Changing press feedback to holographic for search buttons. (Bug: 5290367)

Change-Id: I50fa849abb816a98d1dbbfd9bf6611fbb87baca9
diff --git a/src/com/android/launcher2/HolographicViewHelper.java b/src/com/android/launcher2/HolographicViewHelper.java
new file mode 100644
index 0000000..c68a5ea
--- /dev/null
+++ b/src/com/android/launcher2/HolographicViewHelper.java
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2011 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.content.res.Resources;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.drawable.StateListDrawable;
+import android.view.View;
+
+public class HolographicViewHelper {
+
+    private final HolographicOutlineHelper mOutlineHelper = new HolographicOutlineHelper();
+    private final Canvas mTempCanvas = new Canvas();
+
+    private boolean mStatesUpdated;
+    private int mHighlightColor;
+
+    public HolographicViewHelper(Context context) {
+        Resources res = context.getResources();
+        mHighlightColor = res.getColor(android.R.color.holo_blue_light);
+    }
+
+    /**
+     * Generate the pressed/focused states if necessary.
+     */
+    void generatePressedFocusedStates(View v) {
+        if (!mStatesUpdated) {
+            mStatesUpdated = true;
+            Bitmap outline = createGlowingOutline(v, mTempCanvas, mHighlightColor, mHighlightColor);
+            FastBitmapDrawable d = new FastBitmapDrawable(outline);
+
+            StateListDrawable states = new StateListDrawable();
+            states.addState(new int[] {android.R.attr.state_pressed}, d);
+            states.addState(new int[] {android.R.attr.state_focused}, d);
+            v.setBackgroundDrawable(states);
+        }
+    }
+
+    /**
+     * Returns a new bitmap to be used as the object outline, e.g. to visualize the drop location.
+     * Responsibility for the bitmap is transferred to the caller.
+     */
+    private Bitmap createGlowingOutline(View v, Canvas canvas, int outlineColor, int glowColor) {
+        final int padding = HolographicOutlineHelper.MAX_OUTER_BLUR_RADIUS;
+        final Bitmap b = Bitmap.createBitmap(
+                v.getWidth() + padding, v.getHeight() + padding, Bitmap.Config.ARGB_8888);
+
+        canvas.setBitmap(b);
+        canvas.save();
+            v.draw(canvas);
+        canvas.restore();
+        mOutlineHelper.applyOuterBlur(b, canvas, outlineColor);
+        canvas.setBitmap(null);
+
+        return b;
+    }
+}