fix: the opacity of preview window isn't changed

the opacity isn't changed by changing the settings in dcc
Add the slot to the signal that opacity changes in dcc

Log:
Bug: https://pms.uniontech.com/bug-view-273041.html

panels/dock/taskmanager/x11preview.cpp

@@ -391,6 +391,12 @@ class AppItemWindowDeletegate : public QAbstractItemDelegate
 
 };
 
+const QString AppearanceService = QStringLiteral("org.deepin.dde.Appearance1");
+const QString AppearancePath = QStringLiteral("/org/deepin/dde/Appearance1");
+const QString PropertiesInterface = QStringLiteral("org.freedesktop.DBus.Properties");
+const QString PropertiesChanged = QStringLiteral("PropertiesChanged");
+const QString OpacityStr = QStringLiteral("Opacity");
+
 X11WindowPreviewContainer::X11WindowPreviewContainer(X11WindowMonitor* monitor, QWidget *parent)
     : DBlurEffectWidget(parent)
     , m_direction(0)
@@ -407,6 +413,8 @@ X11WindowPreviewContainer::X11WindowPreviewContainer(X11WindowMonitor* monitor,
     setMouseTracking(true);
     initUI();
 
+    QDBusConnection::sessionBus().connect(AppearanceService, AppearancePath, PropertiesInterface, PropertiesChanged, this, SLOT(onPropertiesChanged(QDBusMessage)));
+
     connect(m_hideTimer, &QTimer::timeout, this, &X11WindowPreviewContainer::callHide);
 
     connect(m_closeAllButton, &DIconButton::clicked, this, [this](){
@@ -428,6 +436,17 @@ X11WindowPreviewContainer::X11WindowPreviewContainer(X11WindowMonitor* monitor,
 
 }
 
+void X11WindowPreviewContainer::onPropertiesChanged(const QDBusMessage &message)
+{
+    QVariantMap changedProps = qdbus_cast<QVariantMap>(message.arguments().at(1).value<QDBusArgument>());
+    for (QVariantMap::const_iterator it = changedProps.cbegin(); it != changedProps.cend(); ++it) {
+        if (it.key().toLatin1() == OpacityStr) {
+            setMaskAlpha(it.value().toFloat() * 255);
+            return;
+        }
+    }
+}
+
 void X11WindowPreviewContainer::showPreview(const QPointer<AppItem> &item, const QPointer<QWindow> &window, int32_t previewXoffset, int32_t previewYoffset, uint32_t direction)
 {
     if (!m_previewItem.isNull()) {

panels/dock/taskmanager/x11preview.h

@@ -17,6 +17,7 @@
 #include <DBlurEffectWidget>
 #include <DGuiApplicationHelper>
 #include <DIconButton>
+#include <QDBusMessage>
 
 DWIDGET_USE_NAMESPACE
 
@@ -89,6 +90,7 @@ public Q_SLOTS:
 private Q_SLOTS:
     void updateOrientation();
     void callHide();
+    void onPropertiesChanged(const QDBusMessage &message);
 
 private:
     bool m_isPreviewEntered;