qquicktextinput: Clear pre-edit text after input method reset

The QPlatformInputContext::reset() function does not allow any further
input method events to be called. Therefore, clearing the pre-edit text
is the sole responsibility of the text input control.

This change modifies the QQuickTextInputPrivate::resetInputMethod()
function and calls QQuickTextInputPrivate::cancelPreedit() instead of
QInputMethod::reset() directly. The cancelPreedit() function will send
a QInputMethodEvent which clears the IM state (in addition of calling
QInputMethod::reset() function).

Also, rename the QQuickTextInputPrivate::resetInputMethod() function to
cancelInput, since it does not call inputMethod()->reset() directly.

Fixes: QTBUG-95461
Change-Id: I6ab3b9dbe71956af72656e2a25a05d79603b34ea
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Inho Lee <inho.lee@qt.io>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
Reviewed-by: Jarkko Koivikko <jarkko.koivikko@code-q.fi>
(cherry picked from commit b2103e33f490c96d0068d211c6f2d5b540ca407e)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

2 files changed, 8 insertions, 6 deletions

diff --git a/src/quick/items/qquicktextinput.cpp b/src/quick/items/qquicktextinput.cpp
index 4f3c7cb141..ba40e8d3c7 100644
--- a/src/quick/items/qquicktextinput.cpp
+++ b/src/quick/items/qquicktextinput.cpp
@@ -2104,7 +2104,7 @@ void QQuickTextInput::undo()
 {
     Q_D(QQuickTextInput);
     if (!d->m_readOnly) {
-        d->resetInputMethod();
+        d->cancelInput();
         d->internalUndo();
         d->finishChange(-1, true);
     }
@@ -2120,7 +2120,7 @@ void QQuickTextInput::redo()
 {
     Q_D(QQuickTextInput);
     if (!d->m_readOnly) {
-        d->resetInputMethod();
+        d->cancelInput();
         d->internalRedo();
         d->finishChange();
     }
@@ -2747,11 +2747,13 @@ void QQuickTextInputPrivate::init()
     m_inputControl = new QInputControl(QInputControl::LineEdit, q);
 }
 
-void QQuickTextInputPrivate::resetInputMethod()
+void QQuickTextInputPrivate::cancelInput()
 {
+#if QT_CONFIG(im)
     Q_Q(QQuickTextInput);
     if (!m_readOnly && q->hasActiveFocus() && qGuiApp)
-        QGuiApplication::inputMethod()->reset();
+        cancelPreedit();
+#endif // im
 }
 
 void QQuickTextInput::updateCursorRectangle(bool scroll)
@@ -4697,7 +4699,7 @@ void QQuickTextInput::ensureVisible(int position)
 void QQuickTextInput::clear()
 {
     Q_D(QQuickTextInput);
-    d->resetInputMethod();
+    d->cancelInput();
     d->clear();
 }
 
diff --git a/src/quick/items/qquicktextinput_p_p.h b/src/quick/items/qquicktextinput_p_p.h
index b4561556aa..1fecd7f9df 100644
--- a/src/quick/items/qquicktextinput_p_p.h
+++ b/src/quick/items/qquicktextinput_p_p.h
@@ -173,7 +173,7 @@ public:
     }
 
     void init();
-    void resetInputMethod();
+    void cancelInput();
     void startCreatingCursor();
     void ensureVisible(int position, int preeditCursor = 0, int preeditLength = 0);
     void updateHorizontalScroll();