GetLabelPosition
(
IVertex oVertex
)
{
Debug.Assert(oVertex != null);
AssertValid();
// Start with the default position.
VertexLabelPosition eLabelPosition = m_eLabelPosition;
// Check for a per-vertex label position.
Object oPerVertexLabelPositionAsObject;
if (oVertex.TryGetValue(ReservedMetadataKeys.PerVertexLabelPosition,
typeof(VertexLabelPosition), out oPerVertexLabelPositionAsObject))
{
eLabelPosition =
(VertexLabelPosition)oPerVertexLabelPositionAsObject;
}
return(eLabelPosition);
}
GetLabelLocation
(
VertexLabelPosition labelPosition
)
{
AssertValid();
Rect oVertexBounds =
WpfGraphicsUtil.TriangleBoundsFromCenterAndHalfWidth(
this.VertexLocation, m_dHalfWidth);
Double dCenterX = oVertexBounds.Left + oVertexBounds.Width / 2.0;
// These were determined experimentally to avoid trigonometry method
// calls and to make the labels look good.
Double dCenterY = oVertexBounds.Top +
1.2 * (oVertexBounds.Height / 2.0);
Double dOffsetX = m_dHalfWidth * 1.0;
switch (labelPosition)
{
case VertexLabelPosition.TopLeft:
case VertexLabelPosition.TopCenter:
case VertexLabelPosition.TopRight:
return(new Point(dCenterX, oVertexBounds.Top));
case VertexLabelPosition.MiddleLeft:
return(new Point(dCenterX - dOffsetX, dCenterY));
case VertexLabelPosition.MiddleCenter:
return(new Point(dCenterX, dCenterY));
case VertexLabelPosition.MiddleRight:
return(new Point(dCenterX + dOffsetX, dCenterY));
case VertexLabelPosition.BottomLeft:
return(oVertexBounds.BottomLeft);
case VertexLabelPosition.BottomCenter:
return(new Point(dCenterX, oVertexBounds.Bottom));
case VertexLabelPosition.BottomRight:
return(oVertexBounds.BottomRight);
default:
Debug.Assert(false);
return(this.VertexLocation);
}
}
//*************************************************************************
// Constructor: VertexLabelDrawer()
//
/// <summary>
/// Initializes a new instance of the <see cref="VertexLabelDrawer" />
/// class.
/// </summary>
///
/// <param name="labelPosition">
/// The default position to use for vertex labels.
/// </param>
//*************************************************************************
public VertexLabelDrawer(
VertexLabelPosition labelPosition
)
{
m_eLabelPosition = labelPosition;
AssertValid();
}
GetLabelLocation
(
VertexLabelPosition labelPosition
)
{
AssertValid();
return(GetLabelLocationOnDiamond(labelPosition, m_dHalfWidth));
}
//*************************************************************************
// Constructor: VertexLabelDrawer()
//
/// <summary>
/// Initializes a new instance of the <see cref="VertexLabelDrawer" />
/// class.
/// </summary>
///
/// <param name="labelPosition">
/// The default position to use for vertex labels.
/// </param>
//*************************************************************************
public VertexLabelDrawer
(
VertexLabelPosition labelPosition
)
{
m_eLabelPosition = labelPosition;
AssertValid();
}
GetLabelLocation
(
VertexLabelPosition labelPosition
)
{
AssertValid();
// The diamond pattern for label locations is appropriate for circles.
return(GetLabelLocationOnDiamond(labelPosition, m_dRadius));
}
GetLabelLocation
(
VertexLabelPosition labelPosition
)
{
AssertValid();
Double dCenterX = m_oRectangle.Left + m_oRectangle.Width / 2.0;
Double dMiddleY = m_oRectangle.Top + m_oRectangle.Height / 2.0;
switch (labelPosition)
{
case VertexLabelPosition.TopLeft:
return(m_oRectangle.TopLeft);
case VertexLabelPosition.TopCenter:
return(new Point(dCenterX, m_oRectangle.Top));
case VertexLabelPosition.TopRight:
return(m_oRectangle.TopRight);
case VertexLabelPosition.MiddleLeft:
return(new Point(m_oRectangle.Left, dMiddleY));
case VertexLabelPosition.MiddleCenter:
return(new Point(dCenterX, dMiddleY));
case VertexLabelPosition.MiddleRight:
return(new Point(m_oRectangle.Right, dMiddleY));
case VertexLabelPosition.BottomLeft:
return(m_oRectangle.BottomLeft);
case VertexLabelPosition.BottomCenter:
return(new Point(dCenterX, m_oRectangle.Bottom));
case VertexLabelPosition.BottomRight:
return(m_oRectangle.BottomRight);
default:
Debug.Assert(false);
return(new Point());
}
}
//*************************************************************************
// Constructor: VertexLabelDrawer()
//
/// <summary>
/// Initializes a new instance of the <see cref="VertexLabelDrawer" />
/// class.
/// </summary>
///
/// <param name="labelPosition">
/// The default position to use for vertex labels.
/// </param>
///
/// <param name="backgroundAlpha">
/// The alpha of the label's background rectangle, as a Byte.
/// </param>
//*************************************************************************
public VertexLabelDrawer
(
VertexLabelPosition labelPosition,
Byte backgroundAlpha
)
{
m_eLabelPosition = labelPosition;
m_btBackgroundAlpha = backgroundAlpha;
AssertValid();
}
//*************************************************************************
// Constructor: VertexLabelDrawer()
//
/// <summary>
/// Initializes a new instance of the <see cref="VertexLabelDrawer" />
/// class.
/// </summary>
///
/// <param name="labelPosition">
/// The default position to use for vertex labels.
/// </param>
///
/// <param name="backgroundAlpha">
/// The alpha of the label's background rectangle, as a Byte.
/// </param>
//*************************************************************************
public VertexLabelDrawer
(
VertexLabelPosition labelPosition,
Byte backgroundAlpha
)
{
m_eLabelPosition = labelPosition;
m_btBackgroundAlpha = backgroundAlpha;
AssertValid();
}
GetLabelLocationOnDiamond
(
VertexLabelPosition eLabelPosition,
Double dHalfWidth
)
{
Debug.Assert(dHalfWidth >= 0);
AssertValid();
Point oVertexLocation = this.VertexLocation;
Double dVertexX = oVertexLocation.X;
Double dVertexY = oVertexLocation.Y;
switch (eLabelPosition)
{
case VertexLabelPosition.TopLeft:
case VertexLabelPosition.TopCenter:
case VertexLabelPosition.TopRight:
return(new Point(dVertexX, dVertexY - dHalfWidth));
case VertexLabelPosition.MiddleLeft:
return(new Point(dVertexX - dHalfWidth, dVertexY));
case VertexLabelPosition.MiddleCenter:
return(oVertexLocation);
case VertexLabelPosition.MiddleRight:
return(new Point(dVertexX + dHalfWidth, dVertexY));
case VertexLabelPosition.BottomLeft:
case VertexLabelPosition.BottomCenter:
case VertexLabelPosition.BottomRight:
return(new Point(dVertexX, dVertexY + dHalfWidth));
default:
Debug.Assert(false);
return(oVertexLocation);
}
}
SetTextAlignment
(
FormattedText oFormattedText,
VertexLabelPosition eLabelPosition
)
{
Debug.Assert(oFormattedText != null);
Debug.Assert(eLabelPosition != VertexLabelPosition.Nowhere);
AssertValid();
TextAlignment eTextAlignment = TextAlignment.Left;
switch (eLabelPosition)
{
case VertexLabelPosition.TopLeft:
case VertexLabelPosition.MiddleLeft:
case VertexLabelPosition.BottomLeft:
eTextAlignment = TextAlignment.Right;
break;
case VertexLabelPosition.TopCenter:
case VertexLabelPosition.MiddleCenter:
case VertexLabelPosition.BottomCenter:
eTextAlignment = TextAlignment.Center;
break;
case VertexLabelPosition.TopRight:
case VertexLabelPosition.MiddleRight:
case VertexLabelPosition.BottomRight:
// eTextAlignment = TextAlignment.Left;
break;
case VertexLabelPosition.Nowhere:
default:
Debug.Assert(false);
break;
}
oFormattedText.TextAlignment = eTextAlignment;
}
//*************************************************************************
// Constructor: VertexDrawer()
//
/// <summary>
/// Initializes a new instance of the <see cref="VertexDrawer" /> class.
/// </summary>
//*************************************************************************
public VertexDrawer()
{
m_eShape = VertexShape.Disk;
m_dRadius = 3.0;
m_oLabelFillColor = SystemColors.WindowColor;
m_eLabelPosition = VertexLabelPosition.TopRight;
m_bLimitVerticesToBounds = true;
AssertValid();
}
DrawLabel
(
DrawingContext drawingContext,
GraphDrawingContext graphDrawingContext,
VertexDrawingHistory vertexDrawingHistory,
Rect vertexBounds,
VertexLabelPosition labelPosition,
FormattedText formattedText
)
{
Debug.Assert(drawingContext != null);
Debug.Assert(graphDrawingContext != null);
Debug.Assert(vertexDrawingHistory != null);
Debug.Assert(formattedText != null);
AssertValid();
Double dHalfVertexBoundsWidth = vertexBounds.Width / 2.0;
Double dHalfVertexBoundsHeight = vertexBounds.Height / 2.0;
Double dLabelHeight = formattedText.Height;
Double dHalfLabelHeight = dLabelHeight / 2.0;
Double dLabelWidth = formattedText.Width;
Double dHalfLabelWidth = dLabelWidth / 2.0;
TextAlignment eTextAlignment = TextAlignment.Left;
formattedText.MaxLineCount = 1;
// This is the point where the label will be drawn. It initially
// assumes a text height of zero with no margin, but that will be
// adjusted within the switch statement below.
Point oDraw = vertexDrawingHistory.GetLabelLocation(labelPosition);
Double dDrawX = oDraw.X;
Double dDrawY = oDraw.Y;
// These are the bounds of the label text.
Double dLabelBoundsLeft = 0;
Double dLabelBoundsRight = 0;
switch (labelPosition)
{
case VertexLabelPosition.TopLeft:
eTextAlignment = TextAlignment.Right;
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.TopCenter:
eTextAlignment = TextAlignment.Center;
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.TopRight:
// eTextAlignment = TextAlignment.Left;
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
case VertexLabelPosition.MiddleLeft:
eTextAlignment = TextAlignment.Right;
dDrawX -= HorizontalMargin;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.MiddleCenter:
eTextAlignment = TextAlignment.Center;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.MiddleRight:
// eTextAlignment = TextAlignment.Left;
dDrawX += HorizontalMargin;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
case VertexLabelPosition.BottomLeft:
eTextAlignment = TextAlignment.Right;
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.BottomCenter:
eTextAlignment = TextAlignment.Center;
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.BottomRight:
// eTextAlignment = TextAlignment.Left;
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
default:
Debug.Assert(false);
break;
}
// Don't let the text exceed the bounds of the graph rectangle.
Double dLabelBoundsTop = dDrawY;
Double dLabelBoundsBottom = dDrawY + dLabelHeight;
Rect oGraphRectangleMinusMargin =
graphDrawingContext.GraphRectangleMinusMargin;
dDrawX += Math.Max(0,
oGraphRectangleMinusMargin.Left - dLabelBoundsLeft);
dDrawX -= Math.Max(0,
dLabelBoundsRight - oGraphRectangleMinusMargin.Right);
dDrawY += Math.Max(0,
oGraphRectangleMinusMargin.Top - dLabelBoundsTop);
dDrawY -= Math.Max(0,
dLabelBoundsBottom - oGraphRectangleMinusMargin.Bottom);
formattedText.TextAlignment = eTextAlignment;
drawingContext.DrawText(formattedText, new Point(dDrawX, dDrawY));
}
GetLabelLocationOnDiamond
(
VertexLabelPosition eLabelPosition,
Double dHalfWidth
)
{
Debug.Assert(dHalfWidth >= 0);
AssertValid();
Point oVertexLocation = this.VertexLocation;
Double dVertexX = oVertexLocation.X;
Double dVertexY = oVertexLocation.Y;
switch (eLabelPosition)
{
case VertexLabelPosition.TopLeft:
case VertexLabelPosition.TopCenter:
case VertexLabelPosition.TopRight:
return ( new Point(dVertexX, dVertexY - dHalfWidth) );
case VertexLabelPosition.MiddleLeft:
return ( new Point(dVertexX - dHalfWidth, dVertexY) );
case VertexLabelPosition.MiddleCenter:
return (oVertexLocation);
case VertexLabelPosition.MiddleRight:
return ( new Point(dVertexX + dHalfWidth, dVertexY) );
case VertexLabelPosition.BottomLeft:
case VertexLabelPosition.BottomCenter:
case VertexLabelPosition.BottomRight:
return ( new Point(dVertexX, dVertexY + dHalfWidth) );
default:
Debug.Assert(false);
return (oVertexLocation);
}
}
GetLabelLocation
(
VertexLabelPosition labelPosition
);
SetTextAlignment
(
FormattedText oFormattedText,
VertexLabelPosition eLabelPosition
)
{
Debug.Assert(oFormattedText != null);
Debug.Assert(eLabelPosition != VertexLabelPosition.Nowhere);
AssertValid();
TextAlignment eTextAlignment = TextAlignment.Left;
switch (eLabelPosition)
{
case VertexLabelPosition.TopLeft:
case VertexLabelPosition.MiddleLeft:
case VertexLabelPosition.BottomLeft:
// eTextAlignment = TextAlignment.Left;
break;
case VertexLabelPosition.TopCenter:
case VertexLabelPosition.MiddleCenter:
case VertexLabelPosition.BottomCenter:
eTextAlignment = TextAlignment.Center;
break;
case VertexLabelPosition.TopRight:
case VertexLabelPosition.MiddleRight:
case VertexLabelPosition.BottomRight:
eTextAlignment = TextAlignment.Right;
break;
default:
Debug.Assert(false);
break;
}
oFormattedText.TextAlignment = eTextAlignment;
}
//*************************************************************************
// Method: GetLabelLocation()
//
/// <summary>
/// Gets the location at which an annotation label should be drawn.
/// </summary>
///
/// <param name="labelPosition">
/// The position of the annotation label.
/// </param>
///
/// <returns>
/// The point at which an annotation label should be drawn.
/// </returns>
///
/// <remarks>
/// The returned point assumes that the label text height is zero and that
/// there is zero margin between the vertex and the label. The caller must
/// adjust the point for the actual text height and any margin.
/// </remarks>
//*************************************************************************
public override Point GetLabelLocation(
VertexLabelPosition labelPosition
)
{
AssertValid();
Rect oVertexBounds =
WpfGraphicsUtil.TriangleBoundsFromCenterAndHalfWidth(
this.VertexLocation, m_dHalfWidth);
Double dCenterX = oVertexBounds.Left + oVertexBounds.Width / 2.0;
// These were determined experimentally to avoid trigonometry method
// calls and to make the labels look good.
Double dCenterY = oVertexBounds.Top +
1.2 * (oVertexBounds.Height / 2.0);
Double dOffsetX = m_dHalfWidth * 0.7;
switch (labelPosition)
{
case VertexLabelPosition.TopLeft:
case VertexLabelPosition.TopCenter:
case VertexLabelPosition.TopRight:
return ( new Point(dCenterX, oVertexBounds.Top) );
case VertexLabelPosition.MiddleLeft:
return ( new Point(dCenterX - dOffsetX, dCenterY) );
case VertexLabelPosition.MiddleCenter:
return ( new Point(dCenterX, dCenterY) );
case VertexLabelPosition.MiddleRight:
return ( new Point(dCenterX + dOffsetX, dCenterY) );
case VertexLabelPosition.BottomLeft:
return (oVertexBounds.BottomLeft);
case VertexLabelPosition.BottomCenter:
return ( new Point(dCenterX, oVertexBounds.Bottom) );
case VertexLabelPosition.BottomRight:
return (oVertexBounds.BottomRight);
default:
Debug.Assert(false);
return (this.VertexLocation);
}
}
DrawLabel
(
DrawingContext drawingContext,
GraphDrawingContext graphDrawingContext,
VertexDrawingHistory vertexDrawingHistory,
VertexLabelPosition labelPosition,
FormattedText formattedText,
Color formattedTextColor,
Boolean drawBackground
)
{
Debug.Assert(drawingContext != null);
Debug.Assert(graphDrawingContext != null);
Debug.Assert(vertexDrawingHistory != null);
Debug.Assert(formattedText != null);
AssertValid();
if (labelPosition == VertexLabelPosition.Nowhere)
{
return;
}
// The alignment needs to be set before the width and height of the
// FormattedText are obtained.
SetTextAlignment(formattedText, labelPosition);
// You can't use FormattedText.Width to get the width of the actual
// text when text wrapping is enabled (FormattedText.MaxTextWidth > 0).
// Instead, use a method that takes wrapping into account.
Double dLabelWidth = WpfGraphicsUtil.GetFormattedTextSize(
formattedText).Width;
Double dLabelHeight = formattedText.Height;
// This is the point where the label will be drawn using
// DrawingContext.Draw(). It initially assumes a text height of zero,
// a margin of zero, and no adjustment for alignment (see
// dAdjustmentForTextAlignmentX below), but this will be modified
// appropriately within the switch statement below.
Point oDraw = vertexDrawingHistory.GetLabelLocation(labelPosition);
Double dDrawX = oDraw.X;
Double dDrawY = oDraw.Y;
// These are the left and right bounds of the rectangle where the text
// will actually appear.
Double dLabelBoundsLeft = 0;
Double dLabelBoundsRight = 0;
AdjustForTextAlignment(dLabelWidth, dLabelHeight, labelPosition,
formattedText, ref dDrawX, ref dDrawY, ref dLabelBoundsLeft,
ref dLabelBoundsRight);
// Don't let the text exceed the bounds of the graph rectangle.
dDrawX = StayWithinHorizontalBounds(
dDrawX, graphDrawingContext, dLabelBoundsLeft, dLabelBoundsRight);
Double dLabelBoundsTop = dDrawY;
Double dLabelBoundsBottom = dDrawY + dLabelHeight;
dDrawY = StayWithinVerticalBounds(
dDrawY, graphDrawingContext, dLabelBoundsTop, dLabelBoundsBottom);
if (drawBackground)
{
dLabelBoundsLeft = StayWithinHorizontalBounds(
dLabelBoundsLeft, graphDrawingContext,
dLabelBoundsLeft, dLabelBoundsRight);
DrawLabelBackground(drawingContext, graphDrawingContext,
formattedText, formattedTextColor, m_btBackgroundAlpha,
new Point(dLabelBoundsLeft, dDrawY));
}
drawingContext.DrawText(formattedText, new Point(dDrawX, dDrawY));
}
AdjustForTextAlignment
(
Double dLabelWidth,
Double dLabelHeight,
VertexLabelPosition eLabelPosition,
FormattedText oFormattedText,
ref Double dDrawX,
ref Double dDrawY,
ref Double dLabelBoundsLeft,
ref Double dLabelBoundsRight
)
{
Debug.Assert(dLabelWidth >= 0);
Debug.Assert(dLabelHeight >= 0);
Debug.Assert(oFormattedText != null);
AssertValid();
Double dHalfLabelHeight = dLabelHeight / 2.0;
Double dHalfLabelWidth = dLabelWidth / 2.0;
Double dMaxTextWidth = oFormattedText.MaxTextWidth;
Double dHalfMaxTextWidth = dMaxTextWidth / 2.0;
// This is the adjustment that needs to be made to the x-coordinate
// passed to DrawingContext.DrawText() to compensate for the way
// centered and right-justified text is positioned.
//
// When wrapping is turned off (FormattedText.MaxTextWidth = 0) and
// FormattedText.TextAlignment = TextAlignment.Center, for example,
// the text gets centered horizontally at the specified drawing point.
// When wrapping is turned on, however (FormattedText.MaxTextWidth
// > 0), the text gets centered horizontally at the point halfway
// between the specified drawing point and the MaxTextWidth value.
Double dAdjustmentForTextAlignmentX = 0;
switch (eLabelPosition)
{
case VertexLabelPosition.TopLeft:
dAdjustmentForTextAlignmentX = -dMaxTextWidth;
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.TopCenter:
dAdjustmentForTextAlignmentX = -dHalfMaxTextWidth;
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.TopRight:
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
case VertexLabelPosition.MiddleLeft:
dAdjustmentForTextAlignmentX = -dMaxTextWidth;
dDrawX -= HorizontalMargin;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.MiddleCenter:
dAdjustmentForTextAlignmentX = -dHalfMaxTextWidth;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.MiddleRight:
dDrawX += HorizontalMargin;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
case VertexLabelPosition.BottomLeft:
dAdjustmentForTextAlignmentX = -dMaxTextWidth;
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.BottomCenter:
dAdjustmentForTextAlignmentX = -dHalfMaxTextWidth;
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.BottomRight:
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
case VertexLabelPosition.Nowhere:
// (This was handled at the top of the method.)
default:
Debug.Assert(false);
break;
}
dDrawX += dAdjustmentForTextAlignmentX;
}
GetLabelLocation
(
VertexLabelPosition labelPosition
)
{
AssertValid();
return ( GetLabelLocationOnDiamond(labelPosition, m_dHalfWidth) );
}
DrawLabel
(
DrawingContext drawingContext,
GraphDrawingContext graphDrawingContext,
VertexDrawingHistory vertexDrawingHistory,
VertexLabelPosition labelPosition,
FormattedText formattedText,
Color formattedTextColor,
Boolean drawBackground
)
{
Debug.Assert(drawingContext != null);
Debug.Assert(graphDrawingContext != null);
Debug.Assert(vertexDrawingHistory != null);
Debug.Assert(formattedText != null);
AssertValid();
if (labelPosition == VertexLabelPosition.Nowhere)
{
return;
}
// The alignment needs to be set before the width and height of the
// FormattedText are obtained.
SetTextAlignment(formattedText, labelPosition);
// You can't use FormattedText.Width to get the width of the actual
// text when text wrapping is enabled (FormattedText.MaxTextWidth > 0).
// Instead, use a method that takes wrapping into account.
Double dLabelWidth = WpfGraphicsUtil.GetFormattedTextSize(
formattedText).Width;
Double dLabelHeight = formattedText.Height;
// This is the point where the label will be drawn using
// DrawingContext.Draw(). It initially assumes a text height of zero,
// a margin of zero, and no adjustment for alignment (see
// dAdjustmentForTextAlignmentX below), but this will be modified
// appropriately within the switch statement below.
Point oDraw = vertexDrawingHistory.GetLabelLocation(labelPosition);
Double dDrawX = oDraw.X;
Double dDrawY = oDraw.Y;
// These are the left and right bounds of the rectangle where the text
// will actually appear.
Double dLabelBoundsLeft = 0;
Double dLabelBoundsRight = 0;
AdjustForTextAlignment(dLabelWidth, dLabelHeight, labelPosition,
formattedText, ref dDrawX, ref dDrawY, ref dLabelBoundsLeft,
ref dLabelBoundsRight);
// Don't let the text exceed the bounds of the graph rectangle.
dDrawX = StayWithinHorizontalBounds(
dDrawX, graphDrawingContext, dLabelBoundsLeft, dLabelBoundsRight);
Double dLabelBoundsTop = dDrawY;
Double dLabelBoundsBottom = dDrawY + dLabelHeight;
dDrawY = StayWithinVerticalBounds(
dDrawY, graphDrawingContext, dLabelBoundsTop, dLabelBoundsBottom);
if (drawBackground)
{
dLabelBoundsLeft = StayWithinHorizontalBounds(
dLabelBoundsLeft, graphDrawingContext,
dLabelBoundsLeft, dLabelBoundsRight);
DrawLabelBackground( drawingContext, graphDrawingContext,
formattedText, formattedTextColor, m_btBackgroundAlpha,
new Point(dLabelBoundsLeft, dDrawY) );
}
drawingContext.DrawText( formattedText, new Point(dDrawX, dDrawY) );
}
GetLabelLocation
(
VertexLabelPosition labelPosition
)
{
AssertValid();
// The diamond pattern for label locations is appropriate for circles.
return ( GetLabelLocationOnDiamond(labelPosition, m_dRadius) );
}
GetLabelLocation
(
VertexLabelPosition labelPosition
);
AdjustForTextAlignment
(
Double dLabelWidth,
Double dLabelHeight,
VertexLabelPosition eLabelPosition,
FormattedText oFormattedText,
ref Double dDrawX,
ref Double dDrawY,
ref Double dLabelBoundsLeft,
ref Double dLabelBoundsRight
)
{
Debug.Assert(dLabelWidth >= 0);
Debug.Assert(dLabelHeight >= 0);
Debug.Assert(oFormattedText != null);
AssertValid();
Double dHalfLabelHeight = dLabelHeight / 2.0;
Double dHalfLabelWidth = dLabelWidth / 2.0;
Double dMaxTextWidth = oFormattedText.MaxTextWidth;
Double dHalfMaxTextWidth = dMaxTextWidth / 2.0;
// This is the adjustment that needs to be made to the x-coordinate
// passed to DrawingContext.DrawText() to compensate for the way
// centered and right-justified text is positioned.
//
// When wrapping is turned off (FormattedText.MaxTextWidth = 0) and
// FormattedText.TextAlignment = TextAlignment.Center, for example,
// the text gets centered horizontally at the specified drawing point.
// When wrapping is turned on, however (FormattedText.MaxTextWidth
// > 0), the text gets centered horizontally at the point halfway
// between the specified drawing point and the MaxTextWidth value.
Double dAdjustmentForTextAlignmentX = 0;
switch (eLabelPosition)
{
case VertexLabelPosition.TopLeft:
dAdjustmentForTextAlignmentX = -dMaxTextWidth;
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.TopCenter:
dAdjustmentForTextAlignmentX = -dHalfMaxTextWidth;
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.TopRight:
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
case VertexLabelPosition.MiddleLeft:
dAdjustmentForTextAlignmentX = -dMaxTextWidth;
dDrawX -= HorizontalMargin;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.MiddleCenter:
dAdjustmentForTextAlignmentX = -dHalfMaxTextWidth;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.MiddleRight:
dDrawX += HorizontalMargin;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
case VertexLabelPosition.BottomLeft:
dAdjustmentForTextAlignmentX = -dMaxTextWidth;
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.BottomCenter:
dAdjustmentForTextAlignmentX = -dHalfMaxTextWidth;
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.BottomRight:
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
case VertexLabelPosition.Nowhere:
// (This was handled at the top of the method.)
default:
Debug.Assert(false);
break;
}
dDrawX += dAdjustmentForTextAlignmentX;
}
//*************************************************************************
// Method: GetLabelLocation()
//
/// <summary>
/// Gets the location at which an annotation label should be drawn.
/// </summary>
///
/// <param name="labelPosition">
/// The position of the annotation label.
/// </param>
///
/// <returns>
/// The point at which an annotation label should be drawn.
/// </returns>
///
/// <remarks>
/// The returned point assumes that the label text height is zero and that
/// there is zero margin between the vertex and the label. The caller must
/// adjust the point for the actual text height and any margin.
/// </remarks>
//*************************************************************************
public override Point GetLabelLocation(
VertexLabelPosition labelPosition
)
{
AssertValid();
Double dCenterX = m_oRectangle.Left + m_oRectangle.Width / 2.0;
Double dMiddleY = m_oRectangle.Top + m_oRectangle.Height / 2.0;
switch (labelPosition)
{
case VertexLabelPosition.TopLeft:
return (m_oRectangle.TopLeft);
case VertexLabelPosition.TopCenter:
return ( new Point(dCenterX, m_oRectangle.Top) );
case VertexLabelPosition.TopRight:
return (m_oRectangle.TopRight);
case VertexLabelPosition.MiddleLeft:
return ( new Point(m_oRectangle.Left, dMiddleY) );
case VertexLabelPosition.MiddleCenter:
return ( new Point(dCenterX, dMiddleY) );
case VertexLabelPosition.MiddleRight:
return ( new Point(m_oRectangle.Right, dMiddleY) );
case VertexLabelPosition.BottomLeft:
return (m_oRectangle.BottomLeft);
case VertexLabelPosition.BottomCenter:
return ( new Point(dCenterX, m_oRectangle.Bottom) );
case VertexLabelPosition.BottomRight:
return (m_oRectangle.BottomRight);
default:
Debug.Assert(false);
return ( new Point() );
}
}
//*************************************************************************
// Method: DrawLabel()
//
/// <summary>
/// Draws a vertex label as an annotation at a specified position.
/// </summary>
///
/// <param name="drawingContext">
/// The DrawingContext to use.
/// </param>
///
/// <param name="graphDrawingContext">
/// Provides access to objects needed for graph-drawing operations.
/// </param>
///
/// <param name="vertexDrawingHistory">
/// Describes how the vertex was drawn.
/// </param>
///
/// <param name="vertexBounds">
/// The vertex's bounding rectangle.
/// </param>
///
/// <param name="labelPosition">
/// The label's position.
/// </param>
///
/// <param name="formattedText">
/// The FormattedText object to use. Several properties get changed by
/// this method.
/// </param>
//*************************************************************************
public void DrawLabel(
DrawingContext drawingContext,
GraphDrawingContext graphDrawingContext,
VertexDrawingHistory vertexDrawingHistory,
Rect vertexBounds,
VertexLabelPosition labelPosition,
FormattedText formattedText
)
{
Debug.Assert(drawingContext != null);
Debug.Assert(graphDrawingContext != null);
Debug.Assert(vertexDrawingHistory != null);
Debug.Assert(formattedText != null);
AssertValid();
Double dHalfVertexBoundsWidth = vertexBounds.Width / 2.0;
Double dHalfVertexBoundsHeight = vertexBounds.Height / 2.0;
Double dLabelHeight = formattedText.Height;
Double dHalfLabelHeight = dLabelHeight / 2.0;
Double dLabelWidth = formattedText.Width;
Double dHalfLabelWidth = dLabelWidth / 2.0;
TextAlignment eTextAlignment = TextAlignment.Left;
formattedText.MaxLineCount = 1;
// This is the point where the label will be drawn. It initially
// assumes a text height of zero with no margin, but that will be
// adjusted within the switch statement below.
Point oDraw = vertexDrawingHistory.GetLabelLocation(labelPosition);
Double dDrawX = oDraw.X;
Double dDrawY = oDraw.Y;
// These are the bounds of the label text.
Double dLabelBoundsLeft = 0;
Double dLabelBoundsRight = 0;
switch (labelPosition)
{
case VertexLabelPosition.TopLeft:
eTextAlignment = TextAlignment.Right;
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.TopCenter:
eTextAlignment = TextAlignment.Center;
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.TopRight:
// eTextAlignment = TextAlignment.Left;
dDrawY -= (dLabelHeight + VerticalMargin);
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
case VertexLabelPosition.MiddleLeft:
eTextAlignment = TextAlignment.Right;
dDrawX -= HorizontalMargin;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.MiddleCenter:
eTextAlignment = TextAlignment.Center;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.MiddleRight:
// eTextAlignment = TextAlignment.Left;
dDrawX += HorizontalMargin;
dDrawY -= dHalfLabelHeight;
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
case VertexLabelPosition.BottomLeft:
eTextAlignment = TextAlignment.Right;
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX - dLabelWidth;
dLabelBoundsRight = dDrawX;
break;
case VertexLabelPosition.BottomCenter:
eTextAlignment = TextAlignment.Center;
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX - dHalfLabelWidth;
dLabelBoundsRight = dDrawX + dHalfLabelWidth;
break;
case VertexLabelPosition.BottomRight:
// eTextAlignment = TextAlignment.Left;
dDrawY += VerticalMargin;
dLabelBoundsLeft = dDrawX;
dLabelBoundsRight = dDrawX + dLabelWidth;
break;
default:
Debug.Assert(false);
break;
}
// Don't let the text exceed the bounds of the graph rectangle.
Double dLabelBoundsTop = dDrawY;
Double dLabelBoundsBottom = dDrawY + dLabelHeight;
Rect oGraphRectangleMinusMargin =
graphDrawingContext.GraphRectangleMinusMargin;
dDrawX += Math.Max(0,
oGraphRectangleMinusMargin.Left - dLabelBoundsLeft);
dDrawX -= Math.Max(0,
dLabelBoundsRight - oGraphRectangleMinusMargin.Right);
dDrawY += Math.Max(0,
oGraphRectangleMinusMargin.Top - dLabelBoundsTop);
dDrawY -= Math.Max(0,
dLabelBoundsBottom - oGraphRectangleMinusMargin.Bottom);
formattedText.TextAlignment = eTextAlignment;
drawingContext.DrawText( formattedText, new Point(dDrawX, dDrawY) );
}
