QColorDialog: Ignore mouse move events when no mouse button is pressed

mouseMoveEvent overrides in QColorLuminancePicker and QColorPicker
have triggered value changes unconditionally. This happened under the
assumption that the widget attribute WA_Hover is not set (which is the
default behavior). In that case, mouseMoveEvents are only delivered if
a button is pressed.

If WA_Hover is set - e.g. by applying a style sheet - mouseMoveEvents
get delivered also when no button is pressed. This leads to faulty
behavior: The color and the luminance change, whenever the mouse is
moved into the respective widget. Color/luminance are changed to the
value representing the edge on which the mouse has left the area.

This patch changes both mouseMoveEvent overrides. They return early
to avoid hovering changing the colors of the luminance/color picker,
but ignore() the event in case anything behind the picker needs hover.

Since this is a purely graphical effect, an autotest was not added.

Fixes: QTBUG-115516
Pick-to: 6.6 6.5 6.2 5.15
Change-Id: I000d113a1c81c46799cbb5197bf9acb3849e7d3b
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/widgets/dialogs/qcolordialog.cpp b/src/widgets/dialogs/qcolordialog.cpp
index 69358b7484..8b3fb28c7d 100644
--- a/src/widgets/dialogs/qcolordialog.cpp
+++ b/src/widgets/dialogs/qcolordialog.cpp
@@ -780,6 +780,10 @@ QColorLuminancePicker::~QColorLuminancePicker()
 
 void QColorLuminancePicker::mouseMoveEvent(QMouseEvent *m)
 {
+    if (m->buttons() == Qt::NoButton) {
+        m->ignore();
+        return;
+    }
     setVal(y2val(m->position().toPoint().y()));
 }
 void QColorLuminancePicker::mousePressEvent(QMouseEvent *m)
@@ -914,6 +918,10 @@ void QColorPicker::setCol(int h, int s)
 void QColorPicker::mouseMoveEvent(QMouseEvent *m)
 {
     QPoint p = m->position().toPoint() - contentsRect().topLeft();
+    if (m->buttons() == Qt::NoButton) {
+        m->ignore();
+        return;
+    }
     setCol(p);
     emit newCol(hue, sat);
 }