Implement divider UX interactions

- Update visuals to spec
- Divider lifts when touching
- Implement basic version of snap points and animations
- Implement touch conflict behavior: If touched around 48x48dp
area around the handle, the divider handles all these touches.
If touched outside of the black background divider, touch goes
directly to underlying window. If touch on the black background
divider, touch is considered slippery and thus the window in
which the touch trace moves gets the touches.

Change-Id: I0307c191ae032672c4b73d439c23cf9833d3fce6
diff --git a/packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java b/packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java
new file mode 100644
index 0000000..dd894ce
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2015 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.systemui.stackdivider;
+
+import android.content.res.Configuration;
+import android.view.LayoutInflater;
+
+import com.android.systemui.R;
+import com.android.systemui.SystemUI;
+
+import static android.content.res.Configuration.ORIENTATION_LANDSCAPE;
+import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
+
+/**
+ * Controls the docked stack divider.
+ */
+public class Divider extends SystemUI {
+    private static final String TAG = "Divider";
+    private int mDividerWindowWidth;
+    private DividerWindowManager mWindowManager;
+
+    @Override
+    public void start() {
+        mWindowManager = new DividerWindowManager(mContext);
+        mDividerWindowWidth = mContext.getResources().getDimensionPixelSize(
+                com.android.internal.R.dimen.docked_stack_divider_thickness);
+        update(mContext.getResources().getConfiguration());
+    }
+
+    @Override
+    protected void onConfigurationChanged(Configuration newConfig) {
+        super.onConfigurationChanged(newConfig);
+        update(newConfig);
+    }
+
+    private void addDivider(Configuration configuration) {
+        DividerView view = (DividerView)
+                LayoutInflater.from(mContext).inflate(R.layout.docked_stack_divider, null);
+        final boolean landscape = configuration.orientation == ORIENTATION_LANDSCAPE;
+        final int width = landscape ? mDividerWindowWidth : MATCH_PARENT;
+        final int height = landscape ? MATCH_PARENT : mDividerWindowWidth;
+        mWindowManager.add(view, width, height);
+        view.setWindowManager(mWindowManager);
+    }
+
+    private void removeDivider() {
+        mWindowManager.remove();
+    }
+
+    private void update(Configuration configuration) {
+        removeDivider();
+        addDivider(configuration);
+    }
+}