Merge "Adding support for generating manachrome icon from a colored icon" into tm-qpr-dev
diff --git a/src/com/android/launcher3/config/FeatureFlags.java b/src/com/android/launcher3/config/FeatureFlags.java
index 797207d..5cab817 100644
--- a/src/com/android/launcher3/config/FeatureFlags.java
+++ b/src/com/android/launcher3/config/FeatureFlags.java
@@ -363,6 +363,11 @@
             "Enable the ability to tap a staged app during split select to launch it in full screen"
     );
 
+    public static final BooleanFlag ENABLE_FORCED_MONO_ICON = getDebugFlag(
+            "ENABLE_FORCED_MONO_ICON", false,
+            "Enable the ability to generate monochromatic icons, if it is not provided by the app"
+    );
+
     public static void initialize(Context context) {
         synchronized (sDebugFlags) {
             for (DebugFlag flag : sDebugFlags) {
diff --git a/src/com/android/launcher3/icons/LauncherIcons.java b/src/com/android/launcher3/icons/LauncherIcons.java
index 5508c49..57fa8a2 100644
--- a/src/com/android/launcher3/icons/LauncherIcons.java
+++ b/src/com/android/launcher3/icons/LauncherIcons.java
@@ -16,7 +16,10 @@
 
 package com.android.launcher3.icons;
 
+import static com.android.launcher3.config.FeatureFlags.ENABLE_FORCED_MONO_ICON;
+
 import android.content.Context;
+import android.graphics.drawable.Drawable;
 
 import com.android.launcher3.InvariantDeviceProfile;
 import com.android.launcher3.graphics.IconShape;
@@ -68,6 +71,8 @@
 
     private LauncherIcons next;
 
+    private MonochromeIconFactory mMonochromeIconFactory;
+
     protected LauncherIcons(Context context, int fillResIconDpi, int iconBitmapSize, int poolId) {
         super(context, fillResIconDpi, iconBitmapSize, IconShape.getShape().enableShapeDetection());
         mMonoIconEnabled = Themes.isThemedIconEnabled(context);
@@ -91,6 +96,18 @@
     }
 
     @Override
+    protected Drawable getMonochromeDrawable(Drawable base) {
+        Drawable mono = super.getMonochromeDrawable(base);
+        if (mono != null || !ENABLE_FORCED_MONO_ICON.get()) {
+            return mono;
+        }
+        if (mMonochromeIconFactory == null) {
+            mMonochromeIconFactory = new MonochromeIconFactory(mIconBitmapSize);
+        }
+        return mMonochromeIconFactory.wrap(base);
+    }
+
+    @Override
     public void close() {
         recycle();
     }
diff --git a/src/com/android/launcher3/icons/MonochromeIconFactory.java b/src/com/android/launcher3/icons/MonochromeIconFactory.java
new file mode 100644
index 0000000..511dcc7
--- /dev/null
+++ b/src/com/android/launcher3/icons/MonochromeIconFactory.java
@@ -0,0 +1,180 @@
+/*
+ * Copyright (C) 2022 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.icons;
+
+import static android.graphics.Paint.FILTER_BITMAP_FLAG;
+
+import android.annotation.TargetApi;
+import android.graphics.Bitmap;
+import android.graphics.Bitmap.Config;
+import android.graphics.BlendMode;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.ColorFilter;
+import android.graphics.ColorMatrix;
+import android.graphics.ColorMatrixColorFilter;
+import android.graphics.Paint;
+import android.graphics.PixelFormat;
+import android.graphics.Rect;
+import android.graphics.drawable.AdaptiveIconDrawable;
+import android.graphics.drawable.Drawable;
+import android.os.Build;
+
+import androidx.annotation.WorkerThread;
+
+import com.android.launcher3.icons.BaseIconFactory.ClippedMonoDrawable;
+
+import java.nio.ByteBuffer;
+
+/**
+ * Utility class to generate monochrome icons version for a given drawable.
+ */
+@TargetApi(Build.VERSION_CODES.TIRAMISU)
+public class MonochromeIconFactory extends Drawable {
+
+    private final Bitmap mFlatBitmap;
+    private final Canvas mFlatCanvas;
+    private final Paint mCopyPaint;
+
+    private final Bitmap mAlphaBitmap;
+    private final Canvas mAlphaCanvas;
+    private final byte[] mPixels;
+
+    private final int mBitmapSize;
+    private final int mEdgePixelLength;
+
+    private final Paint mDrawPaint;
+    private final Rect mSrcRect;
+
+    MonochromeIconFactory(int iconBitmapSize) {
+        float extraFactor = AdaptiveIconDrawable.getExtraInsetFraction();
+        float viewPortScale = 1 / (1 + 2 * extraFactor);
+        mBitmapSize = Math.round(iconBitmapSize * 2 * viewPortScale);
+        mPixels = new byte[mBitmapSize * mBitmapSize];
+        mEdgePixelLength = mBitmapSize * (mBitmapSize - iconBitmapSize) / 2;
+
+        mFlatBitmap = Bitmap.createBitmap(mBitmapSize, mBitmapSize, Config.ARGB_8888);
+        mFlatCanvas = new Canvas(mFlatBitmap);
+
+        mAlphaBitmap = Bitmap.createBitmap(mBitmapSize, mBitmapSize, Config.ALPHA_8);
+        mAlphaCanvas = new Canvas(mAlphaBitmap);
+
+        mDrawPaint = new Paint(FILTER_BITMAP_FLAG);
+        mDrawPaint.setColor(Color.WHITE);
+        mSrcRect = new Rect(0, 0, mBitmapSize, mBitmapSize);
+
+        mCopyPaint = new Paint(FILTER_BITMAP_FLAG);
+        mCopyPaint.setBlendMode(BlendMode.SRC);
+
+        // Crate a color matrix which converts the icon to grayscale and then uses the average
+        // of RGB components as the alpha component.
+        ColorMatrix satMatrix = new ColorMatrix();
+        satMatrix.setSaturation(0);
+        float[] vals = satMatrix.getArray();
+        vals[15] = vals[16] = vals[17] = .3333f;
+        vals[18] = vals[19] = 0;
+        mCopyPaint.setColorFilter(new ColorMatrixColorFilter(vals));
+    }
+
+    private void drawDrawable(Drawable drawable) {
+        if (drawable != null) {
+            drawable.setBounds(0, 0, mBitmapSize, mBitmapSize);
+            drawable.draw(mFlatCanvas);
+        }
+    }
+
+    /**
+     * Creates a monochrome version of the provided drawable
+     */
+    @WorkerThread
+    public Drawable wrap(Drawable icon) {
+        if (icon instanceof AdaptiveIconDrawable) {
+            AdaptiveIconDrawable aid = (AdaptiveIconDrawable) icon;
+            mFlatCanvas.drawColor(Color.BLACK);
+            drawDrawable(aid.getBackground());
+            drawDrawable(aid.getForeground());
+            generateMono();
+            return new ClippedMonoDrawable(this);
+        } else {
+            mFlatCanvas.drawColor(Color.WHITE);
+            drawDrawable(icon);
+            generateMono();
+            return this;
+        }
+    }
+
+    @WorkerThread
+    private void generateMono() {
+        mAlphaCanvas.drawBitmap(mFlatBitmap, 0, 0, mCopyPaint);
+
+        // Scale the end points:
+        ByteBuffer buffer = ByteBuffer.wrap(mPixels);
+        buffer.rewind();
+        mAlphaBitmap.copyPixelsToBuffer(buffer);
+
+        int min = 0xFF;
+        int max = 0;
+        for (byte b : mPixels) {
+            min = Math.min(min, b & 0xFF);
+            max = Math.max(max, b & 0xFF);
+        }
+
+        if (min < max) {
+            // rescale pixels to increase contrast
+            float range = max - min;
+
+            // In order to check if the colors should be flipped, we just take the average color
+            // of top and bottom edge which should correspond to be background color. If the edge
+            // colors have more opacity, we flip the colors;
+            int sum = 0;
+            for (int i = 0; i < mEdgePixelLength; i++) {
+                sum += (mPixels[i] & 0xFF);
+                sum += (mPixels[mPixels.length - 1 - i] & 0xFF);
+            }
+            float edgeAverage = sum / (mEdgePixelLength * 2f);
+            float edgeMapped = (edgeAverage - min) / range;
+            boolean flipColor = edgeMapped > .5f;
+
+            for (int i = 0; i < mPixels.length; i++) {
+                int p = mPixels[i] & 0xFF;
+                int p2 = Math.round((p - min) * 0xFF / range);
+                mPixels[i] = flipColor ? (byte) (255 - p2) : (byte) (p2);
+            }
+            buffer.rewind();
+            mAlphaBitmap.copyPixelsFromBuffer(buffer);
+        }
+    }
+
+    @Override
+    public void draw(Canvas canvas) {
+        canvas.drawBitmap(mAlphaBitmap, mSrcRect, getBounds(), mDrawPaint);
+    }
+
+    @Override
+    public int getOpacity() {
+        return PixelFormat.TRANSLUCENT;
+    }
+
+    @Override
+    public void setAlpha(int i) {
+        mDrawPaint.setAlpha(i);
+    }
+
+    @Override
+    public void setColorFilter(ColorFilter colorFilter) {
+        mDrawPaint.setColorFilter(colorFilter);
+    }
+}