//-------------------------------------------------------------------
// Retrieve text position index from the distance.
//
// distance - distance relative to the beginning of the line
//
// Returns: Text position index.
//-------------------------------------------------------------------
internal CharacterHit GetTextPositionFromDistance(double distance)
{
// Adjust distance to account for a line shift due to rendering of trailing spaces
double delta = CalculateXOffsetShift();
if (_line.HasOverflowed && _owner.ParagraphProperties.TextTrimming != TextTrimming.None)
{
System.Windows.Media.TextFormatting.TextLine line = _line.Collapse(GetCollapsingProps(_wrappingWidth, _owner.ParagraphProperties));
Invariant.Assert(DoubleUtil.AreClose(delta, 0));
Invariant.Assert(line.HasCollapsed, "Line has not been collapsed");
return(line.GetCharacterHitFromDistance(distance));
}
return(_line.GetCharacterHitFromDistance(distance - delta));
}
/// <summary>
/// Gets the visual column from a document position (relative to top left of the document).
/// If the user clicks between two visual columns, rounds to the nearest column.
/// </summary>
public int GetVisualColumn(TextLine textLine, double xPos, bool allowVirtualSpace)
{
if (xPos > textLine.WidthIncludingTrailingWhitespace) {
if (allowVirtualSpace && textLine == TextLines[TextLines.Count - 1]) {
int virtualX = (int)Math.Round((xPos - textLine.WidthIncludingTrailingWhitespace) / textView.WideSpaceWidth);
return VisualLengthWithEndOfLineMarker + virtualX;
}
}
CharacterHit ch = textLine.GetCharacterHitFromDistance(xPos);
return ch.FirstCharacterIndex + ch.TrailingLength;
}
// ------------------------------------------------------------------
// Hit tests to the correct ContentElement within the line.
//
// offset - offset within the line.
//
// Returns: ContentElement which has been hit.
// ------------------------------------------------------------------
internal override IInputElement InputHitTest(double offset)
{
TextContainer tree;
DependencyObject element;
CharacterHit charHit;
TextPointer position;
TextPointerContext type = TextPointerContext.None;
element = null;
// We can only support hittesting text elements in a TextContainer.
// If the TextContainer is not a TextContainer, return null which higher up the stack
// will be converted into a reference to the control itself.
tree = _owner.TextContainer as TextContainer;
// Adjusted offset for shift due to trailing spaces rendering
double delta = CalculateXOffsetShift();
if (tree != null)
{
if (_line.HasOverflowed && _owner.ParagraphProperties.TextTrimming != TextTrimming.None)
{
// We should not shift offset in this case
Invariant.Assert(DoubleUtil.AreClose(delta, 0));
System.Windows.Media.TextFormatting.TextLine line = _line.Collapse(GetCollapsingProps(_wrappingWidth, _owner.ParagraphProperties));
Invariant.Assert(line.HasCollapsed, "Line has not been collapsed");
// Get TextPointer from specified distance.
charHit = line.GetCharacterHitFromDistance(offset);
}
else
{
charHit = _line.GetCharacterHitFromDistance(offset - delta);
}
position = new TextPointer(_owner.ContentStart, CalcPositionOffset(charHit), LogicalDirection.Forward);
if (position != null)
{
if (charHit.TrailingLength == 0)
{
// Start of character. Look forward
type = position.GetPointerContext(LogicalDirection.Forward);
}
else
{
// End of character. Look backward
type = position.GetPointerContext(LogicalDirection.Backward);
}
// Get element only for Text & Start/End element, for all other positions
// return null (it means that the line owner has been hit).
if (type == TextPointerContext.Text || type == TextPointerContext.ElementEnd)
{
element = position.Parent as TextElement;
}
else if (type == TextPointerContext.ElementStart)
{
element = position.GetAdjacentElementFromOuterPosition(LogicalDirection.Forward);
}
}
}
return(element as IInputElement);
}
