private void DrawBorder(ACanvas canvas, CorneredContentView control)
{
if (control.BorderThickness > 0)
{
float borderThickness = this.Context.ToPixels(control.BorderThickness);
float halfBorderThickness = borderThickness / 2;
using (Paint paint = new Paint {
AntiAlias = true
})
using (Path.Direction direction = Path.Direction.Cw)
using (Paint.Style style = Paint.Style.Stroke)
using (RectF rect = new RectF(!control.HasShadow ? -halfBorderThickness : halfBorderThickness,
!control.HasShadow ? -halfBorderThickness : halfBorderThickness,
!control.HasShadow ? canvas.Width + halfBorderThickness : canvas.Width - halfBorderThickness,
!control.HasShadow ? canvas.Height + halfBorderThickness : canvas.Height - halfBorderThickness))
{
Path path = new Path();
path.AddRoundRect(rect, this.GetRadii(control), direction);
paint.Color = control.BorderColor.ToAndroid();
paint.StrokeCap = Paint.Cap.Square;
paint.StrokeWidth = borderThickness;
paint.SetStyle(style);
canvas.DrawPath(path, paint);
}
}
}
protected override bool DrawChild(ACanvas canvas, global::Android.Views.View child, long drawingTime)
{
if (this.Element == null)
{
return(false);
}
CorneredContentView control = (CorneredContentView)this.Element;
this.SetClipChildren(true);
//Create path to clip the child
using (Path path = new Path())
{
path.AddRoundRect(new RectF(0, 0, this.Width, this.Height), this.GetRadii(control), Path.Direction.Ccw);
canvas.Save();
canvas.ClipPath(path);
}
// Draw the child first so that the border shows up above it.
bool result = base.DrawChild(canvas, child, drawingTime);
canvas.Restore();
this.DrawBorder(canvas, control);
return(result);
}
private void SetupShadow(CorneredContentView corneredContentView)
{
// clear previous shadow/elevation
this.Elevation = 0;
this.TranslationZ = 0;
// If it has a shadow, give it a default Droid looking shadow.
if (corneredContentView.HasShadow)
{
this.Elevation = 10;
this.TranslationZ = 10;
this.OutlineProvider = null;
this.ClipToOutline = false;
}
}
private float[] GetRadii(CorneredContentView control)
{
float topLeft = this.Context.ToPixels(control.CornerRadius.TopLeft);
float topRight = this.Context.ToPixels(control.CornerRadius.TopRight);
float bottomRight = this.Context.ToPixels(control.CornerRadius.BottomRight);
float bottomLeft = this.Context.ToPixels(control.CornerRadius.BottomLeft);
float[] radii = new[] { topLeft, topLeft, topRight, topRight, bottomRight, bottomRight, bottomLeft, bottomLeft };
if (control.HasShadow)
{
radii = new[] { topLeft, topLeft, topLeft, topLeft, topLeft, topLeft, topLeft, topLeft };
}
return(radii);
}
protected override void OnElementChanged(ElementChangedEventArgs <ContentView> e)
{
base.OnElementChanged(e);
if (e.NewElement != null && e.OldElement == null)
{
CorneredContentView corneredContentView = (this.Element as CorneredContentView);
if (corneredContentView.Content == null)
{
corneredContentView.Content = new Grid();
}
this.Validate(corneredContentView);
this.SetBackground(this._drawable = new CorneredContentViewDrawable(corneredContentView, this.Context.ToPixels));
this.SetupShadow(corneredContentView);
}
}
protected override void OnDraw(ACanvas canvas)
{
if (this.Element == null)
{
return;
}
CorneredContentView control = (CorneredContentView)this.Element;
this.SetClipChildren(true);
//Create path to clip the child
using (Path path = new Path())
{
path.AddRoundRect(new RectF(0, 0, this.Width, this.Height), this.GetRadii(control), Path.Direction.Ccw);
canvas.Save();
canvas.ClipPath(path);
}
this.DrawBorder(canvas, control);
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
CorneredContentView corneredContentView = this.Element as CorneredContentView;
this.Validate(corneredContentView);
base.OnElementPropertyChanged(sender, e);
switch (e.PropertyName)
{
case nameof(VisualElement.BackgroundColor):
{
this._drawable.Dispose();
this.SetBackground(this._drawable = new CorneredContentViewDrawable(corneredContentView, this.Context.ToPixels));
break;
}
case nameof(CorneredContentView.CornerRadius):
{
this.Invalidate();
this.SetupShadow(corneredContentView);
break;
}
case nameof(CorneredContentView.BorderColor):
case nameof(CorneredContentView.BorderThickness):
{
this.Invalidate();
break;
}
case nameof(CorneredContentView.HasShadow):
{
this.SetupShadow(corneredContentView);
break;
}
}
}
public CorneredContentViewDrawable(CorneredContentView corneredContentView, Func <double, float> convertToPixels)
{
this._corneredContentView = corneredContentView;
this._convertToPixels = convertToPixels;
this._corneredContentView.PropertyChanged += this.CorneredContentViewOnPropertyChanged;
}
private void Validate(CorneredContentView corneredContentView)
{
}
