概述
当点击一个view时,然后一个水波纹就会从点击处扩散开来,模拟水波背景动效实现。
实现思路
任何东西都可以在生活中找到案例,我们要做水波纹效果,就想象一下,每个人应该都有把石头扔进进水里的经历,首先水波是从中心点的小圆慢慢放大为大圆,然后慢慢消失,我们模拟的时候只需要画圆,通过Canvas. drawCircle(float x, float y, float radius, Paint paint); 方法来实现,通过一点点放大半径在根据变化速率设置透明度的方式实现。
效果如下:
实现过程:
通过计算view的最大宽度 / 2为布局的最大半径,最小半径就是0然后给它一个插值动画让它动起来,每次点击就让它绘制圆,圆的半径为 (this.radiusMax * 插值动画比例 ),插值动画比例的变化曲率为 0 - 1 根据比例计算出半径从小到大的大小,代码如下:
- //初始化画笔
- private void inint() {
- this.animationRunning = false;
- this.paint = new Paint();
- this.paint.setAntiAlias(true);
- this.paint.setStyle(FILLANDSTROKE_STYLE);
- this.paint.setColor(new Color(Color.getIntColor("#0000FF")));//设置水波纹的颜色
- }
-
- @Override
- public void onDraw(Component component, Canvas canvas) {
- float touchX = (float) this.getWidth() / 2;
- float touchY = (float) this.getHeight() / 2;
- this.paint.setAlpha(1 - 1* this.ripplePose);//透明都也是从0到1 因为ripplePose 是从0-1变换
- this.radiusMax = component.getWidth()/2;
- float radiusMax2 = component.getWidth()/4;
- //根据比例设置半径大小
- canvas.drawCircle(touchX, touchY, this.radiusMax * this.ripplePose +radiusMax2, this.paint);
- }
this.ripplePose的变化曲率为 0 - 1 根据比例计算出半径从小到大的大小,来绘制圆,这里我为什么加 radiusMax2是因为给他一个初始半径,让他不要从圆心开始,这样看起来就比较舒服了, 在点击的时候触发动画,代码如下:
- @Override
- public boolean onTouchEvent(Component component, TouchEvent touchEvent) {
- if (touchEvent.getPointerCount() == 1 && touchEvent.getAction() == PRIMARY_POINT_DOWN) { // 一个手指按下
- this.downX = this.getTouchX(touchEvent, 0);
- this.createAnimation(this.getTouchX(touchEvent, 0), this.getTouchY(touchEvent, 0));
- } else if (touchEvent.getPointerCount() == 1 && touchEvent.getAction() == POINT_MOVE) { // 一个手指移动
-
-
- } else if (touchEvent.getPointerCount() == 1 && touchEvent.getAction() == PRIMARY_POINT_UP) { //一个手指抬起
- this.invalidate();
- }
- return false;
- }
效果如下:
但是当我把水波纹应用到 PageSlider 中带有ListContainer 的时候,滑动的时候也会触发水波纹,所以需要解决事件冲突。
事件冲突解决
在添加了长按阴影效果后,在滑动PageSlider 页面的时候listContainer的子item也会触发点击事件,导致各种事件冲突,解决方法就是 在Touch事件中计算定义出各种事件,各个击破。
点击事件:抬起时间-按下时间 没有超过200ms
长按事件:按下超过200ms
长按滑动事件:移动监听里面计算 滑动距离超过20,时间超过200 没有抬起
短按滑动事件: 时间少于200ms 距离超过 200px 没有抬起
然后处理各种事件
另外发现,手机点击的时候移动事件会触发,而模拟器不会触发,这个也需要注意!
这样就完成了整个绘制过程,代码如下:
-
- public boolean onTouchEvent(Component component, TouchEvent touchEvent) {
- if (touchEvent.getPointerCount() == NUM1 && touchEvent.getAction() == NUM1) {
- this.downX = this.getTouchX(touchEvent, 0);
- this.downY = this.getTouchY(touchEvent, 0);
- this.downTime = System.currentTimeMillis();
- this.isDownPose = true;
- this.isSlide = false;
- isYinYing = false;
- } else if (touchEvent.getPointerCount() == NUM1 && touchEvent.getAction() == NUM3) {
- float upx = this.getTouchX(touchEvent, 0);
- long theTime = System.currentTimeMillis();
- int xjuli = (int) Math.abs(upx - downX);
- int timejuli = (int) Math.abs(theTime - this.downTime);
- if (isDownPose && timejuli > NUM200 && xjuli < NUM2 && !isSlide) {
- this.createAnimation(this.getTouchX(touchEvent, 0), this.getTouchY(touchEvent, 0));
- myevenHandler.sendEvent(1, NUM250);
- this.isSlide = true;
- return true;
- }
- return true;
- } else if (touchEvent.getPointerCount() == NUM1 && touchEvent.getAction() == NUM2) {
- float upx = this.getTouchX(touchEvent, 0);
- long upTimes = System.currentTimeMillis();
- isDownPose = false;
- isYinYing = false;
- int xjuli = (int) Math.abs(upx - downX);
- if (!this.isDownPose && upTimes - this.downTime < NUM200 && xjuli < NUM5) {
- this.isDownPose = false;
- this.createAnimation(this.getTouchX(touchEvent, 0), this.getTouchY(touchEvent, 0));
- } else if (!this.isDownPose && System.currentTimeMillis() - this.downTime > NUM250) {
- this.invalidate();
- } else {
- this.isDownPose = false;
- }
- this.isDownPose = false;
- }
- return true;
- }
-
-
- @Override
- public void onLongClicked(Component component) {
- this.createAnimation(this.downX, this.downY);
- myevenHandler.sendEvent(1, NUM250);
- this.isSlide = true;
- }
-
-
-
- public void onDraw(Component var1, Canvas var2) {
- if (isYinYing) {
- this.paint.setAlpha(NUM03F);
- var2.drawCircle(this.touchX, this.touchY, this.radiusMax * this.ripplePose - 0 / NUM2F, this.paint);
- } else {
- if (this.getWidth() != 0 && this.getHeight() != 0) {
- this.radiusMax = (float) Math.sqrt(this.getWidth()
- * this.getWidth() + this.getHeight() * this.getHeight());
- if (this.rippleType != NUM2) {
- this.radiusMax /= NUM2F;
- }
- this.radiusMax -= (float) this.ripplePadding;
- if (this.isCentered || this.rippleType == 1) {
- this.touchX = (float) this.getWidth() / NUM2F;
- this.touchY = (float) this.getHeight() / NUM2F;
- }
- this.paint.setAlpha(this.rippleAlpha - this.rippleAlpha * this.ripplePose);
- float var3 = 0.0F;
- if (this.rippleType == NUM1 && this.ripplePose > NUM04) {
- this.paint.setStyle(Paint.Style.STROKE_STYLE);
- var3 = this.radiusMax * this.ripplePose - this.radiusMax * (this.ripplePose - NUM04) / NUM06;
- this.paint.setStrokeWidth(this.radiusMax * this.ripplePose
- - this.radiusMax * (this.ripplePose - NUM04) / NUM06);
- } else {
- this.paint.setStyle(Paint.Style.FILL_STYLE);
- }
- var2.drawCircle(this.touchX, this.touchY, this.radiusMax * this.ripplePose - var3 / NUM2F, this.paint);
- }
- }
- }
效果如下: