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

1 files changed, 193 insertions, 0 deletions

diff --git a/core/java/com/android/internal/widget/ActionBarOverlayLayout.java b/core/java/com/android/internal/widget/ActionBarOverlayLayout.java
new file mode 100644
index 0000000..5f36bb6
--- /dev/null
+++ b/core/java/com/android/internal/widget/ActionBarOverlayLayout.java
@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import com.android.internal.app.ActionBarImpl;
+
+import android.animation.LayoutTransition;
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Rect;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.view.View;
+import android.view.ViewTreeObserver;
+import android.widget.FrameLayout;
+
+/**
+ * Special layout for the containing of an overlay action bar (and its
+ * content) to correctly handle fitting system windows when the content
+ * has request that its layout ignore them.
+ */
+public class ActionBarOverlayLayout extends FrameLayout {
+    private int mActionBarHeight;
+    private ActionBarImpl mActionBar;
+    private int mWindowVisibility = View.VISIBLE;
+    private View mContent;
+    private View mActionBarTop;
+    private ActionBarContainer mContainerView;
+    private ActionBarView mActionView;
+    private View mActionBarBottom;
+    private int mLastSystemUiVisibility;
+    private final Rect mZeroRect = new Rect(0, 0, 0, 0);
+
+    static final int[] mActionBarSizeAttr = new int [] {
+            com.android.internal.R.attr.actionBarSize
+    };
+
+    public ActionBarOverlayLayout(Context context) {
+        super(context);
+        init(context);
+    }
+
+    public ActionBarOverlayLayout(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        init(context);
+    }
+
+    private void init(Context context) {
+        TypedArray ta = getContext().getTheme().obtainStyledAttributes(mActionBarSizeAttr);
+        mActionBarHeight = ta.getDimensionPixelSize(0, 0);
+        ta.recycle();
+    }
+
+    public void setActionBar(ActionBarImpl impl) {
+        mActionBar = impl;
+        if (getWindowToken() != null) {
+            // This is being initialized after being added to a window;
+            // make sure to update all state now.
+            mActionBar.setWindowVisibility(mWindowVisibility);
+            if (mLastSystemUiVisibility != 0) {
+                int newVis = mLastSystemUiVisibility;
+                onWindowSystemUiVisibilityChanged(newVis);
+                requestFitSystemWindows();
+            }
+        }
+    }
+
+    @Override
+    public void onWindowSystemUiVisibilityChanged(int visible) {
+        super.onWindowSystemUiVisibilityChanged(visible);
+        pullChildren();
+        final int diff = mLastSystemUiVisibility ^ visible;
+        mLastSystemUiVisibility = visible;
+        final boolean barVisible = (visible&SYSTEM_UI_FLAG_FULLSCREEN) == 0;
+        final boolean wasVisible = mActionBar != null ? mActionBar.isShowing() : true;
+        if (barVisible != wasVisible || (diff&SYSTEM_UI_FLAG_LAYOUT_STABLE) != 0) {
+            if (mActionBar != null) {
+                if (barVisible) mActionBar.show(true, true);
+                else mActionBar.hide(true);
+                requestFitSystemWindows();
+            }
+        }
+    }
+
+    @Override
+    protected void onWindowVisibilityChanged(int visibility) {
+        super.onWindowVisibilityChanged(visibility);
+        mWindowVisibility = visibility;
+        if (mActionBar != null) {
+            mActionBar.setWindowVisibility(visibility);
+        }
+    }
+
+    private boolean applyInsets(View view, Rect insets, boolean left, boolean top,
+            boolean bottom, boolean right) {
+        boolean changed = false;
+        FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams)view.getLayoutParams();
+        if (left && lp.leftMargin != insets.left) {
+            changed = true;
+            lp.leftMargin = insets.left;
+        }
+        if (top && lp.topMargin != insets.top) {
+            changed = true;
+            lp.topMargin = insets.top;
+        }
+        if (right && lp.rightMargin != insets.right) {
+            changed = true;
+            lp.rightMargin = insets.right;
+        }
+        if (bottom && lp.bottomMargin != insets.bottom) {
+            changed = true;
+            lp.bottomMargin = insets.bottom;
+        }
+        return changed;
+    }
+
+    @Override
+    protected boolean fitSystemWindows(Rect insets) {
+        pullChildren();
+
+        final int vis = getWindowSystemUiVisibility();
+        final boolean stable = (vis & SYSTEM_UI_FLAG_LAYOUT_STABLE) != 0;
+
+        // The top and bottom action bars are always within the content area.
+        boolean changed = applyInsets(mActionBarTop, insets, true, true, false, true);
+        changed |= applyInsets(mActionBarBottom, insets, true, false, true, true);
+
+        // If the window has not requested system UI layout flags, we need to
+        // make sure its content is not being covered by system UI...  though it
+        // will still be covered by the action bar since they have requested it to
+        // overlay.
+        if ((vis & SYSTEM_UI_LAYOUT_FLAGS) == 0) {
+            changed |= applyInsets(mContent, insets, true, true, true, true);
+            // The insets are now consumed.
+            insets.set(0, 0, 0, 0);
+        } else {
+            changed |= applyInsets(mContent, mZeroRect, true, true, true, true);
+        }
+
+
+        if (stable || mActionBarTop.getVisibility() == VISIBLE) {
+            // The action bar creates additional insets for its content to use.
+            insets.top += mActionBarHeight;
+        }
+
+        if (mActionBar != null && mActionBar.hasNonEmbeddedTabs()) {
+            View tabs = mContainerView.getTabContainer();
+            if (stable || (tabs != null && tabs.getVisibility() == VISIBLE)) {
+                // If tabs are not embedded, adjust insets to account for them.
+                insets.top += mActionBarHeight;
+            }
+        }
+
+        if (mActionView.isSplitActionBar()) {
+            if (stable || (mActionBarBottom != null
+                    && mActionBarBottom.getVisibility() == VISIBLE)) {
+                // If action bar is split, adjust buttom insets for it.
+                insets.bottom += mActionBarHeight;
+            }
+        }
+
+        if (changed) {
+            requestLayout();
+        }
+
+        return super.fitSystemWindows(insets);
+    }
+
+    void pullChildren() {
+        if (mContent == null) {
+            mContent = findViewById(com.android.internal.R.id.content);
+            mActionBarTop = findViewById(com.android.internal.R.id.top_action_bar);
+            mContainerView = (ActionBarContainer)findViewById(
+                    com.android.internal.R.id.action_bar_container);
+            mActionView = (ActionBarView) findViewById(com.android.internal.R.id.action_bar);
+            mActionBarBottom = findViewById(com.android.internal.R.id.split_action_bar);
+        }
+    }
+}