Fix pre-edit text on shadow input when reselecting the first word

The shadow input control did not receive pre-edit text when the first
word was reselected. In this case, the text is transferred from the
input field to pre-edit field.

Analysis shows that QInputMethodEvent::Selection cannot be used
together when complete text buffer is replaced. This is because of
quirks found in QQuickTextInput's processInputMethodEvent.

Fix by handling text replacement and selection as separate events.

Pick-to: 6.5 6.4
Change-Id: I2f730a491685e55ff28a98a4929a1cd1b5bf0e6a
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Inho Lee <inho.lee@qt.io>

1 files changed, 11 insertions, 5 deletions

diff --git a/src/virtualkeyboard/shadowinputcontext.cpp b/src/virtualkeyboard/shadowinputcontext.cpp
index 72c0c90f..808cb8b0 100644
--- a/src/virtualkeyboard/shadowinputcontext.cpp
+++ b/src/virtualkeyboard/shadowinputcontext.cpp
@@ -176,22 +176,28 @@ void ShadowInputContext::update(Qt::InputMethodQueries queries)
     const int newCursorPosition = d->inputContext->cursorPosition();
     const int newAnchorPosition = d->inputContext->anchorPosition();
 
+    const QString newPreeditText = d->inputContext->preeditText();
+    const QList<QInputMethodEvent::Attribute> newPreeditAttributes = d->inputContext->preeditTextAttributes();
+
     bool updateSurroundingText = newSurroundingText != surroundingText;
     bool updateSelection = newCursorPosition != cursorPosition || newAnchorPosition != anchorPosition;
+    if (updateSurroundingText) {
+        QInputMethodEvent inputEvent;
+        inputEvent.setCommitString(newSurroundingText, -cursorPosition, surroundingText.size());
+        QGuiApplication::sendEvent(d->inputItem, &inputEvent);
+    }
+
     if (updateSurroundingText || updateSelection) {
         QList<QInputMethodEvent::Attribute> attributes;
         attributes.append(QInputMethodEvent::Attribute(QInputMethodEvent::Selection,
                                                        newAnchorPosition,
                                                        newCursorPosition - newAnchorPosition, QVariant()));
         QInputMethodEvent inputEvent(QString(), attributes);
-        if (updateSurroundingText)
-            inputEvent.setCommitString(newSurroundingText, -cursorPosition, surroundingText.size());
         QGuiApplication::sendEvent(d->inputItem, &inputEvent);
     }
 
-    const QString newPreeditText = d->inputContext->preeditText();
-    const QList<QInputMethodEvent::Attribute> newPreeditAttributes = d->inputContext->preeditTextAttributes();
-    if (d->preeditText != newPreeditText || d->preeditTextAttributes != newPreeditAttributes) {
+    const bool forcePreeditText = !newPreeditText.isEmpty() && (updateSurroundingText || updateSelection);
+    if (forcePreeditText || d->preeditText != newPreeditText || d->preeditTextAttributes != newPreeditAttributes) {
         d->preeditText = newPreeditText;
         d->preeditTextAttributes = newPreeditAttributes;
         QInputMethodEvent inputEvent(d->preeditText, d->preeditTextAttributes);