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>

2 files changed, 160 insertions, 0 deletions

diff --git a/tests/auto/qquickpopup/data/disabledPalette.qml b/tests/auto/qquickpopup/data/disabledPalette.qml
new file mode 100644
index 00000000..f080f5e8
--- /dev/null
+++ b/tests/auto/qquickpopup/data/disabledPalette.qml
@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.12
+import QtQuick.Controls 2.12
+
+ApplicationWindow {
+    width: 400
+    height: 400
+
+    property alias popup: popup
+
+    function disableOverlay() {
+        popup.Overlay.overlay.enabled = false
+    }
+
+    Popup {
+        id: popup
+        width: 200
+        height: 200
+        background: Rectangle {
+            color: popup.palette.base
+        }
+    }
+}
diff --git a/tests/auto/qquickpopup/tst_qquickpopup.cpp b/tests/auto/qquickpopup/tst_qquickpopup.cpp
index 35d05244..81b2d583 100644
--- a/tests/auto/qquickpopup/tst_qquickpopup.cpp
+++ b/tests/auto/qquickpopup/tst_qquickpopup.cpp
@@ -86,6 +86,8 @@ private slots:
     void orientation_data();
     void orientation();
     void qquickview();
+    void disabledPalette();
+    void disabledParentPalette();
 };
 
 void tst_QQuickPopup::initTestCase()
@@ -1083,6 +1085,92 @@ void tst_QQuickPopup::qquickview()
     // QTBUG-72746: shouldn't crash on application exit after closing a Dialog when using QQuickView.
 }
 
+// TODO: also test it out without setting enabled directly on menu, but on a parent
+
+// QTBUG-73447
+void tst_QQuickPopup::disabledPalette()
+{
+    QQuickApplicationHelper helper(this, "disabledPalette.qml");
+
+    QQuickWindow *window = helper.window;
+    window->show();
+    QVERIFY(QTest::qWaitForWindowActive(window));
+
+    QQuickPopup *popup = window->property("popup").value<QQuickPopup*>();
+    QVERIFY(popup);
+
+    QSignalSpy popupEnabledSpy(popup, SIGNAL(enabledChanged()));
+    QVERIFY(popupEnabledSpy.isValid());
+    QSignalSpy popupPaletteSpy(popup, SIGNAL(paletteChanged()));
+    QVERIFY(popupPaletteSpy.isValid());
+
+    QSignalSpy popupItemEnabledSpy(popup->popupItem(), SIGNAL(enabledChanged()));
+    QVERIFY(popupItemEnabledSpy.isValid());
+    QSignalSpy popupItemPaletteSpy(popup->popupItem(), SIGNAL(paletteChanged()));
+    QVERIFY(popupItemPaletteSpy.isValid());
+
+    QPalette palette = popup->palette();
+    palette.setColor(QPalette::Active, QPalette::Base, Qt::green);
+    palette.setColor(QPalette::Disabled, QPalette::Base, Qt::red);
+    popup->setPalette(palette);
+    QCOMPARE(popupPaletteSpy.count(), 1);
+    QCOMPARE(popupItemPaletteSpy.count(), 1);
+    QCOMPARE(popup->background()->property("color").value<QColor>(), Qt::green);
+
+    popup->setEnabled(false);
+    QCOMPARE(popupEnabledSpy.count(), 1);
+    QCOMPARE(popupItemEnabledSpy.count(), 1);
+    QCOMPARE(popupPaletteSpy.count(), 2);
+    QCOMPARE(popupItemPaletteSpy.count(), 2);
+    QCOMPARE(popup->background()->property("color").value<QColor>(), Qt::red);
+}
+
+void tst_QQuickPopup::disabledParentPalette()
+{
+    QQuickApplicationHelper helper(this, "disabledPalette.qml");
+
+    QQuickWindow *window = helper.window;
+    window->show();
+    QVERIFY(QTest::qWaitForWindowActive(window));
+
+    QQuickPopup *popup = window->property("popup").value<QQuickPopup*>();
+    QVERIFY(popup);
+
+    QSignalSpy popupEnabledSpy(popup, SIGNAL(enabledChanged()));
+    QVERIFY(popupEnabledSpy.isValid());
+    QSignalSpy popupPaletteSpy(popup, SIGNAL(paletteChanged()));
+    QVERIFY(popupPaletteSpy.isValid());
+
+    QSignalSpy popupItemEnabledSpy(popup->popupItem(), SIGNAL(enabledChanged()));
+    QVERIFY(popupItemEnabledSpy.isValid());
+    QSignalSpy popupItemPaletteSpy(popup->popupItem(), SIGNAL(paletteChanged()));
+    QVERIFY(popupItemPaletteSpy.isValid());
+
+    QPalette palette = popup->palette();
+    palette.setColor(QPalette::Active, QPalette::Base, Qt::green);
+    palette.setColor(QPalette::Disabled, QPalette::Base, Qt::red);
+    popup->setPalette(palette);
+    QCOMPARE(popupPaletteSpy.count(), 1);
+    QCOMPARE(popupItemPaletteSpy.count(), 1);
+    QCOMPARE(popup->background()->property("color").value<QColor>(), Qt::green);
+
+    // Disable the overlay (which is QQuickPopupItem's parent) to ensure that
+    // the palette is changed when the popup is indirectly disabled.
+    popup->open();
+    QTRY_VERIFY(popup->isOpened());
+    QVERIFY(QMetaObject::invokeMethod(window, "disableOverlay"));
+    QVERIFY(!popup->isEnabled());
+    QVERIFY(!popup->popupItem()->isEnabled());
+    QCOMPARE(popup->background()->property("color").value<QColor>(), Qt::red);
+    QCOMPARE(popupEnabledSpy.count(), 1);
+    QCOMPARE(popupItemEnabledSpy.count(), 1);
+    QCOMPARE(popupPaletteSpy.count(), 2);
+    QCOMPARE(popupItemPaletteSpy.count(), 2);
+
+    popup->close();
+    QTRY_VERIFY(!popup->isVisible());
+}
+
 QTEST_QUICKCONTROLS_MAIN(tst_QQuickPopup)
 
 #include "tst_qquickpopup.moc"