fix: prevent dragging items to fixed plugin section

Added validation to prevent drag and drop operations from targeting
fixed plugin sections in the system tray. The changes include:
1. Implemented isForbiddenDropTarget function to check if drop target is
a fixed section
2. Added drag event rejection when attempting to drop on fixed sections
3. Marked quick settings toggle as fixed section in the model
4. This prevents users from accidentally moving or reordering critical
system components

fix: 防止拖拽项目到固定插件区域

添加验证以防止拖放操作目标为系统托盘中的固定插件区域。更改包括：
1. 实现 isForbiddenDropTarget 函数检查拖放目标是否为固定区域
2. 在尝试拖放到固定区域时添加拖放事件拒绝
3. 在模型中标记快速设置切换为固定区域
4. 防止用户意外移动或重新排列关键系统组件

Pms: BUG-289447 BUG-289445

Author: wjyrich

panels/dock/tray/package/TrayContainer.qml

@@ -145,6 +145,7 @@ Item {
         property bool dragExited: false
         property string source: ""
         property string surfaceId: ""
+
         onEntered: function (dragEvent) {
             dragExited = false
             isDropped = false
@@ -161,11 +162,19 @@ Item {
         onPositionChanged: function (dragEvent) {
             let surfaceId = dragEvent.getDataAsString("text/x-dde-shell-tray-dnd-surfaceId")
             let pos = root.isHorizontal ? drag.x : drag.y
-            let currentItemIndex = pos / (root.itemVisualSize + root.itemSpacing)
-            let currentPosMapToItem = pos % (root.itemVisualSize + root.itemSpacing)
-            let isBefore = currentPosMapToItem < root.itemVisualSize / 2
-            dropHoverIndex = Math.floor(currentItemIndex)
+            let dropIdx = DDT.TrayItemPositionManager.itemIndexByPoint(Qt.point(drag.x, drag.y))
+            let currentItemIndex = dropIdx.index
+            let isBefore = dropIdx.isBefore            
             let isStash = dragEvent.getDataAsString("text/x-dde-shell-tray-dnd-sectionType") === "stashed"
+            dropHoverIndex = dropIdx.index
+            
+            // 检查当前悬停位置是否是禁止拖拽的插件
+            let modelIndex = DDT.TraySortOrderModel.getModelIndexByVisualIndex(currentItemIndex)
+            let sectionType =root.model.data(modelIndex, DDT.TraySortOrderModel.SectionTypeRole)
+            if (sectionType === "fixed") {
+                dragEvent.accepted = false
+                return
+            }
 
             // 检查 ActionShowStashDelegate 是否显示
             let showStashActionVisible = false

panels/dock/tray/traysortordermodel.cpp

@@ -10,6 +10,7 @@
 #include <QDBusConnection>
 
 #include <DConfig>
+#include <qabstractitemmodel.h>
 
 namespace docktray {
 
@@ -428,6 +429,7 @@ void TraySortOrderModel::updateVisualIndexes()
     // "internal/action-toggle-quick-settings"
     results = findItems("internal/action-toggle-quick-settings");
     Q_ASSERT(!results.isEmpty());
+    results[0]->setData(SECTION_FIXED, TraySortOrderModel::SectionTypeRole);
     results[0]->setData(currentVisualIndex, TraySortOrderModel::VisualIndexRole);
     currentVisualIndex++;
 
@@ -551,4 +553,18 @@ void TraySortOrderModel::handlePluginVisibleChanged(const QString &surfaceId, bo
     }
 }
 
+QModelIndex TraySortOrderModel::getModelIndexByVisualIndex(int visualIndex) const
+{
+    for (int i = 0; i < rowCount(); i++) {
+        QModelIndex index = this->index(i, 0);
+        int itemVisualIndex = data(index, VisualIndexRole).toInt();
+        bool visibility = data(index, VisibilityRole).toBool();
+        
+        if (visibility && itemVisualIndex == visualIndex) {
+            return index;
+        }
+    }
+    return QModelIndex();
+}
+
 }

panels/dock/tray/traysortordermodel.h

@@ -63,6 +63,7 @@ class TraySortOrderModel : public QStandardItemModel
     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;
+    Q_INVOKABLE QModelIndex getModelIndexByVisualIndex(int visualIndex) const;
 
 signals:
     void collapsedChanged(bool);