public override Offset getPositionForChild(Size size, Size childSize)
{
_MenuLimits menuLimits = route.getMenuLimits(buttonRect, size.height, route.selectedIndex ?? 0);
D.assert(() => {
Rect container = Offset.zero & size;
if (container.intersect(buttonRect) == buttonRect)
{
D.assert(menuLimits.top >= 0.0f);
D.assert(menuLimits.top + menuLimits.height <= size.height);
}
return(true);
});
D.assert(textDirection != null);
float left = 0;
switch (textDirection)
{
case TextDirection.rtl:
left = (buttonRect.right.clamp(0.0f, size.width)) - childSize.width;
break;
case TextDirection.ltr:
left = buttonRect.left.clamp(0.0f, size.width - childSize.width);
break;
}
return(new Offset(left, menuLimits.top ?? 0));
}
void _handleFocusChange(bool focused)
{
bool inTraditionalMode = false;
switch (FocusManager.instance.highlightMode)
{
case FocusHighlightMode.touch:
inTraditionalMode = false;
break;
case FocusHighlightMode.traditional:
inTraditionalMode = true;
break;
}
if (focused && inTraditionalMode)
{
_MenuLimits menuLimits = widget.route.getMenuLimits(
widget.buttonRect, widget.constraints.maxHeight, widget.itemIndex ?? 0);
widget.route.scrollController.animateTo(
menuLimits.scrollOffset ?? 0,
curve: Curves.easeInOut,
duration: new TimeSpan(0, 0, 0, 0, 100)
);
}
}
public override Widget build(BuildContext context)
{
D.assert(WidgetsD.debugCheckHasDirectionality(context));
if (route.scrollController == null)
{
_MenuLimits menuLimits = route.getMenuLimits(buttonRect, constraints.maxHeight, selectedIndex ?? 0);
route.scrollController = new ScrollController(initialScrollOffset: menuLimits.scrollOffset ?? 0);
}
TextDirection textDirection = Directionality.of(context);
Widget menu = new _DropdownMenu <T>(
route: route,
padding: padding.resolve(textDirection),
buttonRect: buttonRect,
constraints: constraints,
dropdownColor: dropdownColor
);
if (theme != null)
{
menu = new Theme(data: theme, child: menu);
}
return(MediaQuery.removePadding(
context: context,
removeTop: true,
removeBottom: true,
removeLeft: true,
removeRight: true,
child: new Builder(
builder: (BuildContext _context) => {
return new CustomSingleChildLayout(
layoutDelegate: new _DropdownMenuRouteLayout <T>(
buttonRect: buttonRect,
route: route,
textDirection: textDirection
),
child: menu
);
}
)
));
}