/// <summary>
/// This is a complete replacement for base.OnPaintBackground(e) within method protected override void OnPaintBackground(PaintEventArgs e).
/// This supports gradient backgrounds with optional background image overlays.
/// The original only supported solid backgrounds with optional background image overlays.
/// </summary>
/// <param name="control">The control that needs its background painted.</param>
/// <param name="e">Paint event args</param>
/// <param name="gradientBrush">Gradient brush object.</param>
internal static void PaintBackground(IGradientControl gradientControl, PaintEventArgs e)
{
GradientBrush gradientBrush = gradientControl.BackgroundGradient;
Control control = (Control)gradientControl;
Rectangle paintRect = control.ClientRectangle;
if (control is GradientGroupBox)
{
const int borderWidth = 1;
int offset = control.Font.Height / 2;
paintRect.X += borderWidth;
paintRect.Width -= (borderWidth * 2);
paintRect.Y += offset + 1;
paintRect.Height -= (offset + borderWidth * 2) + 1;
PaintTransparentBackground(control, e, control.ClientRectangle);
}
else if (RenderColorTransparent(control, gradientBrush.Color1) ||
RenderColorTransparent(control, gradientBrush.Color2))
{
PaintTransparentBackground(control, e, control.ClientRectangle);
}
int num;
switch (control)
{
case Form _:
//case MdiClient _:
num = control.IsMirrored ? 1 : 0;
break;
default:
num = 0;
break;
}
bool flag = num != 0;
if (control.BackgroundImage != null && !DisplayInformation_HighContrast && !flag)
{
if (control.BackgroundImageLayout == ImageLayout.Tile && ControlPaint_IsImageTransparent(control.BackgroundImage))
{
PaintTransparentBackground(control, e, control.ClientRectangle);
}
var scrollOffset1 = control is ScrollableControl && ((ScrollableControl)control).AutoScroll ? ((ScrollableControl)control).AutoScrollPosition : Point.Empty;
if (ControlPaint_IsImageTransparent(control.BackgroundImage))
{
PaintBackColor(e, paintRect, gradientBrush);
}
ControlPaint_DrawBackgroundImage(e.Graphics, control.BackgroundImage, control.BackColor, control.BackgroundImageLayout, control.ClientRectangle, e.ClipRectangle, scrollOffset1, control.RightToLeft);
}
else
{
PaintBackColor(e, paintRect, gradientBrush);
}
}
public GradientDrawable(IGradientControl control)
{
_control = control;
MaskDrawable = new MaskDrawable <DrawContext>(
new EllipseMaskPainter(),
new RectangleMaskPainter(),
new TextMaskPainter(),
new PathMaskPainter());
}
public GradientDrawable(IGradientControl control)
{
_control = control;
_linearPainter = new LinearGradientPainter();
_radialPainter = new RadialGradientPainter();
_maskDrawable = new MaskDrawable <DrawContext>(
new EllipseMaskPainter(),
new RectangleMaskPainter(),
new TextMaskPainter(),
new PathMaskPainter());
}
public static void SetBindingContext(this IGradientControl control, object bindingContext)
{
if (control.GradientSource is BindableObject bindable)
{
BindableObject.SetInheritedBindingContext(bindable, bindingContext);
}
if (control.Mask is BindableObject maskBindable)
{
BindableObject.SetInheritedBindingContext(maskBindable, bindingContext);
}
}
public void ReadAttributes(IGradientControl view, Context context, IAttributeSet attrs)
{
var typedArray = context.ObtainStyledAttributes(attrs, Resource.Styleable.GradientView);
try
{
ReadGradient(view, typedArray);
if (typedArray.HasValue(Resource.Styleable.GradientView_maskShape))
{
ReadMask(view, typedArray);
}
}
finally
{
typedArray.Recycle();
}
}
private void ReadGradient(IGradientControl view, TypedArray typedArray)
{
var source = typedArray.GetString(Resource.Styleable.GradientView_gradientSource);
if (source != null)
{
var converter = new CssGradientSourceTypeConverter();
view.GradientSource = (IGradientSource)converter.ConvertFromInvariantString(source);
}
var size = typedArray.GetString(Resource.Styleable.GradientView_gradientSize);
if (size != null)
{
var converter = new DimensionsTypeConverter();
view.GradientSize = (Dimensions)converter.ConvertFromInvariantString(size);
}
var repeat = typedArray.GetInt(Resource.Styleable.GradientView_gradientRepeat, 0);
view.GradientRepeat = (BackgroundRepeat)repeat;
}
private void ReadMask(IGradientControl view, TypedArray typedArray)
{
var maskShape = (MaskShape)typedArray.GetInt(Resource.Styleable.GradientView_maskShape, 0);
GradientMask mask = maskShape switch
{
MaskShape.Rectangle => new RectangleMask
{
Size = GetSize(typedArray),
Corners = GetCorners(typedArray)
},
MaskShape.Ellipse => new EllipseMask {
Size = GetSize(typedArray)
},
MaskShape.Path => new PathMask(typedArray.GetString(Resource.Styleable.GradientView_maskData)),
_ => null
};
if (mask != null)
{
mask.Stretch = (Stretch)typedArray.GetInt(Resource.Styleable.GradientView_maskStretch, 0);
view.Mask = mask;
}
}
public static void BuildFor(this GradientBuilder builder, IGradientControl control)
{
control.GradientSource = builder.BuildSource();
}
