Bug when enabling/disabling container components

[jhickman]

When using a container such as a ButtonsGroup, the DisableUtil is used to query FOCUSABLE_ELEMENTS children and disable/enable.

However, if disabling the container component multiple times, it puts the children in a state where they have to be enabled twice before they actually enable.

Scenario:
ButtonsGroup containing 2 buttons

• call .disable() on the group. call enable() on the group. All is fine
• call .disable() on the group. call disable() on the group again. call enable() on the group; buttons are not enabled. call enable() again on the group and then the buttons are enabled

This behavior is due to the logic in the DisableUtil.disableChild method. Calling disable on a parent will double disable the children. On the first time disabling, it adds the “disabled” attribute and "disabled" css class to the children. The second time, if child.isDisabled() it adds the dui-disabled attribute.

When enabling, it sees the dui-disabled attribute and removes it; but doesn’t remove the ‘disabled’ attribute and ‘disabled’ css class.

For a workaround, I'm having to double up on my enable/disable calls on the parent container component. This ensures that the children disable state is handled correctly.

buttonsGroup.setDisabled(disabled);
buttonsGroup.setDisabled(disabled);