WindowsLoad

 

public class WindowsLoad extends View{    private float pi = (float) Math.PI;    private String TAG = "WindowsLoad";    private Paint paint;    private int R;    private float circleR;    private ValueAnimator circleAnimator1;    private ValueAnimator circleAnimator2;    private ValueAnimator circleAnimator3;    private boolean init = true;    float x1, x2, x3, y1, y2, y3;    public WindowsLoad(Context context, AttributeSet attrs) {        super(context, attrs);        paint = new Paint(Paint.ANTI_ALIAS_FLAG);        paint.setColor(Color.parseColor("#ffff4444"));        R = 10;    }    float[] circleCentre;    float[] start1;    float[] start2;    float[] start3;    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        //初始化        if (init) {            circleCentre = new float[]{getWidth() / 2, getHeight() / 2};            start1 = new float[]{getWidth() / 2, R};            start2 = onCiecleCoordinate(-0.5f, start1, circleCentre);            start3 = onCiecleCoordinate(-0.5f, start2, circleCentre);            init = false;            loading();        }//        canvas.drawCircle(start1[0], start1[1], R, paint);//        Log.d(TAG, "onDraw() returned: "+ start1[0]+"   "+start1[1] +"   "+ start2[0]+"   "+start2[1]);        //第一个点初始位置        if (!circleAnimator1.isRunning()) {            canvas.drawCircle(start1[0], start1[1], R, paint);        }        //第二个点初始位置        if (!circleAnimator2.isRunning()) {            canvas.drawCircle(start2[0], start2[1], R, paint);        }        //第三个点初始位置        if (!circleAnimator3.isRunning()) {            canvas.drawCircle(start3[0], start3[1], R, paint);        }        if (circleAnimator1.isRunning()) {            x1 = (float) (circleCentre[0] + circleR * Math.cos((float) circleAnimator1.getAnimatedValue()));            y1 = (float) (circleCentre[1] + circleR * Math.sin((float) circleAnimator1.getAnimatedValue()));            canvas.drawCircle(x1, y1, R, paint);        }        if (circleAnimator2.isRunning()) {            x2 = (float) (circleCentre[0] + circleR * Math.cos((float) circleAnimator2.getAnimatedValue()));            y2 = (float) (circleCentre[1] + circleR * Math.sin((float) circleAnimator2.getAnimatedValue()));            canvas.drawCircle(x2, y2, R, paint);        }        if (circleAnimator3.isRunning()) {            x3 = (float) (circleCentre[0] + circleR * Math.cos((float) circleAnimator3.getAnimatedValue()));            y3 = (float) (circleCentre[1] + circleR * Math.sin((float) circleAnimator3.getAnimatedValue()));            canvas.drawCircle(x3, y3, R, paint);        }        if (circleAnimator1.isRunning() || circleAnimator2.isRunning() || circleAnimator3.isRunning()) {            invalidate();        }    }    private void loading() {        circleAnimator1 = getCircleData(start1, circleCentre, 0);        circleAnimator1.start();        circleAnimator2 = getCircleData(start2, circleCentre, 300);        circleAnimator2.start();        circleAnimator3 = getCircleData(start3, circleCentre, 600);        circleAnimator3.start();        postDelayed(new Runnable() {            @Override            public void run() {                loading();                invalidate();            }        }, circleAnimator3.getDuration() + 600);    }    private SlowToQuick slowToQuick = new SlowToQuick();    private ValueAnimator getCircleData(float[] startCoordinate, float[] RCoordinate, int delay) {        float x1 = startCoordinate[0];        float y1 = startCoordinate[1];        float x0 = RCoordinate[0];        float y0 = RCoordinate[1];//        Log.i(TAG, "getCircleData x y: " + x1+"  ,"+y1+"  x0  "+x0+ " y0  "+y0);        circleR = (float) Math.sqrt((x1 - x0) * (x1 - x0) + (y1 - y0) * (y1 - y0));        float param = (float) (Math.abs(y1 - y0) / circleR);        if (param < -1.0) {            param = -1.0f;        } else if (param > 1.0) {            param = 1.0f;        }        float a = (float) Math.asin(param);        if (x1 >= x0 && y1 >= y0) {            a = a;        } else if (x1 < x0 && y1 >= y0) {            a = pi - a;        } else if (x1 < x0 && y1 < y0) {            a = a + pi;        } else {            a = 2 * pi - a;        }        ValueAnimator circleAnimator = ValueAnimator.ofFloat(a, a + 2 * pi);        circleAnimator.setDuration(1500);        circleAnimator.setInterpolator(slowToQuick);        circleAnimator.setStartDelay(delay);        return circleAnimator;    }    //获取同一个圆上，间隔固定角度的点坐标    private float[] onCiecleCoordinate(float angle, float[] start, float[] center) {        float x1 = start[0];        float y1 = start[1];        float x0 = center[0];        float y0 = center[1];        float R = (float) Math.sqrt((x1 - x0) * (x1 - x0) + (y1 - y0) * (y1 - y0));        float param = (float) (Math.abs(y1 - y0) / R);        if (param < -1.0) {            param = -1.0f;        } else if (param > 1.0) {            param = 1.0f;        }        float a = (float) Math.asin(param);        if (x1 >= x0 && y1 >= y0) {            a = a;        } else if (x1 < x0 && y1 >= y0) {            a = pi - a;        } else if (x1 < x0 && y1 < y0) {            a = a + pi;        } else {            a = 2 * pi - a;        }        float x = (float) (center[0] + R * Math.cos(a + angle));        float y = (float) (center[1] + R * Math.sin(a + angle));        return new float[]{x, y};    }    class SlowToQuick implements Interpolator {        @Override        public float getInterpolation(float input) {            return input * input;        }    }}