fix: Disable dropping of already displayed plugin.

as title

Log: as title
Bug: https://pms.uniontech.com/bug-view-266651.html

Author: yixinshark

panels/dock/tray/package/TrayContainer.qml

@@ -142,7 +142,13 @@ Item {
         anchors.fill: parent
         keys: ["text/x-dde-shell-tray-dnd-surfaceId"]
         onEntered: function (dragEvent) {
-            console.log(dragEvent.getDataAsString("text/x-dde-shell-tray-dnd-surfaceId"))
+            let surfaceId = dragEvent.getDataAsString("text/x-dde-shell-tray-dnd-surfaceId")
+            console.log(surfaceId)
+            if (DDT.TraySortOrderModel.isDisplayedSurface(surfaceId)) {
+                dragEvent.accepted = false
+            } else {
+                dragEvent.accepted = true
+            }
         }
 
         onPositionChanged: function (dragEvent) {

panels/dock/tray/traysortordermodel.cpp

@@ -206,6 +206,11 @@ void TraySortOrderModel::setSurfaceVisible(const QString &surfaceId, bool visibl
     updateVisualIndexes();
 }
 
+bool TraySortOrderModel::isDisplayedSurface(const QString &surfaceId) const
+{
+    return !m_hiddenIds.contains(surfaceId);
+}
+
 QStandardItem *TraySortOrderModel::findItemByVisualIndex(int visualIndex, VisualSections visualSection) const
 {
     QStandardItem * result = nullptr;

panels/dock/tray/traysortordermodel.h

@@ -61,6 +61,7 @@ class TraySortOrderModel : public QStandardItemModel
     Q_INVOKABLE bool dropToStashTray(const QString & draggedSurfaceId, int dropVisualIndex, bool isBefore);
     Q_INVOKABLE bool dropToDockTray(const QString & draggedSurfaceId, int dropVisualIndex, bool isBefore);
     Q_INVOKABLE void setSurfaceVisible(const QString & surfaceId, bool visible);
+    Q_INVOKABLE bool isDisplayedSurface(const QString &surfaceId) const;
 
 signals:
     void collapsedChanged(bool);