Commit the done-so-far IME composition on mouse click.

Before this change, it was possible to select parts of the pre-edit
text in an ongoing IME composition, by click-dragging with the mouse
(which also looked wrong, because the styling of the text did not
change to a selection box to signal selection).

This is inconsistent with how Chrome does it, which commits the
pre-edit string entered so far, when clicking anywhere in the content
area or in the input.

This change makes sure to commit the pre-edit string when a mouse
click is done anywhere on the displayed web page.
The behavior was present on Windows and Linux.

Change-Id: I9cb148c591b5d09fb4dd477ae96c29ca32cc34de
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/core/render_widget_host_view_qt.cpp b/src/core/render_widget_host_view_qt.cpp
index bb024c557..ef7367e06 100644
--- a/src/core/render_widget_host_view_qt.cpp
+++ b/src/core/render_widget_host_view_qt.cpp
@@ -954,6 +954,19 @@ void RenderWidgetHostViewQt::handleMouseEvent(QMouseEvent* event)
         QCursor::setPos(m_lockedMousePosition);
     }
 
+    if (m_imeInProgress && event->type() == QMouseEvent::MouseButtonPress) {
+        m_imeInProgress = false;
+        // Tell input method to commit the pre-edit string entered so far, and finish the
+        // composition operation.
+#ifdef Q_OS_WIN
+        // Yes the function name is counter-intuitive, but commit isn't actually implemented
+        // by the Windows QPA, and reset does exactly what is necessary in this case.
+        qApp->inputMethod()->reset();
+#else
+        qApp->inputMethod()->commit();
+#endif
+    }
+
     m_host->ForwardMouseEvent(webEvent);
 }