@IntDef cleanup in browser/java/appmenu

@IntDef/@StringDef annotation are preferred way for declaring
set of String/int values:

1. they need less space in APK than enum, see
https://developer.android.com/topic/performance/reduce-apk-size#remove-enums
2. they give more control over allowed values than "static final" values

Main goal of patch is writing "static final" values, enum
and some classes in one common @IntDef/@StringDef form:

1. with @IntDef/@StringDef first, @Retention second
   and related @interface third
2. with values inside @interface
3. with NUM_ENTRIES declaring number of entries if necessary
4. with comment about numbering from 0 without gaps when necessary
5. with @Retention(RetentionPolicy.SOURCE)
6. without "static final" in the @interface

Additionally there are done some other trivial cleanups.

Change-Id: Ie6b59c0f1a8ec6fe50d3177619f0768798f97508
Reviewed-on: https://chromium-review.googlesource.com/1128092
Commit-Queue: Marcin Wiącek <marcin@mwiacek.com>
Commit-Queue: Theresa <twellington@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574382}

chrome/android/java/src/org/chromium/chrome/browser/appmenu/AppMenuAdapter.java

@@ -9,6 +9,7 @@ import android.animation.AnimatorListenerAdapter;
 import android.animation.AnimatorSet;
 import android.animation.ObjectAnimator;
 import android.graphics.drawable.Drawable;
+import android.support.annotation.IntDef;
 import android.support.v7.content.res.AppCompatResources;
 import android.text.TextUtils;
 import android.view.LayoutInflater;
@@ -27,6 +28,8 @@ import org.chromium.chrome.browser.widget.ViewHighlighter;
 import org.chromium.ui.base.LocalizationUtils;
 import org.chromium.ui.interpolators.BakedBezierInterpolator;
 
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
 import java.util.List;
 
 /**
@@ -41,41 +44,41 @@ import java.util.List;
  * 3) Hope that the icon row still fits on small phones.
  */
 class AppMenuAdapter extends BaseAdapter {
-    /**
-     * Regular Android menu item that contains a title and an icon if icon is specified.
-     */
-    private static final int STANDARD_MENU_ITEM = 0;
-
-    /**
-     * Menu item that has two buttons, the first one is a title and the second one is an icon.
-     * It is different from the regular menu item because it contains two separate buttons.
-     */
-    private static final int TITLE_BUTTON_MENU_ITEM = 1;
-
-    /**
-     * Menu item that has three buttons. Every one of these buttons is displayed as an icon.
-     */
-    private static final int THREE_BUTTON_MENU_ITEM = 2;
-
-    /**
-     * Menu item that has four buttons. Every one of these buttons is displayed as an icon.
-     */
-    private static final int FOUR_BUTTON_MENU_ITEM = 3;
-
-    /**
-     * Menu item that has five buttons. Every one of these buttons is displayed as an icon.
-     */
-    private static final int FIVE_BUTTON_MENU_ITEM = 4;
-
-    /**
-     * Menu item for updating Chrome; uses a custom layout.
-     */
-    private static final int UPDATE_MENU_ITEM = 5;
-
-    /**
-     * The number of view types specified above.  If you add a view type you MUST increment this.
-     */
-    private static final int VIEW_TYPE_COUNT = 6;
+    @IntDef({MenuItemType.STANDARD, MenuItemType.TITLE_BUTTON, MenuItemType.THREE_BUTTON,
+            MenuItemType.FOUR_BUTTON, MenuItemType.FIVE_BUTTON, MenuItemType.UPDATE})
+    @Retention(RetentionPolicy.SOURCE)
+    private @interface MenuItemType {
+        /**
+         * Regular Android menu item that contains a title and an icon if icon is specified.
+         */
+        int STANDARD = 0;
+        /**
+         * Menu item for updating Chrome; uses a custom layout.
+         */
+        int UPDATE = 1;
+        /**
+         * Menu item that has two buttons, the first one is a title and the second one is an icon.
+         * It is different from the regular menu item because it contains two separate buttons.
+         */
+        int TITLE_BUTTON = 2;
+        /**
+         * Menu item that has three buttons. Every one of these buttons is displayed as an icon.
+         */
+        int THREE_BUTTON = 3;
+        /**
+         * Menu item that has four buttons. Every one of these buttons is displayed as an icon.
+         */
+        int FOUR_BUTTON = 4;
+        /**
+         * Menu item that has five buttons. Every one of these buttons is displayed as an icon.
+         */
+        int FIVE_BUTTON = 5;
+        /**
+         * The number of view types specified above.  If you add a view type you MUST increment
+         * this.
+         */
+        int NUM_ENTRIES = 6;
+    }
 
     /** IDs of all of the buttons in icon_row_menu_item.xml. */
     private static final int[] BUTTON_IDS = {
@@ -117,26 +120,26 @@ class AppMenuAdapter extends BaseAdapter {
 
     @Override
     public int getViewTypeCount() {
-        return VIEW_TYPE_COUNT;
+        return MenuItemType.NUM_ENTRIES;
     }
 
     @Override
-    public int getItemViewType(int position) {
+    public @MenuItemType int getItemViewType(int position) {
         MenuItem item = getItem(position);
         int viewCount = item.hasSubMenu() ? item.getSubMenu().size() : 1;
 
         if (item.getItemId() == R.id.update_menu_id) {
-            return UPDATE_MENU_ITEM;
-        } else if (viewCount == 5) {
-            return FIVE_BUTTON_MENU_ITEM;
-        } else if (viewCount == 4) {
-            return FOUR_BUTTON_MENU_ITEM;
-        } else if (viewCount == 3) {
-            return THREE_BUTTON_MENU_ITEM;
+            return MenuItemType.UPDATE;
         } else if (viewCount == 2) {
-            return TITLE_BUTTON_MENU_ITEM;
+            return MenuItemType.TITLE_BUTTON;
+        } else if (viewCount == 3) {
+            return MenuItemType.THREE_BUTTON;
+        } else if (viewCount == 4) {
+            return MenuItemType.FOUR_BUTTON;
+        } else if (viewCount == 5) {
+            return MenuItemType.FIVE_BUTTON;
         }
-        return STANDARD_MENU_ITEM;
+        return MenuItemType.STANDARD;
     }
 
     @Override
@@ -156,7 +159,7 @@ class AppMenuAdapter extends BaseAdapter {
     public View getView(int position, View convertView, ViewGroup parent) {
         final MenuItem item = getItem(position);
         switch (getItemViewType(position)) {
-            case STANDARD_MENU_ITEM: {
+            case MenuItemType.STANDARD: {
                 StandardMenuItemViewHolder holder = null;
                 if (convertView == null
                         || !(convertView.getTag() instanceof StandardMenuItemViewHolder)) {
@@ -172,11 +175,10 @@ class AppMenuAdapter extends BaseAdapter {
                 } else {
                     holder = (StandardMenuItemViewHolder) convertView.getTag();
                 }
-
                 setupStandardMenuItemViewHolder(holder, convertView, item);
                 break;
             }
-            case UPDATE_MENU_ITEM: {
+            case MenuItemType.UPDATE: {
                 CustomMenuItemViewHolder holder = null;
                 if (convertView == null
                         || !(convertView.getTag() instanceof CustomMenuItemViewHolder)) {
@@ -193,7 +195,6 @@ class AppMenuAdapter extends BaseAdapter {
                 } else {
                     holder = (CustomMenuItemViewHolder) convertView.getTag();
                 }
-
                 setupStandardMenuItemViewHolder(holder, convertView, item);
                 String summary = UpdateMenuItemHelper.getInstance().getMenuItemSummaryText(
                         mInflater.getContext());
@@ -202,22 +203,18 @@ class AppMenuAdapter extends BaseAdapter {
                 } else {
                     holder.summary.setText(summary);
                 }
-
                 break;
             }
-            case THREE_BUTTON_MENU_ITEM: {
+            case MenuItemType.THREE_BUTTON:
                 convertView = createMenuItemRow(convertView, parent, item, 3);
                 break;
-            }
-            case FOUR_BUTTON_MENU_ITEM: {
+            case MenuItemType.FOUR_BUTTON:
                 convertView = createMenuItemRow(convertView, parent, item, 4);
                 break;
-            }
-            case FIVE_BUTTON_MENU_ITEM: {
+            case MenuItemType.FIVE_BUTTON:
                 convertView = createMenuItemRow(convertView, parent, item, 5);
                 break;
-            }
-            case TITLE_BUTTON_MENU_ITEM: {
+            case MenuItemType.TITLE_BUTTON: {
                 assert item.hasSubMenu();
                 final MenuItem titleItem = item.getSubMenu().getItem(0);
                 final MenuItem subItem = item.getSubMenu().getItem(1);

chrome/android/java/src/org/chromium/chrome/browser/appmenu/AppMenuDragHelper.java

@@ -9,6 +9,7 @@ import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.content.res.Resources;
 import android.graphics.Rect;
+import android.support.annotation.IntDef;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewConfiguration;
@@ -20,6 +21,8 @@ import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.chrome.R;
 
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
 import java.util.concurrent.TimeUnit;
 
@@ -35,9 +38,13 @@ class AppMenuDragHelper {
     private final AppMenu mAppMenu;
 
     // Internally used action constants for dragging.
-    private static final int ITEM_ACTION_HIGHLIGHT = 0;
-    private static final int ITEM_ACTION_PERFORM = 1;
-    private static final int ITEM_ACTION_CLEAR_HIGHLIGHT_ALL = 2;
+    @IntDef({ItemAction.HIGHLIGHT, ItemAction.PERFORM, ItemAction.CLEAR_HIGHLIGHT_ALL})
+    @Retention(RetentionPolicy.SOURCE)
+    private @interface ItemAction {
+        int HIGHLIGHT = 0;
+        int PERFORM = 1;
+        int CLEAR_HIGHLIGHT_ALL = 2;
+    }
 
     private static final float AUTO_SCROLL_AREA_MAX_RATIO = 0.25f;
 
@@ -83,8 +90,8 @@ class AppMenuDragHelper {
 
             // Force touch move event to highlight items correctly for the scrolled position.
             if (!Float.isNaN(mLastTouchX) && !Float.isNaN(mLastTouchY)) {
-                menuItemAction(Math.round(mLastTouchX), Math.round(mLastTouchY),
-                        ITEM_ACTION_HIGHLIGHT);
+                menuItemAction(
+                        Math.round(mLastTouchX), Math.round(mLastTouchY), ItemAction.HIGHLIGHT);
             }
         });
 
@@ -122,7 +129,7 @@ class AppMenuDragHelper {
         // needed to by menuItemAction. Only clear highlighting if the menu is still showing.
         // See crbug.com/589805.
         if (mAppMenu.getPopup().isShowing()) {
-            menuItemAction(0, 0, ITEM_ACTION_CLEAR_HIGHLIGHT_ALL);
+            menuItemAction(0, 0, ItemAction.CLEAR_HIGHLIGHT_ALL);
         }
         mDragScrolling.cancel();
     }
@@ -175,14 +182,15 @@ class AppMenuDragHelper {
         if (!mDragScrolling.isRunning()) return false;
 
         boolean didPerformClick = false;
-        int itemAction = ITEM_ACTION_CLEAR_HIGHLIGHT_ALL;
+        @ItemAction
+        int itemAction = ItemAction.CLEAR_HIGHLIGHT_ALL;
         switch (eventActionMasked) {
             case MotionEvent.ACTION_DOWN:
             case MotionEvent.ACTION_MOVE:
-                itemAction = ITEM_ACTION_HIGHLIGHT;
+                itemAction = ItemAction.HIGHLIGHT;
                 break;
             case MotionEvent.ACTION_UP:
-                itemAction = ITEM_ACTION_PERFORM;
+                itemAction = ItemAction.PERFORM;
                 break;
             default:
                 break;
@@ -231,7 +239,7 @@ class AppMenuDragHelper {
      * @param action  Action type to perform, it should be one of ITEM_ACTION_* constants.
      * @return true whether or not a menu item is performed (executed).
      */
-    private boolean menuItemAction(int screenX, int screenY, int action) {
+    private boolean menuItemAction(int screenX, int screenY, @ItemAction int action) {
         ListView listView = mAppMenu.getListView();
 
         // Starting M, we have a popup menu animation that slides down. If we process dragging
@@ -268,17 +276,17 @@ class AppMenuDragHelper {
                     && getScreenVisibleRect(itemView).contains(screenX, screenY);
 
             switch (action) {
-                case ITEM_ACTION_HIGHLIGHT:
+                case ItemAction.HIGHLIGHT:
                     itemView.setPressed(shouldPerform);
                     break;
-                case ITEM_ACTION_PERFORM:
+                case ItemAction.PERFORM:
                     if (shouldPerform) {
                         RecordUserAction.record("MobileUsingMenuBySwButtonDragging");
                         itemView.performClick();
                         didPerformClick = true;
                     }
                     break;
-                case ITEM_ACTION_CLEAR_HIGHLIGHT_ALL:
+                case ItemAction.CLEAR_HIGHLIGHT_ALL:
                     itemView.setPressed(false);
                     break;
                 default: