/**
 * 下落的表情
 */
public class DropLook {

    // x轴坐标
    private float x;
    // y轴坐标
    private float y;
    // 初始旋转角度
    private float rotation;
    // 下落速度
    private float speed;
    // 旋转速度
    private float rotationSpeed;
    // 宽度
    private int width;
    // 高度
    private int height;
    // 图片
    private Bitmap bitmap;

    public float getX() {
        return x;
    }

    public void setX(float x) {
        this.x = x;
    }

    public float getY() {
        return y;
    }

    public void setY(float y) {
        this.y = y;
    }

    public float getRotationSpeed() {
        return rotationSpeed;
    }

    public void setRotationSpeed(float rotationSpeed) {
        this.rotationSpeed = rotationSpeed;
    }

    public float getRotation() {
        return rotation;
    }

    public void setRotation(float rotation) {
        this.rotation = rotation;
    }

    public float getSpeed() {
        return speed;
    }

    public void setSpeed(float speed) {
        this.speed = speed;
    }

    public int getWidth() {
        return width;
    }

    public void setWidth(int width) {
        this.width = width;
    }

    public Bitmap getBitmap() {
        return bitmap;
    }

    public void setBitmap(Bitmap bitmap) {
        this.bitmap = bitmap;
    }

    public int getHeight() {
        return height;
    }

    public void setHeight(int height) {
        this.height = height;
    }

}

/**
 * Pass the touch screen motion event down to the target view, or this
 * view if it is the target.
 *
 * @param event The motion event to be dispatched.
 * @return True if the event was handled by the view, false otherwise.
 */
 public boolean dispatchTouchEvent(MotionEvent event) {
    // If the event should be handled by accessibility focus first.
    if (event.isTargetAccessibilityFocus()) {
        // We don't have focus or no virtual descendant has it, do not handle the event.
        if (!isAccessibilityFocusedViewOrHost()) {
            return false;
        }
        // We have focus and got the event, then use normal event dispatch.
        event.setTargetAccessibilityFocus(false);
    }

    boolean result = false;

    if (mInputEventConsistencyVerifier != null) {
        mInputEventConsistencyVerifier.onTouchEvent(event, 0);
    }

    final int actionMasked = event.getActionMasked();
    if (actionMasked == MotionEvent.ACTION_DOWN) {
        // Defensive cleanup for new gesture
        stopNestedScroll();
    }

    if (onFilterTouchEventForSecurity(event)) {
        //noinspection SimplifiableIfStatement
        ListenerInfo li = mListenerInfo;
        if (li != null && li.mOnTouchListener != null
                && (mViewFlags & ENABLED_MASK) == ENABLED
                && li.mOnTouchListener.onTouch(this, event)) {
            result = true;
        }

        if (!result && onTouchEvent(event)) {
            result = true;
        }
    }

    if (!result && mInputEventConsistencyVerifier != null) {
        mInputEventConsistencyVerifier.onUnhandledEvent(event, 0);
    }

    // Clean up after nested scrolls if this is the end of a gesture;
    // also cancel it if we tried an ACTION_DOWN but we didn't want the rest
    // of the gesture.
    if (actionMasked == MotionEvent.ACTION_UP ||
            actionMasked == MotionEvent.ACTION_CANCEL ||
            (actionMasked == MotionEvent.ACTION_DOWN && !result)) {
        stopNestedScroll();
    }

    return result;
}

public class MyScrollView extends ScrollView {

    private OnScrollListener listener;

	/**
	 * 设置滑动距离监听器
	 */
    public void setOnScrollListener(OnScrollListener listener) {
        this.listener = listener;
    }

    public MyScrollView(Context context) {
        super(context);
    }

    public MyScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

	// 滑动距离监听器
    public interface OnScrollListener{

		/**
		 * 在滑动的时候调用，scrollY为已滑动的距离
		 */
        void onScroll(int scrollY);
    }

    @Override
    public void computeScroll() {
        super.computeScroll();
        if(listener!=null){
            listener.onScroll(getScrollY());
        }
    }
}

/**
 * 重写ListView，解决与ScrollView的冲突
 */
public class MyListView extends ListView {
	
    public MyListView(Context context) {
        super(context);
    }

    public MyListView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public MyListView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,
                MeasureSpec.AT_MOST);
        super.onMeasure(widthMeasureSpec, expandSpec);
    }
}

public abstract class AsyncTask<Params, Progress, Result> {
	...
}

public class FirstActivity extends AppCompatActivity {

    public static final String TAG = "FirstActivity";
    private static Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case 0:
                    Log.i(TAG, "handler receive msg.what = " + msg.what);
                    break;
                default:
                    break;
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_first);
        new Thread(new Runnable() {
            @Override
            public void run() {
                //这里做相关操作
                handler.sendEmptyMessage(0);
            }
        }).start();
    }

}