Updating the virtual preloader UX.

> No click feedback when in preloader mode
> No preloader UI when drawn in drag layer
> The preloader consists of a background 9 patch image and a circular progress
is drawn in the content region of the background.
> The preloader is drawn in a slightly larget area than the actual bounds to
make the circular progress more prominent compared to the icon.

issue: 15835307
Change-Id: Ifec3d93ecf1fac994d1128b517da3797247e7ed6

1 files changed, 81 insertions, 0 deletions

diff --git a/src/com/android/launcher3/Utilities.java b/src/com/android/launcher3/Utilities.java
index 0a711c5dd..87c2d7515 100644
--- a/src/com/android/launcher3/Utilities.java
+++ b/src/com/android/launcher3/Utilities.java
@@ -29,6 +29,7 @@ import android.content.pm.ResolveInfo;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
+import android.graphics.Color;
 import android.graphics.Matrix;
 import android.graphics.Paint;
 import android.graphics.PaintFlagsDrawFilter;
@@ -39,6 +40,7 @@ import android.graphics.drawable.PaintDrawable;
 import android.os.Build;
 import android.util.DisplayMetrics;
 import android.util.Log;
+import android.util.SparseArray;
 import android.view.View;
 import android.widget.Toast;
 
@@ -393,4 +395,83 @@ public final class Utilities {
             return false;
         }
     }
+
+    /**
+     * 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.
+     */
+    static int findDominantColorByHue(Bitmap bitmap, int samples) {
+        final int height = bitmap.getHeight();
+        final int width = bitmap.getWidth();
+        int sampleStride = (int) Math.sqrt((height * width) / samples);
+        if (sampleStride < 1) {
+            sampleStride = 1;
+        }
+
+        // This is an out-param, for getting the hsv values for an rgb
+        float[] hsv = new float[3];
+
+        // 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 highScore = -1;
+        int bestHue = -1;
+
+        for (int y = 0; y < height; y += sampleStride) {
+            for (int x = 0; x < width; x += sampleStride) {
+                int argb = bitmap.getPixel(x, y);
+                int alpha = 0xFF & (argb >> 24);
+                if (alpha < 0x80) {
+                    // Drop mostly-transparent pixels.
+                    continue;
+                }
+                // Remove the alpha channel.
+                int rgb = argb | 0xFF000000;
+                Color.colorToHSV(rgb, hsv);
+                // Bucket colors by the 360 integer hues.
+                int hue = (int) hsv[0];
+                if (hue < 0 || hue >= hueScoreHistogram.length) {
+                    // Defensively avoid array bounds violations.
+                    continue;
+                }
+                float score = hsv[1] * hsv[2];
+                hueScoreHistogram[hue] += score;
+                if (hueScoreHistogram[hue] > highScore) {
+                    highScore = hueScoreHistogram[hue];
+                    bestHue = hue;
+                }
+            }
+        }
+
+        SparseArray<Float> rgbScores = new SparseArray<Float>();
+        int bestColor = 0xff000000;
+        highScore = -1;
+        // Go back over the RGB colors that match the winning hue,
+        // creating a histogram of weighted s*v scores, for up to 100*100 [s,v] buckets.
+        // The highest-scoring RGB color wins.
+        for (int y = 0; y < height; y += sampleStride) {
+            for (int x = 0; x < width; x += sampleStride) {
+                int rgb = bitmap.getPixel(x, y) | 0xff000000;
+                Color.colorToHSV(rgb, hsv);
+                int hue = (int) hsv[0];
+                if (hue == bestHue) {
+                    float s = hsv[1];
+                    float v = hsv[2];
+                    int bucket = (int) (s * 100) + (int) (v * 10000);
+                    // Score by cumulative saturation * value.
+                    float score = s * v;
+                    Float oldTotal = rgbScores.get(bucket);
+                    float newTotal = oldTotal == null ? score : oldTotal + score;
+                    rgbScores.put(bucket, newTotal);
+                    if (newTotal > highScore) {
+                        highScore = newTotal;
+                        // All the colors in the winning bucket are very similar. Last in wins.
+                        bestColor = rgb;
+                    }
+                }
+            }
+        }
+        return bestColor;
+    }
 }