TabHost key handling corrected

When receiving key presses in TabHost.java, focus should be
requested for the selected tab indicator provided that the
following conditions are fulfilled:
1) A content view inside an embedded activity is currently focused.
2) No focusable view exists in the direction of the navigation
key press inside the embedded activity.
3) The TabWidget is located in the direction of the navigation
key press.
This should work for all locations of the TabWidget, not only
when the TabWidget is located above the tab content.

Change-Id: Ic5862cb72d2cc95aed9de92e42d6e0faf959fd43

Author: Roger Olsson

core/java/android/widget/TabHost.java

@@ -48,6 +48,10 @@
  */
 public class TabHost extends FrameLayout implements ViewTreeObserver.OnTouchModeChangeListener {
 
+    private static final int TABWIDGET_LOCATION_LEFT = 0;
+    private static final int TABWIDGET_LOCATION_TOP = 1;
+    private static final int TABWIDGET_LOCATION_RIGHT = 2;
+    private static final int TABWIDGET_LOCATION_BOTTOM = 3;
     private TabWidget mTabWidget;
     private FrameLayout mTabContent;
     private List<TabSpec> mTabSpecs = new ArrayList<TabSpec>(2);
@@ -293,22 +297,73 @@ public FrameLayout getTabContentView() {
         return mTabContent;
     }
 
+    /**
+     * Get the location of the TabWidget.
+     *
+     * @return The TabWidget location.
+     */
+    private int getTabWidgetLocation() {
+        int location = TABWIDGET_LOCATION_TOP;
+
+        switch (mTabWidget.getOrientation()) {
+            case LinearLayout.VERTICAL:
+                location = (mTabContent.getLeft() < mTabWidget.getLeft()) ? TABWIDGET_LOCATION_RIGHT
+                        : TABWIDGET_LOCATION_LEFT;
+                break;
+            case LinearLayout.HORIZONTAL:
+            default:
+                location = (mTabContent.getTop() < mTabWidget.getTop()) ? TABWIDGET_LOCATION_BOTTOM
+                        : TABWIDGET_LOCATION_TOP;
+                break;
+        }
+        return location;
+    }
+
     @Override
     public boolean dispatchKeyEvent(KeyEvent event) {
         final boolean handled = super.dispatchKeyEvent(event);
 
-        // unhandled key ups change focus to tab indicator for embedded activities
-        // when there is nothing that will take focus from default focus searching
+        // unhandled key events change focus to tab indicator for embedded
+        // activities when there is nothing that will take focus from default
+        // focus searching
         if (!handled
                 && (event.getAction() == KeyEvent.ACTION_DOWN)
-                && (event.getKeyCode() == KeyEvent.KEYCODE_DPAD_UP)
                 && (mCurrentView != null)
                 && (mCurrentView.isRootNamespace())
-                && (mCurrentView.hasFocus())
-                && (mCurrentView.findFocus().focusSearch(View.FOCUS_UP) == null)) {
-            mTabWidget.getChildTabViewAt(mCurrentTab).requestFocus();
-            playSoundEffect(SoundEffectConstants.NAVIGATION_UP);
-            return true;
+                && (mCurrentView.hasFocus())) {
+            int keyCodeShouldChangeFocus = KeyEvent.KEYCODE_DPAD_UP;
+            int directionShouldChangeFocus = View.FOCUS_UP;
+            int soundEffect = SoundEffectConstants.NAVIGATION_UP;
+
+            switch (getTabWidgetLocation()) {
+                case TABWIDGET_LOCATION_LEFT:
+                    keyCodeShouldChangeFocus = KeyEvent.KEYCODE_DPAD_LEFT;
+                    directionShouldChangeFocus = View.FOCUS_LEFT;
+                    soundEffect = SoundEffectConstants.NAVIGATION_LEFT;
+                    break;
+                case TABWIDGET_LOCATION_RIGHT:
+                    keyCodeShouldChangeFocus = KeyEvent.KEYCODE_DPAD_RIGHT;
+                    directionShouldChangeFocus = View.FOCUS_RIGHT;
+                    soundEffect = SoundEffectConstants.NAVIGATION_RIGHT;
+                    break;
+                case TABWIDGET_LOCATION_BOTTOM:
+                    keyCodeShouldChangeFocus = KeyEvent.KEYCODE_DPAD_DOWN;
+                    directionShouldChangeFocus = View.FOCUS_DOWN;
+                    soundEffect = SoundEffectConstants.NAVIGATION_DOWN;
+                    break;
+                case TABWIDGET_LOCATION_TOP:
+                default:
+                    keyCodeShouldChangeFocus = KeyEvent.KEYCODE_DPAD_UP;
+                    directionShouldChangeFocus = View.FOCUS_UP;
+                    soundEffect = SoundEffectConstants.NAVIGATION_UP;
+                    break;
+            }
+            if (event.getKeyCode() == keyCodeShouldChangeFocus
+                    && mCurrentView.findFocus().focusSearch(directionShouldChangeFocus) == null) {
+                mTabWidget.getChildTabViewAt(mCurrentTab).requestFocus();
+                playSoundEffect(soundEffect);
+                return true;
+            }
         }
         return handled;
     }