Resizing an NSView mid-animation - macos

Question

I have a normal NSView that is resizable by dragging the window edges.
If the view is resized during an [NSView animator] animation, it continues to animate to the final size of the original animation, but does not take into account the new window size.
Here is a simple example project. Double click to begin the animation, then resize the window before it finishes.
What is the best way to make the animation take account of the new frame size?

Answer 1

IMHO, the best way would be to stop the animation as soon as the resizing phase begins.
During the resize phase, the user is in control and sets the size of the window manually.
When the resizing phase ends, the window is already set to the desired size, so there is non need to do more.

Answer 2

This kind of problem is best solved with an NSTimer instead of the animator function:
Let the timer call a function repeatedly, until the animation is "complete".
Once complete, end the timer (invalidate).
The function to be called repeatedly in each loop grabs the actual framesize of the window and the actual framesize of your view and simply adds the third of the difference of the two to the frame of the view, like:
frame.size.height += diffHeight/3.0;
So, no matter what happens, the view grows or shrinks closer and closer to its destination.
Once the abs(of the difference) is less then e.g. 0.2 you set the view directly to the desired size and end the timer.
This is direct, uses only little code and you need not listen to any events while it performs pretty well. :-)
Here are the critical codes to initiallize the animation (timer must be an instance of your class):
if(timer)return;
timer = [NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:#selector(resizeView:) userInfo:[NSNumber numberWithBool:status] repeats:YES];
[timer setTolerance:0.02];
I use the word status instead of your word closed, the function to be repeatedly called might then look somewhat like:
- (void)resizeView:(id)userInfo;
{
BOOL status = [(NSNumber *)[userInfo userInfo] boolValue];
double startwid,stopwid;
NSRect newSizeRect = [[self window] frame];
stopwid = newSizeRect.size.width;
if(status){
stopwid -= 100.0;
}
NSRect cbgRect = [self frame];
startwid = cbgRect.size.width;
double diff = stopwid-startwid;
if(fabs(diff)<0.2){
diff = 0;
startwid = stopwid;
[timer invalidate];
timer = nil;
//NSLog(#"stop");
}
//NSLog(#"%f - %f = %f /10 = %f",stopwid,startwid,diff,diff/3.0);
cbgRect.size.width = startwid+diff/3.0;
[self setFrame:cbgRect];
}