안녕하세요.
커스텀 달력 그리기 공부중에 궁한 점이 있어서 질문을 올립니다.
아래 소스 코드를 보면 onMeasure 메소드 내부에 각 날자가 들어가는 view의 크기를 계산하는 부분이 있는데
이 부분이 어떤걸 의미하는지는 알겠는데 작동 Logic이 이해가 되지 않아서 도움을 요청하려고 합니다.
1. for 문에서 if(child.getVisibility() == INVISIBLE) continue;가 뜻하는게 무엇인가요?
2. maxWidth += Math.max(maxWidth, child.getMeasuredWidth());
mLeftWidth += child.getMeasuredWidth();
이 코드가 이해가 되질 않습니다.
만약 첫번째 view의 크기를 계산한다고 가정했을때 maxWidth의 초기 값은 0이고 child.getMeasuredWidth()도 아직 계산된 값이 없기 때문에 0이고 그렇게 되면 view의 크기가 없는게 아닌가요?
public class CalendarView extends ViewGroup {
private final int mScreenWidth;
private final int mWidthDate;
private long mMillis;
/**
* 1일의 요일
*/
private int mDateOfWeek;
/**
* 해당월의 마지막 날짜
*/
private int mMaxtDateOfMonth;
private int mDefaultTextSize = 40;
// private int mTextColor = Color.BLUE;
// private Paint mPaint = makePaint(mTextColor);
// private Paint mTestPaint = makePaint(mTextColor);
// public CalendarItemView mCurrentSelectedView = null;
public static String[] DAY_OF_WEEK = null;
public CalendarView(Context context, AttributeSet attrs) {
super(context, attrs);
mScreenWidth = getResources().getDisplayMetrics().widthPixels;
mWidthDate = mScreenWidth / 7;
DAY_OF_WEEK = getResources().getStringArray(R.array.day_of_week);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int count = getChildCount();
// Measurement will ultimately be computing these values.
int maxHeight = 0;
int maxWidth = 0;
int childState = 0;
int mLeftWidth = 0;
int rowCount = 0;
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() == INVISIBLE)
continue;
// Measure the child.
measureChild(child, widthMeasureSpec, heightMeasureSpec);
maxWidth += Math.max(maxWidth, child.getMeasuredWidth());
mLeftWidth += child.getMeasuredWidth();
if ((mLeftWidth / mScreenWidth) > rowCount) {
maxHeight += child.getMeasuredHeight();
rowCount++;
} else {
maxHeight = Math.max(maxHeight, child.getMeasuredHeight());
}
childState = combineMeasuredStates(childState, child.getMeasuredState());
}
maxHeight = (int) (Math.ceil((count + mDateOfWeek - 1) / 7d) * (mWidthDate * 0.75));// 요일중 일요일이 1부터 시작하므로 1을 빼줌
maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth());
int expandSpec = MeasureSpec.makeMeasureSpec(MEASURED_SIZE_MASK, MeasureSpec.AT_MOST);
setMeasuredDimension(resolveSizeAndState(maxWidth, widthMeasureSpec, childState),
resolveSizeAndState(maxHeight, expandSpec, childState << MEASURED_HEIGHT_STATE_SHIFT));
LayoutParams params = getLayoutParams();
params.height = getMeasuredHeight();
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
final int count = getChildCount();
int curWidth, curHeight, curLeft, curTop, maxHeight;
final int childLeft = this.getPaddingLeft();
final int childTop = this.getPaddingTop();
final int childRight = this.getMeasuredWidth() - this.getPaddingRight();
final int childBottom = this.getMeasuredHeight() - this.getPaddingBottom();
final int childWidth = childRight - childLeft;
final int childHeight = childBottom - childTop;
maxHeight = 0;
curLeft = childLeft;
curTop = childTop;
for (int i = 0; i < count; i++) {
View child = getChildAt(i);
if (child.getVisibility() == GONE)
return;
child.measure(MeasureSpec.makeMeasureSpec(childWidth, MeasureSpec.AT_MOST), MeasureSpec.makeMeasureSpec(childHeight, MeasureSpec.AT_MOST));
curWidth = mWidthDate;
curHeight = (int) (mWidthDate * 0.75);
if (curLeft + curWidth >= childRight) {
curLeft = childLeft;
curTop += maxHeight;
maxHeight = 0;
}
if (i == 7) {
curLeft = (mDateOfWeek - 1) * curWidth;
}
child.layout(curLeft, curTop, curLeft + curWidth, curTop + curHeight);
if (maxHeight < curHeight) {
maxHeight = curHeight;
}
curLeft += curWidth;
}
}
public void setDate(long millis) {
mMillis = millis;
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(millis);
calendar.set(Calendar.DATE, 1);
mDateOfWeek = calendar.get(Calendar.DAY_OF_WEEK);
mMaxtDateOfMonth = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
invalidate();
}
// TODO : touch로 scale in/out 기능 추가
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
break;
case MotionEvent.ACTION_MOVE:
break;
case MotionEvent.ACTION_UP:
break;
}
return super.onTouchEvent(event);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
}
private Paint makePaint(int color) {
Paint p = new Paint(Paint.ANTI_ALIAS_FLAG);
p.setColor(color);
p.setTextSize(mDefaultTextSize);
return p;
}
public void initCalendar(int dayOfWeek, int maxDateOfMonth) {
mDateOfWeek = dayOfWeek;
mMaxtDateOfMonth = maxDateOfMonth;
}
public void setCurrentSelectedView(View view) {
if (getParent() instanceof ViewPager) {
ViewPager pager = (ViewPager) getParent();
View tagView = (View) pager.getTag();
if (tagView != null) {
long time = (long) tagView.getTag();
Calendar c = Calendar.getInstance();
c.setTimeInMillis(time);
for (int i = 0; i < pager.getChildCount(); i++) {
for (int j = 0; j < getChildCount(); j++) {
CalendarItemView child = (CalendarItemView) ((CalendarView) pager.getChildAt(i)).getChildAt(j);
if (child == null) {
continue;
}
if (child.isStaticText()) {
continue;
}
if (child.isSameDay((Long) child.getTag(), (Long) tagView.getTag())) {
child.invalidate();
break;
}
}
}
}
if (tagView == view) {
pager.setTag(null);
return;
}
long time = (long) view.getTag();
Calendar cal = Calendar.getInstance();
cal.setTimeInMillis(time);
pager.setTag(view);
view.invalidate();
}
}
}
