使用layout方法实现控件的移动并且不影响点击事件

简单的效果图如下

<?xml version="1.0" encoding="utf-8"?>
<com.oushangfeng.floatactionbuttondemo.MyCoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".MainActivity">

<android.support.design.widget.AppBarLayout
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:theme="@style/AppTheme.AppBarOverlay">

<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme.PopupOverlay"/>

</android.support.design.widget.AppBarLayout>

<include layout="@layout/content_main"/>

<com.oushangfeng.floatactionbuttondemo.DraggableFloatingButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="@dimen/fab_margin"
android:src="@android:drawable/ic_dialog_email"/>

</com.oushangfeng.floatactionbuttondemo.MyCoordinatorLayout>

// 记录上次的xy坐标
private int mLastX, mLastY;
// 记录按下和松开手指的时间
private long mDownTime, mUpTime;

// 记录上次移动完的上下左右坐标
private int mLastLeft = -1;
private int mLastRight = -1;
private int mLastTop = -1;
private int mLastBottom = -1;

public int getLastLeft() {
return mLastLeft;
}

public int getLastRight() {
return mLastRight;
}

public int getLastTop() {
return mLastTop;
}

public int getLastBottom() {
return mLastBottom;
}

@Override
public boolean onTouchEvent(MotionEvent event) {
int x = (int) event.getRawX();
int y = (int) event.getRawY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mDownTime = System.currentTimeMillis();
break;
case MotionEvent.ACTION_MOVE:

int deltaX = x - mLastX;
int deltaY = y - mLastY;

// 移动后的上下左右坐标
int left = getLeft() + deltaX;
int right = getRight() + deltaX;
int top = getTop() + deltaY;
int bottom = getBottom() + deltaY;

int marginLeft = 0;
int marginRight = 0;
int marginTop = 0;
int marginBottom = 0;

if (getLayoutParams() instanceof ViewGroup.MarginLayoutParams) {
// 获取margin值，做移动的边界判断
ViewGroup.MarginLayoutParams lp = (ViewGroup.MarginLayoutParams)
getLayoutParams();
marginLeft = lp.leftMargin;
marginRight = lp.rightMargin;
marginTop = lp.topMargin;
marginBottom = lp.bottomMargin;
}

int parentWidth = 0;
int parentHeight = 0;

if (getParent() != null && getParent() instanceof ViewGroup) {

ViewGroup parent = (ViewGroup) getParent();

// 拿到父布局宽高
parentWidth = parent.getWidth();
parentHeight = parent.getHeight();

if (left < marginLeft) {
// 移到到最左的时候，限制在marginLeft
left = marginLeft;
right = getWidth() + left;
}

if (right > parentWidth - marginRight) {
// 移动到最右
right = parentWidth - marginRight;
left = right - getWidth();
}

if (top < marginTop) {
// 移动到顶部
top = marginTop;
bottom = getHeight() + top;
}

if (bottom > parentHeight - marginBottom) {
// 移动到底部
bottom = parentHeight - marginBottom;
top = bottom - getHeight();
}

layout(left, top, right, bottom);

// 记录移动后的坐标值
mLastLeft = left;
mLastRight = right;
mLastTop = top;
mLastBottom = bottom;

}

break;
case MotionEvent.ACTION_UP:
mLastX = x;
mLastY = y;
mUpTime = System.currentTimeMillis();
// 点击事件的处理
return mUpTime - mDownTime > 200 || super.onTouchEvent(event);
}

mLastX = x;
mLastY = y;

return super.onTouchEvent(event);
}

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
for (int i = 0; i < getChildCount(); i++) {
if (getChildAt(i) instanceof DraggableFloatingButton) {
// 为了防止浮动按钮恢复原位，布局子控件位置时使用上次记录的位置
DraggableFloatingButton child = (DraggableFloatingButton) getChildAt(i);
if (child.getLastLeft() != -1) {
child.layout(child.getLastLeft(), child.getLastTop(), child.getLastRight(),
child.getLastBottom());
}
break;
}
}
}