Hi Jon, Thanks! That did the trick -- I was way off.
Chris ----- Original Message ---- > From: Jonathan Hess <jh...@apple.com> > To: Chris Carson <cucar...@yahoo.com> > Cc: cocoa-dev@lists.apple.com > Sent: Tuesday, May 12, 2009 1:19:11 AM > Subject: Re: instance management in IB > > Hey Chris - > > This line "pointPath = [NSBezierPath bezierPath];" in the init method creates > an > NSBezierPath instance that may (will!) be destroyed with the next autorelease > pool flush. You should be creating your bezier path with "pointPath = > [[NSBezierPath alloc] init];" and then add a "[pointPath release]" to your > dealloc method. > > http://developer.apple.com/documentation/Cocoa/Conceptual/MemoryMgmt/MemoryMgmt.html > > Good Luck - > Jon Hess > > On May 11, 2009, at 6:29 PM, Chris Carson wrote: > > > > > Hello, > > > > I've been scratching my head trying to get a basic delegate/data source > Cocoa/AppKit program working and feel that I'm misunderstanding something > basic > (I've included the code is at the end). > > > > I set a breakpoint within the if statement in the init method of MyModel > > and > see it called more than once. The second time the debugger throws a > EXC_BAD_ACCESS. This message goes away if I comment out the two lines in > stepAnimation that call the getBuffer and getLength methods and then modify > the > buffer. All this makes me think that somehow the instance of MyModel is being > deallocated as soon as the data source message returns, but before the data > is > copied into the pointBuffer. > > > > I created an NSView and NSObject in Interface Builder, assigning the MyView > subclass to the NSView object and MyModel to the NSObject object. Then I > connected the dataSource outlet on MyView to th MyModel object. > > > > What am I missing? How can I get the data from MyModel to be viewable my > MyView? > > > > Sidenote: Ultimately I'm trying to plot a real-time frequency spectrum. My > plan is to pull in data over a CFMessagePort in the model and have the view > access it view the data source. > > > > Help is much appreciated! > > > > Chris > > > > main.m > > ---------- > > > > int main(int argc, char *argv[]) { > > // Launch Cocoa application > > return NSApplicationMain(argc, (const char **) argv); > > } > > > > MyView.m: > > ---------- > > @implementation MyView > > > > - (id)initWithFrame:(NSRect)frame { > > self = [super initWithFrame:frame]; > > if (self) { > > pointPath = [NSBezierPathbezierPath]; > > pointBuffer = malloc (sizeof(NSPoint) * 100); > > [NSTimerscheduledTimerWithTimeInterval:0.1 > > target:self > > selector:@selector(stepAnimation:) > > userInfo:nil > > repeats:YES]; > > } > > return self; > > } > > > > - (void)drawRect:(NSRect)rect { > > [pointPath removeAllPoints]; > > [pointPathappendBezierPathWithPoints:(NSPointArray)pointBuffercount:100]; > > [pointPathstroke]; > > } > > > > - (void)setDataSource:(id)inDataSource { > > dataSource = inDataSource; > > } > > > > - (id)dataSource { > > returndataSource; > > } > > > > - (void)stepAnimation:(NSTimer *)timer { > > float*inBuffer; > > int i, length; > > > > > > // Fetch buffer pointer > > inBuffer = [[self dataSource] getBuffer:self]; > > length = [[self dataSource] getLength:self]; > > > > // Copy to point buffer > > for (i = 0; i < length; i++) { > > pointBuffer[i].y = inBuffer[i]; > > pointBuffer[i].x = i; > > } > > > > // Mark display for painting > > [selfsetNeedsDisplay:YES]; > > } > > > > - (void)dealloc { > > free(pointBuffer); > > [super dealloc]; > > } > > > > @end > > > > MyView.h > > ---------- > > @interface MyView : NSView { > > IBOutletid dataSource; > > NSBezierPath *pointPath; > > NSPoint *pointBuffer; > > } > > > > - (void)setDataSource:(id)inDataSource; > > - (id)dataSource; > > - (void)stepAnimation:(NSTimer *)timer; > > > > @end > > > > @interface NSObject(MyViewDataSource) > > > > - (float *)getBuffer:(MyView *)view; > > - (int)getLength:(MyView *)view; > > > > @end > > > > MyModel.m > > ---------- > > @implementationMyModel > > > > - (id)init { > > self= [superinit]; > > if (self) { > > buffer = malloc (sizeof(float) * 100); > > length = 100; > > } > > return self; > > } > > > > - (float *)getBuffer:(GraphView *)view { > > returnbuffer; > > } > > > > - (int)getLength:(GraphView *)view { > > returnlength; > > } > > > > - (void)dealloc { > > free (buffer); > > [super dealloc]; > > } > > > > @end > > > > MyModel.h > > ---------- > > @interface MyModel : NSObject { > > float *buffer; > > int length; > > } > > > > - (float *)getBuffer:(GraphView *)view; > > - (int)getLength:(GraphView *)view; > > > > @end > > > > > > > > > > _______________________________________________ > > > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > > > Please do not post admin requests or moderator comments to the list. > > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > > > Help/Unsubscribe/Update your Subscription: > > http://lists.apple.com/mailman/options/cocoa-dev/jhess%40apple.com > > > > This email sent to jh...@apple.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. 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