Add gravity settings to PopupWindow/ListPopupWindow/PopupMenu

Allow calling code to specify left/right/start/end gravity when
showing a popup attached to an anchor. This allows easy alignment of
either the right or left edges of the popup and anchor view.

Bug 10728401

Change-Id: Ie0844a04ea0576fa67b0972f5873aaa4c5b823f6

core/java/com/android/internal/view/menu/ActionMenuPresenter.java

@@ -25,6 +25,7 @@ import android.transition.Transition;
 import android.transition.TransitionManager;
 import android.util.SparseBooleanArray;
 import android.view.ActionProvider;
+import android.view.Gravity;
 import android.view.MenuItem;
 import android.view.SoundEffectConstants;
 import android.view.View;
@@ -665,6 +666,7 @@ public class ActionMenuPresenter extends BaseMenuPresenter
         public OverflowPopup(Context context, MenuBuilder menu, View anchorView,
                 boolean overflowOnly) {
             super(context, menu, anchorView, overflowOnly);
+            setGravity(Gravity.END);
             setCallback(mPopupPresenterCallback);
         }
 

core/java/com/android/internal/view/menu/MenuPopupHelper.java

@@ -19,6 +19,7 @@ package com.android.internal.view.menu;
 import android.content.Context;
 import android.content.res.Resources;
 import android.os.Parcelable;
+import android.view.Gravity;
 import android.view.KeyEvent;
 import android.view.LayoutInflater;
 import android.view.MenuItem;
@@ -69,6 +70,8 @@ public class MenuPopupHelper implements AdapterView.OnItemClickListener, View.On
     /** Cached content width from {@link #measureContentWidth}. */
     private int mContentWidth;
 
+    private int mDropDownGravity = Gravity.NO_GRAVITY;
+
     public MenuPopupHelper(Context context, MenuBuilder menu) {
         this(context, menu, null, false);
     }
@@ -102,6 +105,10 @@ public class MenuPopupHelper implements AdapterView.OnItemClickListener, View.On
         mForceShowIcon = forceShow;
     }
 
+    public void setGravity(int gravity) {
+        mDropDownGravity = gravity;
+    }
+
     public void show() {
         if (!tryShow()) {
             throw new IllegalStateException("MenuPopupHelper cannot be used without an anchor");
@@ -126,6 +133,7 @@ public class MenuPopupHelper implements AdapterView.OnItemClickListener, View.On
             if (addGlobalListener) mTreeObserver.addOnGlobalLayoutListener(this);
             anchor.addOnAttachStateChangeListener(this);
             mPopup.setAnchorView(anchor);
+            mPopup.setDropDownGravity(mDropDownGravity);
         } else {
             return false;
         }