Add new feature to let apps layout over status bar / system bar.

The main change is a few new flags you can supply to
View.setSystemUiVisibility().  One is a new visibility mode,
SYSTEM_UI_FLAG_FULLSCREEN, which is basically the same as
the global FLAG_FULLSCREEN option for windows, but driven as
part of the system UI state.

There are also three new flags for telling the framework that you
would like to have your application's UI ignore screen
decorations -- SYSTEM_UI_FLAG_LAYOUT_NO_NAVIGATION for going
behind the navigation bar and SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
for ignoring full screen decorations (that is the status bar).

In combination with this you can use SYSTEM_UI_FLAG_LAYOUT_STABLE
to have the framework report consistent insets to your application.

When using NO_NAVIGATION, when the user taps the screen we now
also automatically clear ONLY_CONTENT, so that we atomically show
both UI elements.  This should make it easy for apps like video
players that want to move between fully full-screen and regular
modes.

The ActionBar has also been extended when in overlay mode so
that it will adjust the system window insets to also account
for its space, and allow it to be hidden using the new
SYSTEM_UI_FLAG_FULLSCREEN.

Change-Id: Ic8db1adec49a0f420bfe40c1d92eb21307856d0b

Author: Dianne Hackborn

api/current.txt

@@ -23240,6 +23240,7 @@ package android.view {
     method public boolean dispatchUnhandledMove(android.view.View, int);
     method protected void dispatchVisibilityChanged(android.view.View, int);
     method public void dispatchWindowFocusChanged(boolean);
+    method public void dispatchWindowSystemUiVisiblityChanged(int);
     method public void dispatchWindowVisibilityChanged(int);
     method public void draw(android.graphics.Canvas);
     method protected void drawableStateChanged();
@@ -23353,6 +23354,7 @@ package android.view {
     method public int getVisibility();
     method public final int getWidth();
     method protected int getWindowAttachCount();
+    method public int getWindowSystemUiVisibility();
     method public android.os.IBinder getWindowToken();
     method public int getWindowVisibility();
     method public void getWindowVisibleDisplayFrame(android.graphics.Rect);
@@ -23456,6 +23458,7 @@ package android.view {
     method public boolean onTrackballEvent(android.view.MotionEvent);
     method protected void onVisibilityChanged(android.view.View, int);
     method public void onWindowFocusChanged(boolean);
+    method public void onWindowSystemUiVisibilityChanged(int);
     method protected void onWindowVisibilityChanged(int);
     method protected boolean overScrollBy(int, int, int, int, int, int, int, int, boolean);
     method public boolean performClick();
@@ -23473,6 +23476,7 @@ package android.view {
     method public boolean removeCallbacks(java.lang.Runnable);
     method public void removeOnAttachStateChangeListener(android.view.View.OnAttachStateChangeListener);
     method public void removeOnLayoutChangeListener(android.view.View.OnLayoutChangeListener);
+    method public void requestFitSystemWindows();
     method public final boolean requestFocus();
     method public final boolean requestFocus(int);
     method public boolean requestFocus(int, android.graphics.Rect);
@@ -23671,9 +23675,14 @@ package android.view {
     field public static final int SOUND_EFFECTS_ENABLED = 134217728; // 0x8000000
     field public static final deprecated int STATUS_BAR_HIDDEN = 1; // 0x1
     field public static final deprecated int STATUS_BAR_VISIBLE = 0; // 0x0
+    field public static final int SYSTEM_UI_FLAG_FULLSCREEN = 4; // 0x4
     field public static final int SYSTEM_UI_FLAG_HIDE_NAVIGATION = 2; // 0x2
+    field public static final int SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN = 1024; // 0x400
+    field public static final int SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION = 512; // 0x200
+    field public static final int SYSTEM_UI_FLAG_LAYOUT_STABLE = 256; // 0x100
     field public static final int SYSTEM_UI_FLAG_LOW_PROFILE = 1; // 0x1
     field public static final int SYSTEM_UI_FLAG_VISIBLE = 0; // 0x0
+    field public static final int SYSTEM_UI_LAYOUT_FLAGS = 1536; // 0x600
     field public static final int TEXT_DIRECTION_ANY_RTL = 2; // 0x2
     field protected static int TEXT_DIRECTION_DEFAULT;
     field public static final int TEXT_DIRECTION_FIRST_STRONG = 1; // 0x1
@@ -24037,6 +24046,7 @@ package android.view {
     method public abstract void requestChildFocus(android.view.View, android.view.View);
     method public abstract boolean requestChildRectangleOnScreen(android.view.View, android.graphics.Rect, boolean);
     method public abstract void requestDisallowInterceptTouchEvent(boolean);
+    method public abstract void requestFitSystemWindows();
     method public abstract void requestLayout();
     method public abstract boolean requestSendAccessibilityEvent(android.view.View, android.view.accessibility.AccessibilityEvent);
     method public abstract void requestTransparentRegion(android.view.View);

core/java/android/app/ActionBar.java

@@ -611,6 +611,10 @@ public void setSplitBackgroundDrawable(Drawable d) { }
      * If the window hosting the ActionBar does not have the feature
      * {@link Window#FEATURE_ACTION_BAR_OVERLAY} it will resize application
      * content to fit the new space available.
+     *
+     * <p>If you are hiding the ActionBar through
+     * {@link View#SYSTEM_UI_FLAG_FULLSCREEN View.SYSTEM_UI_FLAG_FULLSCREEN},
+     * you should not call this function directly.
      */
     public abstract void show();
 
@@ -619,6 +623,12 @@ public void setSplitBackgroundDrawable(Drawable d) { }
      * If the window hosting the ActionBar does not have the feature
      * {@link Window#FEATURE_ACTION_BAR_OVERLAY} it will resize application
      * content to fit the new space available.
+     *
+     * <p>Instead of calling this function directly, you can also cause an
+     * ActionBar using the overlay feature to hide through
+     * {@link View#SYSTEM_UI_FLAG_FULLSCREEN View.SYSTEM_UI_FLAG_FULLSCREEN}.
+     * Hiding the ActionBar through this system UI flag allows you to more
+     * seamlessly hide it in conjunction with other screen decorations.
      */
     public abstract void hide();