Fixing drop target area, and adding bg color indicators.

- Merging wallpaper fix and PagedViewIconCache key fix

Change-Id: I2a65bc4b642f020dfc4d2223a36d3ebcf41de5f5

src/com/android/launcher2/ButtonDropTarget.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2010 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.launcher2;
+
+import android.content.Context;
+import android.graphics.Paint;
+import android.util.AttributeSet;
+import android.widget.FrameLayout;
+
+import com.android.launcher.R;
+
+
+/**
+ * Implements a DropTarget.
+ */
+public class ButtonDropTarget extends FrameLayout implements DropTarget, DragController.DragListener {
+
+    protected final int mTransitionDuration;
+
+    protected Launcher mLauncher;
+
+    /** Whether this drop target is active for the current drag */
+    protected boolean mActive;
+
+    /** The paint applied to the drag view on hover */
+    protected final Paint mHoverPaint = new Paint();
+
+    public ButtonDropTarget(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public ButtonDropTarget(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+
+        mTransitionDuration =
+            context.getResources().getInteger(R.integer.config_dropTargetBgTransitionDuration);
+    }
+
+    void setLauncher(Launcher launcher) {
+        mLauncher = launcher;
+    }
+
+    public boolean acceptDrop(DragObject d) {
+        return false;
+    }
+
+    public void onDrop(DragObject d) {
+        // Do nothing
+    }
+
+    public void onDragEnter(DragObject d) {
+        d.dragView.setPaint(mHoverPaint);
+    }
+
+    public void onDragOver(DragObject d) {
+        // Do nothing
+    }
+
+    public void onDragExit(DragObject d) {
+        d.dragView.setPaint(null);
+    }
+
+    public void onDragStart(DragSource source, Object info, int dragAction) {
+        // Do nothing
+    }
+
+    public boolean isDropEnabled() {
+        return mActive;
+    }
+
+    public void onDragEnd() {
+        // Do nothing
+    }
+
+    @Override
+    public DropTarget getDropTargetDelegate(DragObject d) {
+        return null;
+    }
+}