QWidgetTextControl: Suppress drag selection for OS-synthesized mouse events.

Add a convenience function to QApplicationPrivate returning
the source of mouse events to be able to detect synthesized
mouse events.

Change-Id: I09f82ed917586cd3de8b4146fc6638d19d428163
Task-number: QTBUG-40461
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/src/widgets/widgets/qwidgettextcontrol.cpp b/src/widgets/widgets/qwidgettextcontrol.cpp
index dfec6a14d4..8f017b7b87 100644
--- a/src/widgets/widgets/qwidgettextcontrol.cpp
+++ b/src/widgets/widgets/qwidgettextcontrol.cpp
@@ -1580,8 +1580,10 @@ void QWidgetTextControlPrivate::mousePressEvent(QEvent *e, Qt::MouseButton butto
             cursor.clearSelection();
         }
     }
+    // Do not start selection on a mouse event synthesized from a touch event.
     if (!(button & Qt::LeftButton) ||
-        !((interactionFlags & Qt::TextSelectableByMouse) || (interactionFlags & Qt::TextEditable))) {
+        !((interactionFlags & Qt::TextSelectableByMouse) || (interactionFlags & Qt::TextEditable))
+        || QApplicationPrivate::mouseEventSource(e) != Qt::MouseEventNotSynthesized) {
             e->ignore();
             return;
     }
@@ -1752,6 +1754,11 @@ void QWidgetTextControlPrivate::mouseReleaseEvent(QEvent *e, Qt::MouseButton but
 {
     Q_Q(QWidgetTextControl);
 
+    if (QApplicationPrivate::mouseEventSource(e) != Qt::MouseEventNotSynthesized) {
+        setCursorPosition(pos); // Emulate Tap to set cursor for events synthesized from touch.
+        return;
+    }
+
     const QTextCursor oldSelection = cursor;
     if (sendMouseEventToInputContext(
             e, QEvent::MouseButtonRelease, button, pos, modifiers, buttons, globalPos)) {