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  • Changing order of children of an SWT Composite

    - by Alexey Romanov
    In my case I have two children of a SashForm, but the question applies to all Composites and different layouts. class MainWindow { Sashform sashform; Tree child1 = null; Table child2 = null; MainWindow(Shell shell) { sashform = new SashForm(shell, SWT.NONE); } // Not called from constructor because it needs data not available at that time void CreateFirstChild() { ... Tree child1 = new Tree(sashform, SWT.NONE); } void CreateSecondChild() { ... Table child2 = new Table(sashform, SWT.NONE); } } I don't know in advance in what order these methods will be called. How can I make sure that child1 is placed on the left, and child2 on the right? Alternately, is there a way to change their order as children of sashform after they are created? Currently my best idea is to put in placeholders like this: class MainWindow { Sashform sashform; private Composite placeholder1; private Composite placeholder2; Tree child1 = null; Table child2 = null; MainWindow(Shell shell) { sashform = new SashForm(shell, SWT.NONE); placeholder1 = new Composite(sashform, SWT.NONE); placeholder2 = new Composite(sashform, SWT.NONE); } void CreateFirstChild() { ... Tree child1 = new Tree(placeholder1, SWT.NONE); } void CreateSecondChild() { ... Table child2 = new Table(placeholder2, SWT.NONE); } }

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  • When software problems reported are not really software problems

    - by AndyUK
    Hi Apologies if this has already been covered or you think it really belongs on wiki. I am a software developer at a company that manufactures microarray printing machines for the biosciences industry. I am primarily involved in interfacing with various bits of hardware (pneumatics, hydraulics, stepper motors, sensors etc) via GUI development in C++ to aspirate and print samples onto microarray slides. On joining the company I noticed that whenever there was a hardware-related problem this would cause the whole setup to freeze, with nobody being any the wiser as to what the specific problem was - hardware / software / misuse etc. Since then I have improved things somewhat by introducing software timeouts and exception handling to better identify and deal with any hardware-related problems that arise eg PLC commands not successfully completed, inappropriate FPGA response commands, and various other deadlock type conditions etc. In addition, the software will now log a summary of the specific problem, inform the user and exit the thread gracefully. This software is not embedded, just interfacing using serial ports. In spite of what has been achieved, non-software guys still do not fully appreciate that in these cases, the 'software' problem they are reporting to me is not really a software problem, rather the software is reporting a problem, but not causing it. Don't get me wrong, there is nothing I enjoy more than to come down on software bugs like a ton of bricks, and looking at ways of improving robustness in any way. I know the system well enough now that I almost have a sixth sense for these things. No matter how many times I try to explain this point to people, it does not really penetrate. They still report what are essentially hardware problems (which eventually get fixed) as software ones. I would like to hear from any others that have endured similar finger-pointing experiences and what methods they used to deal with them.

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  • Object addSubview only works in viewDidLoad

    - by DecodingSand
    Hi, I'm new to iPhone dev and need some help with adding subViews. I have a reusable object that I made that is stored in a separate .h .m and xib file. I would like to use this object in my main project's view controller. I have included the header and the assignment of the object generates no errors. I am able to load the object into my main project but can only do things with it inside my viewDidLoad method. I intend to have a few of these objects on my screen and am looking fora solution that is more robust then just hard wiring up multiple copies of the shape object. As soon as I try to access the object outside of the viewDidLoad it produces a variable unknown error - first use in this function. Here is my viewDidLoad method: shapeViewController *shapeView = [[shapeViewController alloc] initWithNibName:@"shapeViewController" bundle:nil]; [self.view addSubview: shapeView.view]; // This is the problem line // This code works changes the display on the shape object [shapeView updateDisplay:@"123456"]; ---- but the same code outside of the viewDidLoad generates the error. So to sum up, everything works except when I try to access the shapeView object in the rest of the methods. Thanks in advance

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  • Covert uiiamge into string

    - by Warrior
    I am new iphone development.Is there any possibility to covert the uiimage into string and then once again back to image. - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)img1 editingInfo:(NSDictionary *)editInfo { [[picker parentViewController] dismissModalViewControllerAnimated:YES]; NSData *data = UIImagePNGRepresentation(img1); NSString *str1; str1 = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding]; MyAppAppDelegate *appDelegate = (MyAppAppDelegate *) [[UIApplication sharedApplication] delegate]; [appDelegate setCurrentLink:str1]; EmailPictureViewController *email = [[EmailPictureViewController alloc] initWithNibName:@"EmailPictureViewController" bundle:nil]; [self.navigationController pushViewController:email animated:YES]; } so i can use delegate methods to tranfer the image from one view to another view. so i should convert the string once again to image and display it in another view. In Another view - (void)viewDidLoad { MyAppAppDelegate *appDelegate =(MyAppAppDelegate *) [[UIApplication sharedApplication] delegate]; str1 = [appDelegate getCurrentLink]; NSLog(@"The String %@",str1); NSData *aData; aData = [str1 dataUsingEncoding: NSASCIIStringEncoding]; NSLog(@"The String Data %@",aData); NSLog(@"Inside Didload3"); [imgview setImage:[UIImage imageWithData:aData]]; } But this doesn't work for me.Where do i go wrong.Is there any way to solve it?.Please help me out.Thanks.

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  • C# How can I return my base class in a webservice

    - by HenriM
    I have a class Car and a derived SportsCar: Car Something like this: public class Car { public int TopSpeed{ get; set; } } public class SportsCar : Car { public string GirlFriend { get; set; } } I have a webservice with methods returning Cars i.e: [WebMethod] public Car GetCar() { return new Car() { TopSpeed = 100 }; } It returns: <Car> <TopSpeed>100</TopSpeed> </Car> I have another method that also returns cars like this: [WebMethod] public Car GetMyCar() { Car mycar = new SportsCar() { GirlFriend = "JLo", TopSpeed = 300 }; return mycar; } It compiles fine and everything, but when invoking it I get: System.InvalidOperationException: There was an error generating the XML document. --- System.InvalidOperationException: The type wsBaseDerived.SportsCar was not expected. Use the XmlInclude or SoapInclude attribute to specify types that are not known statically. I find it strange that it can't serialize this as a straight car, as mycar is a car. Adding XmlInclude on the WebMethod of ourse removes the error: [WebMethod] [XmlInclude(typeof(SportsCar))] public Car GetMyCar() { Car mycar = new SportsCar() { GirlFriend = "JLo", TopSpeed = 300 }; return mycar; } and it now returns: <Car xsi:type="SportsCar"> <TopSpeed>300</TopSpeed> <GirlFriend>JLo</GirlFriend> </Car> But I really want the base class returned, without the extra properties etc from the derived class. Is that at all possible without creating mappers etc? Please say yes ;)

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  • How does the PHP IteratorIterator class work?

    - by WilliamMartin
    Try as I might I cannot get my head around what the IteratorIterator class actually does. I understand that classes can implement Traversable so the engine knows it can loop using foreach and I realise that IteratorIterator is supposed to convert anything that is Traversable into an Iterator but I cannot for the life of me understand how. Take for example, the PDOStatement class; how would the standard Iterator methods (next, key, rewind, etc) be implemented to allow iteration over a PDOStatement? Sorry if my question is unclear, I am just struggling to grasp the exact reason for this class and the documentation on it is scant. Thanks, Will Update: Going through the phpt files, I found one test which uses IteratorIterator: <?php $root = simplexml_load_string('<?xml version="1.0"?> <root> <child>Hello</child> <child>World</child> </root> '); foreach (new IteratorIterator($root->child) as $child) { echo $child."\n"; } ?> The expected output is: Hello World I don't really follow how the IteratorIterator construct takes $root-child as an argument and how it manages to iterate over the child elements.

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  • When to choose which machine learning classifier?

    - by LM
    Suppose I'm working on some classification problem. (Fraud detection and comment spam are two problems I'm working on right now, but I'm curious about any classification task in general.) How do I know which classifier I should use? (Decision tree, SVM, Bayesian, logistic regression, etc.) In which cases is one of them the "natural" first choice, and what are the principles for choosing that one? Examples of the type of answers I'm looking for (from Manning et al.'s "Introduction to Information Retrieval book": http://nlp.stanford.edu/IR-book/html/htmledition/choosing-what-kind-of-classifier-to-use-1.html): a. If your data is labeled, but you only have a limited amount, you should use a classifier with high bias (for example, Naive Bayes). [I'm guessing this is because a higher-bias classifier will have lower variance, which is good because of the small amount of data.] b. If you have a ton of data, then the classifier doesn't really matter so much, so you should probably just choose a classifier with good scalability. What are other guidelines? Even answers like "if you'll have to explain your model to some upper management person, then maybe you should use a decision tree, since the decision rules are fairly transparent" are good. I care less about implementation/library issues, though. Also, for a somewhat separate question, besides standard Bayesian classifiers, are there 'standard state-of-the-art' methods for comment spam detection (as opposed to email spam)? [Not sure if stackoverflow is the best place to ask this question, since it's more machine learning than actual programming -- if not, any suggestions for where else?]

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  • Properly design a code editor application

    - by Hemaulo
    I'm working on personal project which is basically a code editor. Imagine standard File menu with menu items New, Open, Save, Save As, Save All, Close, Close All. I'm stuck with proper design. Currently I have: A Document class which represents a document - code editing control, respective tab in tab bar and various properties such as Caption, Filename, IsModified etc. A Documents class which represents all open documents. Contains methods like New, Open(FileName), ... The problem is that I can't figure out which class / menu command is responsible for which tasks. For example, with File-New menu command is simple - call Documents.New and that's it. But what for File-Open? The Documents.Open method expects filename as a parameter. So before calling this method I need to open an file selection dialog, let user select files and for each file call Documents.Open(FileName). Where is best place for this supporting code, in menu command, rewrite Documents.Open and put it there? The same with Save actions. Which is responsible for saving? Is it Documents class which uses Document.Editor.SaveToFile(FileName) or better create Save method in Document class? Somewhere in the middle also need to ask user if he wants to save current document... I'm stuck. Any ideas? Edited: The programming language is Delphi.

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  • how to update div tag in javascript with data from model for onsubmit form asp.net mvc

    - by michael
    In my page i have a form tag which submits to server ,gets data and redirects to same page. problem is the the div tag which has the data from server is not getting updated. how to do that in javascript <% using (Html.BeginForm("Addfile", "uploadfile", FormMethod.Post, new { id = "uploadform", enctype = "multipart/form-data" })) { %> <input type="file" id="addedFile" name="addedFile" /><br /> <input type="submit" id="addfile" value="Addfile" /> <div id="MyGrid"> //data from the model(server side) filelist is not updating</div> what will be the form onsubmit javascript function to update the div tag with the data from the model. and my uploadfile controller get post methods are as [AcceptVerbs(HttpVerbs.Get)] public ActionResult Upload() { return View(); } [AcceptVerbs(HttpVerbs.Post)] public ActionResult AddFile(HttpPostedFileBase addedFile) { static List<string> fileList = new List<string>(); string filename = Path.GetFileName(addedFile.FileName); file.SaveAs(@"D:\Upload\" + filename); fileList.Add(filename); return("Upload",fileList); } thanks, michaela

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  • Poor performance using RMI-proxies with Swing components

    - by Patrick
    I'm having huge performance issues when I add RMI proxy references to a Java Swing JList-component. I'm retrieving a list of user Profiles with RMI from a server. The retrieval itself takes just a second or so, so that's acceptable under the circumstances. However, when I try to add these proxies to a JList, with the help of a custom ListModel and a CellRenderer, it takes between 30-60 seconds to add about 180 objects. Since it is a list of users' names, it's preferrable to present them alphabetically. The biggest performance hit is when I sort the elements as they get added to the ListModel. Since the list will always be sorted, I opted to use the built-in Collections.binarySearch() to find the correct position for the next element to be added, and the comparator uses two methods that are defined by the Profile interface, namely getFirstName() and getLastName(). Is there any way to speed this process up, or am I simply implementing it the wrong way? Or is this a "feature" of RMI? I'd really love to be able to cache some of the data of the remote objects locally, to minimize the remote method calls.

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  • JBoss Clustered Service that sends emails from txt file

    - by michael lucas
    I need a little push in the right direction. Here's my problem: I have to create an ultra-reliable service that sends email messages to clients whose addresses are stored in txt file on FTP server. Single txt file may contain unlimited number of entries. Most often the file contains about 300,000 entries. Service exposes interface with just two simple methods: TaskHandle sendEmails(String ftpFilePath); ProcessStatus checkProcessStatus(TaskHandle taskHandle); Method sendEmails() returns TaskHandle by which we can ask for ProcessStatus. For such a service to be reliable clustering is necessary. Processing single txt file might take a long time. Restarting one node in a cluster should have no impact on sending emails. We use JBoss AS 4.2.0 which comes with a nice HASingletonController that ensure one instance of service is running at given time. But once a fail-over happens, the second service should continue work from where the first one stopped. How can I share state between nodes in a cluster in such a way that leaves no possibility of sending some emails twice?

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  • Prototypal inheritance should save memory, right?

    - by Techpriester
    Hi Folks, I've been wondering: Using prototypes in JavaScript should be more memory efficient than attaching every member of an object directly to it for the following reasons: The prototype is just one single object. The instances hold only references to their prototype. Versus: Every instance holds a copy of all the members and methods that are defined by the constructor. I started a little experiment with this: var TestObjectFat = function() { this.number = 42; this.text = randomString(1000); } var TestObjectThin = function() { this.number = 42; } TestObjectThin.prototype.text = randomString(1000); randomString(x) just produces a, well, random String of length x. I then instantiated the objects in large quantities like this: var arr = new Array(); for (var i = 0; i < 1000; i++) { arr.push(new TestObjectFat()); // or new TestObjectThin() } ... and checked the memory usage of the browser process (Google Chrome). I know, that's not very exact... However, in both cases the memory usage went up significantly as expected (about 30MB for TestObjectFat), but the prototype variant used not much less memory (about 26MB for TestObjectThin). I also checked: The TestObjectThin instances contain the same string in their "text" property, so they are really using the property of the prototype. Now, I'm not so sure what to think about this. The prototyping doesn't seem to be the big memory saver at all. I know that prototyping is a great idea for many other reasons, but I'm specifically concerned with memory usage here. Any explanations why the prototype variant uses almost the same amount of memory? Am I missing something?

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  • Does adding to a method group count as using a variable?

    - by Vaccano
    I have the following code example taken from the code of a Form: protected void SomeMethod() { SomeOtherMethod(this.OnPaint); } private void SomeOtherMethod(Action<PaintEventArgs> onPaint) { onPaint += MyPaint; } protected void MyPaint(PaintEventArgs e) { // paint some stuff } The second method (SomeOtherMethod) has resharper complaining at me. It says of onPaint that "Value assigned is not used in any execution path". To my mind it was used because I added a method to the list of methods called when a paint was done. But usually when resharper tells me something like this it is because I am not understanding some part of C#. Like maybe when the param goes out of goes out of scope the item I added to the list gets removed (or something like that). I thought I would ask here to see if any one knows what resharper is trying to tell me. (Side Note: I usually just override OnPaint. But I am trying to get OnPaint to call a method in another class. I don't want to expose that method publicly so I thought I would pass in the OnPaint group and add to it.)

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  • Vertically Aligning Elements

    - by Naz
    I'm trying to understand how to center elements within a div. I have this basic code I am working with and am trying to get the 'This is a button' element to be in the center <body> <div style="width:960px;background-color:#d7d7d7;"> <div style=" width:400px; padding:10px; height:auto; background-color:#006699; display:inline-block; "> <p> Vivamus vel sapien. Praesent nisl tortor, laoreet eu, dapibus quis, egestas non, mauris. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Vivamus vel sapien. Praesent nisl tortor, laoreet eu, dapibus quis, egestas non, mauris. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus.</p> </div> <div style=" width:100px; padding:10px; height:auto; background-color:#b1b1b1; float:right; display:inline-block; margin:auto!important; vertical-align:middle; "> <p>This is a button</p> </div> </div> </body> It's essentially 1 div, divided into 2 with text on the left hand side and a 'This is a button' label to be in the center of the right side, but I can;t figure out how to get it to center, I've tried all sorts of methods. All help/advice is appreciated.

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  • Resolve php endless recursion issue

    - by Matt
    Hey all, I'm currently running into an endless recursion situation. I'm implementing a message service that calls various object methods.. it's quite similar to observer pattern.. Here's whats going on: Dispatcher.php class Dispatcher { ... public function message($name, $method) { // Find the object based on the name $object = $this->findObjectByName($name); // Slight psuedocode.. for ease of example if($this->not_initialized($object)) $object = new $object(); // This is where it locks up. } return $object->$method(); ... } class A { function __construct() { $Dispatcher->message("B", "getName"); } public function getName() { return "Class A"; } } class B { function __construct() { // Assume $Dispatcher is the classes $Dispatcher->message("A", "getName"); } public function getName() { return "Class B"; } } It locks up when neither object is initialized. It just goes back and forth from message each other and no one can be initialized. I'm looking for some kind of queue implementation that will make messages wait for each other.. One where the return values still get set. I'm looking to have as little boilerplate code in class A and class B as possible Any help would be immensely helpful.. Thanks! Matt Mueller

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  • Flex ChangeWatcher bind to a negative condition

    - by bedwyr
    I have a bindable getter in a component which informs me when a [hidden] timer is running. I also have a context menu which, if this timer is running, should disable one of the menu items. Is it possible to create a ChangeWatcher which watches for the negative condition of a bindable property/getter and changes the enabled property of the menu item? Here are the basic methods I'm trying to bind together: Class A: [Bindable] public function get isPlaying():Boolean { return (_timer != null) ? _timer.running : false; } Class B: private var _playingWatcher:ChangeWatcher; public function createContextMenu():void { //...blah blah, creating context menu var newItem:ContextMenuItem = new ContextMenuItem(); _playingWatcher = BindingUtils.bindProperty(newItem, "enabled", _classA, "isPlaying"); } In the code above, I have the inverse case: when isPlaying() is true, the menu item is enabled; I want it to only be enabled when the condition is false. I could create a second getter (there are other bindings which rely on the current getter) to return the inverse condition, but that sounds ugly to me: [Bindable] public function get isNotPlaying():Boolean { return !isPlaying; } Is this possible, or is there another approach I'm completely missing?

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  • Awkward looking uses of Contract.ValueAtReturn()

    - by devoured elysium
    I am designing a method that will add an element to an internal list. The structure of the class is something along the lines of: class MyCustomerDatabase { private IList<Customer> _customers = new List<Customer>(); public int NumberOfCustomers { get { return _customers; } } public void AddCustomer(Customer customer) { _customers.Add(customer); } } Now, I was thinking of adding a Contract.Ensures() about the size of the _customers growing by 1 with this call. The problem is that I end up with some weird looking code: public void AddCustomer(Customer customer) { int numberOfCustomersAtReturn; Contract.Ensures(Contract.ValueAtReturn<int>(out numberOfCustomersAtReturn) == Contract.OldValue<int>(NumberOfCustomers) + 1); _customers.Add(customer); numberOfCustomersAtReturn = NumberOfCustomers; } The main problem is that properties are in fact methods, so you can't just reference them direcly when using Contract.ValueAtReturn() as its only parameter accepts variables as out. The situation gets even odder if I want to achieve the same but this time with a method that should return a value: public int MyReturningMethod() { ... return abc(); //abc will add by one the number of customers in list } //gets converted to public int MyReturningMethod() { int numberOfCustomersAtReturn; Contract.Ensures(Contract.ValueAtReturn<int>(out numberOfCustomersAtReturn) == Contract.OldValue<int>(NumberOfCustomers) + 1); int returnValue = abc(); numberOfCustomersAtReturn = NumberOfCustomers; return returnValue; } This seems pretty clumsy :( Code Contracts should aim to get things clearer and this seems right the opposite. Am I doing something wrong? Thanks

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  • Is XMLReader a SAX parser, a DOM parser, or neither?

    - by Renesis
    I am testing various methods to read (possibly large, and very often) XML configuration files in PHP. No writing is ever needed. I have two successful implementations, one using SimpleXML (which I know is a DOM parser) and one using XMLReader. I know that a DOM reader must read the whole tree and therefore uses more memory. My tests reflect that. I also know that A SAX parser is an "event-based" parser that uses less memory because it reads each node from the stream without checking what is next. XMLReader also reads from a stream with the cursor providing data about the node it is currently at. So, it definitely sounds like XMLReader (http://us2.php.net/xmlreader) is not a DOM parser, but my question is, is it a SAX parser, or something else? It seems like XMLReader behaves the way a SAX parser does but does not throw the events themselves (in other words, can you construct a SAX parser with XMLReader?) If it is something else, does the classification it's in have a name?

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  • VSC++, virtual method at bad adress, curious bug

    - by antoon.groenewoud
    Hello, This guy: virtual phTreeClass* GetTreeClass() const { return (phTreeClass*)m_entity_class; } When called, crashed the program with an access violation, even after a full recompile. All member functions and virtual member functions had correct memory adresses (I hovered mouse over the methods in debug mode), but this function had a bad memory adress: 0xfffffffc. Everything looked okay: the 'this' pointer, and everything works fine up until this function call. This function is also pretty old and I didn't change it for a long time. The problem just suddenly popped up after some work, which I commented all out to see what was doing it, without any success. So I removed the virtual, compiled, and it works fine. I add virtual, compiled, and it still works fine! I basically changed nothing, and remember that I did do a full recompile earlier, and still had the error back then. I wasn't able to reproduce the problem. But now it is back. I didn't change anything. Removing virtual fixes the problem. Sincerely, Antoon

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  • Giving another object a NSManagedObject

    - by Wayfarer
    Alright, so I'm running into an issue with my code. What I have done is subclassed UIButton so I can give it some more infomormation that pertain to my code. I have been able to create the buttons and they work great. Capiche. However, one of the things I want my subclass to hold is a reference to a NSMangedObject. I have this code in my header file: @interface ButtonSubclass : UIButton { NSManagedObjectContext *context; NSManagedObject *player; } @property (nonatomic, retain) NSManagedObject *player; @property (nonatomic, retain) NSManagedObjectContext *context; - (id)initWithFrame:(CGRect)frame andTitle:(NSString*)title; //- (void)setPlayer:(NSManagedObject *)aPlayer; @end As you can see, it has a instance variable to the NSMangedobject I want it to hold (as well as the Context). But for the life of me, I can't get it to hold that NSManagedObject. I run both the @synthesize methods in the Implementation file. @synthesize context; @synthesize player; So I'm not sure what I'm doing wrong. This is how I create my button: ButtonSubclass *playerButton = [[ButtonSubclass alloc] initWithFrame:frame andTitle:@"20"]; //works playerButton.context = self.context; //works playerButton.player = [players objectAtIndex:i]; //FAILS And I have initilaized the players array earlier, where I get the objects. Another weird thing is that when it gets to this spot in the code, the app crashes (woot) and the the console output stops. It doesn't give me any error, and notification at all that the app has crashed. It just... stops. So I don't even know what the error is that is crashing the code, besides it has to do with that line up there setting the "player" variable. Thoughts and ideas? I'd love your wisdom!

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  • non static method cannot be referenced from a static context.

    - by David
    First some code: import java.util.*; ... class TicTacToe { ... public static void main (String[]arg) { Random Random = new Random() ; toerunner () ; // this leads to a path of methods that eventualy gets us to the rest of the code } ... public void CompTurn (int type, boolean debug) { ... boolean done = true ; int a = 0 ; while (!done) { a = Random.nextInt(10) ; if (debug) { int i = 0 ; while (i<20) { System.out.print (a+", ") ; i++; }} if (possibles[a]==1) done = true ; } this.board[a] = 2 ; } ... } //to close the class Here is the error message: TicTacToe.java:85: non-static method nextInt(int) cannot be referenced from a static context a = Random.nextInt(10) ; ^ What exactly went wrong? What does that error message "non static method cannot be referenced from a static context" mean?

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  • Programming style question on how to code functions

    - by shawnjan
    Hey all! So, I was just coding a bit today, and I realized that I don't have much consistency when it comes to a coding style when programming functions. One of my main concerns is whether or not its proper to code it so that you check that the input of the user is valid OUTSIDE of the function, or just throw the values passed by the user into the function and check if the values are valid in there. Let me sketch an example: I have a function that lists hosts based on an environment, and I want to be able to split the environment into chunks of hosts. So an example of the usage is this: listhosts -e testenv -s 2 1 This will get all the hosts from the "testenv", split it up into two parts, and it is displaying part one. In my code, I have a function that you pass it in a list, and it returns a list of lists based on you parameters for splitting. BUT, before I pass it a list, I first verify the parameters in my MAIN during the getops process, so in the main I check to make sure there are no negatives passed by the user, I make sure the user didnt request to split into say, 4 parts, but asking to display part 5 (which would not be valid), etc. tl;dr: Would you check the validity of a users input the flow of you're MAIN class, or would you do a check in your function itself, and either return a valid response in the case of valid input, or return NULL in the case of invalid input? Obviously both methods work, I'm just interested to hear from experts as to which approach is better :) Thanks for any comments and suggestions you guys have!

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  • MVC2 DataAnnotations on ViewModel - Don't understand using it with MVVM pattern

    - by ScottSEA
    I have an MVC2 Application that uses MVVM pattern. I am trying use Data Annotations to validate form input. In my ThingsController I have two methods: [HttpGet] public ActionResult Index() { return View(); } public ActionResult Details(ThingsViewModel tvm) { if (!ModelState.IsValid) return View(tvm); try { Query q = new Query(tvm.Query); ThingRepository repository = new ThingRepository(q); tvm.Things = repository.All(); return View(tvm); } catch (Exception) { return View(); } } My Details.aspx view is strongly typed to the ThingsViewModel: <%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<Config.Web.Models.ThingsViewModel>" %> The ViewModel is a class consisting of a IList of returned Thing objects and the Query string (which is submitted on the form) and has the Required data annotation: public class ThingsViewModel { public IList<Thing> Things{ get; set; } [Required(ErrorMessage="You must enter a query")] public string Query { get; set; } } When I run this, and click the submit button on the form without entering a value I get a YSOD with the following error: The model item passed into the dictionary is of type 'Config.Web.Models.ThingsViewModel', but this dictionary requires a model item of type System.Collections.Generic.IEnumerable`1[Config.Domain.Entities.Thing]'. How can I get Data Annotations to work with a ViewModel? I cannot see what I'm missing or where I'm going wrong - the VM was working just fine before I started mucking around with validation.

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  • handle large Parcelable ArrayList in Android

    - by Gal Ben-Haim
    I'm developing an Android app that is a client to a JSON webservice API. I have classes of resource objects (some are nested) and I pass results from an IntentService that access the webserive using the Parcelable interface for all the resource classes. the webservice returns arrays or results that can be potentially large (because of the nesting, for example, a post object also contains comments array, each comment also contains a user object). currently I'm either inserting the results into a SQlite database or displaying them in a ListView. (my relevant methods are accepting ArrayList<resourceClass> as arguments). (some data need to be persistent stored and some should not). since I don't know what size of lists I can handle this way without reaching the memory limits, is this a good practice ? is it a better idea to save the parsed JSON to a local file immediately and pass the file path to the ResultReceiver, then either insert to database from that file or display the data ? is there a better way to handle this ? btw - I'm parsing the JSON as a stream with Gson's Reader so there shouldn't be memory issues at that stage.

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  • How to append a row to a TableViewSection in Titanium?

    - by Mike Trpcic
    I'm developing an iPhone application in Titanium, and need to append a row to a particular TableViewSection. I can't do this on page load, as it's done dynamically by the user throughout the lifecycle of the application. The documentation says that the TableViewSection has an add method which takes two arguments, but I can't make it work. Here's my existing code: for(var i = 0; i <= product_count; i++){ productsTableViewSection.add( Ti.UI.createTableViewRow({ title:'Testing...' }) ); } That is just passing one argument in, and that causes Titanium to die with an uncaught exception: 2010-04-26 16:57:18.056 MyApplication[72765:207] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 2. The number of rows contained in an existing section after the update (2) must be equal to the number of rows contained in that section before the update (1), plus or minus the number of rows inserted or deleted from that section (0 inserted, 0 deleted).' 2010-04-26 16:57:18.056 MyApplication[72765:207] Stack: ( The exception looks like it did add the row, but it's not allowed to for some reason. Since the documentation says that TableViewSection takes in "view" and "row", I tried the following: for(var i = 0; i <= product_count; i++){ productsTableViewSection.add( Ti.UI.createView({}), Ti.UI.createTableViewRow({ title:'Testing...' }) ); } The above code doesn't throw the exception, but it gives a [WARN]: [WARN] Invalid type passed to function. expected: TiUIViewProxy, was: TiUITableViewRowProxy in -[TiUITableViewSectionProxy add:] (TiUITableViewSectionProxy.m:62) TableViewSections don't seem to support any methods like appendRow, or insertRow, so I don't know where else to go with this. I've looked through the KitchenSink app, but there are no examples that I could find of adding a row to a TableViewSection. Any help is appreciated.

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