Creating a custom drawable to customize shadow.

> Fixing DrapTargetBar set to visible (with alpha = 0) in the start
causing unnecessary draw

Bug: 37616877
Change-Id: Iaaff96099910f504f6e2f81c9376ddacde50ff6a

proguard.flags

@@ -82,6 +82,10 @@
   *;
 }
 
+-keep class com.android.launcher3.graphics.ShadowDrawable {
+  public <init>(...);
+}
+
 # Proguard will strip methods required for talkback to properly scroll to
 # next row when focus is on the last item of last row when using a RecyclerView
 # Keep optimized and shrunk proguard to prevent issues like this when using

res/drawable-v24/ic_info_shadow.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2017 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.
+-->
+<com.android.launcher3.graphics.ShadowDrawable
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:src="@drawable/ic_info_no_shadow" />

res/drawable-v24/ic_remove_shadow.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2017 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.
+-->
+<com.android.launcher3.graphics.ShadowDrawable
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:src="@drawable/ic_remove_no_shadow" />

res/drawable-v24/ic_uninstall_shadow.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2017 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.
+-->
+<com.android.launcher3.graphics.ShadowDrawable
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:src="@drawable/ic_uninstall_no_shadow" />

res/drawable/ic_info_no_shadow.xml

@@ -17,8 +17,9 @@
         android:width="24dp"
         android:height="24dp"
         android:viewportWidth="24.0"
-        android:viewportHeight="24.0">
+        android:viewportHeight="24.0"
+        android:tint="?android:attr/textColorPrimary" >
     <path
-        android:fillColor="?android:attr/textColorPrimary"
+        android:fillColor="#FFFFFFFF"
         android:pathData="M11 17h2v-6h-2v6zm1-15C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm0 18c-4.41 0-8-3.59-8-8s3.59-8 8-8 8 3.59 8 8-3.59 8-8 8zM11 9h2V7h-2v2z"/>
 </vector>

res/drawable/ic_remove_no_shadow.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2017 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.
+-->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0"
+        android:tint="?android:attr/textColorPrimary" >
+    <path
+        android:fillColor="#FFFFFFFF"
+        android:pathData="M19 6.41L17.59 5 12 10.59 6.41 5 5 6.41 10.59 12 5 17.59 6.41 19 12 13.41 17.59 19 19 17.59 13.41 12z"/>
+</vector>

res/drawable/ic_uninstall_no_shadow.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2017 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.
+-->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0"
+        android:tint="?android:attr/textColorPrimary" >
+    <path
+        android:fillColor="#FFFFFFFF"
+        android:pathData="M6 19c0 1.1.9 2 2 2h8c1.1 0 2-.9 2-2V7H6v12zM19 4h-3.5l-1-1h-5l-1 1H5v2h14V4z"/>
+</vector>

res/layout/drop_target_bar_horz.xml

@@ -20,6 +20,7 @@
     android:theme="@style/HomeScreenElementTheme"
     android:layout_width="match_parent"
     android:layout_height="@dimen/dynamic_grid_drop_target_size"
+    android:visibility="invisible"
     android:layout_gravity="center_horizontal|top"
     android:focusable="false">
 

res/layout/drop_target_bar_vert.xml

@@ -21,6 +21,7 @@
     android:orientation="vertical"
     android:layout_height="match_parent"
     android:layout_gravity="left"
+    android:visibility="invisible"
     android:focusable="false"
     android:paddingTop="@dimen/vert_drop_target_vertical_gap" >
 

res/values/attrs.xml

@@ -16,7 +16,7 @@
 */
 -->
 
-<resources>
+<resources xmlns:android="http://schemas.android.com/apk/res/android">
 
     <!-- BubbleTextView specific attributes. -->
     <declare-styleable name="BubbleTextView">
@@ -111,4 +111,8 @@
         </attr>
     </declare-styleable>
 
+    <declare-styleable name="ShadowDrawable">
+        <attr name="android:src" />
+        <attr name="android:shadowColor" />
+    </declare-styleable>
 </resources>

res/values/dimens.xml

@@ -146,6 +146,7 @@
     <dimen name="blur_size_medium_outline">2dp</dimen>
     <dimen name="blur_size_click_shadow">4dp</dimen>
     <dimen name="click_shadow_high_shift">2dp</dimen>
+    <dimen name="drawable_shadow_size">2dp</dimen>
 
 <!-- Pending widget -->
     <dimen name="pending_widget_min_padding">8dp</dimen>

res/values/drawables.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2017 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.
+-->
+<resources>
+    <drawable name="ic_info_shadow">@drawable/ic_info_no_shadow</drawable>
+    <drawable name="ic_remove_shadow">@drawable/ic_remove_no_shadow</drawable>
+    <drawable name="ic_uninstall_shadow">@drawable/ic_uninstall_no_shadow</drawable>
+</resources>

src/com/android/launcher3/DeleteDropTarget.java

@@ -40,7 +40,7 @@ public class DeleteDropTarget extends ButtonDropTarget {
         // Get the hover color
         mHoverColor = getResources().getColor(R.color.delete_target_hover_tint);
 
-        setDrawable(R.drawable.ic_remove_launcher);
+        setDrawable(R.drawable.ic_remove_shadow);
     }
 
     @Override

src/com/android/launcher3/InfoDropTarget.java

@@ -40,12 +40,10 @@ public class InfoDropTarget extends UninstallDropTarget {
     }
 
     @Override
-    protected void onFinishInflate() {
-        super.onFinishInflate();
+    protected void setupUi() {
         // Get the hover color
         mHoverColor = Themes.getColorAccent(getContext());
-
-        setDrawable(R.drawable.ic_info_launcher);
+        setDrawable(R.drawable.ic_info_shadow);
     }
 
     @Override

src/com/android/launcher3/UninstallDropTarget.java

@@ -28,10 +28,13 @@ public class UninstallDropTarget extends ButtonDropTarget {
     @Override
     protected void onFinishInflate() {
         super.onFinishInflate();
+        setupUi();
+    }
+
+    protected void setupUi() {
         // Get the hover color
         mHoverColor = getResources().getColor(R.color.uninstall_target_hover_tint);
-
-        setDrawable(R.drawable.ic_uninstall_launcher);
+        setDrawable(R.drawable.ic_uninstall_shadow);
     }
 
     @Override

src/com/android/launcher3/graphics/ShadowDrawable.java

@@ -0,0 +1,191 @@
+/*
+ * Copyright (C) 2017 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.graphics;
+
+import android.content.res.Resources;
+import android.content.res.TypedArray;
+import android.graphics.Bitmap;
+import android.graphics.BlurMaskFilter;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.ColorFilter;
+import android.graphics.Paint;
+import android.graphics.PixelFormat;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+import android.util.AttributeSet;
+
+import com.android.launcher3.R;
+import com.android.launcher3.Utilities;
+
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlPullParserException;
+
+import java.io.IOException;
+
+/**
+ * A drawable which adds shadow around a child drawable.
+ */
+public class ShadowDrawable extends Drawable {
+
+    private final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
+
+    private final ShadowDrawableState mState;
+
+    public ShadowDrawable() {
+        this(new ShadowDrawableState());
+    }
+
+    private ShadowDrawable(ShadowDrawableState state) {
+        mState = state;
+    }
+
+    @Override
+    public void draw(Canvas canvas) {
+        Rect bounds = getBounds();
+        if (bounds.isEmpty()) {
+            return;
+        }
+        if (mState.mLastDrawnBitmap == null) {
+            regenerateBitmapCache();
+        }
+        canvas.drawBitmap(mState.mLastDrawnBitmap, null, bounds, mPaint);
+    }
+
+    @Override
+    public void setAlpha(int alpha) {
+        mPaint.setAlpha(alpha);
+        invalidateSelf();
+    }
+
+    @Override
+    public void setColorFilter(ColorFilter colorFilter) {
+        mPaint.setColorFilter(colorFilter);
+        invalidateSelf();
+    }
+
+    @Override
+    public ConstantState getConstantState() {
+        return mState;
+    }
+
+    @Override
+    public int getOpacity() {
+        return PixelFormat.TRANSLUCENT;
+    }
+
+    @Override
+    public int getIntrinsicHeight() {
+        return mState.mIntrinsicHeight;
+    }
+
+    @Override
+    public int getIntrinsicWidth() {
+        return mState.mIntrinsicWidth;
+    }
+
+    /**
+     * Sets the color for the generated shadow
+     */
+    public void setShadowColor(int color) {
+        if (mState.mShadowColor != color) {
+            mState.mShadowColor = color;
+            mState.mLastDrawnBitmap = null;
+            invalidateSelf();
+        }
+    }
+
+    private void regenerateBitmapCache() {
+        Bitmap bitmap = Bitmap.createBitmap(mState.mIntrinsicWidth, mState.mIntrinsicHeight,
+                Bitmap.Config.ARGB_8888);
+        Canvas canvas = new Canvas(bitmap);
+
+        // Call mutate, so that the pixel allocation by the underlying vector drawable is cleared.
+        Drawable d = mState.mChildState.newDrawable().mutate();
+        d.setBounds(mState.mShadowSize, mState.mShadowSize,
+                mState.mIntrinsicWidth - mState.mShadowSize,
+                mState.mIntrinsicHeight - mState.mShadowSize);
+        d.draw(canvas);
+
+        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
+        paint.setMaskFilter(new BlurMaskFilter(mState.mShadowSize, BlurMaskFilter.Blur.NORMAL));
+        int[] offset = new int[2];
+        Bitmap shadow = bitmap.extractAlpha(paint, offset);
+
+        paint.setMaskFilter(null);
+        paint.setColor(mState.mShadowColor);
+        bitmap.eraseColor(Color.TRANSPARENT);
+        canvas.drawBitmap(shadow, offset[0], offset[1], paint);
+        d.draw(canvas);
+
+        if (Utilities.isAtLeastO()) {
+            bitmap = bitmap.copy(Bitmap.Config.HARDWARE, false);
+        }
+        mState.mLastDrawnBitmap = bitmap;
+    }
+
+    @Override
+    public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs,
+            Resources.Theme theme) throws XmlPullParserException, IOException {
+        super.inflate(r, parser, attrs, theme);
+
+        final TypedArray a = theme == null
+                ? r.obtainAttributes(attrs, R.styleable.ShadowDrawable)
+                : theme.obtainStyledAttributes(attrs, R.styleable.ShadowDrawable, 0, 0);
+
+        try {
+            Drawable d = a.getDrawable(R.styleable.ShadowDrawable_android_src);
+            if (d == null) {
+                throw new XmlPullParserException("missing src attribute");
+            }
+            mState.mShadowColor = a.getColor(
+                    R.styleable.ShadowDrawable_android_shadowColor, Color.BLACK);
+            mState.mShadowSize = r.getDimensionPixelSize(R.dimen.drawable_shadow_size);
+
+            mState.mIntrinsicHeight = d.getIntrinsicHeight() + 2 * mState.mShadowSize;
+            mState.mIntrinsicWidth = d.getIntrinsicWidth() + 2 * mState.mShadowSize;
+            mState.mChangingConfigurations = d.getChangingConfigurations();
+
+            mState.mChildState = d.getConstantState();
+        } finally {
+            a.recycle();
+        }
+    }
+
+    private static class ShadowDrawableState extends ConstantState {
+
+        int mChangingConfigurations;
+        int mIntrinsicWidth;
+        int mIntrinsicHeight;
+
+        int mShadowColor;
+        int mShadowSize;
+
+        Bitmap mLastDrawnBitmap;
+        ConstantState mChildState;
+
+        @Override
+        public Drawable newDrawable() {
+            return new ShadowDrawable(this);
+        }
+
+        @Override
+        public int getChangingConfigurations() {
+            return mChangingConfigurations;
+        }
+    }
+}