这是一个悬浮 【指示器 – 菜单】的控件容器，支持 上滑|下滑 的百分比进度跟踪，去掉了对 layout布局文件的依赖，去掉了对values 属性文件的依赖，由于这是第二次维护这个小demo了，以后会的多了，在改进。。。
FloatTitleLayout.gif
核心代码如下
<pre>
/*处理滑动事件：开始*/
if (Math.abs(distanceX) > Math.abs(distanceY * 0.8)) {
/*上下滑动的 距离 表现不明显*/
return super.dispatchTouchEvent(event);
}
//KLog.e(“isFloated = “+isFloated+” isChildOnTop = “+isChildOnTop);
/*非悬浮状态，向上滑动↓*/
if ((!isFloated) && (distanceY > 0)) {
/*非悬浮状态，向上滑动，速度过大↓*/
if (yVelocity < -yVelocityMax) {
int indicatorScrollDistanceCurr = 0;
/*非悬浮状态，向上滑动，速度过大，导航条在初始状态，直接将导航条，全部拖上去↓*/
if (paramsIvTopBackground.topMargin == 0) {
distanceY = titleHeight – ivTopBackground.getHeight();
indicatorScrollDistanceCurr = indicatorScrollDistanceMax;
} else {
/*非悬浮状态，向上滑动，速度过大，导航条不在初始状态，直接将导航条，全部拖上去↑*/
distanceY = -locationIndicatorYInScreen + titleHeight + statusHeight;
indicatorScrollDistanceCurr = indicatorScrollDistanceMax;
}
paramsIvTopBackground.topMargin = paramsIvTopBackground.topMargin + (int) distanceY;
ivTopBackground.setLayoutParams(paramsIvTopBackground);
updateScrollProgress(indicatorScrollDistanceCurr);
isFloated = true;
return true;
} else if (yVelocity >= -yVelocityMax) {
/*非悬浮状态，向上滑动，速度正常↓*/
if (titleHeight + statusHeight + distanceY > locationIndicatorYInScreen) {
distanceY = locationIndicatorYInScreen – titleHeight – statusHeight;
}
paramsIvTopBackground.topMargin = paramsIvTopBackground.topMargin – (int) distanceY;
ivTopBackground.setLayoutParams(paramsIvTopBackground);
/*计算后得到当前真实的 locationIndicatorYInScreen*/
int locationIndicatorYInScreenTrue = (locationIndicatorYInScreen – (int) distanceY);
int indicatorScrollDistanceCurr = ivTopBackground.getHeight() + statusHeight – locationIndicatorYInScreenTrue;
//KLog.e(“计算后的 locationIndicatorYInScreen “+locationIndicatorYInScreenTrue+” indicatorScrollDistanceCurr = “+indicatorScrollDistanceCurr);
//KLog.e(“背景图高度 = “+ivTopBackground.getHeight()+” locationIvTopBackgroundYInScreen = “+locationIvTopBackgroundYInScreen+” locationIndicatorYInScreen = ” + locationIndicatorYInScreen + ” statusHeight = ” + statusHeight + ” titleHeight = ” + titleHeight+” distanceY = “+distanceY+” indicatorScrollDistanceMax = “+indicatorScrollDistanceMax);
updateScrollProgress(indicatorScrollDistanceCurr);
return true;
}
} else if ((!isFloated) && (distanceY < 0)) {
/*非悬浮状态，向下滑动 ↑*/
//&& isChildOnTop
int indicatorScrollDistanceCurr = 0;
if (locationIndicatorYInScreen == (ivTopBackground.getHeight() + statusHeight)) {
/*非悬浮状态，向下滑动 ，当前导航条在初始状态↑*/
return super.dispatchTouchEvent(event);
}
if (yVelocity > yVelocityMax) {
/*非悬浮状态，向下滑动，速度过大*/
indicatorScrollDistanceCurr = 0;
paramsIvTopBackground.topMargin = 0;
} else if (yVelocity < yVelocityMax) {
/*非悬浮状态，向下滑动 ，速度正常*/
//KLog.e(“topMargin = “+paramsIvTopBackground.topMargin+” locationIndicatorYInScreen = “+locationIndicatorYInScreen+” distanceY = “+distanceY);
if ((locationIndicatorYInScreen – (int) distanceY) <= (ivTopBackground.getHeight() + statusHeight)) {
paramsIvTopBackground.topMargin = paramsIvTopBackground.topMargin – (int) distanceY;
indicatorScrollDistanceCurr = ivTopBackground.getHeight() + statusHeight – (locationIndicatorYInScreen – (int) distanceY);
} else {
paramsIvTopBackground.topMargin = 0;
indicatorScrollDistanceCurr = 0;
}
}
ivTopBackground.setLayoutParams(paramsIvTopBackground);
updateScrollProgress(indicatorScrollDistanceCurr);
return true;
} else if (isFloated && (distanceY < 0) && isChildOnTop) {
isFloated = false;
int indicatorScrollDistanceCurr = 0;
/*悬浮状态，向下滑动，ScrollView 展示第一条数据 ↑*/
if (yVelocity > yVelocityMax) {
/*悬浮状态，向下滑动，ScrollView 展示第一条数据 ，速度过大，直接将背景图，全部拖出来*/
indicatorScrollDistanceCurr = 0;
paramsIvTopBackground.topMargin = 0;
} else if (yVelocity <= yVelocityMax) {
/*悬浮状态，向下滑动，ScrollView 展示第一条数据 ，速度正常，将背景图，慢慢拖出来*/
//KLog.e(“distanceY = “+distanceY+” locationIndicatorYInScreen = “+locationIndicatorYInScreen);
if ((locationIndicatorYInScreen – (int) distanceY) <= (ivTopBackground.getHeight() + statusHeight)) {
paramsIvTopBackground.topMargin = paramsIvTopBackground.topMargin – (int) distanceY;
indicatorScrollDistanceCurr = ivTopBackground.getHeight() + statusHeight – (locationIndicatorYInScreen – (int) distanceY);
} else {
paramsIvTopBackground.topMargin = ivTopBackground.getHeight() + statusHeight;
indicatorScrollDistanceCurr = indicatorScrollDistanceMax;
}
}
ivTopBackground.setLayoutParams(paramsIvTopBackground);
updateScrollProgress(indicatorScrollDistanceCurr);
}
/*处理滑动事件：结束*/
</pre>
此时此刻，很开心功能可以实现了，不用被鄙视了。
国际惯例 附上源码
<a href=”https://github.com/Alex-Cin/FloatIndicatorLayout”>https://github.com/Alex-Cin/FloatIndicatorLayout</a>
