Question

I have a window whose size I need to change when the user clicks on it. I am using [self setFrame:windowFrame display:YES animate:YES] to accomplish this.

Even though the window successfully changes size (I increase its height), it moves the contents of the window up with it. How do I prevent this from happening? I want the contents to remain in place.

I am on OSX Mountain Lion developing an app for OSX using Objective-C and Cocoa.

EDIT: Constraints and/or Springs and Struts will not work as I need to move the contents around after the window is resized.

Answer 1

Constraints and/or Springs and Struts will not work as I need to move the contents around after the window is resized.

In that case, you should use NSViewAnimation.

A single view animation can actually perform multiple animations to multiple views, and you can even do one to a window, despite the class’s name and the fact that windows aren’t views in Cocoa.

You create a view animation with initWithViewAnimations:, which takes an array of dictionaries. Each dictionary identifies the target (NSViewAnimationTargetKey) and what to do to it: Either change the target’s frame (NSViewAnimationStartFrameKey and NSViewAnimationEndFrameKey) or fade the target in or out (NSViewAnimationEffectKey). For your case, you’ll be changing the targets’ frames.

When the user does the thing that causes the resize of the window, you’ll need to compute the desired overall size of the window (taking care to adjust its frame’s position so it doesn’t grow off the screen), as well as the new frames—both positions and sizes—of your views. Everything that will move and/or change size, create a dictionary for it and throw it into the array. Then create the view animation.

An NSViewAnimation is a kind of NSAnimation, which provides all the methods for starting and stopping the animation, monitoring its progress, hooking into it, and chaining multiple NSAnimations together. If nothing else, you’ll need to start the animation.