protected override void OnPaint(PaintEventArgs e)
{
// I could use a Graphics.Save() / Restore() but I figure storing only the Clip is more efficient...
Region originalRegion = e.Graphics.Clip.Clone();
if (HasBorder && RectangleIntersectsWithBorder(e.ClipRectangle))
{
e.Graphics.SetClip(ContentSurfaceWithScrolls, CombineMode.Exclude);
PaintBorderRegion(e.Graphics);
e.Graphics.Clip = originalRegion;
}
// to be more precise, we could use originalRegion.IsVisible(ContentSurface) here, but the dotnet framework
// doesn't actually call GetUpdateRgn to get the real update region. Instead, we just get e.ClipRectangle that is the
// bounds of the update region and the e.Graphics.Clip is equals to this ClipRectangle
// So... TLDR : we will always get a rectangle to update, never a complex region
if (ContentSurface.IntersectsWith(e.ClipRectangle))
{
e.Graphics.SetClip(ContentSurface, CombineMode.Intersect);
PaintContentSurface(e.Graphics);
e.Graphics.Clip = originalRegion;
}
PaintScrollBars(e, originalRegion);
}
/// <summary>
/// Handle mouse double click to select word under the mouse.
/// </summary>
protected override void OnMouseDoubleClick(MouseEventArgs e)
{
base.OnMouseDoubleClick(e);
if (ContentSurface.Contains(e.Location))
{
_htmlContainer?.HandleMouseDoubleClick(this, e);
}
}
/// <summary>
/// Handle mouse up to handle selection and link click.
/// </summary>
protected override void OnMouseUp(MouseEventArgs e)
{
if (ContentSurface.Contains(e.Location))
{
OnMouseClick(e);
}
_htmlContainer?.HandleMouseUp(this, e);
base.OnMouseUp(e);
}
/// <summary>
/// Handle mouse move to handle hover cursor and text selection.
/// </summary>
protected override void OnMouseMove(MouseEventArgs e)
{
base.OnMouseMove(e);
if (ContentSurface.Contains(e.Location))
{
_htmlContainer?.HandleMouseMove(this, e);
}
else
{
Cursor = DefaultCursor;
}
}
