Use case

I have a widget that shows a row of buttons and I want to apply an IconTheme to them for setting their size.

Currently, I have to set the size for each icon within each button individually, because the CupertinoButton widget overwrites any IconTheme provided above it in the tree.

Proposal

I'd like to propose that the build method in _CupertinoButtonState uses IconTheme.of(context).copyWith(color: foregroundColor) to set the theme instead of just IconTheme(color: foregroundColor).

This way, it sets the correct color but also incorporates any parent styles.