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  • Context Menu on QGraphicsWidget

    - by onurozcelik
    Hi, In my application I have two object type. One is field item, other is composite item. Composite items may contain two or more field items. Here is my composite item implementation. #include "compositeitem.h" CompositeItem::CompositeItem(QString id,QList<FieldItem *> _children) { children = _children; } CompositeItem::~CompositeItem() { } QRectF CompositeItem::boundingRect() const { //Not carefully thinked about it return QRectF(QPointF(-50,-150),QSizeF(250,250)); } void CompositeItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget ) { FieldItem *child; foreach(child,children) { child->paint(painter,option,widget); } } QSizeF CompositeItem::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const { QSizeF itsSize(0,0); FieldItem *child; foreach(child,children) { // if its size empty set first child size to itsSize if(itsSize.isEmpty()) itsSize = child->sizeHint(Qt::PreferredSize); else { QSizeF childSize = child->sizeHint(Qt::PreferredSize); if(itsSize.width() < childSize.width()) itsSize.setWidth(childSize.width()); itsSize.setHeight(itsSize.height() + childSize.height()); } } return itsSize; } void CompositeItem::contextMenuEvent(QGraphicsSceneContextMenuEvent *event) { qDebug()<<"Test"; } My first question is how I can propagate context menu event to specific child. Picture on the above demonstrates one of my possible composite item. If you look on the code above you will see that I print "Test" when context menu event occurs. When I right click on the line symbol I see that "Test" message is printed. But when I right click on the signal symbol "Test" is not printed and I want it to be printed. My second question what cause this behaviour. How do I overcome this.

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  • Unexpected performance curve from CPython merge sort

    - by vkazanov
    I have implemented a naive merge sorting algorithm in Python. Algorithm and test code is below: import time import random import matplotlib.pyplot as plt import math from collections import deque def sort(unsorted): if len(unsorted) <= 1: return unsorted to_merge = deque(deque([elem]) for elem in unsorted) while len(to_merge) > 1: left = to_merge.popleft() right = to_merge.popleft() to_merge.append(merge(left, right)) return to_merge.pop() def merge(left, right): result = deque() while left or right: if left and right: elem = left.popleft() if left[0] > right[0] else right.popleft() elif not left and right: elem = right.popleft() elif not right and left: elem = left.popleft() result.append(elem) return result LOOP_COUNT = 100 START_N = 1 END_N = 1000 def test(fun, test_data): start = time.clock() for _ in xrange(LOOP_COUNT): fun(test_data) return time.clock() - start def run_test(): timings, elem_nums = [], [] test_data = random.sample(xrange(100000), END_N) for i in xrange(START_N, END_N): loop_test_data = test_data[:i] elapsed = test(sort, loop_test_data) timings.append(elapsed) elem_nums.append(len(loop_test_data)) print "%f s --- %d elems" % (elapsed, len(loop_test_data)) plt.plot(elem_nums, timings) plt.show() run_test() As much as I can see everything is OK and I should get a nice N*logN curve as a result. But the picture differs a bit: Things I've tried to investigate the issue: PyPy. The curve is ok. Disabled the GC using the gc module. Wrong guess. Debug output showed that it doesn't even run until the end of the test. Memory profiling using meliae - nothing special or suspicious. ` I had another implementation (a recursive one using the same merge function), it acts the similar way. The more full test cycles I create - the more "jumps" there are in the curve. So how can this behaviour be explained and - hopefully - fixed? UPD: changed lists to collections.deque UPD2: added the full test code UPD3: I use Python 2.7.1 on a Ubuntu 11.04 OS, using a quad-core 2Hz notebook. I tried to turn of most of all other processes: the number of spikes went down but at least one of them was still there.

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  • Storing Arbitrary Contact Information in Ruby on Rails

    - by Anthony Chivetta
    Hi, I am currently working on a Ruby on Rails app which will function in some ways like a site-specific social networking site. As part of this, each user on the site will have a profile where they can fill in their contact information (phone numbers, addresses, email addresses, employer, etc.). A simple solution to modeling this would be to have a database column per piece of information I allow users to enter. However, this seems arbitrary and limited. Further, to support allowing users to enter as many phone numbers as they would like requires the addition of another database table and joins. It seems to me that a better solution would be to serialize all the contact information entered by a user into a single field in their row. Since I will never be conditioning a SQL query on this information, such a solution wouldn't be any less efficient. Ideally, I would like to use a vCard as my serialization format. vCards are the standard solution to storing contact information across the web, and reusing tested solutions is a Good Thing. Alternative serialization formats would include simply marshaling a ruby hash, or YAML. Regardless of serialization format, supporting the reading and updating of this information in a rails-like way seems to be a major implementation challenge. So, here's the question: Has anyone seen this approach used in a rails application? Are there any rails plugins or gems that make such a system easy to implement? Ideally what I would like is an acts_as_vcard to add to my model object that would handle editing the vcard for me and saving it back to the database.

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  • Why I got some memory problems?

    - by Tattat
    I got this error from XCode: objc[8422]: FREED(id): message release sent to freed object=0x3b120c0 I googled and find that is related to the memory. But I don't know which line of code I go wrong, any ideas? @implementation MyAppDelegate @synthesize window; @synthesize viewController; - (void)applicationDidFinishLaunching:(UIApplication *)application { // Override point for customization after app launch [window addSubview:viewController.view]; [window makeKeyAndVisible]; [self changeScene:[MainGameMenuScene class]]; } - (void)dealloc { [viewController release]; [window release]; [super dealloc]; } - (void) changeScene: (Class) scene { BOOL animateTransition = true; if(animateTransition){ [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.5]; [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:window cache:YES]; //does nothing without this line. } if( viewController.view != nil ) { [viewController.view removeFromSuperview]; //remove view from window's subviews. [viewController.view release]; //release gamestate } viewController.view = [[scene alloc] initWithFrame:CGRectMake(0, 0, IPHONE_WIDTH, IPHONE_HEIGHT) andManager:self]; //now set our view as visible [window addSubview:viewController.view]; [window makeKeyAndVisible]; if(animateTransition){ [UIView commitAnimations]; } }

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  • How save selected switch option

    - by Rkm
    System UIviewcontroller has button , Tap on button i need to fire Info Tableviewcontroller. Tableviewcontroller itself UISwitch. My question is I need to save last selected switch option ON/OFF in UISwitch how to set my control. @implementation Info // Customize the appearance of table view cells. - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } if (indexPath.section) { cell.textLabel.text = @"Sounds"; cell.selectionStyle = UITableViewCellSelectionStyleNone; UISwitch *switchView = [[UISwitch alloc] initWithFrame:CGRectZero]; cell.accessoryView = switchView; [switchView setOn:NO animated:NO]; [switchView addTarget:self action:@selector(switchChanged_Sounds:) forControlEvents:UIControlEventValueChanged]; [switchView release]; return cell ; } } - (void) switchChanged_Sounds:(id)sender { UISwitch* switchControl = sender; NSLog( @"The switchChanged_Sounds is %@", switchControl.on ? @"ON" : @"OFF" ); }

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  • How do I edit a row in NSTableView to allow deleting the data in that row and replacing with new d

    - by lampShade
    I'm building a to-do-list application and I want to be able to edit the entries in the table and replace them with new entries. I'm close to being able to do what I want but not quit. Here is my code so far: /* IBOutlet NSTextField *textField; IBOutlet NSTabView *tableView; IBOutlet NSButton *button; NSMutableArray *myArray; */ #import "AppController.h" @implementation AppController -(IBAction)addNewItem:(id)sender { [myArray addObject:[textField stringValue]]; [tableView reloadData]; } - (int)numberOfRowsInTableView:(NSTableView *)aTableView { return [myArray count]; } - (id)tableView:(NSTableView *)aTableView objectValueForTableColumn:(NSTableColumn *)aTableColumn row:(int)rowIndex { return [myArray objectAtIndex:rowIndex]; } - (id)init { [super init]; myArray = [[NSMutableArray alloc] init]; return self; } -(IBAction)removeItem:(id)sender { NSLog(@"This is the index of the selected row: %d",[tableView selectedRow]); NSLog(@"the clicked row is %d",[tableView clickedRow]); [myArray replaceObjectAtIndex:[tableView selectedRow] withObject:[textField stringValue]]; [myArray addObject:[textField stringValue]]; //[tableView reloadData]; } @end

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  • Adding a custom subview (created in a xib) to a view controller's view - What am I doing wrong

    - by Fran
    I've created a view in a xib (with an activity indicator, a progress view and a label). Then I've created .h/.m files: #import <UIKit/UIKit.h> @interface MyCustomView : UIView { IBOutlet UIActivityIndicatorView *actIndicator; IBOutlet UIProgressView *progressBar; IBOutlet UILabel *statusMsg; } @end #import "MyCustomView.h" @implementation MyCustomView - (id)initWithFrame:(CGRect)frame { if ((self = [super initWithFrame:frame])) { // Initialization code } return self; } - (void)dealloc { [super dealloc]; } @end In IB, I set the file's owner and view identity to MyCustomView and connect the IBOutlet to the File's owner In MyViewController.m, I've: - (void)viewDidLoad { [super viewDidLoad]; UIView *subView = [[MyCustomView alloc] initWithFrame:myTableView.frame]; [subView setBackgroundColor:[UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0.5]]; [myTableView addSubview:subView]; [subView release]; } When I run the app, the view is added, but I can't see the label, the progress bar and the activity indicator. What am I doing wrong?

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  • Can Haskell's Parsec library be used to implement a recursive descent parser with backup?

    - by Thor Thurn
    I've been considering using Haskell's Parsec parsing library to parse a subset of Java as a recursive descent parser as an alternative to more traditional parser-generator solutions like Happy. Parsec seems very easy to use, and parse speed is definitely not a factor for me. I'm wondering, though, if it's possible to implement "backup" with Parsec, a technique which finds the correct production to use by trying each one in turn. For a simple example, consider the very start of the JLS Java grammar: Literal: IntegerLiteral FloatingPointLiteral I'd like a way to not have to figure out how I should order these two rules to get the parse to succeed. As it stands, a naive implementation like this: literal = do { x <- try (do { v <- integer; return (IntLiteral v)}) <|> (do { v <- float; return (FPLiteral v)}); return(Literal x) } Will not work... inputs like "15.2" will cause the integer parser to succeed first, and then the whole thing will choke on the "." symbol. In this case, of course, it's obvious that you can solve the problem by re-ordering the two productions. In the general case, though, finding things like this is going to be a nightmare, and it's very likely that I'll miss some cases. Ideally, I'd like a way to have Parsec figure out stuff like this for me. Is this possible, or am I simply trying to do too much with the library? The Parsec documentation claims that it can "parse context-sensitive, infinite look-ahead grammars", so it seems like something like I should be able to do something here.

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  • NSDate out of scope

    - by therealtkd
    Having problems with out of scope for NSDate in an iphone app. I have an interface defined like this: @interface MyObject : NSoObject { NSMutableArray *array; BOOL checkThis; NSDate *nextDue; } Now in the implementation I have this: -(id) init { if( (self=[super init]) ) { checkThis = NO; array = [[NSMutableArray alloc] init]; nextDue = [[NSDate date] retain]; NSDate *testDate = [NSDate date]; } return self; } Now, if I trace through the init, before I actually assign the variables checkThis shows as boolean. array shows as pointer 0x0 because it hasn't ben assigned. But the nextDue is showing as 'out of scope'. I don't understand why this is out of scope but the other variables aren't. If I trace through the code until after the variables are assigned, array now shows as being correctly assigned but nextDue is still out of scope. Interestingly, the testDate variable is assigned just fine and the debugger shows this as a valid date. Further interesting point is if I move the mouse over the testDate variable while I am debugging, it shows as an 'NSDate *' type which I would expect since that's its definition. Yet the nextDue, which to me is defined the same way is showing as a '_NSCFDate *'. Any googling I did on the subject said that the retain is the problem, but its actually out of scope before I even try to assign the variable. However, in another class, the same definition for NSDate work ok. It shows as nil before a value is assigned to it. Arghhh

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  • Exception Handling in ASP.NET MVC and Ajax - [HandleException] filter

    - by Graham
    All, I'm learning MVC and using it for a business app (MVC 1.0). I'm really struggling to get my head around exception handling. I've spent a lot of time on the web but not found anything along the lines of what I'm after. We currently use a filter attribute that implements IExceptionFilter. We decorate a base controller class with this so all server side exceptions are nicely routed to an exception page that displays the error and performs logging. I've started to use AJAX calls that return JSON data but when the server side implementation throws an error, the filter is fired but the page does not redirect to the Error page - it just stays on the page that called the AJAX method. Is there any way to force the redirect on the server (e.g. a ASP.NET Server.Transfer or redirect?) I've read that I must return a JSON object (wrapping the .NET Exception) and then redirect on the client, but then I can't guarantee the client will redirect... but then (although I'm probably doing something wrong) the server attempts to redirect but then gets an unauthorised exception (the base controller is secured but the Exception controller is not as it does not inherit from this) Has anybody please got a simple example (.NET and jQuery code). I feel like I'm randomly trying things in the hope it will work Exception Filter so far... public class HandleExceptionAttribute : FilterAttribute, IExceptionFilter { #region IExceptionFilter Members public void OnException(ExceptionContext filterContext) { if (filterContext.ExceptionHandled) { return; } filterContext.Controller.TempData[CommonLookup.ExceptionObject] = filterContext.Exception; if (filterContext.HttpContext.Request.IsAjaxRequest()) { filterContext.Result = AjaxException(filterContext.Exception.Message, filterContext); } else { //Redirect to global handler filterContext.Result = new RedirectToRouteResult(new RouteValueDictionary(new { controller = AvailableControllers.Exception, action = AvailableActions.HandleException })); filterContext.ExceptionHandled = true; filterContext.HttpContext.Response.Clear(); } } #endregion private JsonResult AjaxException(string message, ExceptionContext filterContext) { if (string.IsNullOrEmpty(message)) { message = "Server error"; //TODO: Replace with better message } filterContext.HttpContext.Response.StatusCode = (int)HttpStatusCode.InternalServerError; filterContext.HttpContext.Response.TrySkipIisCustomErrors = true; //Needed for IIS7.0 return new JsonResult { Data = new { ErrorMessage = message }, ContentEncoding = Encoding.UTF8, }; } }

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  • Using Pylint with Django

    - by rcreswick
    I would very much like to integrate pylint into the build process for my python projects, but I have run into one show-stopper: One of the error types that I find extremely useful--:E1101: *%s %r has no %r member*--constantly reports errors when using common django fields, for example: E1101:125:get_user_tags: Class 'Tag' has no 'objects' member which is caused by this code: def get_user_tags(username): """ Gets all the tags that username has used. Returns a query set. """ return Tag.objects.filter( ## This line triggers the error. tagownership__users__username__exact=username).distinct() # Here is the Tag class, models.Model is provided by Django: class Tag(models.Model): """ Model for user-defined strings that help categorize Events on on a per-user basis. """ name = models.CharField(max_length=500, null=False, unique=True) def __unicode__(self): return self.name How can I tune Pylint to properly take fields such as objects into account? (I've also looked into the Django source, and I have been unable to find the implementation of objects, so I suspect it is not "just" a class field. On the other hand, I'm fairly new to python, so I may very well have overlooked something.) Edit: The only way I've found to tell pylint to not warn about these warnings is by blocking all errors of the type (E1101) which is not an acceptable solution, since that is (in my opinion) an extremely useful error. If there is another way, without augmenting the pylint source, please point me to specifics :) See here for a summary of the problems I've had with pychecker and pyflakes -- they've proven to be far to unstable for general use. (In pychecker's case, the crashes originated in the pychecker code -- not source it was loading/invoking.)

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  • Getting started with massive data

    - by Max
    I'm a math guy and occasionally do some statistics/machine learning analysis consulting projects on the side. The data I have access to are usually on the smaller side, at most a couple hundred of megabytes (and almost always far less), but I want to learn more about handling and analyzing data on the gigabyte/terabyte scale. What do I need to know and what are some good resources to learn from? Hadoop/MapReduce is one obvious start. Is there a particular programming language I should pick up? (I primarily work now in Python, Ruby, R, and occasionally Java, but it seems like C and Clojure are often used for large-scale data analysis?) I'm not really familiar with the whole NoSQL movement, except that it's associated with big data. What's a good place to learn about it, and is there a particular implementation (Cassandra, CouchDB, etc.) I should get familiar with? Where can I learn about applying machine learning algorithms to huge amounts of data? My math background is mostly on the theory side, definitely not on the numerical or approximation side, and I'm guessing most of the standard ML algorithms don't really scale. Any other suggestions on things to learn would be great!

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  • How to implement menuitems that depend on current selection in WPF MVVM explorer-like application

    - by Doug
    I am new to WPF and MVVM, and I am working on an application utilizing both. The application is similar to windows explorer, so consider an app with a main window with menu (ShellViewModel), a tree control (TreeViewModel), and a list control (ListViewModel). I want to implement menu items such as Edit - Delete, which deletes the currently selected item (which may be in the tree or in the list). I am using Josh Smith's RelayCommand, and binding the menuitem to a DeleteItemCommand in the ShellViewModel is easy. It seems like implementing the DeleteItemCommand, however, requires some fairly tight coupling between the ShellViewModel and the two child view models (TreeViewModel and ListViewModel) to keep track of the focus/selection and direct the action to the proper child for implementation. That seems wrong to me, and makes me think I'm missing something. Writing a focus manager and/or selection manager to do the bookkeeping does not seem too hard, and could be done without coupling the classes together. The windowing system is already keeping track of which view has the focus, and it seems like I'd be duplicating code. What I'm not sure about is how I would route the command from the ShellViewModel down to either the ListViewModel or the TreeViewModel to do the actual work without making a mess of the code. Some day, the application will be extended to include more than two children, and I want the shell to be as ignorant of the children as possible to make that extension as painless as possible. Looking at some sample WPF/MVVM applications (Karl Shifflett's CipherText, Josh Smith's MVVM Demo, etc.), I haven't seen any code that does this (or I didn't understand it). Regardless of whether you think my approach is way off base or I'm just missing a small nuance, please share your thoughts and help me get back on track. Thanks!

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  • how to use Remote Service ?

    - by LEE YONGGUN
    Hi im trying to use Remote Service btween two simple application, But its not easy to me. So any advice you have will help me. here`s my case. I made one app which is playing Music in service, There are two components. one is Activity controlling service by using three buttons, play,pause, stop. and it is working fine. and another one is just simple Activity which also has four buttons bind,play,stop,unbind. when i click bind, it`s confirmed by Toast msg, but when i click play button,it occurs error. i want to control first activitys Music playing service in second Activity. So im trying to use remote service. i made same .aidl file in each app project. In aidl file, i defined methods "playing","stoping" and i implement those methods in Music service class, implementation is simply use intent and startService & stopService. In DDMS there is "java.lang.SecurityException : Binder invocation to an incorrect interface" thats the case what im doing. So please tell me what`s the problem. any advice could help me. thanks Gun.

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  • Would it be possible to have a UTF-8-like encoding limited to 3 bytes per character?

    - by dan04
    UTF-8 requires 4 bytes to represent characters outside the BMP. That's not bad; it's no worse than UTF-16 or UTF-32. But it's not optimal (in terms of storage space). There are 13 bytes (C0-C1 and F5-FF) that are never used. And multi-byte sequences that are not used such as the ones corresponding to "overlong" encodings. If these had been available to encode characters, then more of them could have been represented by 2-byte or 3-byte sequences (of course, at the expense of making the implementation more complex). Would it be possible to represent all 1,114,112 Unicode code points by a UTF-8-like encoding with at most 3 bytes per character? If not, what is the maximum number of characters such an encoding could represent? By "UTF-8-like", I mean, at minimum: The bytes 0x00-0x7F are reserved for ASCII characters. Byte-oriented find / index functions work correctly. You can't find a false positive by starting in the middle of a character like you can in Shift-JIS.

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  • Simulating O_NOFOLLOW (2): Is this other approach safe?

    - by Daniel Trebbien
    As a follow-up question to this one, I thought of another approach which builds off of @caf's answer for the case where I want to append to file name and create it if it does not exist. Here is what I came up with: Create a temporary directory with mode 0700 in a system temporary directory on the same filesystem as file name. Create an empty, temporary, regular file (temp_name) in the temporary directory (only serves as placeholder). Open file name for reading only, just to create it if it does not exist. The OS may follow name if it is a symbolic link; I don't care at this point. Make a hard link to name at temp_name (overwriting the placeholder file). If the link call fails, then exit. (Maybe someone has come along and removed the file at name, who knows?) Use lstat on temp_name (now a hard link). If S_ISLNK(lst.st_mode), then exit. open temp_name for writing, append (O_WRONLY | O_APPEND). Write everything out. Close the file descriptor. unlink the hard link. Remove the temporary directory. (All of this, by the way, is for an open source project that I am working on. You can view the source of my implementation of this approach here.) Is this procedure safe against symbolic link attacks? For example, is it possible for a malicious process to ensure that the inode for name represents a regular file for the duration of the lstat check, then make the inode a symbolic link with the temp_name hard link now pointing to the new, symbolic link? I am assuming that a malicious process cannot affect temp_name.

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  • Haskell math performance

    - by Travis Brown
    I'm in the middle of porting David Blei's original C implementation of Latent Dirichlet Allocation to Haskell, and I'm trying to decide whether to leave some of the low-level stuff in C. The following function is one example—it's an approximation of the second derivative of lgamma: double trigamma(double x) { double p; int i; x=x+6; p=1/(x*x); p=(((((0.075757575757576*p-0.033333333333333)*p+0.0238095238095238) *p-0.033333333333333)*p+0.166666666666667)*p+1)/x+0.5*p; for (i=0; i<6 ;i++) { x=x-1; p=1/(x*x)+p; } return(p); } I've translated this into more or less idiomatic Haskell as follows: trigamma :: Double -> Double trigamma x = snd $ last $ take 7 $ iterate next (x' - 1, p') where x' = x + 6 p = 1 / x' ^ 2 p' = p / 2 + c / x' c = foldr1 (\a b -> (a + b * p)) [1, 1/6, -1/30, 1/42, -1/30, 5/66] next (x, p) = (x - 1, 1 / x ^ 2 + p) The problem is that when I run both through Criterion, my Haskell version is six or seven times slower (I'm compiling with -O2 on GHC 6.12.1). Some similar functions are even worse. I know practically nothing about Haskell performance, and I'm not terribly interested in digging through Core or anything like that, since I can always just call the handful of math-intensive C functions through FFI. But I'm curious about whether there's low-hanging fruit that I'm missing—some kind of extension or library or annotation that I could use to speed up this numeric stuff without making it too ugly.

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  • Objective-C autorelease pool not releasing object

    - by Chris
    Hi I am very new to Objective-C and was reading through memory management. I was trying to play around a bit with the NSAutoreleasePool but somehow it wont release my object. I have a class with a setter and getter which basically sets a NSString *name. After releasing the pool I tried to NSLog the object and it still works but I guess it should not? @interface TestClass : NSObject { NSString *name; } - (void) setName: (NSString *) string; - (NSString *) name; @end @implementation TestClass - (void) setName: (NSString *) string { name = string; } - (NSString *) name { return name; } @end int main (int argc, const char * argv[]) { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; TestClass *var = [[TestClass alloc] init]; [var setName:@"Chris"]; [var autorelease]; [pool release]; // This should not be possible? NSLog(@"%@",[var name]); return 0; }

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  • Key Tips in WPF

    - by Brad Leach
    Office 2007 and the Ribbon introduced the concept of "Key Tips". In short, every single command in the Ribbon receives a letter which you can press to activate that command. ... The letters are indicated by small "KeyTips" which indicate the letter to press to activate the control. KeyTips are displayed using the Alt key, so using them feels similar to how menu navigation works in Windows. (Source: http://blogs.msdn.com/jensenh/archive/2006/04/12/574930.aspx) An example of the Key Tips can be shown as follows. In this diagram, the use has pressed the ALT key, and is awaiting further input. Are there any WPF Open Source examples of "Key Tips"? How would you go about implementing something like this feature in a generic way (i.e. not requiring a Ribbon)? How would you implement this using a MVVM pattern (given that ICommand does not support InputBindings). Note: ActiPro have implemented this feature in their implementation of a Ribbon, but they have not released source code.

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  • ContextMenu not popping up on Long click

    - by primal
    Hi, The context menu is not popping up on the long click on the list items in the list view. I've extended the base adapter and used a view holder to implement the custom list with textviews and an imagebutton. adapter = new MyClickableListAdapter(this, R.layout.timeline, mObjectList); list.setAdapter(adapter); registerForContextMenu(list); Implementation of onCreateContextMenu @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { // TODO Auto-generated method stub super.onCreateContextMenu(menu, v, menuInfo); Log.d(TAG, "Entering Context Menu"); menu.setHeaderTitle("Context Menu"); menu.add(Menu.NONE, DELETE_ID, Menu.NONE, "Delete") .setIcon(R.drawable.icon); } The XML for listview is here <ListView android:id="@+id/list" android:layout_width="fill_parent" android:layout_height="wrap_content" /> I've been trying this for many days. I think its impossible to register Context-menu for a custom list view like this. Correct me if I am wrong (possibly with sample code). Now I am thinking of a adding a button to the list item and it displays a menu on clicking it. Is it possible with some other way than using Dialogs? Any help would be much appreciated..

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  • Java: Initializing a public static field in superclass that needs a different value in every subclas

    - by BinaryMuse
    Good evening, I am developing a set of Java classes so that a container class Box contains a List of a contained class Widget. A Widget needs to be able to specify relationships with other Widgets. I figured a good way to do this would be to do something like this: public abstract class Widget { public static class WidgetID { // implementation stolen from Google's GWT private static int nextHashCode; private final int index; public WidgetID() { index = ++nextHashCode; } public final int hashCode() { return index; } } public abstract WidgetID getWidgetID(); } so sublcasses of Widget could: public class BlueWidget extends Widget { public static final WidgetID WIDGETID = new WidgetID(); @Override public WidgetID getWidgetID() { return WIDGETID; } } Now, BlueWidget can do getBox().addWidgetRelationship(RelationshipTypes.SomeType, RedWidget.WIDGETID, and Box can iterate through it's list comparing the second parameter to iter.next().getWidgetID(). Now, all this works great so far. What I'm trying to do is keep from having to declare the public static final WidgetID WIDGETID in all the subclasses and implement it instead in the parent Widget class. The problem is, if I move that line of code into Widget, then every instance of a subclass of Widget appears to get the same static final WidgetID for their Subclassname.WIDGETID. However, making it non-static means I can no longer even call Subclassname.WIDGETID. So: how do I create a static WidgetID in the parent Widget class while ensuring it is different for every instance of Widget and subclasses of Widget? Or am I using the wrong tool for the job here? Thanks!

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  • Dependency between operations in scala actors

    - by paradigmatic
    I am trying to parallelise a code using scala actors. That is my first real code with actors, but I have some experience with Java Mulithreading and MPI in C. However I am completely lost. The workflow I want to realise is a circular pipeline and can be described as the following: Each worker actor has a reference to another one, thus forming a circle There is a coordinator actor which can trigger a computation by sending a StartWork() message When a worker receives a StartWork() message, it process some stuff locally and sends DoWork(...) message to its neighbour in the circle. The neighbours do some other stuff and sends in turn a DoWork(...) message to its own neighbour. This continues until the initial worker receives a DoWork() message. The coordinator can send a GetResult() message to the initial worker and wait for a reply. The point is that the coordinator should only receive a result when data is ready. How can a worker wait that the job returned to it before answering the GetResult() message ? To speed up computation, any worker can receive a StartWork() at any time. Here is my first try pseudo-implementation of the worker: class Worker( neighbor: Worker, numWorkers: Int ) { var ready = Foo() def act() { case StartWork() => { val someData = doStuff() neighbor ! DoWork( someData, numWorkers-1 ) } case DoWork( resultData, remaining ) => if( remaining == 0 ) { ready = resultData } else { val someOtherData = doOtherStuff( resultData ) neighbor ! DoWork( someOtherData, remaining-1 ) } case GetResult() => reply( ready ) } } On the coordinator side: worker ! StartWork() val result = worker !? GetResult() // should wait

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  • Update mapping table in Linq

    - by Gary McGill
    I have a table Customers with a CustomerId field, and a table of Publications with a PublicationId field. Finally, I have a mapping table CustomersPublications that records which publications a customer can access - it has two fields: CustomerId field PublicationId. For a given customer, I want to update the CustomersPublications table based on a list of publication ids. I want to remove records in CustomersPublications where the PublicationId is not in the list, and add new records where the PublicationId is in the list but not already in the table. This would be easy in SQL, but I can't figure out how to do it in Linq. For the delete part, I tried: var recordsToDelete = dataContext.CustomersPublications.Where ( cp => (cp.CustomerId == customerId) && ! publicationIds.Contains(cp.PublicationId) ); dataContext.CustomersPublications.DeleteAllOnSubmit(recordsToDelete); ... but that didn't work. I got an error: System.NotSupportedException: Method 'Boolean Contains(Int32)' has no supported translation to SQL So, I tried using Any(), as follows: var recordsToDelete = dataContext.CustomersPublications.Where ( cp => (cp.CustomerId == customerId) && ! publicationIds.Any(p => p == cp.PublicationId) ); ... and this just gives me another error: System.NotSupportedException: Local sequence cannot be used in LINQ to SQL implementation of query operators except the Contains() operator Any pointers? [I have to say, I find Linq baffling (and frustrating) for all but the simplest queries. Better error messages would help!]

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  • Getting exception when trying to monkey patch pymongo.connection._Pool

    - by Creotiv
    I use pymongo 1.9 on Ubuntu 10.10 with python 2.6.6 When i trying to monkey patch pymongo.connection._Pool i'm getting error on connection: AutoReconnect: could not find master/primary But when i change _Pool class in pymongo.connection module, it work pretty fine. Even if i copy _Pool implementation from pymongo.connection module and will try to monkey patch by the same code, it still giving same exception. I need to remove threading.local from _Pool class, because i use gevent and i need to implement Pool for all mongo connections(for all threads). I use this code: import pymongo class GPool: """A simple connection pool. Uses thread-local socket per thread. By calling return_socket() a thread can return a socket to the pool. Right now the pool size is capped at 10 sockets - we can expose this as a parameter later, if needed. """ # Non thread-locals __slots__ = ["sockets", "socket_factory", "pool_size","sock"] #sock = None def __init__(self, socket_factory): self.pool_size = 10 if not hasattr(self,"sock"): self.sock = None self.socket_factory = socket_factory if not hasattr(self, "sockets"): self.sockets = [] def socket(self): # we store the pid here to avoid issues with fork / # multiprocessing - see # test.test_connection:TestConnection.test_fork for an example # of what could go wrong otherwise pid = os.getpid() if self.sock is not None and self.sock[0] == pid: return self.sock[1] try: self.sock = (pid, self.sockets.pop()) except IndexError: self.sock = (pid, self.socket_factory()) return self.sock[1] def return_socket(self): if self.sock is not None and self.sock[0] == os.getpid(): # There's a race condition here, but we deliberately # ignore it. It means that if the pool_size is 10 we # might actually keep slightly more than that. if len(self.sockets) < self.pool_size: self.sockets.append(self.sock[1]) else: self.sock[1].close() self.sock = None pymongo.connection._Pool = GPool

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  • tabBarController and navigationControllers in landscape mode, episode II

    - by unforgiven
    I have a UITabBarController, and each tab handles a different UIViewController that pushes on the stack new controllers as needed. In two of these tabs I need, when a specific controller is reached, the ability to rotate the iPhone and visualize a view in landscape mode. After struggling a lot I have found that it is mandatory subclassing UITabBarController to override shouldAutorotateToInterfaceOrientation. However, if i simply return YES in the implementation, the following undesirable side effect arises: every controller in every tab is automatically put in landscape mode when rotating the iPhone. Even overriding shouldAutorotateToInterfaceOrientation in each controller to return NO does not work: when the iPhone is rotated, the controller is put in landscape mode. I implemented shouldAutorotateToInterfaceOrientation as follows in the subclassed UITabBarController: (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { if([self selectedIndex] == 0 || [self selectedIndex] == 3) return YES; return NO; } So that only the two tabs I am interested in actually get support for landscape mode. Is there a way to support landscape mode for a specific controller on the stack of a particular tab? I tried, without success, something like (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { if([self selectedIndex] == 0 || [self selectedIndex] == 3) { if ([[self selectedViewController] isKindOfClass: [landscapeModeViewController class]]) return YES; } return NO; } Also, I tried using the delegate method didSelectViewController, without success. Any help is greatly appreciated. Thank you.

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