private void newLine() {
if (mLine != null && mLine.size() > 0 && !mLines.contains(mLine)) {
mLines.add(mLine);
}
mLine = new Line();
mCurrentWidth = 0;
}
@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());
}