UIView stretching side instead of adjusting width & origin

Question

This is probably an easy question, whether its possible or not i have no idea; but easy none the less.

Screen       = 0x   0y 1000w 1000h
UIView Start = 500x 0y 500w  1000h
UIView End   = 0x   0y 1000w 1000h

I have a UIView lets say covering the right side of the screen with the dimensions and coordinates above. Right now i know to get to the end point i have to do

CGRectMake(start.origin.x - 500, start.origin.y, start.size.width + 500, start.size.height)

Is it possible to just do something like

[uiview stretchLeftSide:500];

that way i do not need to touch the origin or width directly. it causes some issues as the view contains controls where i cannot manage there anchoring so they just jump to the specified location, then the view adjusts (this is all animated BTW).

Answer 1

As far as i know relocating & resizing a UIView this way - CGRectMake(start.origin.x - 500, start.origin.y, start.size.width + 500, start.size.height) is the way to do it.

It's ugly but that's what I used to do. But you could inherit UIView and add a method stretchLeftSide and implement what you want. In longer running projects this makes absolute sense and should be done as a practice...

Answer 2

First, I'm assuming your UIView (let's just call it view) is a subview of Screen (ie you did something like [Screen addSubview:view] ).

If you want to do the animation so the left side stretches the way you want, basically, all you have to do is set the origin of view to (0,0) and the size to be the same as Screen . For this, you can use Screen.bounds which is exactly what you want the final frame of view to be. The bounds property of a view will always have an origin of (0,0) and a size equal to the size of the view.

If you have a reference to Screen , you can use Screen.bounds as I mentioned above, but if you don't, and you know that view is a subView of Screen , then you can use view.superview.bounds .

Now the animation. Because I have to write apps that support iOS versions as old as 3.0, I can't use block animations. Instead, I use UIView class methods like this:

// Here you can enter an identifier to identify your animation
// and an object that will be passed to your delegate. 
// These 2 parameters are only useful if you set an animation delegate 
// using [UIView setAnimationDelegate:delegate];
[UIView beginAnimations:nil context:nil];  

// Duration in seconds    
[UIView setAnimationDuration:0.5];  

// Perform you changes here.
view.frame = view.superview.bounds;

// Commit the changes
[UIView commitAnimations];