Android 系统默认Launcher3 菜单模式双层改成单层-3

Android 系统默认自带Launcher3 
 

菜单都为双层模式

各手机大厂的Launcher的菜单模式都为单层

如何将launcher3的菜单模式改为单层模式

        mOverviewPanel = (ViewGroup) findViewById(R.id.overview_panel);
         mWidgetsButton = findViewById(R.id.widget_button);
         mWidgetsButton.setOnClickListener(new OnClickListener() {
diff --git a/packages/apps/Launcher3/src/com/android/launcher3/Workspace.java b/packages/apps/Launcher3/src/com/android/launcher3/Workspace.java
index 
--- a/packages/apps/Launcher3/src/com/android/launcher3/Workspace.java
+++ b/packages/apps/Launcher3/src/com/android/launcher3/Workspace.java
@@  @@ public class Workspace extends PagedView
 
             Runnable resizeRunnable = null;
             if (dropTargetLayout != null && !d.cancelled) {
+
+                if (LauncherAppState.is