Make common base class to update container bounds and to handle scroll logic.

Bug: 20763871

Change-Id: I8c2f45cfb10964e4be7e9c07c89dd336585c9989

src/com/android/launcher3/BaseContainerView.java

@@ -0,0 +1,100 @@
+/*
+ * 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.launcher3;
+
+import android.content.Context;
+import android.graphics.Rect;
+import android.util.AttributeSet;
+import android.widget.FrameLayout;
+
+/**
+ * A base container view, which supports resizing.
+ */
+public class BaseContainerView extends FrameLayout implements Insettable {
+
+    protected Rect mInsets = new Rect();
+    protected Rect mFixedBounds = new Rect();
+    protected int mFixedBoundsContainerInset;
+
+    public BaseContainerView(Context context) {
+        this(context, null);
+    }
+
+    public BaseContainerView(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public BaseContainerView(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        mFixedBoundsContainerInset = context.getResources().getDimensionPixelSize(
+                R.dimen.container_fixed_bounds_inset);
+    }
+
+    @Override
+    final public void setInsets(Rect insets) {
+        mInsets.set(insets);
+        onUpdateBackgrounds();
+        onUpdatePaddings();
+    }
+
+    /**
+     * Sets the fixed bounds for this container view.
+     */
+    final public void setFixedBounds(Rect fixedBounds) {
+        if (!fixedBounds.isEmpty() && !fixedBounds.equals(mFixedBounds)) {
+            mFixedBounds.set(fixedBounds);
+            if (Launcher.DISABLE_ALL_APPS_SEARCH_INTEGRATION) {
+                mFixedBounds.top = mInsets.top;
+                mFixedBounds.bottom = getMeasuredHeight();
+            }
+            // To ensure that the child RecyclerView has the full width to handle touches right to
+            // the edge of the screen, we only apply the top and bottom padding to the bounds
+            mFixedBounds.inset(0, mFixedBoundsContainerInset);
+            onFixedBoundsUpdated();
+        }
+        // Post the updates since they can trigger a relayout, and this call can be triggered from
+        // a layout pass itself.
+        post(new Runnable() {
+            @Override
+            public void run() {
+                onUpdateBackgrounds();
+                onUpdatePaddings();
+            }
+        });
+    }
+
+    /**
+     * Update the UI in response to a change in the fixed bounds.
+     */
+    protected void onFixedBoundsUpdated() {
+        // Do nothing
+    }
+
+    /**
+     * Update the paddings in response to a change in the bounds or insets.
+     */
+    protected void onUpdatePaddings() {
+        // Do nothing
+    }
+
+    /**
+     * Update the backgrounds in response to a change in the bounds or insets.
+     */
+    protected void onUpdateBackgrounds() {
+        // Do nothing
+    }
+}