In my application I'm using a custom toolbar (just another UIView) at the top of the screen; it sits above a UITextView. I'm using auto layout.
Because I'm using this custom toolbar - I'm doing the following to make the UITextView look correct with respect to margins and scroll indicators:
// the height of the custom toolbar is 55
_textView.textContainerInset = UIEdgeInsetsMake(68, 5, 8, 5);
_textView.scrollIndicatorInsets = UIEdgeInsetsMake(54, 0, 0, 0);
When the keyboard is showing, I remove the toolbar. When the keyboard is dismissed, I show the toolbar. I animate the change of the toolbar's position, like this:
- (void)animateTopToolbarOn
{
[self.view removeConstraints:_topToolbarOffScreenVerticalConstraints];
[self.view addConstraints:_topToolbarOnScreenVerticalConstraints];
[UIView animateWithDuration:0.6 animations:^{
[self.view layoutIfNeeded];
}];
// this is the bit I need to get right:
_textView.textContainerInset = UIEdgeInsetsMake(68, 5, 8, 5);
_textView.scrollIndicatorInsets = UIEdgeInsetsMake(54, 0, 0, 0);
}
- (void)animateTopToolbarOff
{
[self.view removeConstraints:_topToolbarOnScreenVerticalConstraints];
[self.view addConstraints:_topToolbarOffScreenVerticalConstraints];
[UIView animateWithDuration:0.6 animations:^{
[self.view layoutIfNeeded];
}];
// this is the bit I need to get right:
_textView.textContainerInset = UIEdgeInsetsMake(8, 5, 8, 5);
_textView.scrollIndicatorInsets = UIEdgeInsetsMake(0, 0, 0, 0);
}
// For reference:
id topGuide = self.topLayoutGuide;
_topToolbarOffScreenVerticalConstraints = [NSLayoutConstraint
constraintsWithVisualFormat:@"V:[_topToolbar][topGuide]"
options:0
metrics:nil
views:views];
_topToolbarOnScreenVerticalConstraints = [NSLayoutConstraint
constraintsWithVisualFormat:@"V:[topGuide][_topToolbar]"
options:0
metrics:nil
views:views];
The animation of the toolbar's position / constraints, works fine, as you'd expect.
The problem is changing the values of the textContainerInset.
Note: I know that I could put the change in the completion block of the animation. Whilst it makes a difference to how it looks/feels, the problem remains, the change to the top margin occurs instantly, so it appears as a jump. It's jarring.
I could anchor the top constraint of the UITextView to the bottom constraint of the toolbar; then I wouldn't need to change either the textContainerInset values or the scrollIndicatorInsets. However, if I do that, the text won't scroll underneath the toolbar. I want to avoid this fallback position, if possible.
Any ideas?
I don't think the values of the textContainerInset can be animated? It doesn't match with the animatable UIView properties...
How can I achieve this setup using a plain UIView acting as a custom toolbar, which animates on and off the screen, to which the margins of the UITextView respond to?
