We follow the approach of [NSTextView mouseDown:] by bailing out if the
input context handled the event, and otherwise passing it along to the
input item.
This allows moving the cursor with a single click in the input item,
which will also commit the current preedit string as is, depending on
the input context.
For some reason 2-Set Korean input results in plain insertText calls
for each step of the composition with an NSTextView, while we get
marked text. The result is that when composing with 2-Set Korean,
a native NSTextView will only require a single click to move the
cursor, while for us it requires two, since the input context says
it handled the event.
We opt to follow the behavior of NSTextView to bail out if the
input context handled the event, instead of trying to emulate
the observed behavior for 2-Set Korean by always passing the
mouse event on, as the former seems like a safer approach.
This is also in line with the recommendations from Apple:
https://lists.apple.com/archives/cocoa-dev/2012/May/msg00539.html
Pick-to: 6.2
Change-Id: I372ac62ee3b8b20531cd7cfa2d412a5efea3eb68
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
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