refactor

Author: yangjian

app/src/main/java/com/jian/explosion/animation/ExplosionAnimator.java

@@ -37,56 +37,60 @@ class ExplosionAnimator extends ValueAnimator {
     private View mContainer;
 
     public ExplosionAnimator(View view, Bitmap bitmap, Rect bound) {
-
-        mPaint = new Paint();
-        mContainer = view;
-
         setFloatValues(0.0f, 1.0f);
         setDuration(DEFAULT_DURATION);
 
+        mPaint = new Paint();
+        mContainer = view;
         mParticles = generateParticles(bitmap, bound);
     }
 
+    // 生成粒子，按行按列生成全部粒子
     private ParticleModel[][] generateParticles(Bitmap bitmap, Rect bound) {
         int w = bound.width();
         int h = bound.height();
 
-        int partW_Count = w / ParticleModel.PART_WH; //横向个数
-        int partH_Count = h / ParticleModel.PART_WH; //竖向个数
+        // 横向粒子的个数
+        int horizontalCount = w / ParticleModel.PART_WH;
+        // 竖向粒子的个数
+        int verticalCount = h / ParticleModel.PART_WH;
 
-        int bitmap_part_w = bitmap.getWidth() / partW_Count;
-        int bitmap_part_h = bitmap.getHeight() / partH_Count;
+        // 粒子宽度
+        int bitmapPartWidth = bitmap.getWidth() / horizontalCount;
+        // 粒子高度
+        int bitmapPartHeight = bitmap.getHeight() / verticalCount;
 
-        ParticleModel[][] particles = new ParticleModel[partH_Count][partW_Count];
-        Point point = null;
-        for (int row = 0; row < partH_Count; row++) { //行
-            for (int column = 0; column < partW_Count; column++) { //列
+        ParticleModel[][] particles = new ParticleModel[verticalCount][horizontalCount];
+        for (int row = 0; row < verticalCount; row++) {
+            for (int column = 0; column < horizontalCount; column++) {
                 //取得当前粒子所在位置的颜色
-                int color = bitmap.getPixel(column * bitmap_part_w, row * bitmap_part_h);
-
-                point = new Point(column, row); //x是列，y是行
+                int color = bitmap.getPixel(column * bitmapPartWidth, row * bitmapPartHeight);
 
-                particles[row][column] = ParticleModel.generateParticle(color, bound, point);
+                Point point = new Point(column, row);
+                particles[row][column] = new ParticleModel(color, bound, point);
             }
         }
-
         return particles;
     }
 
+    // 由view调用，在View上绘制全部的粒子
     void draw(Canvas canvas) {
-        if (!isStarted()) { //动画结束时停止
+        // 动画结束时停止
+        if (!isStarted()) {
             return;
         }
+        // 遍历粒子，并绘制在View上
         for (ParticleModel[] particle : mParticles) {
             for (ParticleModel p : particle) {
                 p.advance((Float) getAnimatedValue());
                 mPaint.setColor(p.color);
-//                mPaint.setAlpha((int) (255 * p.alpha)); //只是这样设置，透明色会显示为黑色
-                mPaint.setAlpha((int) (Color.alpha(p.color) * p.alpha)); //这样透明颜色就不是黑色了
+                // 错误的设置方式只是这样设置，透明色会显示为黑色
+                // mPaint.setAlpha((int) (255 * p.alpha));
+                // 正确的设置方式，这样透明颜色就不是黑色了
+                mPaint.setAlpha((int) (Color.alpha(p.color) * p.alpha));
                 canvas.drawCircle(p.cx, p.cy, p.radius, mPaint);
             }
         }
-
         mContainer.invalidate();
     }
 

app/src/main/java/com/jian/explosion/animation/ExplosionField.java

@@ -51,9 +51,7 @@ protected void onDraw(Canvas canvas) {
     }
 
     /**
-     * 爆破
-     *
-     * @param view 使得该view爆破
+     * 执行爆破破碎动画
      */
     public void explode(final View view, final AnimatorListenerAdapter listener) {
         Rect rect = new Rect();
@@ -62,6 +60,7 @@ public void explode(final View view, final AnimatorListenerAdapter listener) {
 
         animator = new ExplosionAnimator(this, createBitmapFromView(view), rect);
 
+        // 接口回调
         animator.addListener(new Animator.AnimatorListener() {
             @Override
             public void onAnimationStart(Animator animation) {
@@ -95,17 +94,14 @@ public void onAnimationRepeat(Animator animation) {
     }
 
     private Bitmap createBitmapFromView(View view) {
-        /*
-         * 为什么屏蔽以下代码段？
-         * 如果ImageView直接得到位图，那么当它设置背景（backgroud)时，不会读取到背景颜色
-         */
+//         为什么屏蔽以下代码段？
+//         如果ImageView直接得到位图，那么当它设置背景（backgroud)时，不会读取到背景颜色
 //        if (view instanceof ImageView) {
 //            Drawable drawable = ((ImageView)view).getDrawable();
 //            if (drawable != null && drawable instanceof BitmapDrawable) {
 //                return ((BitmapDrawable) drawable).getBitmap();
 //            }
 //        }
-
         //view.clearFocus(); //不同焦点状态显示的可能不同——（azz:不同就不同有什么关系？）
 
         Bitmap bitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);
@@ -114,14 +110,15 @@ private Bitmap createBitmapFromView(View view) {
             synchronized (mCanvas) {
                 mCanvas.setBitmap(bitmap);
                 view.draw(mCanvas);
-                mCanvas.setBitmap(null); //清除引用
+                // 清除引用
+                mCanvas.setBitmap(null);
             }
         }
         return bitmap;
     }
 
     /**
-     * 给Activity加上全屏覆盖的ExplosionField
+     * 将创建的ExplosionField添加到Activity上
      */
     private void attach2Activity(Activity activity) {
         ViewGroup rootView = activity.findViewById(Window.ID_ANDROID_CONTENT);
@@ -131,6 +128,9 @@ private void attach2Activity(Activity activity) {
         rootView.addView(this, lp);
     }
 
+    /**
+     * 将ExplosionField从Activity上移除
+     */
     private void removeFromActivity(Activity activity) {
         ViewGroup rootView = activity.findViewById(Window.ID_ANDROID_CONTENT);
         rootView.removeView(this);

app/src/main/java/com/jian/explosion/animation/ParticleModel.java

@@ -27,41 +27,36 @@
  * 时间：2017/12/26.
  */
 class ParticleModel {
-    static final int PART_WH = 8; //默认小球宽高
-
-    //原本的值（不可变）
-//    float originCX;
-//    float originCY;
-//    float originRadius;
-
-    //实际的值（可变）
-    float cx; //center x of circle
-    float cy; //center y of circle
+    // 默认小球宽高
+    static final int PART_WH = 8;
+    // 随机数，随机出位置和大小
+    static Random random = new Random();
+    //center x of circle
+    float cx;
+    //center y of circle
+    float cy;
+    // 半径
     float radius;
-
+    // 颜色
     int color;
+    // 透明度
     float alpha;
-
-    static Random random = new Random();
-
+    // 整体边界
     Rect mBound;
 
-    static ParticleModel generateParticle(int color, Rect bound, Point point) {
+    ParticleModel(int color, Rect bound, Point point) {
         int row = point.y; //行是高
         int column = point.x; //列是宽
 
-        ParticleModel particle = new ParticleModel();
-        particle.mBound = bound;
-        particle.color = color;
-        particle.alpha = 1f;
-
-        particle.radius = PART_WH;
-        particle.cx = bound.left + PART_WH * column;
-        particle.cy = bound.top + PART_WH * row;
-
-        return particle;
+        this.mBound = bound;
+        this.color = color;
+        this.alpha = 1f;
+        this.radius = PART_WH;
+        this.cx = bound.left + PART_WH * column;
+        this.cy = bound.top + PART_WH * row;
     }
 
+    // 每一步动画都得重新计算出自己的状态值
     void advance(float factor) {
         cx = cx + factor * random.nextInt(mBound.width()) * (random.nextFloat() - 0.5f);
         cy = cy + factor * random.nextInt(mBound.height() / 2);