Change size of window in Cocoa?

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

You are going to have to iterate through all of your subviews and change their frame positions based on the delta of your window frame.

so if you expand your window frame by 20 in all directions, all your subviews are going to have to increase their frame positions by (20,20) to offset the windows movement.

Answer 2

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.

Answer 3

In constraint-based layout, set the views around the edge of your window to be a fixed distance from their superview's edge.

Xcode will infer a lot of resizability from that; if anything still isn't resizing properly, adjust its constraints so that its width and/or height is no longer constant.

The easiest way is to move your views until blue lines show up in the editor. Each blue line corresponds to a rule in the HIG about how things should be lain out, and if you drop the view there, Xcode will create constraints matching those guidelines. For example, if you set a view 20 points from the right edge of its superview, you'll get a blue line for that, and if you drop the view there, you'll create a constraint that the view must remain that distance from that edge.

The superview isn't the only view with which you can create HIG-based constraints. You can also create guideline constraints between sibling views. For example, if you put a button next to another button at the appropriate distance, you'll get a blue line across that distance, and if you drop it, you'll create a constraint that those two buttons must remain that distance from each other.

If you want to do something really custom, the three buttons in the lower-right corner of the nib editor will let you create any constraint you want. What you have selected determines what constraints you can create; the nib editor's outline view will help you make sure you have the selection you want.

Answer 4

If you are using the Interface Builder to build these views, then I believe one approach is to set the "struts and springs." These are available under the "size inspector" and are the red arrows and bars above the "autosizing" label. Play around with these to get the effect that you want, but the general idea is that the arrows control how the size of the view adjusts to changes in the size of the parent view, and the bars control the relationship of the edges of the view to the edges of the parent view as the size changes.