Support text-input-unstable-v4-wip

This feature can be enabled by -feature-wayland-text-input-v4-wip.
It is disabled by default.

TextInputManagerV4 is available in a compositor.
zwp_text_input_v4 is available for QT_WAYLAND_TEXT_INPUT_PROTOCOL in
a client
It supports Hangul(Korean) with a qtvirtualkeyboard patchset
(refs/changes/02/357902/3)
It includes some workarounds for ibus because each ibus module has its own
policy for focus-in/focus-out.
enter/leave will synchronize with enable/disable and they will happen
whenever focus-in/focus-out happen.
Cursor/anchor positions are byte offsets.
Surrounding text will be trimmed when it is over 4000 byte.

For debugging,
uses "qt.waylandcompositor.textinput" in a compositor side
uses "qt.qpa.wayland.textinput" in a client side

Tested on qtvirtualkeyboard and ibus

TODO :
 * QTBUG-97248 - event:preedit_commit_mode is not implemented yet. Current
    preedit_commit_mode is 'commit'.
 * request:set_text_change_cause is not implemented.

Task-number: QTBUG-94327
Change-Id: I72644893f40f30c4b03cd6a7d05483d12bde1070
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

1 files changed, 5 insertions, 1 deletions

diff --git a/src/client/qwaylandinputcontext.cpp b/src/client/qwaylandinputcontext.cpp
index 9ac1c3df6..c59485277 100644
--- a/src/client/qwaylandinputcontext.cpp
+++ b/src/client/qwaylandinputcontext.cpp
@@ -70,7 +70,11 @@ QWaylandInputContext::~QWaylandInputContext()
 
 bool QWaylandInputContext::isValid() const
 {
-    return mDisplay->textInputManager() != nullptr;
+#if QT_WAYLAND_TEXT_INPUT_V4_WIP
+    return mDisplay->textInputManagerv2() != nullptr || mDisplay->textInputManagerv4() != nullptr;
+#else //  QT_WAYLAND_TEXT_INPUT_V4_WIP
+    return mDisplay->textInputManagerv2() != nullptr;
+#endif // QT_WAYLAND_TEXT_INPUT_V4_WIP
 }
 
 void QWaylandInputContext::reset()