private static Brush GetArrowButtonBackgroundBrush(ScrollBarArrowButtonStyle Style, Hotness Hotness, out Brush TriangleBrush)
{
switch (Hotness)
{
case Hotness.VeryHot:
TriangleBrush = SystemBrushes.ButtonHighlight;
return(SystemBrushes.ControlText);
case Hotness.Warm:
TriangleBrush = SystemBrushes.ControlText;
return(SystemBrushes.ButtonHighlight);
default:
TriangleBrush = SystemBrushes.ControlText;
return(Style == ScrollBarArrowButtonStyle.FlatBorderless ? SystemBrushes.ScrollBar : SystemBrushes.ButtonFace);
}
}
/// <summary>
/// Call this in <see cref="Control.OnPaint"/> with the most recent known values.
/// </summary>
public void Paint(Graphics g, ref LayoutInfo LayoutInfo, ScrollBarArrowButtonStyle ArrowButtonStyle)
{
this.LastLayoutInfo = LayoutInfo;
var Metrics = this.GetControlMetrics();
// NOTE: We can't just check the current mouse position here. Even if the mouse is actually hovering over an element, it might not be in the hover state if another
// control has capture. We have to do this with the last known mouse position, set in the mouse events after all.
var HoveredItem = this.UpdateHoveredItem(ref Metrics, InvalidateIfChanged: false);
//Debug.WriteLine($"paint ({frame++})");
var OldSmoothingMode = g.SmoothingMode;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighSpeed;
var OldTransform = g.Transform;
g.TranslateTransform(LayoutInfo.Bounds.Left, LayoutInfo.Bounds.Top);
// Track (above thumb)
{
Brush Brush = GetTrackBrush(this.GetItemHotness(HoveredItem, ScrollBarElement.TrackAboveThumb));
if (LayoutInfo.Horizontal)
{
g.FillRectangle(Brush, Metrics.TrackStart, 0, Metrics.ThumbStart - Metrics.TrackStart, LayoutInfo.Bounds.Height);
}
else
{
g.FillRectangle(Brush, 0, Metrics.TrackStart, LayoutInfo.Bounds.Width, Metrics.ThumbStart - Metrics.TrackStart);
}
}
// Track (below thumb)
{
Brush Brush = GetTrackBrush(this.GetItemHotness(HoveredItem, ScrollBarElement.TrackBelowThumb));
if (LayoutInfo.Horizontal)
{
g.FillRectangle(Brush, Metrics.ThumbStart + Metrics.ThumbSize, 0, Metrics.BottomButtonStart - (Metrics.ThumbStart + Metrics.ThumbSize), LayoutInfo.Bounds.Height);
}
else
{
g.FillRectangle(Brush, 0, Metrics.ThumbStart + Metrics.ThumbSize, LayoutInfo.Bounds.Width, Metrics.BottomButtonStart - (Metrics.ThumbStart + Metrics.ThumbSize));
}
}
// Thumb
{
Brush Brush;
switch (this.GetItemHotness(HoveredItem, ScrollBarElement.Thumb, CanBeHotWithoutHover: true))
{
case Hotness.VeryHot:
Brush = SystemBrushes.ButtonHighlight;
break;
case Hotness.Warm:
Brush = SystemBrushes.ControlDarkDark;
break;
default:
Brush = SystemBrushes.ControlDark;
break;
}
if (LayoutInfo.Horizontal)
{
g.FillRectangle(Brush, Metrics.ThumbStart, 0, Metrics.ThumbSize, LayoutInfo.Bounds.Height);
}
else
{
g.FillRectangle(Brush, 0, Metrics.ThumbStart, LayoutInfo.Bounds.Width, Metrics.ThumbSize);
}
}
float TriangleScale = (LayoutInfo.Horizontal ? LayoutInfo.Bounds.Height : LayoutInfo.Bounds.Width) / 4.0f;
// Top Button
{
Brush BackgroundBrush = GetArrowButtonBackgroundBrush(ArrowButtonStyle, this.GetItemHotness(HoveredItem, ScrollBarElement.TopButton), out Brush TriangleBrush);
Rectangle Rect;
if (LayoutInfo.Horizontal)
{
Rect = new Rectangle(0, 0, Metrics.TrackStart, LayoutInfo.Bounds.Height);
}
else
{
Rect = new Rectangle(0, 0, LayoutInfo.Bounds.Width, Metrics.TrackStart - 0); // "0" stands for top button start
}
g.FillRectangle(BackgroundBrush, Rect);
if (ArrowButtonStyle != ScrollBarArrowButtonStyle.FlatBorderless)
{
g.DrawRectangle(SystemPens.ControlText, Rect.X + 0.5f, Rect.Y + 0.5f, Rect.Width - 1.0f, Rect.Height - 1.0f);
}
this.DrawTriangle(g, new PointF(Rect.Width / 2.0f + Rect.X, Rect.Height / 2.0f + Rect.Y), TriangleScale, TriangleBrush, LayoutInfo.Horizontal);
}
// Bottom Button
{
Brush BackgroundBrush = GetArrowButtonBackgroundBrush(ArrowButtonStyle, this.GetItemHotness(HoveredItem, ScrollBarElement.BottomButton), out Brush TriangleBrush);
Rectangle Rect;
if (LayoutInfo.Horizontal)
{
Rect = new Rectangle(Metrics.BottomButtonStart, 0, LayoutInfo.Bounds.Width - Metrics.BottomButtonStart, LayoutInfo.Bounds.Height);
}
else
{
Rect = new Rectangle(0, Metrics.BottomButtonStart, LayoutInfo.Bounds.Width, LayoutInfo.Bounds.Height - Metrics.BottomButtonStart);
}
g.FillRectangle(BackgroundBrush, Rect);
if (ArrowButtonStyle != ScrollBarArrowButtonStyle.FlatBorderless)
{
g.DrawRectangle(SystemPens.ControlText, Rect.X + 0.5f, Rect.Y + 0.5f, Rect.Width - 1.0f, Rect.Height - 1.0f);
}
this.DrawTriangle(g, new PointF(Rect.Width / 2.0f + Rect.X, Rect.Height / 2.0f + Rect.Y), -TriangleScale, TriangleBrush, LayoutInfo.Horizontal);
}
// Restore all state
g.Transform = OldTransform;
g.SmoothingMode = OldSmoothingMode;
//TextRenderer.DrawText(g, this.CapturedItem + Environment.NewLine + this.HoveredItem + Environment.NewLine + this.IsCapturedItemActive, new Font("Microsoft Sans Serif", 9.75f), new Point(0, 0), Color.Red);
}