CODEWITHSUNDEEP
iphoneioscocoa-touch
jcb344
jcb344

Reputation: 323

Scaling a sub classed UIView

I have created a subclass of UIView and am trying to scale and move the view from within its m file but am running into some problems. When I used the command: self.frame = CGRectMake(self.frame.origin.x-10,self.frame.origin.y-10,self.frame.size.width/2,self.frame.size.height/2); the object moves location but does not resize (the view only contains a few UIImageViews). In the xib file of the sub class I have the options checked to Clip Subviews and to Autoresize Subviews but neither appears to happen. Any ideas as to why the view will not resize with this command and how I could get it to resize.

Upvotes: 0

Views: 729

Answers (1)

fzwo
fzwo

Reputation: 9902

Resizing your view is not the same as scaling it. Think of your view as a picture frame. What you're doing above is moving the frame, and also moving the lower right corner (you're shortening the frame's wood bars) - but that does not automatically shrink the picture.

There are four ways of resizing a view with subviews:

  1. Let the superview clips its subviews (by setting view.clipsToBounds = YES): Subviews do not resize or relayout, but only show in the area that is inside the frame.
  2. Let the superview not clip its subviews (by setting view.clipsToBounds = NO): Changing superview size does not have any visual effect on subviews, they also show outside of the frame.
  3. Give the subviews autoresizingMasks: The subviews do not change size, but they relayout according to their autoresizing mask (for instance, a subview may always stay 10 px off the lower right corner of the frame, or may always span exactly the width of the frame.) Note that this does not necessarily automatically scale subview content. Set subview.contentMode accordingly.
  4. Scale the superview: By setting superview.transform = CGAffineTransformScale(superview.transform, 0.5, 0.5), you shrink the superview and all its subviews (you essentially zoom out). Note that this makes superview.frame undefined, which means you shouldn't use that anymore. It can also make things a bit blurry.

You could also "manually" change all the subviews, but that kind of defeats the purpose of having a nice view hierarchy.

As MishieMoo said, temporarily set the backgroundColor of your superview to something visible. This will very likely show you that your view is indeed changing.

Upvotes: 1

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