public void ensureSelectedTabIsVisible(boolean animate) {
if (currentAnimation_ != null) {
currentAnimation_.cancel();
currentAnimation_ = null;
}
Element selectedTab =
(Element)
DomUtils.findNode(
getElement(),
true,
false,
new NodePredicate() {
public boolean test(Node n) {
if (n.getNodeType() != Node.ELEMENT_NODE) return false;
return ((Element) n).getClassName().contains("gwt-TabLayoutPanelTab-selected");
}
});
if (selectedTab == null) {
return;
}
selectedTab = selectedTab.getFirstChildElement().getFirstChildElement();
Element tabBar = getTabBarElement();
if (!isVisible() || !isAttached() || tabBar.getOffsetWidth() == 0) return; // not yet loaded
final Element tabBarParent = tabBar.getParentElement();
final int start = tabBarParent.getScrollLeft();
int end =
DomUtils.ensureVisibleHoriz(
tabBarParent, selectedTab, padding_, padding_ + rightMargin_, true);
// When tabs are closed, the overall width shrinks, and this can lead
// to cases where there's too much empty space on the screen
Node lastTab = getLastChildElement(tabBar);
if (lastTab == null || lastTab.getNodeType() != Node.ELEMENT_NODE) return;
int edge =
DomUtils.getRelativePosition(tabBarParent, Element.as(lastTab)).x
+ Element.as(lastTab).getOffsetWidth();
end = Math.min(end, Math.max(0, edge - (tabBarParent.getOffsetWidth() - rightMargin_)));
if (edge <= tabBarParent.getOffsetWidth() - rightMargin_) end = 0;
if (start != end) {
if (!animate) {
tabBarParent.setScrollLeft(end);
} else {
final int finalEnd = end;
currentAnimation_ =
new Animation() {
@Override
protected void onUpdate(double progress) {
double delta = (finalEnd - start) * progress;
tabBarParent.setScrollLeft((int) (start + delta));
}
@Override
protected void onComplete() {
if (this == currentAnimation_) {
tabBarParent.setScrollLeft(finalEnd);
currentAnimation_ = null;
}
}
};
currentAnimation_.run(Math.max(200, Math.min(1500, Math.abs(end - start) * 2)));
}
}
}
/** Kindly borrowed from PlayN. * */
protected static float getRelativeX(NativeEvent e, Element target) {
return e.getClientX()
- target.getAbsoluteLeft()
+ target.getScrollLeft()
+ target.getOwnerDocument().getScrollLeft();
}