/// <summary>
/// Updates the <see cref="VisualText"/> including text wrapping.
/// </summary>
/// <param name="text">The text.</param>
/// <param name="textWidth">The available width.</param>
/// <param name="font">The font.</param>
private void UpdateVisualText(string text, float textWidth, SpriteFont font)
{
VisualText.Clear();
WrapText(textWidth, font);
if (_lineStarts == null || _lineStarts.Count == 0)
{
// Single-line: Just add all text. The renderer has to clip the text.
VisualText.Append(text);
}
else
{
// Multiline: Add line by line.
for (int i = 0; i < _lineStarts.Count; i++)
{
int start = _lineStarts[i];
int end = (i + 1 < _lineStarts.Count) ? _lineStarts[i + 1] : -text.Length;
VisualText.Append(text, Math.Abs(start), Math.Abs(end) - Math.Abs(start));
// A positive index indicates that a newline character needs to be added
// for text wrapping.
if (end > 0)
{
VisualText.Append('\n');
}
}
}
}
protected override Vector2F OnMeasure(Vector2F availableSize)
{
// This control can only measure itself if it is in a screen because it needs a font.
var screen = Screen;
if (screen == null)
{
return(base.OnMeasure(availableSize));
}
// Clear old renderer info.
VisualClip = false;
VisualText.Clear();
string text = Text;
float width = Width;
float height = Height;
bool hasWidth = Numeric.IsPositiveFinite(width);
bool hasHeight = Numeric.IsPositiveFinite(height);
if (string.IsNullOrEmpty(text))
{
// No text --> Abort.
return(new Vector2F(
hasWidth ? width : 0,
hasHeight ? height : 0));
}
// Limit constraint size by user-defined width and height.
if (hasWidth && width < availableSize.X)
{
availableSize.X = width;
}
if (hasHeight && height < availableSize.Y)
{
availableSize.Y = height;
}
// Remove padding from constraint size.
Vector4 padding = Padding;
Vector2F contentSize = availableSize;
if (Numeric.IsPositiveFinite(availableSize.X))
{
contentSize.X -= padding.X + padding.Z;
}
if (Numeric.IsPositiveFinite(availableSize.Y))
{
contentSize.Y -= padding.Y + padding.W;
}
// Measure text size.
var font = screen.Renderer.GetFont(Font);
Vector2F size = (Vector2F)font.MeasureString(text);
if (size < contentSize)
{
// All text is visible. (VisualText is equal to Text.)
VisualText.Append(text);
return(new Vector2F(
hasWidth ? width : size.X + padding.X + padding.Z,
hasHeight ? height : size.Y + padding.Y + padding.W));
}
// Get number of lines.
int numberOfLines = 1;
for (int i = 0; i < text.Length - 1; i++)
{
if (text[i] == '\n')
{
numberOfLines++;
}
}
if (numberOfLines == 1 && size.Y > contentSize.Y)
{
// Not enough space for a single line height. --> Keep all text and use clipping.
VisualText.Append(text);
VisualClip = true;
return(new Vector2F(
hasWidth ? width : size.X + padding.X + padding.Z,
hasHeight ? height : size.Y + padding.Y + padding.W));
}
if (!WrapText)
{
// Not using word wrapping.
// Compute desired size.
Vector2F desiredSize = new Vector2F(
hasWidth ? width : availableSize.X,
hasHeight ? height : availableSize.Y);
desiredSize.X = Math.Min(desiredSize.X, size.X + padding.X + padding.Z);
desiredSize.Y = Math.Min(desiredSize.Y, size.Y + padding.Y + padding.W);
if (numberOfLines > 1 || // 2 or more lines?
!UseEllipsis || // No ellipsis needed?
size.Y > contentSize.Y) // Single line is already to high?
{
// Just clip the text.
VisualClip = true;
VisualText.Append(text);
}
else
{
// 1 line that is too long and we have to insert an ellipsis.
VisualText.Append(text);
TrimText(VisualText, font, contentSize.X);
}
return(desiredSize);
}
// Get words.
var words = SplitText();
// Note: We can compute line heights without font.MeasureString(). But we cannot compute
// line widths without font.MeasureString() because we do not have kerning information.
int lineHeight = font.LineSpacing;
Debug.Assert(lineHeight <= contentSize.Y, "At least one line must fit into content");
float currentHeight = lineHeight;
// Add words to string builder until space runs out.
// In each loop iteration one line is built.
int index = 0;
int lineWordCount = 0;
var line = new StringBuilder();
while (currentHeight < contentSize.Y && // Room for one more line?
index < words.Count) // Words left?
{
if (index > 0)
{
VisualText.Append(line.ToString()); // Add line of last iteration.
VisualText.Append("\n");
// If the next word is a newline, then we can skip it because we start a new line
// anyways.
if (words[index] == null)
{
index++;
}
}
// Start with empty line.
line.Remove(0, line.Length);
lineWordCount = 0;
// Build line.
while (index < words.Count && // As long as we have words.
words[index] != null) // And as long the next word is not a newline.
{
// Add spaces after first word.
if (lineWordCount > 0)
{
line.Append(" ");
}
// Add next word.
line.Append(words[index]);
lineWordCount++;
index++;
float lineWidth = font.MeasureString(line).X;
if (lineWidth > contentSize.X)
{
// Line is too long! Remove last word + blank. But keep at least one word per line.
if (lineWordCount > 1)
{
index--;
lineWordCount--;
int wordLength = words[index].Length;
line.Remove(line.Length - wordLength - 1, wordLength + 1);
}
else
{
VisualClip = true; // A single word is too long and must be clipped.
}
break;
}
}
currentHeight += lineHeight;
}
// Nearly all visible text is in VisualText.
// The last line is in "line" and was not yet added to VisualText.
if (UseEllipsis)
{
if ((index < words.Count || // Not enough space to print all words.
font.MeasureString(line).X > contentSize.X)) // The last line is too long and needs to be trimmed.
{
// Trim the last line and add an ellipsis.
line.Append("�");
while (lineWordCount > 0 && font.MeasureString(line).X > contentSize.X)
{
index--;
// We have to remove one word before the ellipsis.
int wordLength = words[index].Length;
line.Remove(line.Length - 1 - wordLength, wordLength);
// Remove ' ' before ellipsis.
int indexBeforeEllipsis = line.Length - 2;
if (indexBeforeEllipsis > 0 && line[indexBeforeEllipsis] == ' ')
{
line.Remove(indexBeforeEllipsis, 1);
}
lineWordCount--;
}
}
}
// Add last line.
VisualText.Append(line);
size = (Vector2F)font.MeasureString(VisualText);
return(new Vector2F(
hasWidth ? width : size.X + padding.X + padding.Z,
hasHeight ? height : size.Y + padding.Y + padding.W));
}
