Pull request #3959: CHART-18881 单元格图表有时候无法点出图表属性面板

Merge in DESIGN/design from ~HENRY.WANG/design:feature/10.0 to feature/10.0

* commit '0f1f2b8c7ee0c26e0e70d84c68ce84956dde6ae7':
  CHART-18881 单元格图表有时候无法点出图表属性面板

designer-chart/src/main/java/com/fr/design/mainframe/ChartPropertyPane.java

@@ -24,15 +24,9 @@ public class ChartPropertyPane extends BaseChartPropertyPane {
      * 创建图表属性表实例.
      */
     private synchronized static ChartPropertyPane getInstance() {
-        //创建新图表时，创建属性表配置面板
-        if (singleton == null) {
-            singleton = new ChartPropertyPane();
-        }
-        return singleton;
+        return new ChartPropertyPane();
     }
 
-    private static ChartPropertyPane singleton;
-
     protected TargetComponentContainer container = new TargetComponentContainer();
 
     protected ChartEditPane chartEditPane;
@@ -160,8 +154,4 @@ public class ChartPropertyPane extends BaseChartPropertyPane {
             chartEditPane.setSupportCellData(supportCellData);
         }
     }
-
-    public synchronized static void clear() {
-        singleton = null;
-    }
 }