Skip logic to find the dominant color when loading recent task icons

- Also move some allocations in ColorExtractor into thread locals to reduce
  allocations

Bug: 78777731
Change-Id: I8819106d476a9af02e864135a2f44b55fe9219cd

3 files changed, 43 insertions, 11 deletions

diff --git a/src/com/android/launcher3/graphics/BitmapInfo.java b/src/com/android/launcher3/graphics/BitmapInfo.java
index ab906e2f0..c905a78e5 100644
--- a/src/com/android/launcher3/graphics/BitmapInfo.java
+++ b/src/com/android/launcher3/graphics/BitmapInfo.java
@@ -35,9 +35,15 @@ public class BitmapInfo {
     }
 
     public static BitmapInfo fromBitmap(Bitmap bitmap) {
+        return fromBitmap(bitmap, null);
+    }
+
+    public static BitmapInfo fromBitmap(Bitmap bitmap, ColorExtractor dominantColorExtractor) {
         BitmapInfo info = new BitmapInfo();
         info.icon = bitmap;
-        info.color = ColorExtractor.findDominantColorByHue(bitmap);
+        info.color = dominantColorExtractor != null
+                ? dominantColorExtractor.findDominantColorByHue(bitmap)
+                : 0;
         return info;
     }
 }
diff --git a/src/com/android/launcher3/graphics/ColorExtractor.java b/src/com/android/launcher3/graphics/ColorExtractor.java
index e9d72b793..da5da9cea 100644
--- a/src/com/android/launcher3/graphics/ColorExtractor.java
+++ b/src/com/android/launcher3/graphics/ColorExtractor.java
@@ -18,22 +18,32 @@ package com.android.launcher3.graphics;
 import android.graphics.Bitmap;
 import android.graphics.Color;
 import android.util.SparseArray;
+import java.util.Arrays;
 
 /**
  * Utility class for extracting colors from a bitmap.
  */
 public class ColorExtractor {
 
-    public static int findDominantColorByHue(Bitmap bitmap) {
-        return findDominantColorByHue(bitmap, 20);
+    private final int NUM_SAMPLES = 20;
+    private final float[] mTmpHsv = new float[3];
+    private final float[] mTmpHueScoreHistogram = new float[360];
+    private final int[] mTmpPixels = new int[NUM_SAMPLES];
+    private final SparseArray<Float> mTmpRgbScores = new SparseArray<>();
+
+    /**
+     * This picks a dominant color, looking for high-saturation, high-value, repeated hues.
+     * @param bitmap The bitmap to scan
+     */
+    public int findDominantColorByHue(Bitmap bitmap) {
+        return findDominantColorByHue(bitmap, NUM_SAMPLES);
     }
 
     /**
      * This picks a dominant color, looking for high-saturation, high-value, repeated hues.
      * @param bitmap The bitmap to scan
-     * @param samples The approximate max number of samples to use.
      */
-    public static int findDominantColorByHue(Bitmap bitmap, int samples) {
+    public int findDominantColorByHue(Bitmap bitmap, int samples) {
         final int height = bitmap.getHeight();
         final int width = bitmap.getWidth();
         int sampleStride = (int) Math.sqrt((height * width) / samples);
@@ -42,15 +52,18 @@ public class ColorExtractor {
         }
 
         // This is an out-param, for getting the hsv values for an rgb
-        float[] hsv = new float[3];
+        float[] hsv = mTmpHsv;
+        Arrays.fill(hsv, 0);
 
         // First get the best hue, by creating a histogram over 360 hue buckets,
         // where each pixel contributes a score weighted by saturation, value, and alpha.
-        float[] hueScoreHistogram = new float[360];
+        float[] hueScoreHistogram = mTmpHueScoreHistogram;
+        Arrays.fill(hueScoreHistogram, 0);
         float highScore = -1;
         int bestHue = -1;
 
-        int[] pixels = new int[samples];
+        int[] pixels = mTmpPixels;
+        Arrays.fill(pixels, 0);
         int pixelCount = 0;
 
         for (int y = 0; y < height; y += sampleStride) {
@@ -82,7 +95,8 @@ public class ColorExtractor {
             }
         }
 
-        SparseArray<Float> rgbScores = new SparseArray<>();
+        SparseArray<Float> rgbScores = mTmpRgbScores;
+        rgbScores.clear();
         int bestColor = 0xff000000;
         highScore = -1;
         // Go back over the RGB colors that match the winning hue,
diff --git a/src/com/android/launcher3/graphics/LauncherIcons.java b/src/com/android/launcher3/graphics/LauncherIcons.java
index 333fe5907..0167a1d9c 100644
--- a/src/com/android/launcher3/graphics/LauncherIcons.java
+++ b/src/com/android/launcher3/graphics/LauncherIcons.java
@@ -90,6 +90,7 @@ public class LauncherIcons implements AutoCloseable {
         synchronized (sPoolSync) {
             // Clear any temporary state variables
             mWrapperBackgroundColor = DEFAULT_WRAPPER_BACKGROUND;
+            mDisableColorExtractor = false;
 
             next = sPool;
             sPool = this;
@@ -105,6 +106,8 @@ public class LauncherIcons implements AutoCloseable {
     private final Context mContext;
     private final Canvas mCanvas;
     private final PackageManager mPm;
+    private final ColorExtractor mColorExtractor;
+    private boolean mDisableColorExtractor;
 
     private final int mFillResIconDpi;
     private final int mIconBitmapSize;
@@ -121,6 +124,7 @@ public class LauncherIcons implements AutoCloseable {
     private LauncherIcons(Context context) {
         mContext = context.getApplicationContext();
         mPm = mContext.getPackageManager();
+        mColorExtractor = new ColorExtractor();
 
         InvariantDeviceProfile idp = LauncherAppState.getIDP(mContext);
         mFillResIconDpi = idp.fillResIconDpi;
@@ -196,7 +200,7 @@ public class LauncherIcons implements AutoCloseable {
      * The bitmap is also visually normalized with other icons.
      */
     public BitmapInfo createBadgedIconBitmap(Drawable icon, UserHandle user, int iconAppTargetSdk,
-            boolean isInstantApp, float [] scale) {
+            boolean isInstantApp, float[] scale) {
         if (scale == null) {
             scale = new float[1];
         }
@@ -223,7 +227,7 @@ public class LauncherIcons implements AutoCloseable {
         } else {
             result = bitmap;
         }
-        return BitmapInfo.fromBitmap(result);
+        return BitmapInfo.fromBitmap(result, mDisableColorExtractor ? null : mColorExtractor);
     }
 
     /**
@@ -245,6 +249,14 @@ public class LauncherIcons implements AutoCloseable {
         mWrapperBackgroundColor = (Color.alpha(color) < 255) ? DEFAULT_WRAPPER_BACKGROUND : color;
     }
 
+    /**
+     * Disables the dominant color extraction for all icons loaded through this session (until
+     * this instance is recycled).
+     */
+    public void disableColorExtraction() {
+        mDisableColorExtractor = true;
+    }
+
     private Drawable normalizeAndWrapToAdaptiveIcon(Drawable icon, int iconAppTargetSdk,
             RectF outIconBounds, float[] outScale) {
         float scale = 1f;