/// <summary>
/// Handle html text selection by mouse move over the html with left mouse button pressed.<br/>
/// Calculate the words in the selected range and set their selected property.
/// </summary>
/// <param name="control">the control hosting the html to invalidate</param>
/// <param name="loc">the mouse location</param>
/// <param name="allowPartialSelect">true - partial word selection allowed, false - only full words selection</param>
private void HandleSelection(RControl control, RPoint loc, bool allowPartialSelect)
{
// get the line under the mouse or nearest from the top
var lineBox = DomUtils.GetCssLineBox(_root, loc);
if (lineBox != null)
{
// get the word under the mouse
var word = DomUtils.GetCssBoxWord(lineBox, loc);
// if no word found under the mouse use the last or the first word in the line
if (word == null && lineBox.Words.Count > 0)
{
if (loc.Y > lineBox.LineBottom)
{
// under the line
word = lineBox.Words[lineBox.Words.Count - 1];
}
else if (loc.X < lineBox.Words[0].Left)
{
// before the line
word = lineBox.Words[0];
}
else if (loc.X > lineBox.Words[lineBox.Words.Count - 1].Right)
{
// at the end of the line
word = lineBox.Words[lineBox.Words.Count - 1];
}
}
// if there is matching word
if (word != null)
{
if (_selectionStart == null)
{
// on start set the selection start word
_selectionStartPoint = loc;
_selectionStart = word;
if (allowPartialSelect)
CalculateWordCharIndexAndOffset(control, word, loc, true);
}
// always set selection end word
_selectionEnd = word;
if (allowPartialSelect)
CalculateWordCharIndexAndOffset(control, word, loc, false);
ClearSelection(_root);
if (CheckNonEmptySelection(loc, allowPartialSelect))
{
CheckSelectionDirection();
SelectWordsInRange(_root, _backwardSelection ? _selectionEnd : _selectionStart, _backwardSelection ? _selectionStart : _selectionEnd);
}
else
{
_selectionEnd = null;
}
_cursorChanged = true;
control.SetCursorIBeam();
control.Invalidate();
}
}
}
/// <summary>
/// Handle mouse move to handle hover cursor and text selection.
/// </summary>
/// <param name="parent">the control hosting the html to set cursor and invalidate</param>
/// <param name="loc">the location of the mouse on the html</param>
public void HandleMouseMove(RControl parent, RPoint loc)
{
if (_root.HtmlContainer.IsSelectionEnabled && _mouseDownInControl && parent.LeftMouseButton)
{
if (_mouseDownOnSelectedWord)
{
// make sure not to start drag-drop on click but when it actually moves as it f***s mouse-up
if ((DateTime.Now - _lastMouseDown).TotalMilliseconds > 200)
StartDragDrop(parent);
}
else
{
HandleSelection(parent, loc, !_isDoubleClickSelect);
_inSelection = _selectionStart != null && _selectionEnd != null && (_selectionStart != _selectionEnd || _selectionStartIndex != _selectionEndIndex);
}
}
else
{
// Handle mouse hover over the html to change the cursor depending if hovering word, link of other.
var link = DomUtils.GetLinkBox(_root, loc);
if (link != null)
{
_cursorChanged = true;
parent.SetCursorHand();
}
else if (_root.HtmlContainer.IsSelectionEnabled)
{
var word = DomUtils.GetCssBoxWord(_root, loc);
_cursorChanged = word != null && !word.IsImage && !(word.Selected && (word.SelectedStartIndex < 0 || word.Left + word.SelectedStartOffset <= loc.X) && (word.SelectedEndOffset < 0 || word.Left + word.SelectedEndOffset >= loc.X));
if (_cursorChanged)
parent.SetCursorIBeam();
else
parent.SetCursorDefault();
}
else if (_cursorChanged)
{
parent.SetCursorDefault();
}
}
}