private bool PlaceIfArea(UIElement element)
{
var elementExtent = GeoArea.Intersection(Geo.GetArea(element), Projection.World);
var isArea = !elementExtent.IsEmpty;
if (isArea)
{
var destRect = Projection.ToRect(elementExtent, VisualExtent);
element.Arrange(destRect);
}
return(isArea);
}
private async void VisualExtentValuesChanged(object sender, PropertyChangedEventArgs e)
{
if (e.PropertyName == string.Empty || e.PropertyName == nameof(Extent.ZoomLevel))
{
PanelExtent = new Rect(Projection.FullMapSizeFor(Extent.ZoomLevel));
// Measurements only change when the zoom level changes. Screen size affects the visual port,
// and GeoArea affects the geographic area under the map
InvalidateMeasure();
}
ScrollOwner?.InvalidateScrollInfo();
InvalidateArrange();
foreach (var child in InternalChildren.OfType <UIElement>().Where(c => !(c is MapLayer)).ToList())
{
Children.Remove(child);
}
var tiles = tileManager.GetTilesForArea(Projection, Extent).ToList();
while (tiles.Any())
{
await Task.WhenAny(tiles);
foreach (var finishedDrawing in tiles.Where(t => t.IsCompleted).ToList())
{
var tileContent = await finishedDrawing;
var visual = new Rectangle();
Geo.SetArea(visual, Geo.GetArea(tileContent));
var brush = new DrawingBrush
{
Drawing = tileContent,
Stretch = Stretch.Fill
};
brush.Freeze();
visual.Fill = brush;
SetZIndex(visual, int.MaxValue);
Children.Add(visual);
tiles.Remove(finishedDrawing);
}
}
}
protected override Size ArrangeOverride(Size finalSize)
{
if (loading || Projection == null || Extent == null || Extent.Area.IsEmpty)
{
return(finalSize);
}
var offset = PanelExtent.TopLeft - ViewPort.TopLeft;
if (ViewPort.Width > PanelExtent.Width)
{
// center horizontally if the viewport is larger than the map
offset.X = (ViewPort.Width - PanelExtent.Width) / 2;
}
if (ViewPort.Height > PanelExtent.Height)
{
// center vertically if the viewport is larger than the map
offset.Y = (ViewPort.Height - PanelExtent.Height) / 2;
}
foreach (UIElement child in InternalChildren)
{
var placement = PanelExtent;
if (!(child is MapLayer))
{
placement = Projection.ToRect(Geo.GetArea(child), Extent);
}
placement.X += offset.X;
placement.Y += offset.Y;
child.Arrange(placement);
}
return(ViewPort.Size);
}