一个css效果的Android实现

大过年的，来瞅瞅效果：

记得以前看过一个css效果，鼠标滑过圆圈，圆圈分成四个子圆圈，子圆圈和原先的圆圈占据的矩形是同一个。这个是Android的版本鼠标滑过的事件变为手指触摸事件。废话不多说，看看代码：

package com.sovnem.fabulouscircle;

import java.util.ArrayList;
import java.util.Random;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;

public class FabulousView extends View {

	int[] colors;
	private Random rand;
	ArrayList<Circle> circles;
	boolean ismeasure;
	Paint paint;

	public FabulousView(Context context) {
		super(context);
		init();
	}

	private void init() {
		Resources res = getContext().getResources();
		colors = new int[] { res.getColor(android.R.color.holo_blue_bright), res.getColor(android.R.color.holo_green_light), res.getColor(android.R.color.holo_orange_light),
				res.getColor(android.R.color.holo_blue_dark), res.getColor(android.R.color.holo_red_light), res.getColor(android.R.color.holo_red_dark),
				res.getColor(android.R.color.holo_blue_dark) };
		rand = new Random();
		circles = new ArrayList<FabulousView.Circle>();
		paint = new Paint();
	}

	@Override
	protected void onDraw(Canvas canvas) {
		super.onDraw(canvas);
		int l = circles.size();
		for (int i = 0; i < l; i++) {
			Circle c = circles.get(i);
			Log.i("info", "" + c.toString());
			paint.setColor(c.color);
			canvas.drawCircle(c.x, c.y, c.r, paint);
		}
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		if (!ismeasure) {

			int w = getResources().getDisplayMetrics().widthPixels;
			int h = getResources().getDisplayMetrics().heightPixels;
			int radius = Math.min(w, h);
			circles.add(new Circle(w / 2, h / 2, radius / 2, getRandomColor()));
			ismeasure = true;
		}
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);
	}

	// 随机一个颜色
	int getRandomColor() {
		return colors[rand.nextInt(colors.length)];
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		// if (event.getAction() == MotionEvent.ACTION_UP)
		handleEvent(event);
		return true;
	}

	private void handleEvent(MotionEvent event) {
		float x = event.getX();
		float y = event.getY();
		int l = circles.size();
		ArrayList<Circle> cs = new ArrayList<FabulousView.Circle>();
		boolean isIn = false;
		int remove = 0;
		for (int i = 0; i < l; i++) {
			Circle c = circles.get(i);
			if (c.isInSelf(x, y)) {
				isIn = true;
				cs.addAll(c.devide(new int[] { getRandomColor(), getRandomColor(), getRandomColor(), getRandomColor() }));
				remove = i;
			}
		}
		if (isIn) {
			circles.remove(remove);
			circles.addAll(cs);
			invalidate();
		}
	}

	class Circle {
		float x, y;
		float r;
		int color;

		public Circle(float x, float y, float r, int color) {
			super();
			this.x = x;
			this.y = y;
			this.r = r;
			this.color = color;
		}

		ArrayList<Circle> devide(int[] colors) {
			ArrayList<Circle> cs = new ArrayList<FabulousView.Circle>();
			cs.add(new Circle(x - r / 2, y - r / 2, r / 2, colors[0]));
			cs.add(new Circle(x + r / 2, y - r / 2, r / 2, colors[1]));
			cs.add(new Circle(x - r / 2, y + r / 2, r / 2, colors[2]));
			cs.add(new Circle(x + r / 2, y + r / 2, r / 2, colors[3]));
			return cs;
		}

		boolean isInSelf(float px, float py) {
			return (this.x - px) * (this.x - px) + (this.y - py) * (this.y - py) <= this.r * this.r;
		}

		@Override
		public String toString() {
			return "Circle [x=" + x + ", y=" + y + ", r=" + r + ", color=" + color + "]";
		}

	}

}