@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
if (tabStrip.isIndicatorAlwaysInCenter() && tabStrip.getChildCount() > 0) {
View firstTab = tabStrip.getChildAt(0);
View lastTab = tabStrip.getChildAt(getChildCount() - 1);
int start = (w - Utils.getMeasuredWidth(firstTab)) / 2 - Utils.getMarginStart(firstTab);
int end = (w - Utils.getMeasuredWidth(lastTab)) / 2 - Utils.getMarginEnd(lastTab);
tabStrip.setMinimumWidth(tabStrip.getMeasuredWidth());
ViewCompat.setPaddingRelative(this, start, getPaddingTop(), end, getPaddingBottom());
setClipToPadding(false);
}
}
private void scrollToTab(int tabIndex, int positionOffset) {
final int tabStripChildCount = mTabStrip.getChildCount();
if (tabStripChildCount == 0 || tabIndex < 0 || tabIndex >= tabStripChildCount) {
return;
}
View selectedChild = mTabStrip.getChildAt(tabIndex);
if (selectedChild != null) {
int targetScrollX = selectedChild.getLeft() + positionOffset;
if (mTabStrip.isIndicatorAlwaysInCenter()) {
targetScrollX -= (mTabStrip.getChildWidthAt(0) - selectedChild.getWidth()) / 2;
} else if (tabIndex > 0 || positionOffset > 0) {
// If we're not at the first child and are mid-scroll, make sure we obey the offset
targetScrollX -= mTitleOffset;
}
scrollTo(targetScrollX, 0);
}
}
private void scrollToTab(int tabIndex, float positionOffset) {
final int tabStripChildCount = tabStrip.getChildCount();
if (tabStripChildCount == 0 || tabIndex < 0 || tabIndex >= tabStripChildCount) {
return;
}
final boolean isLayoutRtl = Utils.isLayoutRtl(this);
View selectedTab = tabStrip.getChildAt(tabIndex);
int widthPlusMargin = Utils.getWidth(selectedTab) + Utils.getMarginHorizontally(selectedTab);
int extraOffset = (int) (positionOffset * widthPlusMargin);
if (tabStrip.isIndicatorAlwaysInCenter()) {
if (0f < positionOffset && positionOffset < 1f) {
View nextTab = tabStrip.getChildAt(tabIndex + 1);
int selectHalfWidth = Utils.getWidth(selectedTab) / 2 + Utils.getMarginEnd(selectedTab);
int nextHalfWidth = Utils.getWidth(nextTab) / 2 + Utils.getMarginStart(nextTab);
extraOffset = Math.round(positionOffset * (selectHalfWidth + nextHalfWidth));
}
View firstTab = tabStrip.getChildAt(0);
int x;
if (isLayoutRtl) {
int first = Utils.getWidth(firstTab) + Utils.getMarginEnd(firstTab);
int selected = Utils.getWidth(selectedTab) + Utils.getMarginEnd(selectedTab);
x = Utils.getEnd(selectedTab) - Utils.getMarginEnd(selectedTab) - extraOffset;
x -= (first - selected) / 2;
} else {
int first = Utils.getWidth(firstTab) + Utils.getMarginStart(firstTab);
int selected = Utils.getWidth(selectedTab) + Utils.getMarginStart(selectedTab);
x = Utils.getStart(selectedTab) - Utils.getMarginStart(selectedTab) + extraOffset;
x -= (first - selected) / 2;
}
scrollTo(x, 0);
return;
}
int x;
if (titleOffset == TITLE_OFFSET_AUTO_CENTER) {
if (0f < positionOffset && positionOffset < 1f) {
View nextTab = tabStrip.getChildAt(tabIndex + 1);
int selectHalfWidth = Utils.getWidth(selectedTab) / 2 + Utils.getMarginEnd(selectedTab);
int nextHalfWidth = Utils.getWidth(nextTab) / 2 + Utils.getMarginStart(nextTab);
extraOffset = Math.round(positionOffset * (selectHalfWidth + nextHalfWidth));
}
if (isLayoutRtl) {
x = -Utils.getWidthWithMargin(selectedTab) / 2 + getWidth() / 2;
} else {
x = Utils.getWidthWithMargin(selectedTab) / 2 - getWidth() / 2;
}
} else {
if (isLayoutRtl) {
x = (tabIndex > 0 || positionOffset > 0) ? titleOffset : 0;
} else {
x = (tabIndex > 0 || positionOffset > 0) ? -titleOffset : 0;
}
}
int start = Utils.getStart(selectedTab);
int startMargin = Utils.getMarginStart(selectedTab);
if (isLayoutRtl) {
x += start + startMargin - extraOffset - getWidth() + Utils.getPaddingHorizontally(this);
} else {
x += start - startMargin + extraOffset;
}
scrollTo(x, 0);
}
