I have an NSCollectionView specified as both my DataSource and my Delegate.
I have two issues:
Rather than doing the registerClass method, attempting to instead use the 3 lines of commented code with the (non-nil) protoNib means of registering with an NSCollectionView causes theItem to always be nil.
Using the class registry option, all works mostly fine. But if I remove the willDisplayItem and didEndDisplayingItem stubs, the system eats up gobs of memory on its first call to itemForRepresentedObjectAtIndexPath (with thousands of internal calls to these two stubs) and eventually crashes. Instruments shows thousands of 4k #autoreleasepool content items being created by AppKit.
Any idea why this might be happening?
-(void)awakeFromNib {
[self registerClass:[MECollectionViewItem class] forItemWithIdentifier:#"EntityItem"];
// NSString *nibName = NSStringFromClass([MECollectionViewItem class]);
// NSNib *protoNib = [[NSNib alloc] initWithNibNamed:nibName bundle:nil];
// [self registerNib:protoNib forItemWithIdentifier:#"EntityItem"];
__weak typeof(self) weakSelf = self;
[self setDelegate:weakSelf];
[self setDataSource:weakSelf];
...
}
- (MECollectionViewItem *)collectionView:(NSCollectionView *)collectionView
itemForRepresentedObjectAtIndexPath:(NSIndexPath *)indexPath;
{
MECollectionViewItem *theItem = [self makeItemWithIdentifier:#"EntityItem"
forIndexPath:indexPath];
return theItem;
}
-(void)collectionView:(NSCollectionView *)collectionView
willDisplayItem:(NSCollectionViewItem *)item
forRepresentedObjectAtIndexPath:(NSIndexPath *)indexPath
{
}
-(void)collectionView:(NSCollectionView *)collectionView
didEndDisplayingItem:(nonnull NSCollectionViewItem *)item
forRepresentedObjectAtIndexPath:(nonnull NSIndexPath *)indexPath
{
}
The Appkit classes are not designed to be their own delegate. NSCollectionView implements several NSCollectionViewDelegate methods and calls the delegate. I don't know why it's implemented like this and it doesn't feel right but it is what it is. If the collection view is its own delegate and a delegate method isn't implemented in the subclass then the call causes an infinite loop. Solution: don't set delegate to self.
Related
I am trying to customize an NSImageCell for NSTableView using NSArrayController and bindings to change the background of the cell which is selected. So, I created two NSImage images and retain them as normalImage and activeImage in the cell instance, which means I should release these two images when the cell calls its dealloc method. And I override
- (void)drawInteriorWithFrame:(NSRect)cellFrame inView:(NSView *)controlView
and
- (void) setObjectValue:(id) inObject
But I find that when I click any cell in the tableview, the cell's dealloc method is called.
So I put NSLog(#"%#", self); in the dealloc method and - (void)drawInteriorWithFrame:inView: and I find that these two instance are not same.
Can anyone tell me why dealloc is called every time I click any cell? Why are these two instances not the same? What does OS X do when I customize the cell in NSTableView?
BTW: I found that the -init is called only once. Why?
EDIT:
My cell code
#implementation SETableCell {
NSImage *_bgNormal;
NSImage *_bgActive;
NSString *_currentString;
}
- (id)init {
if (self = [super init]) {
NSLog(#"setup: %#", self);
_bgNormal = [[NSImage imageNamed:#"bg_normal"] retain];
_bgActive = [[NSImage imageNamed:#"bg_active"] retain];
}
return self;
}
- (void)dealloc {
// [_bgActive release]; _bgActive = nil;
// [_bgNormal release]; _bgNormal = nil;
// [_currentString release]; _currentString = nil;
NSLog(#"dealloc: %#", self);
[super dealloc];
}
- (void)drawInteriorWithFrame:(NSRect)cellFrame inView:(NSView *)controlView {
NSLog(#"draw: %#", self);
NSPoint point = cellFrame.origin;
NSImage *bgImg = self.isHighlighted ? _bgActive : _bgNormal;
[bgImg drawAtPoint:p fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1.0];
NSPoint strPoint = cellFrame.origin;
strPoint.x += 30;
strPoint.y += 30;
[_currentString drawAtPoint:strPoint withAttributes:nil];
}
- (void) setObjectValue:(id) inObject {
if (inObject != nil && ![inObject isEqualTo:_currentString]) {
[self setCurrentInfo:inObject];
}
}
- (void)setCurrentInfo:(NSString *)info {
if (_currentString != info) {
[_currentString release];
_currentString = [info copy];
}
}
#end
As a normal recommendation, you should move to ARC as it takes cares of most of the memory management tasks that you do manually, like retain, releases. My answers will assume that you are using manual memory management:
Can anyone tell me why dealloc is called every time I click any cell ?
The only way for this to happen, is if you are releasing or auto-releasing your cell. If you are re-using cells, they shouldn't be deallocated.
Why these tow instance are not same ?
If you are re-using them, the cell that you clicked, and the cell that has been deallocated, they should be different. Pay close attention to both your questions, in one you assume that you are releasing the same cell when you click on it, on the second you are seeing that they are different.
What does Apple do when I custom the cell in NSTableView ?
Apple as a company? Or Apple as in the native frameworks you are using? I am assuming you are going for the second one: a custom cell is just a subclass of something that the NSTableView is expecting, it should behave the same as a normal one plus your custom implementation.
BTW: I found that the init is called only once, and why ?
Based on this, you are probably re-using cells, and only in the beginning they are actually being initialised.
It would be very useful to see some parts of your code:
Your Cell's code
Your NSTableView cell's creation code.
I populated my NStableView with tableView Controller and it's working fine. I only want to know why every time I am getting the data (Presented in table Cell) whenever the user hovers on a particular cell in a tableview, it starts displaying the data in console.
I found that this - (NSCell *)tableView:(NSTableView *)tableView dataCellForTableColumn:(NSTableColumn *)tableColumn row:(NSInteger)row calls every time and I stack traced using instruments and this method is taking a lot of memory.
Is there any way to stop this method drawing the data every time.
Add the delegate -viewWillMoveToWindow to the view subclass contain the table. here i have used the BOOL named reloadTable. NSTrackingArea is the answer for your problem
- (void) viewWillMoveToWindow:(NSWindow *)newWindow
{
// Setup a new tracking area when the view is added to the window.
NSTrackingArea* trackingArea = [[NSTrackingArea alloc] initWithRect:[yourTable frame]
options: (NSTrackingMouseEnteredAndExited |
NSTrackingActiveAlways|NSTrackingEnabledDuringMouseDrag) owner:self userInfo:nil];
[self addTrackingArea:trackingArea];
}
- (void) mouseEntered:(NSEvent*)theEvent {
reloadTable=YES;
NSLog(#"enter %#",theEvent);
}
- (void) mouseExited:(NSEvent*)theEvent {
reloadTable=YES;
}
then use it in your NSTableViewDataSource methods
I have a NSDocument class, where I'd need to access the main menu window, the one that gets opened when the app start. When I operate in that window from the app all seems to work, but when trying to do the same operations from readFromFileWrapper:ofType:error: the window I access seems to be nil. Why this happens?
EDIT: Some code which deals with this:
- (BOOL)readFromFileWrapper:(NSFileWrapper *)fileWrapper ofType:(NSString *)typeName error:(NSError **)outError
{
if([[NSFileManager alloc] fileExistsAtPath:[NSString stringWithFormat:#"%#/Project.plist",[[self fileURL] path]]]) {
NSLog(#"%#", [[self fileURL] path]);
NSDictionary *project = [NSDictionary dictionaryWithContentsOfFile:[NSString stringWithFormat:#"%#/Project.plist",[[self fileURL] path]]];
if([[project objectForKey:#"type"] isEqualToString:#"vote"]) {
[self openProject:[[self fileURL] path] type:#"vote"];
return YES;
} else if([[project objectForKey:#"type"] isEqualToString:#"quiz"]) {
[self openProject:[[self fileURL] path] type:#"quiz"];
return YES;
} else {
return NO;
}
} else {
return NO;
}
}
That is my readFromFileWrapper:ofType:error: method. Here is my openProject:type: method:
-(void)openProject:(NSString *)filepath type:(NSString *)type
{
NSLog(#"Opening project # %#",filepath);
NSLog(#"%#", [MainWindow description]);
[projectDesignerView setFrame:[[[[MainWindow contentView] subviews] objectAtIndex:0] frame]];
[projectDesignerToolbar setFrame:[MainWindow frame] display:FALSE];
[[MainWindow contentView] replaceSubview:[[[MainWindow contentView] subviews]objectAtIndex:0] with:projectDesignerView];
[[projectDesignerToolbar toolbar] setShowsBaselineSeparator:YES];
[MainWindow setToolbar:[projectDesignerToolbar toolbar]];
[MainWindow setRepresentedFilename:filepath];
[MainWindow setTitle:[NSString stringWithFormat:#"%# - %#", [[filepath lastPathComponent] stringByDeletingPathExtension], [projectDesignerToolbar title]]];
NSString *path = [[NSBundle mainBundle] pathForResource:#"projectDesigner" ofType:#"html"];
NSURL *url = [NSURL fileURLWithPath:path];
[[projectDesignerWebview mainFrame] loadRequest:[NSURLRequest requestWithURL:url]];
}
NSLog(#"%#", [MainWindow description]); returns nil, when MainWindow should be the Main App Window. I think the problem is that double-clicking on a file reallocs all, and hence is failing.
It's not entirely clear what you're asking. You mention that MainWindow is an outlet in MainMenu.xib but you don't specify what class is defining the outlet.
If this window is designed to have a single main "project" window then you should assign the outlet property in your application delegate.
You can then access this from other classes using something like [(YourAppDelegate*)[NSApp delegate] mainWindow];.
If, however, you are trying to obtain a reference to the window of the current document then it's a little bit more complicated.
The reason that NSDocument does not have a window outlet by default is that it is designed to work with instances of NSWindowController that themselves manage the various windows related to the document. This is so a document can have multiple windows showing different views of the same data, additional palettes related to the document and so on. Each instance of NSWindowController would have its own window nib file and window outlet.
By default, NSDocument creates a single instance of NSWindowController for you if you do not specifically create and assign NSWindowController instances to the document. This is automatic, you don't need to even know the window controller exists.
That means that if you aren't managing your document windows with NSWindowController instances yourself, you can get the window attached to the NSWindowController that is automatically-created by NSDocument like so:
/* Only implement this in an NSDocument instance where the
automatic window controller is being used.
If the document has multiple window controllers, you must
keep track of the main window controller yourself
and return its window
*/
- (NSWindow*)documentWindow
{
if([[self windowControllers] count] == 1)
{
return [[[self windowControllers] firstObject] window];
}
return nil;
}
The normal way to handle this is to add an IBOutlet to your NSDocument subclass, then hook it up to the document window in the .xib file.
In your .h:
#interface MyDocument : NSDocument
#property (nonatomic, assign) IBOutlet NSWindow *docWindow;
#end
In your .m:
#implementation MyDocument : NSDocument
#synthesize docWindow;
#end
Then, the most important part, open up MyDocument.xib (or whatever it's called), and drag a connection from File's Owner (assuming that's your NSDocument subclass, which it is by default) to the main document window, and hook it up to the docWindow outlet.
I have a view MyView, and it has images which I want to bind with an array in my AppDelegate.
MyView class
#interface MyView : NSView {
#private
NSArray *images;
}
#end
+ (void)initialize
{
[self exposeBinding:#"images"];
}
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
NSLog(#"Changed!");
}
My AppDelegate
#property (retain) NSArray *images;
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
images = [[NSMutableArray alloc] init];
[view bind:#"images" toObject:self withKeyPath:#"images" options:nil];
// [self addObserver:view forKeyPath:#"images" options:0 context:nil]; // !!!
MyImage *img = [[MyImage alloc] ...];
[self willChangeValueForKey:#"images"];
[[self images] addObject:img];
[self didChangeValueForKey:#"images"];
[img release];
}
Without [self addObserver:view forKeyPath:#"images" options:0 context:nil]; the method observeValueForKeyPath: is never called.
Is it necessary to call addObserver: when using bind:? Does bind: set the KVO? And why doesn't binding work?
What you need is an implemented setter for the images property like below. The most common use-case for this is that you need to invalidate the drawing and request redraw with
-setNeedsDisplay:YES.
- (void)setImages:(NSArray *)newImages
{
if(newImages != images) {
[images release];
images = newImages;
[images retain];
}
[self setNeedsDisplay:YES]; // Addition and only difference to synthesized setter
}
You can drop the -exposeBinding: call, since that has only influence on plugins for Interface Builder, and those where lost with the introduction of Xcode 4.
The reason why the -observeValueForKeyPath:ofObject:change:context: message is not send is that for a binding the observer is not the bound-to object. There is another object in the background. (In the stack form a breakpoint you can see that its class is NSEditableBinder.) So it is correct to register as observer from within the view to the view property #"images".
Another way to get notified about a change in the view is to override -setValue:forKey: method. Then you would need to check the key string and see if it was equal to #"images". But since there are other methods from the KVC protocol like -setValue:forKeyPath:, you would need to be extra careful to not disturb the machinery, i.e. always call super.
Uh. I just realize that my answer so far assumes the easier case where you replace the whole array. Your question was for an array modification. (You do declare an immutable array property in your example, though, which only allows replacement. So keep it as declared, and my approach so far will work. Below I show the other alternative.)
Ok, lets assume you do this in the app delegate, a replacement:
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
[view bind:#"images" toObject:self withKeyPath:#"images" options:nil];
MyImage *img = [[MyImage alloc] ...];
self.images = [NSArray arrayWithObject:img];
[img release];
}
You don't need to post the change (using willChangeValueForKey: and didChangeValueForKey:, since you go through the declared property. They do that for you.
Now to the other approach where you modify an array. For that you need to use a mutable array property and modify it through an KVO-notifying proxy, like this:
[self mutableArrayValueForKey:#"images"] addObject:img];
This would pick up the change on the sending (bound-to) side. Then it would be transported to the view through the binding machinery, and eventually set using KVC.
There, on the receiving end in the view, you would need to pick up the property change to #"images". That could be done by overwriting the collection accessor method(s) and do more work there, instead of just accepting the the change. But that is a bit complicated, since there are quite a few accessor methods (See docs). Or, simpler, you could add another observation relationship from within the view.
For that, somewhere in initialization (-awakeFromNib: for example) of the view:
[self addObserver:self forKeyPath:#"images" options:0 context:nil];
and then:
- (void)observeValueForKeyPath:(NSString *)keyPath
ofObject:(id)object
change:(NSDictionary *)change
context:(void *)context
{
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
if([keyPath isEqualToString:#"images"]) {
[self setNeedsDisplay:YES]; // or what else you need to do then.
}
}
Note that this last observer relationship has nothing to do with the binding any longer. The value change to the bound property properly arrives at the view without, you just don't realize (get notified).
That should work.
The only way to have observeValueForKeyPath called is to call addObserver. Binding works through a different mechanism.
Background
Cocoa app using core data Two
processes - daemon and a main UI
Daemon constantly writing to a data store
UI process reads from same data
store
Columns in NSOutlineView in UI bound to
an NSTreeController
NSTreeControllers managedObjectContext is bound to
Application with key path of
delegate.interpretedMOC
NSTreeControllers entity is set to TrainingGroup (NSManagedObject subclass is called JGTrainingGroup)
What I want
When the UI is activated, the outline view should update with the latest data inserted by the daemon.
The Problem
Main Thread Approach
I fetch all the entities I'm interested in, then iterate over them, doing refreshObject:mergeChanges:YES. This works OK - the items get refreshed correctly. However, this is all running on the main thread, so the UI locks up for 10-20 seconds whilst it refreshes. Fine, so let's move these refreshes to NSOperations that run in the background instead.
NSOperation Multithreaded Approach
As soon as I move the refreshObject:mergeChanges: call into an NSOperation, the refresh no longer works. When I add logging messages, it's clear that the new objects are loaded in by the NSOperation subclass and refreshed. It seems that no matter what I do, the NSOutlineView won't refresh.
What I've tried
I've messed around with this for 2 days solid and tried everything I can think of.
Passing objectIDs to the NSOperation to refresh instead of an entity name.
Resetting the interpretedMOC at various points - after the data refresh and before the outline view reload.
I'd subclassed NSOutlineView. I discarded my subclass and set the view back to being an instance of NSOutlineView, just in case there was any funny goings on here.
Added a rearrangeObjects call to the NSTreeController before reloading the NSOutlineView data.
Made sure I had set the staleness interval to 0 on all managed object contexts I was using.
I've got a feeling this problem is somehow related to caching core data objects in memory. But I've totally exhausted all my ideas on how I get this to work.
I'd be eternally grateful to anyone who can shed any light as to why this might not be working.
Code
Main Thread Approach
// In App Delegate
-(void)applicationDidBecomeActive:(NSNotification *)notification {
// Delay to allow time for the daemon to save
[self performSelector:#selector(refreshTrainingEntriesAndGroups) withObject:nil afterDelay:3];
}
-(void)refreshTrainingEntriesAndGroups {
NSSet *allTrainingGroups = [[[NSApp delegate] interpretedMOC] fetchAllObjectsForEntityName:kTrainingGroup];
for(JGTrainingGroup *thisTrainingGroup in allTrainingGroups)
[interpretedMOC refreshObject:thisTrainingGroup mergeChanges:YES];
NSError *saveError = nil;
[interpretedMOC save:&saveError];
[windowController performSelectorOnMainThread:#selector(refreshTrainingView) withObject:nil waitUntilDone:YES];
}
// In window controller class
-(void)refreshTrainingView {
[trainingViewTreeController rearrangeObjects]; // Didn't really expect this to have any effect. And it didn't.
[trainingView reloadData];
}
NSOperation Multithreaded Approach
// In App Delegate (just the changed method)
-(void)refreshTrainingEntriesAndGroups {
JGRefreshEntityOperation *trainingGroupRefresh = [[JGRefreshEntityOperation alloc] initWithEntityName:kTrainingGroup];
NSOperationQueue *refreshQueue = [[NSOperationQueue alloc] init];
[refreshQueue setMaxConcurrentOperationCount:1];
[refreshQueue addOperation:trainingGroupRefresh];
while ([[refreshQueue operations] count] > 0) {
[[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.05]];
// At this point if we do a fetch of all training groups, it's got the new objects included. But they don't show up in the outline view.
[windowController performSelectorOnMainThread:#selector(refreshTrainingView) withObject:nil waitUntilDone:YES];
}
// JGRefreshEntityOperation.m
#implementation JGRefreshEntityOperation
#synthesize started;
#synthesize executing;
#synthesize paused;
#synthesize finished;
-(void)main {
[self startOperation];
NSSet *allEntities = [imoc fetchAllObjectsForEntityName:entityName];
for(id thisEntity in allEntities)
[imoc refreshObject:thisEntity mergeChanges:YES];
[self finishOperation];
}
-(void)startOperation {
[self willChangeValueForKey:#"isExecuting"];
[self willChangeValueForKey:#"isStarted"];
[self setStarted:YES];
[self setExecuting:YES];
[self didChangeValueForKey:#"isExecuting"];
[self didChangeValueForKey:#"isStarted"];
imoc = [[NSManagedObjectContext alloc] init];
[imoc setStalenessInterval:0];
[imoc setUndoManager:nil];
[imoc setPersistentStoreCoordinator:[[NSApp delegate] interpretedPSC]];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(mergeChanges:)
name:NSManagedObjectContextDidSaveNotification
object:imoc];
}
-(void)finishOperation {
saveError = nil;
[imoc save:&saveError];
if (saveError) {
NSLog(#"Error saving. %#", saveError);
}
imoc = nil;
[self willChangeValueForKey:#"isExecuting"];
[self willChangeValueForKey:#"isFinished"];
[self setExecuting:NO];
[self setFinished:YES];
[self didChangeValueForKey:#"isExecuting"];
[self didChangeValueForKey:#"isFinished"];
}
-(void)mergeChanges:(NSNotification *)notification {
NSManagedObjectContext *mainContext = [[NSApp delegate] interpretedMOC];
[mainContext performSelectorOnMainThread:#selector(mergeChangesFromContextDidSaveNotification:)
withObject:notification
waitUntilDone:YES];
}
-(id)initWithEntityName:(NSString *)entityName_ {
[super init];
[self setStarted:false];
[self setExecuting:false];
[self setPaused:false];
[self setFinished:false];
[NSThread setThreadPriority:0.0];
entityName = entityName_;
return self;
}
#end
// JGRefreshEntityOperation.h
#interface JGRefreshEntityOperation : NSOperation {
NSString *entityName;
NSManagedObjectContext *imoc;
NSError *saveError;
BOOL started;
BOOL executing;
BOOL paused;
BOOL finished;
}
#property(readwrite, getter=isStarted) BOOL started;
#property(readwrite, getter=isPaused) BOOL paused;
#property(readwrite, getter=isExecuting) BOOL executing;
#property(readwrite, getter=isFinished) BOOL finished;
-(void)startOperation;
-(void)finishOperation;
-(id)initWithEntityName:(NSString *)entityName_;
-(void)mergeChanges:(NSNotification *)notification;
#end
UPDATE 1
I just found this question. I can't understand how I missed it before I posted mine, but the summary is: Core Data wasn't designed to do what I'm doing. Only one process should be using a data store.
NSManagedObjectContext and NSArrayController reset/refresh problem
However, in a different area of my application I have two processes sharing a data store with one having read only access and this seemed to work fine. Plus none of the answers to my last question on this topic mentioned that this wasn't supported in Core Data.
I'm going to re-architect my app so that only one process writes to the data store at any one time. I'm still skeptical that this will solve my problem though. It looks to me more like an NSOutlineView refreshing problem - the objects are created in the context, it's just the outline view doesn't pick them up.
I ended up re-architecting my app. I'm only importing items from one process or the other at once. And it works perfectly. Hurrah!