/// <summary>
/// Calculates the parameters with which to draw the selection.
/// </summary>
private void UpdateSelection()
{
if (View == null || textLayoutStream.Count == 0 || !selectionPosition.HasValue || pendingTextLayout)
return;
if (SelectionLength == 0)
{
selectionLineStart = 0;
selectionLineCount = 0;
selectionTop = default(Ultraviolet.Rectangle);
selectionBottom = default(Ultraviolet.Rectangle);
}
else
{
var selectionStart = SelectionStart;
var selectionStartLineInfo = default(LineInfo);
var selectionStartGlyphBounds = View.Resources.TextRenderer.GetGlyphBounds(textLayoutStream,
selectionStart, out selectionStartLineInfo, true);
var selectionEnd = SelectionStart + (SelectionLength - 1);
var selectionEndLineInfo = default(LineInfo);
var selectionEndGlyphBounds = View.Resources.TextRenderer.GetGlyphBounds(textLayoutStream,
selectionEnd, out selectionEndLineInfo, true);
selectionLineStart = selectionStartLineInfo.LineIndex;
selectionLineCount = 1 + (selectionEndLineInfo.LineIndex - selectionStartLineInfo.LineIndex);
// Top
var selectionTopX = selectionStartGlyphBounds.X;
var selectionTopY = selectionStartGlyphBounds.Y;
var selectionTopWidth = (selectionLineCount == 1) ? selectionEndGlyphBounds.Right - selectionStartGlyphBounds.Left :
selectionStartLineInfo.Width - (selectionStartGlyphBounds.X - selectionStartLineInfo.X);
var selectionTopHeight = selectionStartLineInfo.Height;
selectionTop = new Ultraviolet.Rectangle(selectionTopX, selectionTopY, selectionTopWidth, selectionTopHeight);
// Bottom
if (selectionLineCount > 1)
{
var selectionBottomX = selectionEndLineInfo.X;
var selectionBottomY = selectionEndGlyphBounds.Y;
var selectionBottomWidth = selectionEndGlyphBounds.Right - selectionBottomX;
var selectionBottomHeight = selectionEndLineInfo.Height;
selectionBottom = new Ultraviolet.Rectangle(selectionBottomX, selectionBottomY, selectionBottomWidth, selectionBottomHeight);
}
}
}
/// <summary>
/// Scrolls to ensure that the caret is within the viewport.
/// </summary>
private void ScrollToCaret(Boolean showMaximumLineWidth, Boolean jumpLeft, Boolean jumpRight)
{
var scrollViewer = Parent as ScrollViewer;
if (scrollViewer == null)
return;
var boundsViewport = new RectangleD(scrollViewer.HorizontalOffset, scrollViewer.VerticalOffset,
scrollViewer.ViewportWidth, scrollViewer.ViewportHeight);
var boundsCaretPixs = new Ultraviolet.Rectangle(caretBounds.X, caretBounds.Y, caretRenderBounds.Width, caretBounds.Height);
var boundsCaretDips = Display.PixelsToDips(boundsCaretPixs);
var isHorizontalScrollingNecessary = (boundsCaretDips.Left < boundsViewport.Left || boundsCaretDips.Right > boundsViewport.Right);
var isVerticalScrollingNecessary = (boundsCaretDips.Top < boundsViewport.Top || boundsCaretDips.Bottom > boundsViewport.Bottom);
if (!isHorizontalScrollingNecessary && !isVerticalScrollingNecessary)
return;
if (isVerticalScrollingNecessary)
{
if (boundsCaretDips.Top < boundsViewport.Top)
{
var verticalOffset = boundsCaretDips.Top;
scrollViewer.ScrollToVerticalOffset(verticalOffset);
}
else
{
var verticalOffset = (boundsCaretDips.Bottom - boundsViewport.Height);
scrollViewer.ScrollToVerticalOffset(verticalOffset);
}
}
if (showMaximumLineWidth)
{
var owner = TemplatedParent as Control;
var alignment = (owner == null) ? TextAlignment.Left : owner.GetValue<TextAlignment>(TextBox.TextAlignmentProperty);
var horizontalOffset = (alignment == TextAlignment.Right) ? boundsCaretDips.Left : boundsCaretDips.Right - boundsViewport.Width;
scrollViewer.ScrollToHorizontalOffset(horizontalOffset);
}
else
{
if (isHorizontalScrollingNecessary)
{
if (boundsCaretDips.Left < boundsViewport.Left)
{
var horizontalOffset = boundsCaretDips.Left -
(jumpLeft ? (boundsViewport.Width / 3.0) : 0);
scrollViewer.ScrollToHorizontalOffset(horizontalOffset);
}
else
{
var horizontalOffset = (boundsCaretDips.Right - boundsViewport.Width) +
(jumpRight ? (boundsViewport.Width / 3.0) : 0);
scrollViewer.ScrollToHorizontalOffset(horizontalOffset);
}
}
}
}
/// <summary>
/// Calculates the position at which to draw the text caret.
/// </summary>
private void UpdateCaret()
{
if (View == null || pendingTextLayout)
return;
var owner = TemplatedParent as Control;
var isReadOnly = (owner != null && owner.GetValue<Boolean>(TextBox.IsReadOnlyProperty));
var fontFace = TextFontFace;
var fontLineSpacing = (fontFace != null) ? fontFace.LineSpacing : 0;
var fontLineSpacingHalf = (Int32)Math.Ceiling(fontLineSpacing / 2f);
var styledCaretWidth = (Int32)Display.DipsToPixels(CaretWidth);
var styledCaretThickness = (Int32)Display.DipsToPixels(CaretThickness);
var caretAlignment = TextAlignment.Left;
var caretRenderX = 0;
var caretRenderY = 0;
var caretRenderWidth = 0;
var caretRenderHeight = 0;
if (caretInsertionMode == CaretMode.Overwrite && !IsLineBreak(caretPosition) && !isReadOnly)
{
actualInsertionMode = CaretMode.Overwrite;
var caretDefaultSize = GetDefaultSizeOfOverwriteCaret();
var caretX = 0;
var caretY = 0;
var caretWidth = caretDefaultSize.Width;
var caretHeight = caretDefaultSize.Height;
if (textLayoutStream.TotalLength > 0)
{
var glyphLineInfo = default(LineInfo);
var glyphBounds = View.Resources.TextRenderer.GetGlyphBounds(textLayoutStream, caretPosition, out glyphLineInfo, true);
caretX = glyphBounds.Left;
caretY = glyphBounds.Top;
caretWidth = glyphBounds.Width;
caretBounds = new Ultraviolet.Rectangle(caretX, caretY, caretWidth, glyphBounds.Height);
caretLineIndex = glyphLineInfo.LineIndex;
}
else
{
caretAlignment = (owner == null) ? TextAlignment.Left : owner.GetValue<TextAlignment>(TextBox.TextAlignmentProperty);
caretBounds = new Ultraviolet.Rectangle(caretX, caretY, caretWidth, fontLineSpacing);
caretLineIndex = 0;
}
caretRenderWidth = caretWidth;
caretRenderHeight = Math.Min(caretBounds.Height, styledCaretThickness);
caretRenderY = caretBounds.Bottom - caretRenderHeight;
}
else
{
actualInsertionMode = CaretMode.Insert;
var caretDefaultSize = GetDefaultSizeOfInsertionCaret();
var caretX = 0;
var caretY = 0;
var caretWidth = caretDefaultSize.Width;
var caretHeight = caretDefaultSize.Height;
if (textLayoutStream.TotalLength > 0)
{
var lineInfo = default(LineInfo);
var boundsGlyph = default(Ultraviolet.Rectangle?);
var boundsInsert = View.Resources.TextRenderer.GetInsertionPointBounds(textLayoutStream,
caretPosition, out lineInfo, out boundsGlyph);
caretX = boundsInsert.X;
caretY = boundsInsert.Y;
caretWidth = (boundsGlyph.HasValue && boundsGlyph.Value.Width > 0) ? boundsGlyph.Value.Width : fontLineSpacingHalf;
caretHeight = boundsInsert.Height;
caretBounds = new Ultraviolet.Rectangle(caretX, caretY, caretWidth, caretHeight);
caretLineIndex = lineInfo.LineIndex;
}
else
{
caretAlignment = (owner == null) ? TextAlignment.Left : owner.GetValue<TextAlignment>(TextBox.TextAlignmentProperty);
caretBounds = new Ultraviolet.Rectangle(caretX, caretY, caretWidth, caretHeight);
caretLineIndex = 0;
}
caretRenderWidth = Math.Min(caretBounds.Width, styledCaretWidth);
caretRenderHeight = caretBounds.Height;
caretRenderY = caretBounds.Top;
}
switch (caretAlignment)
{
case TextAlignment.Left:
caretRenderX = caretBounds.Left;
break;
case TextAlignment.Center:
caretRenderX = caretBounds.Center.X - (caretRenderWidth / 2);
break;
case TextAlignment.Right:
caretRenderX = (caretBounds.Right - caretRenderWidth);
break;
}
caretRenderBounds = new Ultraviolet.Rectangle(caretRenderX, caretRenderY, caretRenderWidth, caretRenderHeight);
}
/// <summary>
/// Draws the current selection.
/// </summary>
private void DrawSelection(UltravioletTime time, DrawingContext dc)
{
if (!selectionPosition.HasValue || SelectionLength == 0)
return;
// Don't draw the selection unless we have keyboard focus (unless IsInactiveSelectionHighlightEnabled is true).
var owner = TemplatedParent as Control;
if (owner == null)
return;
var isActive = owner.IsKeyboardFocusWithin;
var isEnabledIfInactive = owner.GetValue<Boolean>(TextBox.IsInactiveSelectionHighlightEnabledProperty);
if (!isActive && !isEnabledIfInactive)
return;
var selectionColor = isActive ? SelectionColor : InactiveSelectionColor;
// Draw the first line
var selectionTopDips = Display.PixelsToDips(selectionTop);
DrawImage(dc, SelectionImage, selectionTopDips, selectionColor, true);
// Draw the middle
if (selectionLineCount > 2)
{
textLayoutStream.AcquirePointers();
var lineInfo = textLayoutStream.GetLineInfo(selectionLineStart);
for (int i = selectionLineStart + 1; i < selectionLineStart + selectionLineCount - 1; i++)
{
textLayoutStream.GetNextLineInfoRef(ref lineInfo, out lineInfo);
var lineBounds = new Ultraviolet.Rectangle(lineInfo.X, lineInfo.Y, lineInfo.Width, lineInfo.Height);
var lineBoundsDips = Display.PixelsToDips(lineBounds);
DrawImage(dc, SelectionImage, lineBoundsDips, selectionColor, true);
}
textLayoutStream.ReleasePointers();
}
// Draw the last line
if (selectionLineCount > 1)
{
var selectionBottomDips = Display.PixelsToDips(selectionBottom);
DrawImage(dc, SelectionImage, selectionBottomDips, selectionColor, true);
}
}
