/// <summary>
/// Highlight text on the page
/// </summary>
/// <param name="pageIndex">Zero-based index of the page</param>
/// <param name="charIndex">Zero-based char index on the page.</param>
/// <param name="charsCount">The number of highlighted characters on the page or -1 for highlight text from charIndex to end of the page.</param>
/// <param name="color">Highlight color</param>
public void HighlightText(int pageIndex, int charIndex, int charsCount, Color color)
{
//normalize all user input
if (pageIndex < 0)
pageIndex = 0;
if (pageIndex > Document.Pages.Count - 1)
pageIndex = Document.Pages.Count - 1;
int charsCnt = Document.Pages[pageIndex].Text.CountChars;
if (charIndex < 0)
charIndex = 0;
if (charIndex > charsCnt - 1)
charIndex = charsCnt - 1;
if (charsCount < 0)
charsCount = charsCnt - charIndex;
if (charIndex + charsCount > charsCnt)
charsCount = charsCnt - 1 - charIndex;
if (charsCount <= 0)
return;
var newEntry = new HighlightInfo() { CharIndex = charIndex, CharsCount = charsCount, Color = color };
if (!_highlightedText.ContainsKey(pageIndex))
{
if (color != Helpers.ColorEmpty)
{
_highlightedText.Add(pageIndex, new List<HighlightInfo>());
_highlightedText[pageIndex].Add(newEntry);
}
}
else
{
var entries = _highlightedText[pageIndex];
//Analize exists entries and remove overlapped and trancate intersecting entries
for (int i = entries.Count - 1; i >= 0; i--)
{
List<HighlightInfo> calcEntries;
if (CalcIntersectEntries(entries[i], newEntry, out calcEntries))
{
if (calcEntries.Count == 0)
entries.RemoveAt(i);
else
for (int j = 0; j < calcEntries.Count; j++)
if (j == 0)
entries[i] = calcEntries[j];
else
entries.Insert(i, calcEntries[j]);
}
}
if (color != Helpers.ColorEmpty)
entries.Add(newEntry);
}
InvalidateVisual();
OnHighlightedTextChanged(EventArgs.Empty);
}
private bool CalcIntersectEntries(HighlightInfo existEntry, HighlightInfo addingEntry, out List<HighlightInfo> calcEntries)
{
calcEntries = new List<HighlightInfo>();
int eStart = existEntry.CharIndex;
int eEnd = existEntry.CharIndex + existEntry.CharsCount - 1;
int aStart = addingEntry.CharIndex;
int aEnd = addingEntry.CharIndex + addingEntry.CharsCount - 1;
if (eStart < aStart && eEnd >= aStart && eEnd <= aEnd)
{
calcEntries.Add(new HighlightInfo()
{
CharIndex = eStart,
CharsCount = aStart - eStart,
Color = existEntry.Color
});
return true;
}
else if (eStart >= aStart && eStart <= aEnd && eEnd > aEnd)
{
calcEntries.Add(new HighlightInfo()
{
CharIndex = aEnd + 1,
CharsCount = eEnd - aEnd,
Color = existEntry.Color
});
return true;
}
else if (eStart >= aStart && eEnd <= aEnd)
return true;
else if (eStart < aStart && eEnd > aEnd)
{
calcEntries.Add(new HighlightInfo()
{
CharIndex = eStart,
CharsCount = aStart - eStart,
Color = existEntry.Color
});
calcEntries.Add(new HighlightInfo()
{
CharIndex = aEnd + 1,
CharsCount = eEnd - aEnd,
Color = existEntry.Color
});
return true;
}
//no intersection
return false;
}
/// <summary>
/// Highlight text on the page
/// </summary>
/// <param name="pageIndex">Zero-based index of the page</param>
/// <param name="highlightInfo">Sets the options for highlighting text</param>
public void HighlightText(int pageIndex, HighlightInfo highlightInfo)
{
HighlightText(pageIndex, highlightInfo.CharIndex, highlightInfo.CharsCount, highlightInfo.Color);
}