add gray for BitmapLess

Author: fengjian

app/src/main/java/com/jayfeng/lesscode/app/activity/BitmapActivity.java

@@ -25,7 +25,7 @@ protected void onCreate(Bundle savedInstanceState) {
         roundImageView = ViewLess.$(this, R.id.image_round);
 
         Bitmap bitmap = ((BitmapDrawable) getResources().getDrawable(R.drawable.girl2)).getBitmap();
-        bitmap = BitmapLess.$round(bitmap, 100, true);
+        bitmap = BitmapLess.$gray(bitmap, true);
         roundImageView.setImageBitmap(bitmap);
     }
 }

app/src/main/java/com/jayfeng/lesscode/app/activity/CacheActivity.java

@@ -2,9 +2,11 @@
 
 import android.app.Activity;
 import android.graphics.Bitmap;
+import android.graphics.BitmapRegionDecoder;
 import android.graphics.Matrix;
 import android.graphics.drawable.BitmapDrawable;
 import android.os.Bundle;
+import android.support.v4.util.LruCache;
 
 import com.jayfeng.lesscode.app.R;
 

lesscode-core/src/main/java/com/jayfeng/lesscode/core/BitmapLess.java

@@ -5,6 +5,8 @@
 import android.graphics.BitmapFactory;
 import android.graphics.Canvas;
 import android.graphics.Color;
+import android.graphics.ColorMatrix;
+import android.graphics.ColorMatrixColorFilter;
 import android.graphics.Matrix;
 import android.graphics.Paint;
 import android.graphics.PorterDuff;
@@ -308,4 +310,30 @@ public final class BitmapLess {
 
         return circleBitmap;
     }
+
+    /**
+     * 灰阶效果
+     * @param originBitmap
+     * @param recycle
+     * @return
+     */
+    public static Bitmap $gray(Bitmap originBitmap, boolean recycle) {
+        Bitmap grayBitmap = Bitmap.createBitmap(originBitmap.getWidth(),
+                originBitmap.getHeight(), Bitmap.Config.RGB_565);
+        Canvas canvas = new Canvas(grayBitmap);
+        Paint paint = new Paint();
+        ColorMatrix colorMatrix = new ColorMatrix();
+        colorMatrix.setSaturation(0);
+        ColorMatrixColorFilter colorMatrixColorFilter =
+                new ColorMatrixColorFilter(colorMatrix);
+        paint.setColorFilter(colorMatrixColorFilter);
+        canvas.drawBitmap(originBitmap, 0, 0, paint);
+
+        // 是否回收原始Bitmap
+        if (recycle && originBitmap != null && !originBitmap.isRecycled()) {
+            originBitmap.recycle();
+        }
+
+        return grayBitmap;
+    }
 }