protected override void OnAttachedTo(VisualElement visualElement)
{
// Set the previous display
currentInfo = new DisplayViewInfo
{
DisplayInfo = DeviceDisplay.MainDisplayInfo,
PageHeight = 0,
PageWidth = 0
};
// Size changed handler
var sizeChangedSubscription = Observable.FromEventPattern(
evt => visualElement.SizeChanged += evt,
evt => visualElement.SizeChanged -= evt
)
.Sample(TimeSpan.FromMilliseconds(1000))
.Select(o => new Tuple <double, double>(visualElement.Width, visualElement.Height))
.Where(t => t.Item1 > 0 && t.Item2 > 0)
//.DistinctUntilChanged()
.ObserveOn(SynchronizationContext.Current)
.Subscribe(value =>
{
var(item1, item2) = value;
currentInfo.PageWidth = item1;
currentInfo.PageHeight = item2;
OnInfoChanged();
}
);
;
disposables.Add(sizeChangedSubscription);
// Orientation changed handler
var displaySubscription = Observable.FromEventPattern <DisplayInfoChangedEventArgs>(
evt => DeviceDisplay.MainDisplayInfoChanged += evt,
evt => DeviceDisplay.MainDisplayInfoChanged -= evt
)
.Select(x => x.EventArgs.DisplayInfo)
.DistinctUntilChanged(this.DisplayInfoComparer)
.Subscribe(info =>
{
currentInfo.DisplayInfo = info;
OnInfoChanged();
})
;
disposables.Add(displaySubscription);
base.OnAttachedTo(visualElement);
}
public IconSizeCalculator(int itemsPerRow)
{
// We need this to get the current orientation in GetItemsPerRowDefault()
this.displayViewInfo = new DisplayViewInfo()
{
DisplayInfo = DeviceDisplay.MainDisplayInfo
};
this.itemInfo = new ListViewItemInfo
{
ItemsPerRow = itemsPerRow > 0 ? itemsPerRow : GetItemsPerRowDefault()
};
this.ScaleFactor = 0.6;
}
public void ChangeDisplayViewInfo(DisplayViewInfo info)
{
this.displayViewInfo = info;
this.OnItemInfoChanged();
}
