@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// 因为过程中会多次测量，所以需要清空。
mLine.clear();
mCurrentLine = null;
// 做测量
// 自己的宽高。MeasureSpec 父容器期望孩子的方法 MeasureSpec.makeMeasureSpec 父容器期望孩子的宽高。
int width = MeasureSpec.getSize(widthMeasureSpec);
int MaxWidth = width - getPaddingLeft() - getPaddingRight();
int count = getChildCount();
for (int i = 0; i < count; i++) {
View view = getChildAt(i);
measureChild(view, widthMeasureSpec, heightMeasureSpec);
if (mCurrentLine == null) {
// 当前行是空的,可以将测量后的view加入到这行中。
mCurrentLine = new Line(MaxWidth, viewSpace);
mCurrentLine.addView(view);
mLine.add(mCurrentLine);
} else {
if (mCurrentLine.canAdd(view)) {
mCurrentLine.addView(view);
} else {
mCurrentLine = new Line(MaxWidth, viewSpace);
mCurrentLine.addView(view);
mLine.add(mCurrentLine);
}
}
}
// 计算出自己(整个)的高度
int TotalHeight = 0;
TotalHeight += getPaddingBottom() + getPaddingTop();
for (int i = 0; i < mLine.size(); i++) {
TotalHeight += mLine.get(i).Height;
}
TotalHeight += (mLine.size() - 1) * VerticlaSpace;
setMeasuredDimension(width, TotalHeight);
// super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
// 布局区域
childrenWidth = widthSize - getPaddingLeft() - getPaddingRight();
int childrenHeight = heightSize - getPaddingTop() - getPaddingBottom();
reset();
for (int i = 0; i < getChildCount(); i++) {
View child = getChildAt(i);
if (child.getVisibility() == View.GONE) {
continue;
}
int childWidthMeasureSpec =
MeasureSpec.makeMeasureSpec(
widthSize, widthMode == MeasureSpec.EXACTLY ? MeasureSpec.AT_MOST : widthMode);
int childHeightMeasureSpec =
MeasureSpec.makeMeasureSpec(
heightSize, heightMode == MeasureSpec.EXACTLY ? MeasureSpec.AT_MOST : heightMode);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
if (mLine == null) {
mLine = new Line();
}
int measuredWidth = child.getMeasuredWidth();
// 子View最大宽度不超过内容区域
if (measuredWidth > childrenWidth) {
child.measure(
MeasureSpec.makeMeasureSpec(childrenWidth, MeasureSpec.EXACTLY),
childHeightMeasureSpec);
}
mCurrentWidth += measuredWidth;
// 不超过一行
if (mCurrentWidth <= childrenWidth) {
mLine.addView(child);
mCurrentWidth += mHorizontalSpacing;
// 加上间距后超过一行
if (mCurrentWidth >= childrenWidth) {
newLine();
}
// 超过一行
} else {
if (mLine.size() == 0) {
mLine.addView(child);
newLine();
} else {
newLine();
mLine.addView(child);
mCurrentWidth += child.getMeasuredWidth() + mHorizontalSpacing;
}
}
// 把最后一行加到集合里
}
if (mLine != null && mLine.size() > 0) {
mLines.add(mLine);
}
int totelHeight = 0;
if (heightMode == MeasureSpec.EXACTLY) {
totelHeight = heightSize;
} else if (heightMode == MeasureSpec.AT_MOST) {
for (int i = 0; i < mLines.size(); i++) {
int lineHeight = mLines.get(i).getLineHeight();
totelHeight += lineHeight;
if (i != 0) {
totelHeight += mVerticalSpacing;
}
}
totelHeight = Math.min(childrenHeight, totelHeight);
}
setMeasuredDimension(widthSize, totelHeight + getPaddingTop() + getPaddingBottom());
}