/// <summary>
/// Draw background of the item
/// </summary>
/// <param name="g">The Graphic used to draw the background of the item</param>
/// <param name="bound">Bound of the item</param>
/// <param name="style">Style of the item</param>
protected virtual void OnDrawBackground(Graphics g, Rectangle bound, StyleListBoxItemStyle style)
{
if (!Selected)
{
g.FillRectangle(new SolidBrush(style.BackColor), bound);
}
else
{
if (style.SelectionStyle == SelectionStyle.Flat)
{
g.FillRectangle(new SolidBrush(style.SelectedBackColor), bound);
}
else
{
// Leave some spaces for selection
Rectangle rect = new Rectangle(bound.X + 1, bound.Y + 1, bound.Width - 2, bound.Height - 2);
// Get lighter color of the background
Color c1 = Color.FromArgb(200, style.SelectedBackColor);
Color c2 = Color.FromArgb(50, style.SelectedBackColor);
g.DrawRectangle(new Pen(style.SelectedBackColor), rect);
g.FillRectangle(new LinearGradientBrush(new Point(rect.X, rect.Y), new Point(rect.X, rect.Bottom), c2, c1), rect);
}
}
// Draw focus border
if (Control != null && Control.FocuedIndex == this.Index)
{
int borderMargin = 1;
if (style.SelectionStyle == SelectionStyle.Crystal)
{
borderMargin = 2;
}
Rectangle focusRect = new Rectangle(bound.X + borderMargin, bound.Y + borderMargin, bound.Width - (borderMargin * 2), bound.Height - (borderMargin * 2));
Pen focusPen;
if (this.Selected)
{
focusPen = new Pen(style.SelectedTextColor);
}
else
{
focusPen = new Pen(style.TextColor);
}
focusPen.DashStyle = DashStyle.Dot;
g.DrawRectangle(focusPen, focusRect);
}
}
/// <summary>
/// Measures the height of the item.
/// </summary>
/// <param name="g">The Graphics used to measure the item</param>
/// <returns>The height of the item.</returns>
public int MeasureItem()
{
StyleListBoxItemStyle style = GetStyle();
if (ImageIndex >= 0 && Control.ImageList != null)
{
return(Math.Max(Control.ImageList.Images[ImageIndex].Height, style.Font.Height) + style.Padding.Top + style.Padding.Bottom);
}
else
{
return(style.Font.Height + style.Padding.Top + style.Padding.Bottom);
}
}
/// <summary>
/// Constructor
/// </summary>
public StyleListBoxItem(String text = "", int imageIndex = -1)
{
_style = new StyleListBoxItemStyle();
_style.OnStyleChange += OnStyleChange;
SuspendUpdateChange();
this.Text = text;
this.ImageIndex = imageIndex;
this.Selected = false;
ResumeUpdateChange();
}
/// <summary>
/// Draw the text part of the item
/// </summary>
/// <param name="g">The Graphics used to draw the text part</param>
/// <param name="bound">The bound of where to draw the text</param>
/// <param name="style">The style of the item</param>
protected virtual void OnDrawText(Graphics g, Rectangle bound, StyleListBoxItemStyle style)
{
// Choose the correct text color
Color textColor;
if (this.Selected)
{
textColor = style.SelectedTextColor;
}
else
{
textColor = style.TextColor;
}
TextRenderer.DrawText(g, this.Text, style.Font, bound, textColor);
}
/// <summary>
/// Clones a new StyleListBoxItemStyle by combining the current
/// StyleListBoxItemStyle with alternative StyleListBoxItemStyle.
///
/// Note:
/// If any property of the current StyleListBoxItemStyle has not
/// set, it will seek for value from the alternative StyleListBoxItemStyle
/// </summary>
/// <param name="other">Other alternative StyleListBoxItemStyle</param>
/// <returns></returns>
public StyleListBoxItemStyle CloneMerge(StyleListBoxItemStyle other)
{
StyleListBoxItemStyle clone = new StyleListBoxItemStyle();
clone.BackColor = (this.BackColor == Color.Empty) ? other.BackColor : this.BackColor;
clone.TextColor = (this.TextColor == Color.Empty) ? other.TextColor : this.TextColor;
clone.Padding = (this.Padding == Padding.Empty) ? other.Padding : this.Padding;
clone.Font = (this.Font == null) ? other.Font : this.Font;
clone.SelectedBackColor = (this.SelectedBackColor == Color.Empty) ? other.SelectedBackColor : this.SelectedBackColor;
clone.SelectedTextColor = (this.SelectedTextColor == Color.Empty) ? other.SelectedTextColor : this.SelectedTextColor;
clone.SelectionStyle = (this.SelectionStyle == SelectionStyle.Inherited) ? other.SelectionStyle : this.SelectionStyle;
clone.TextAlignment = (this.TextAlignment == StyleItemAlignment.None) ? other.TextAlignment : this.TextAlignment;
clone.TextVerticalAlignment = (this.TextVerticalAlignment == StyleItemVerticalAlignment.None) ? other.TextVerticalAlignment : this.TextVerticalAlignment;
clone.ImageAlignment = (this.ImageAlignment == StyleItemAlignment.None) ? other.ImageAlignment : this.ImageAlignment;
return(clone);
}
/// <summary>
/// Constructor
/// </summary>
public StyleListBox()
{
itemList = new StyleListBoxItemCollection(this);
itemSelectedList = new StyleListBoxSelectedItemCollection();
itemCacheHeight = new List <int>();
defaultItemStyle = new StyleListBoxItemStyle();
defaultItemStyle.BackColor = Color.White;
defaultItemStyle.TextColor = Color.Black;
defaultItemStyle.SelectedBackColor = Color.Blue;
defaultItemStyle.SelectedTextColor = Color.White;
defaultItemStyle.Padding = new Padding(2, 2, 2, 2);
defaultItemStyle.Font = new Font(this.Font, FontStyle.Regular);
defaultItemStyle.SelectionStyle = SelectionStyle.Flat;
defaultItemStyle.OnStyleChange += OnDefaultStyleChange;
this.DoubleBuffered = true;
SelectionMode = SelectionMode.One;
// Handles collection events
itemList.OnItemAdded += OnCollectionItemAdded;
itemList.OnItemRemoved += OnCollectionItemRemoved;
itemList.OnItemChanged += OnCollectionItemChanged;
itemList.OnItemSelectionChanged += OnCollectionItemSelectionChanged;
// Create scroll bar
scroll = new VScrollBar();
scroll.Width = 20;
scroll.Left = this.Width - scroll.Width;
scroll.Top = 0;
scroll.Height = this.Height;
scroll.Visible = false;
scroll.Minimum = 0;
scroll.Maximum = 0;
scroll.Value = 0;
scroll.SmallChange = 50;
scroll.LargeChange = 50;
scroll.ValueChanged += Scroll_OnValueChanged;
scroll.KeyDown += Scroll_OnKeyDown;
this.Controls.Add(scroll);
}
/// <summary>
/// Measure the size of the text area
/// </summary>
/// <param name="g">The Graphic used to draw the text</param>
/// <param name="style">Style of the item</param>
/// <returns></returns>
protected virtual Size OnMeasureText(Graphics g, StyleListBoxItemStyle style)
{
return(TextRenderer.MeasureText(this.Text, style.Font));
}
/// <summary>
/// Overridable method to draw item on specified bounds.
/// </summary>
/// <param name="g">The Graphics used to draw the item.</param>
/// <param name="bound">The Rectangle that specfies the bounds of the item</param>
/// <param name="style">The Style used to draw the item.</param>
public virtual void OnDrawItem(Graphics g, Rectangle bound, StyleListBoxItemStyle style)
{
int leftX = style.Padding.Left;
int rightX = bound.Right - style.Padding.Right;
int textX;
Size textSize = OnMeasureText(g, style);
Rectangle textBound;
Rectangle imageBound = new Rectangle();
OnDrawBackground(g, bound, style);
// Draw image
if (Control.ImageList != null && this.ImageIndex >= 0)
{
// Calculate the bound of the image
Image image = Control.ImageList.Images[this.ImageIndex];
if (style.ImageAlignment == StyleItemAlignment.Left || style.ImageAlignment == StyleItemAlignment.None)
{
if (image.Height < textSize.Height)
{
imageBound = new Rectangle(leftX, bound.Y + style.Padding.Top + (image.Height - textSize.Height) / 2, image.Width, image.Height);
}
else
{
imageBound = new Rectangle(leftX, bound.Y + style.Padding.Top, image.Width, image.Height);
}
leftX += image.Width;
}
else
{
rightX -= image.Width;
if (image.Height > textSize.Height)
{
imageBound = new Rectangle(rightX, bound.Y + style.Padding.Top + (image.Height - textSize.Height) / 2, image.Width, image.Height);
}
else
{
imageBound = new Rectangle(rightX, bound.Y + style.Padding.Top, image.Width, image.Height);
}
}
OnDrawImage(g, imageBound, image);
}
// Calculate the text bound
if (style.TextAlignment == StyleItemAlignment.Right)
{
textX = rightX - textSize.Width;
}
else
{
textX = leftX;
}
if (style.TextVerticalAlignment == StyleItemVerticalAlignment.Top)
{
textBound = new Rectangle(textX, bound.Y + style.Padding.Top, textSize.Width, textSize.Height);
}
else if (style.TextVerticalAlignment == StyleItemVerticalAlignment.Bottom)
{
textBound = new Rectangle(textX, bound.Bottom - style.Padding.Bottom - textSize.Height, textSize.Width, textSize.Height);
}
else
{
if (textSize.Height < imageBound.Height)
{
textBound = new Rectangle(textX, bound.Y + style.Padding.Top + (imageBound.Height - textSize.Height) / 2, textSize.Width, textSize.Height);
}
else
{
textBound = new Rectangle(textX, bound.Y + style.Padding.Top, textSize.Width, textSize.Height);
}
}
// Draw text
OnDrawText(g, textBound, style);
}
/// <summary>
/// Draws list item on specified bounds.
/// </summary>
/// <param name="g">The Graphics used to draw the item.</param>
/// <param name="bound">The Rectangle that specifies the bounds of the item</param>
public void DrawItem(Graphics g, Rectangle bound)
{
StyleListBoxItemStyle style = GetStyle();
OnDrawItem(g, bound, style);
}