Animate size of View keeping its bottom left point fixed - ios

Question

I have a UIView at the bottom left of its superview, i.e.its frame is like
[myView setFrame:CGRectMake(0,superView.bounds.size.height-myViewHeight,myViewWidth,myViewHeight)];
I want to animate its size such that its bottom left point remains fixed at its position. I am not sure how to play with anchor point property of layers.
Currently I am increasing its size using the following lines of code.
[UIView animateWithDuration:0.2 animations:^{
[bottomLbl setFrame:CGRectMake(0, bottomView.bounds.size.height-250, 300, 250)];
This works fine but when I try to bring back to its original size, its bottom point gets lifted at the start of animation and settles down at the end of animation.

Answer 1

First define the point for the bottom left corner...
CGPoint bottomLeft = CGPointMake(0, 480); // this can be anything.
Then you need to define the sizes (big and small).
CGSize bigSize = CGSizeMake(280, 280);
CGSize smallSize = CGSizeMake(50, 50); // again, these can be anything.
Then animate them...
// create the rect for the frame
CGRect bigFrame = CGRectMake(bottomLeft.x, bottomLeft.y - bigSize.height, bigSize.width, bigSize.height);
CGRect smallFrame = CGRectMake(bottomLeft.x, bottomLeft.y - smallSize.height, smallSize.width, smallSize.height);
[UIView animateWithDuration:0.2
animations:^{
// set the rect onto the view
bottomLbl.frame = bigFrame;
// or
bottomLbl.frame = smallFrame;
}];
As long as you set the frame and the calculated end frames are correct and it's all done in one animation then the bottom left corner won't move.
If this doesn't help can you please post a video of what is happening (and all your animation code).
EDIT
[UIView animateWithDuration:0.2
delay:0.0
options:UIViewAnimationOptionBeginFromCurrentState
animations:^{
// set the rect onto the view
bottomLbl.frame = bigFrame;
// or
bottomLbl.frame = smallFrame;
}
completion:nil];