Question

I would like to make a generic class that when tapped, makes the element grayish.

Facebook’s app is the perfect example of what I want to achieve. All their links and images become gray when tapped.

I can only guess that they are subclassing UIButton.

I have made my button’s style UIButtonTypeCustom to get rid of the rounded border. Beyond this, I don’t know how to have the gray overlay because I see no such property in the documentation.

Answer 1

Its simple:

#define TAG_GRAYVIEW 5671263 // some random number

// add the gray overlay
UIView *grayView = [[UIView alloc] initWithFrame:button.bounds];
grayView.backgroundColor = [UIColor grayColor];
grayView.tag = TAG_GRAYVIEW; 

[button addSubview:grayView];

// remove the gray overlay
UIView *grayView = [button viewWithTag:TAG_GRAYVIEW];
[grayView removeFromSuperview];