/// <summary>
/// Calculate the requested display size for the radio button.
/// </summary>
/// <param name="context">Render context.</param>
/// <param name="palette">Palette for sourcing display values.</param>
/// <param name="enabled">Should check box be displayed as enabled.</param>
/// <param name="checkState">Checked state of the radio button.</param>
/// <param name="tracking">Should check box be displayed as hot tracking.</param>
/// <param name="pressed">Should check box be displayed as pressed.</param>
public override Size GetRadioButtonPreferredSize(ViewLayoutContext context,
IPalette palette,
bool enabled,
bool checkState,
bool tracking,
bool pressed)
{
// Grab an image appropriate to the state
Image drawImage = palette.GetRadioButtonImage(enabled, checkState, tracking, pressed);
if (drawImage == null)
{
// Convert incoming parameters to radio button state
RadioButtonState state = DiscoverRadioButtonState(enabled, checkState, tracking, pressed);
// Request the drawing size of the radio button glyph
return RadioButtonRenderer.GetGlyphSize(context.Graphics, state);
}
else
return drawImage.Size;
}
/// <summary>
/// Perform drawing of a radio button.
/// </summary>
/// <param name="context">Render context.</param>
/// <param name="displayRect">Display area available for drawing.</param>
/// <param name="palette">Palette for sourcing display values.</param>
/// <param name="enabled">Should radio button be displayed as enabled.</param>
/// <param name="checkState">Checked state of the radio button.</param>
/// <param name="tracking">Should radio button be displayed as hot tracking.</param>
/// <param name="pressed">Should radio button be displayed as pressed.</param>
public override void DrawRadioButton(RenderContext context,
Rectangle displayRect,
IPalette palette,
bool enabled,
bool checkState,
bool tracking,
bool pressed)
{
Debug.Assert(context != null);
Debug.Assert(palette != null);
// Validate parameter references
if (context == null) throw new ArgumentNullException("context");
if (palette == null) throw new ArgumentNullException("palette");
// Grab an image appropriate to the state
Image drawImage = palette.GetRadioButtonImage(enabled, checkState, tracking, pressed);
// If no image from the palette then get a system radio button
if (drawImage == null)
{
// Convert incoming parameters to radio button state
RadioButtonState state = DiscoverRadioButtonState(enabled, checkState, tracking, pressed);
// Request the glyph be drawn at the top left of the display rectangle
RadioButtonRenderer.DrawRadioButton(context.Graphics, displayRect.Location, state);
}
else
{
// Find the offset to center the image
int xOffset = (displayRect.Width - drawImage.Width) / 2;
int yOffset = (displayRect.Height - drawImage.Height) / 2;
// Draw the image centered
context.Graphics.DrawImage(drawImage,
displayRect.X + xOffset, displayRect.Y + yOffset,
drawImage.Width, drawImage.Height);
}
}