Samsung's Korean keyboard has a bug where it always attempts to combine
characters based on its internal state, ignoring if and when the cursor
is moved programmatically. EG typing "ㄴㅇ" and then moving the cursor
back to the front of the text and typing "ㄴ" again would result in
"ㄴㅇㄴ", not "ㄴㄴㅇ".
Fully restarting the IMM works around this because it flushes the
keyboard's internal state and stops it from trying to incorrectly
combine characters. However this also has some negative performance
implications, so we only apply the workaround on Samsung devices set
to use Korean input.
This also effectively disables the feature on Samsung keyboards that
allowed users to re-open a composing region for previously typed
characters. See https://github.com/flutter/flutter/issues/29341#issuecomment-531283508.
Fixesflutter/flutter#29341.
#9203 broke the keyboard_resize integration test(see more details in flutter/flutter#34085 (comment)).
This re-lands @9203 and fixes the issue the integration test uncovered by always allowing to hide the keyboard.
The difference from the original change is 07d2598
Generally what this PR is doing is setting up a delegation mechanism
for Android's onCreateInputConnection.
It works by letting the framework know when an embedded view gets loses
focus(within the virtual display), the framework maintains a focus node
for each Android view that is kept in sync with the focus state of the
embedded view.
The TextInputPlugin is extended to allow for 2 type of text clients a
"framework client"(what we had before) and a "platform view client".
When the AndroidView's focus node in the framework is focused the
framework sets a "platform view text client" for the TextInputPlugin,
which will result in the TextInputPlugin delegating
createInputConnection to the platform view.
When a platform view is resized, we are detaching it from a virtual
display and attaching it to a new one, as a side affect a platform view
might lose an active input connection, to workaround that we "lock" the
connection when resizing(by caching it and forcing the cached copy until
the resize is done).
Additional things worth calling out in this PR:
To properly answer which views are allowed for input connection
proxying we compare a candidate view's root view to the set of root
views of all virtual displays.
We also preserve a view's focus state across resizes.
Note that this PR only wires text for the io.flutter.view.FlutterView
For the new Android embedding some additional plumbing is necessary.
Corresponding framework PR: flutter/flutter#33901flutter/flutter#19718
Gary Qian
Dan Field
Justin McCandless
Jason Simmons
Michael Klimushyn
Matt Carroll
Amir Hardon
Jonah Williams
Chris Bracken