void ClipChild(Canvas canvas)
{
var bounds = new Graphics.RectF(0, 0, canvas.Width, canvas.Height);
if (_invalidateClip || _lastPathSize != bounds.Size || _currentPath == null)
{
_invalidateClip = false;
var path = Clip.PathForBounds(bounds);
_currentPath = path?.AsAndroidPath();
_lastPathSize = bounds.Size;
}
if (_currentPath != null)
{
canvas.ClipPath(_currentPath);
}
}
void ClipChild(Canvas canvas)
{
var density = Context.GetDisplayDensity();
var newSize = new SizeF(canvas.Width, canvas.Height);
var bounds = new Graphics.RectF(Graphics.Point.Zero, newSize / density);
if (_invalidateClip || _lastPathSize != newSize || _currentPath == null)
{
_invalidateClip = false;
var path = Clip.PathForBounds(bounds);
_currentPath = path?.AsAndroidPath(scaleX: density, scaleY: density);
_lastPathSize = newSize;
}
if (_currentPath != null)
{
canvas.ClipPath(_currentPath);
}
}
void DrawShadow(Canvas canvas)
{
if (_shadowCanvas == null)
{
_shadowCanvas = new Canvas();
}
if (_shadowPaint == null)
{
_shadowPaint = new Android.Graphics.Paint
{
AntiAlias = true,
Dither = true,
FilterBitmap = true
}
}
;
Graphics.Color solidColor = null;
// If need to redraw shadow
if (_invalidateShadow)
{
var viewHeight = _viewBounds.Height();
var viewWidth = _viewBounds.Width();
if (GetChildAt(0) is AView child)
{
if (viewHeight == 0)
{
viewHeight = child.MeasuredHeight;
}
if (viewWidth == 0)
{
viewWidth = child.MeasuredWidth;
}
}
// If bounds is zero
if (viewHeight != 0 && viewWidth != 0)
{
var bitmapHeight = viewHeight + MaximumRadius;
var bitmapWidth = viewWidth + MaximumRadius;
// Reset bitmap to bounds
_shadowBitmap = Bitmap.CreateBitmap(
bitmapWidth, bitmapHeight, Bitmap.Config.Argb8888
);
// Reset Canvas
_shadowCanvas.SetBitmap(_shadowBitmap);
_invalidateShadow = false;
// Create the local copy of all content to draw bitmap as a
// bottom layer of natural canvas.
base.DispatchDraw(_shadowCanvas);
// Get the alpha bounds of bitmap
Bitmap extractAlpha = _shadowBitmap.ExtractAlpha();
// Clear past content content to draw shadow
_shadowCanvas.DrawColor(Android.Graphics.Color.Black, PorterDuff.Mode.Clear);
var shadowOpacity = (float)Shadow.Opacity;
if (Shadow.Paint is LinearGradientPaint linearGradientPaint)
{
var linearGradientShaderFactory = PaintExtensions.GetLinearGradientShaderFactory(linearGradientPaint, shadowOpacity);
_shadowPaint.SetShader(linearGradientShaderFactory.Resize(bitmapWidth, bitmapHeight));
}
if (Shadow.Paint is RadialGradientPaint radialGradientPaint)
{
var radialGradientShaderFactory = PaintExtensions.GetRadialGradientShaderFactory(radialGradientPaint, shadowOpacity);
_shadowPaint.SetShader(radialGradientShaderFactory.Resize(bitmapWidth, bitmapHeight));
}
if (Shadow.Paint is SolidPaint solidPaint)
{
solidColor = solidPaint.ToColor();
#pragma warning disable CA1416 // https://github.com/xamarin/xamarin-android/issues/6962
_shadowPaint.Color = solidColor.WithAlpha(shadowOpacity).ToPlatform();
#pragma warning restore CA1416
}
// Apply the shadow radius
var radius = Shadow.Radius;
if (radius <= 0)
{
radius = 0.01f;
}
if (radius > 100)
{
radius = MaximumRadius;
}
_shadowPaint.SetMaskFilter(new BlurMaskFilter(radius, BlurMaskFilter.Blur.Normal));
float shadowOffsetX = (float)Shadow.Offset.X;
float shadowOffsetY = (float)Shadow.Offset.Y;
if (Clip == null)
{
_shadowCanvas.DrawBitmap(extractAlpha, shadowOffsetX, shadowOffsetY, _shadowPaint);
}
else
{
var bounds = new Graphics.RectF(0, 0, canvas.Width, canvas.Height);
var path = Clip.PathForBounds(bounds)?.AsAndroidPath();
path.Offset(shadowOffsetX, shadowOffsetY);
_shadowCanvas.DrawPath(path, _shadowPaint);
}
// Recycle and clear extracted alpha
extractAlpha.Recycle();
}
else
{
// Create placeholder bitmap when size is zero and wait until new size coming up
_shadowBitmap = Bitmap.CreateBitmap(1, 1, Bitmap.Config.Rgb565 !);
}
}
// Reset alpha to draw child with full alpha
if (solidColor != null)
#pragma warning disable CA1416 // https://github.com/xamarin/xamarin-android/issues/6962
{
_shadowPaint.Color = solidColor.ToPlatform();
}
#pragma warning restore CA1416
// Draw shadow bitmap
if (_shadowCanvas != null && _shadowBitmap != null && !_shadowBitmap.IsRecycled)
{
canvas.DrawBitmap(_shadowBitmap, 0.0F, 0.0F, _shadowPaint);
}
}
void ClearShadowResources()
{
_shadowCanvas?.Dispose();
_shadowPaint?.Dispose();
_shadowBitmap?.Dispose();
_shadowCanvas = null;
_shadowPaint = null;
_shadowBitmap = null;
}
}
