Android未读消息拖动气泡示例

原标题：Android未读消息拖动气泡示例

拖动清除未读消息可以说在很多应用中都很常见，也被用户广泛接受。本文是一个可以供参考的Demo，希望能有帮助。

提示：以下是本篇文章正文内容，下面案例可供参考

实现关键：气泡中间的两条边，分别是以ab，cd为数据点，G为控制点的贝塞尔曲线。

步骤：绘制圆背景以及文本；连接情况绘制贝塞尔曲线；另外端点绘制一个圆

1.定义，初始化等

状态：静止、连接、分离、消失
在onSizeChanged中初始化状态，固定气泡以及可动气泡的圆心

代码如下（示例）：

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
init(w, h);
}
private void init(int w, int h) {
mBubbleState = BUBBLE_STATE_DEFAULT;
//设置固定气泡圆心初始坐标
if (mBubFixedCenter == null) {
mBubFixedCenter = new PointF(w / 2, h / 2);
} else {
mBubFixedCenter.set(w / 2, h / 2);
}
//设置可动气泡圆心初始坐标
if (mBubMovableCenter == null) {
mBubMovableCenter = new PointF(w / 2, h / 2);
} else {
mBubMovableCenter.set(w / 2, h / 2);
}
}


2.onDraw中绘制包括三样绘制

第一样：静止，连接，分离状态都需要绘制圆背景以及文本：

//静止，连接，分离状态都需要绘制圆背景以及文本
if (mBubbleState != BUBBLE_STATE_DISMISS) {
canvas.drawCircle(mBubMovableCenter.x, mBubMovableCenter.y, mBubMovableRadius, mBubblePaint);
mTextPaint.getTextBounds(mTextStr, 0, mTextStr.length(), mTextRect);
canvas.drawText(mTextStr, mBubMovableCenter.x - mTextRect.width() / 2, mBubMovableCenter.y + mTextRect.height() / 2, mTextPaint);
}


第二样：连接状态绘制贝塞尔曲线①。

if (mBubbleState == BUBBLE_STATE_CONNECT) {
//绘制静止的气泡
canvas.drawCircle(mBubFixedCenter.x, mBubFixedCenter.y, mBubFixedRadius, mBubblePaint);
//计算控制点的坐标
int iAnchorX = (int) ((mBubMovableCenter.x + mBubFixedCenter.x) / 2);
int iAnchorY = (int) ((mBubMovableCenter.y + mBubFixedCenter.y) / 2);
float sinTheta = (mBubMovableCenter.y - mBubFixedCenter.y) / mDist;
float cosTheta = (mBubMovableCenter.x - mBubFixedCenter.x) / mDist;
//D
float iBubFixedStartX = mBubFixedCenter.x - mBubFixedRadius * sinTheta;
float iBubFixedStartY = mBubFixedCenter.y + mBubFixedRadius * cosTheta;
//C
float iBubMovableEndX = mBubMovableCenter.x - mBubMovableRadius * sinTheta;
float iBubMovableEndY = mBubMovableCenter.y + mBubMovableRadius * cosTheta;
//A
float iBubFixedEndX = mBubFixedCenter.x + mBubFixedRadius * sinTheta;
float iBubFixedEndY = mBubFixedCenter.y - mBubFixedRadius * cosTheta;
//B
float iBubMovableStartX = mBubMovableCenter.x + mBubMovableRadius * sinTheta;
float iBubMovableStartY = mBubMovableCenter.y - mBubMovableRadius * cosTheta;
mBezierPath.reset();
mBezierPath.moveTo(iBubFixedStartX, iBubFixedStartY);
mBezierPath.quadTo(iAnchorX, iAnchorY, iBubMovableEndX, iBubMovableEndY);
mBezierPath.lineTo(iBubMovableStartX, iBubMovableStartY);
mBezierPath.quadTo(iAnchorX, iAnchorY, iBubFixedEndX, iBubFixedEndY);
mBezierPat文章来源地址38100.htmlh.close();
canvas.drawPath(mBezierPath, mBubblePaint);
}


第三样：消失状态执行爆炸动画

// 认为是消失状态，执行爆炸动画
if (mBubbleState == BUBBLE_STATE_DISMISS && mCurDrawableIndex < mBurstBitmapsArray.length) {
mBwww.yii666.comurstRect.set(
(int) (mBubMovableCenter.x - mBubMovableRadius),
(int) (mBubMovableCenter.y - mBubMovableRadius),
(int) (mBubMovableCenter.x + mBubMovableRadius),
(int) (mBubMovableCenter.y + mBubMovableRadius));
canvas.drawBitmap(mBurstBitmapsArray[mCurDrawableIndex], null, mBurstRect, mBubblePaint);
}


3.onTouchEvent中

按下：区分静止状态和连接状态

case MotionEvent.ACTION_DOWN:
if (mBubbleState != BUBBLE_STATE_DISMISS) {
mDist = (float) Math.hypot(event.getX() - mBubFixedCenter.x, event.getY() - mBubFixedCenter.y);
if (mDist < mBubbleRadius + MOVE_OFFSET) {
//加上MOVE_OFFSET是为了方便拖拽
mBubbleState = BUBBLE_STATE_CONNECT;
} else {
mBubbleState = BUBBLE_STATE_DEFAULT;
}
}
break;


移动：判断是否到了分离状态

case MotionEvent.ACTION_MOVE:
if (mBubbleState != BUBBLE_STATE_DEFAULT) {
mDist = (float) Math.hypot(event.getX() - mBubFixedCenter.x, event.getY() - mBubFixedCenter.y);
mBubMovableCenter.x = event.getX();
mBubMovableCenter.y = event.getY();
if (mBubbleState == BUBBLE_STATE_CONNECT) {
if (mDist < mMaxDist - MOVE_OFFSET) {
mBubFixedRadius = mBubbleRadius - mDist / 8;
} else {
mBubbleState = BUBBLE_STATE_APART;
}
}
invalidate();
}
break;


弹起：判断是否已经到了分离状态，分离状态爆炸，未分离反弹

case MotionEvent.ACTION_UP:
if (mBubbleState == BUBBLE_STATE_CONNECT) {
// 橡皮筋动画
startBubbleRestAnim();
} else if (mBubbleState == BUBBLE_STATE_APART) {
if (mDist < 2 * mBubbleRadius){
//反弹动画
startBubbleRestAnim();
}else{
// 爆炸动画
startBubbleBurstAnim();
}
}
break;


4.反弹和爆炸动画

/**
* 连接状态下松开手指，执行类似橡皮筋动画
*/
private void startBubbleRestAnim() {
ValueAnimator anim = ValueAnimator.ofObject(new PointFEvaluator(),
new PointF(mBubMovableCenter.x, mBubMovableCenter.y),
new PointF(mBubFixedCenter.x, mBubFixedCenter.y));
anim.setDuration(200);
anim.setInterpolator(new OvershootInterpolator(5f));
anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
mBubMovableCenter = (PointF) animation.getAnimatedValue();
invalidate();
}
});
anim.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
文章来源地址38100.html mBubbleState = BUBBLE_STATE_DEFAULT;
}
});
anim.start();
}


/**
* 爆炸动画
*/
private void startBubbleBurstAnim() {
//将气泡改成消失状态
mBubbleState = BUBBLE_STATE_DISMISS;
ValueAnimator animator = ValueAnimator.ofInt(0, mBurstBitmapsArray.length);
animator.setInterpolator(new LinearInterpolator());
animator.setDuration(500);
animator.addUpdateListener(new ValueAnimatwww.yii666.comor.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
mCurDrawableIndex = (int) animation.getAnimatedValue();
invalidate();
}
});
anima文章来源站点https://www.yii666.com/tor.start();
}


注：①贝塞尔曲线参考博文

本文完，有需要参考的同学→文中Demo下载地址

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来源于：Android未读消息拖动气泡示例