Popup: ensure that "palette" is reevaluated when enabled state changes

When changing the enabled state of a Menu after component completion,
the background would not change. The problem was that
QQuickPopup::paletteChanged() was not being emitted when the enabled
state changed, resulting in QQuickControl::palette() (which
QQuickPopup::palette() forwards calls to via its popupItem) not
being called. QQuickControl::palette() changes the palette's current
color group to QPalette::Disabled when it is disabled, so if it's not
called, the popup's colors won't change.

Fix the issue by adding a virtual enabledChange() function to
QQuickControl, which QQuickPopupItem can override to emit both
QQuickPopup::enabledChanged() (saving a connection in the process)
and QQuickPopup::paletteChanged(). This ensures that bindings to
QQuickPopup::palette are re-evaluated.

The patch adds a virtual instead of just emitting paletteChanged()
in QQuickPopup::setEnabled(), because we also want to be notified
of indirect enabled state changes, such as those coming from
parent items.

Change-Id: Ibdbd05f27b5a74fe731bda9d6698cbf6b8f81785
Fixes: QTBUG-73447
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/quicktemplates2/qquickcontrol.cpp b/src/quicktemplates2/qquickcontrol.cpp
index 1fa70662..a61df3ca 100644
--- a/src/quicktemplates2/qquickcontrol.cpp
+++ b/src/quicktemplates2/qquickcontrol.cpp
@@ -943,6 +943,7 @@ void QQuickControl::itemChange(QQuickItem::ItemChange change, const QQuickItem::
     switch (change) {
     case ItemEnabledHasChanged:
         emit paletteChanged();
+        enabledChange();
         break;
     case ItemVisibleHasChanged:
 #if QT_CONFIG(quicktemplates2_hover)
@@ -2184,6 +2185,10 @@ void QQuickControl::geometryChanged(const QRectF &newGeometry, const QRectF &old
         emit availableHeightChanged();
 }
 
+void QQuickControl::enabledChange()
+{
+}
+
 void QQuickControl::fontChange(const QFont &newFont, const QFont &oldFont)
 {
     Q_UNUSED(newFont);