConnected = false; } catch { MessageBox.Show("DisconnectFromDevice Error."); } _deviceSocket = null; } _deviceWriter = null; _deviceAddress = null; } private void ReaderThreadProc(object state) { var reader = (StreamReader)state; try { while (true) { var line = reader.ReadLine(); if (line == null) break; _line = _line + line + Environment.NewLine; } // Need to create EventHandler to notify the TextBoxes to update with _line } catch { MessageBox.Show("ReaderThreadProc Error."); } } }

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  • logic of button to be disabled or not in mvc

    - by rod
    Hi All, Here's an excerpt from a book I'm reading about application design with MVC: Ideally, the view is so simple and logic-free as to need virtually no testing. Users (and developers before users) can reasonably test the view by simply looking at the pixels on the screen. Anything else beyond pure graphical rendering should ideally be taken out of the view and placed in the controller and model. This includes, for example, the logic that determines whether a certain button should be enabled or grayed out at some point. what does the bold statement mean to you? what would this look like? thanks, rod.

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  • How to promote/market an event that needs many people?

    - by stjowa
    My team is about to launch a new web application, http://wethepixels.com, that requires a lot of people to be on the site at the same time for the concept to be successful. Our team is preparing to promote/market an event for a specific date and time, in order to try to grab a large group of people to the site at once. For those who have gone through a similar web launch, we would love to hear ideas on the best way to market for a large group in a relatively short period of time. We have created a Facebook page and a Facebook event, but it has yet to grab much attention (surprisingly to us). Is there a better way to attract a large number of users in a short period of time? Thanks

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  • Which method should I use ?

    - by Ivan
    I want to do this exercise but I don't know exactly which method should I use for an exercise like this and what data will I use to test the algorithm. The driving distance between Perth and Adelaide is 1996 miles. On the average, the fuel consumption of a 2.0 litre 4 cylinder car is 8 litres per 100 kilometres. The fuel tank capacity of such a car is 60 litres. Design and implement a JAVA program that prompts for the fuel consumption and fuel tank capacity of the aforementioned car. The program then displays the minimum number of times the car’s fuel tank has to be filled up to drive from Perth to Adelaide. Note that 62 miles is equal to 100 kilometres. What data will you use to test that your algorithm works correctly?

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  • Views performance in MySQL

    - by Gianluca Bargelli
    I am currently writing my truly first PHP Application and i would like to know how to project/design/implement MySQL Views properly; In my particular case User data is spread across several tables (as a consequence of Database Normalization) and i was thinking to use a View to group data into one large table: CREATE VIEW `Users_Merged` ( name, surname, email, phone, role ) AS ( SELECT name, surname, email, phone, 'Customer' FROM `Customer` ) UNION ( SELECT name, surname, email, tel, 'Admin' FROM `Administrator` ) UNION ( SELECT name, surname, email, tel, 'Manager' FROM `manager` ); This way i can use the View's data from the PHP app easily but i don't really know how much this can affect performance. For example: SELECT * from `Users_Merged` WHERE role = 'Admin'; Is the right way to filter view's data or should i filter BEFORE creating the view itself? (I need this to have a list of users and the functionality to filter them by role).

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  • Is testability alone justification for dependency injection?

    - by fearofawhackplanet
    The advantages of DI, as far as I am aware, are: Reduced Dependencies More Reusable Code More Testable Code More Readable Code Say I have a repository, OrderRepository, which acts as a repository for an Order object generated through a Linq to Sql dbml. I can't make my orders repository generic as it performs mapping between the Linq Order entity and my own Order POCO domain class. Since the OrderRepository by necessity is dependent on a specific Linq to Sql DataContext, parameter passing of the DataContext can't really be said to make the code reuseable or reduce dependencies in any meaningful way. It also makes the code harder to read, as to instantiate the repository I now need to write new OrdersRepository(new MyLinqDataContext()) which additionally is contrary to the main purpose of the repository, that being to abstract/hide the existence of the DataContext from consuming code. So in general I think this would be a pretty horrible design, but it would give the benefit of facilitating unit testing. Is this enough justification? Or is there a third way? I'd be very interested in hearing opinions.

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  • State pattern: Why doesn't the context class implement or inherit the State abstract interface/class

    - by Ricket
    I'm reading about the State pattern. I have only just begun, so of course I begin by reading the entire Wikipedia article on it. I noticed that both of the examples in the article have some base abstract class or Java interface for a generic State's methods/functions. Then there are some states which inherit from the base and implement those methods/functions in different ways. Then there's a Context class which has a private member of type State and which, at any time, can be equal to an instance of one of the implementations. That context class also implements the same methods, and passes them onto the current state instance, and then has an additional method to change the state (or depending on design I understand the change of state could be a reaction to one of the implemented methods). Why doesn't this context class specifically "extend" or "implement" the generic State base class/interface?

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  • Race condition firing events in AS3

    - by crispclean
    Hello I have some troubles firing and removing events in the right chronicle order. The code below gives the following output: save poster into db, and dispatch event calling service, dispatch event removed = false calling service, dispatch event removed = false calling service, dispatch event removed = true save poster into db, and dispatch event save poster into db, and dispatch event of course this should be more something like: save poster into db, and dispatch event calling service, dispatch event removed = true save poster into db, and dispatch event calling service, dispatch event removed = true save poster into db, and dispatch event calling service, dispatch event removed = true Can someone help me with this? I'm running out of ideas on how to tackle this. thx! for(var i:int = 0;i< 3;i++){ createPoster(); } function createPoster(){ Main.db.savePoster(); Main.db.addEventListener(Config.evt_SAVEPOSTER_READY, callService); } function callService(){ Main.db.removeEventListener(Config.evt_SAVEPOSTER_READY, callService); }

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  • How to simulate a mouse click in Cocoa for the iPhone?

    - by eagle
    I'm trying to setup automated unit tests for an iPhone application. I'm using a UIWebBrowser and need to simulate clicks on different links. I've tried doing this with JavaScript, but it doesn't produce the same results as when the I manually click on the links. The main problem is with links that have their target property set. I believe the only way for this automated unit test to work correctly is to simulate a mouse click at a specific x/y coordinate (i.e. where the link is located). Since the unit testing will only be used internally, private API calls are fine. It seems like this should be possible since the iPhone app isimulate seems to do something similar. Is there any way to do this in the framework?

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  • How to listen to keyboard events in GWT table?

    - by Olaf Mertens
    In my GWT program I have a table that has a selected row. I'd like to move the row selection with the up- and down-keys on the keyboard. So I have to catch the key events somehow. The GWT docs handle key events in input fields only. But I don't have an input field! Is this possible at all? Maybe it is a DOM/Javascript restriction that GWT cannot work around...

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  • Capturing USB Plug/Unplug events in Firemonkey

    - by radsdau
    [RAD Studio XE3 / C++] I have a FMX project running in Windows only at this stage, but I need to detect events when USB devices are connected and disconnected. I have a similar VCL app that can do this fine, but the Application-HookMainWindow is not exposed in FMX (only VCL). Is there an elegant way to handle this? Or do I have to hack some VCL stuff into my FMX app to make that work? I'd imagine I have to abstract it so I can support other platforms down the track. For the meantime though I need to get the Windows solution working. If the 'VCL hack' thing is required, how would I reference the vcl::Forms::Application from within my Fmx app? Cheers.

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  • A general question about inheritence in the .NET framework

    - by Grant
    I have a general question about inheritance in the .NET framework, lets say you have 2 classes, the first is called Parent and the second is called Child. Child inherits from Parent. Parent wants to ensure that each instance of child executes a specific piece of code when it loads irrespective of whether the child has their own onLoad code explicitly specified. From my experience, if i handle onLoad in the parent and not in the child, the parents onLoad code will fire but if its handled in both classes only the child's code will fire. Is this correct? and if so how can i ensure the parents code will always fire for the child...

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  • How to make addValueChangeHandler act just like addChangeHandler

    - by Konoplianko
    Hi. I have a problem. I made a wrap widget that implements interface HasChangeHandlers But i just can't fit events to each other. public HandlerRegistration addChangeHandler( final ChangeHandler handler ) { HandlerRegistration registration1 = dateFrom.addValueChangeHandler( handler );// Compile error HandlerRegistration registration2 = dateTo.addValueChangeHandler( new ValueChangeHandler<Date>() { @Override public void onValueChange( ValueChangeEvent<Date> dateValueChangeEvent ) { //have to fire handler ?? } } ); return null; // what i should return here? } Thanks in advance !

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  • Using ManualResetEvent to wait for multiple Image.ImageOpened events

    - by umlgorithm
    Dictionary<Image, ManualResetEvent> waitHandleMap = new Dictionary<Image, ManualResetEvent>(); List<Image> images = GetImagesWhichAreAlreadyInVisualTree(); foreach (var image in images) { image.Source = new BitmapImage(new Uri("some_valid_image_url")); waitHandleMap.Add(image, new ManualResetEvent(false)); image.ImageOpened += delegate { waitHandleMap[image].Set(); }; image.ImageFailed += delegate { waitHandleMap[image].Set(); }; } WaitHandle.WaitAll(waitHandleMap.Values.ToArray()); WaitHandle.WaitAll blocks the current UI thread, so ImageOpened/ImageFailed events would never get fired. Could you suggest me an easy workaround to wait for the multiple ui events?

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  • jQuery stopPropagation bubble down

    - by Jasie
    I have a div with a link inside of it: <div id="myDiv"> <a href="http://www.lol.com">Lol</a> </div> Clicking the <div /> should go somewhere, but clicking the child <a /> should go to www.lol.com. I've seen from previous questions and the jQuery website that .stopPropagation prevents bubbling upwards, but how do I prevent a bubble downwards (isn't that what's necessary here?).

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