/// <summary>
/// Calculate index of the location
/// where the caret should move to after pressing "up" key.
/// </summary>
public static int Calc_Up(IViewInternal view)
{
Point pt;
int newIndex;
Document doc = view.Document;
// get screen location of the caret
pt = view.GetVirPosFromIndex(doc.CaretIndex);
// calculate next location
pt.X = view.GetDesiredColumn();
pt.Y -= view.LineSpacing;
newIndex = view.GetIndexFromVirPos(pt);
if (newIndex < 0)
{
return(doc.CaretIndex); // don't move
}
// In line selection mode,
// moving caret across the line which contains the anchor position
// should select the line and a line above.
// To select a line above, calculate index of the char at one more line above.
if (doc.SelectionMode == TextDataType.Line &&
newIndex == doc.AnchorIndex &&
view.IsLineHeadIndex(newIndex))
{
pt.Y -= view.LineSpacing;
if (0 <= pt.Y)
{
newIndex = view.GetIndexFromVirPos(pt);
}
}
return(newIndex);
}
/// <summary>
/// Calculate index of the location
/// where the caret should move to after pressing "down" key.
/// </summary>
public static int Calc_Down(IViewInternal view)
{
Point pt;
int newIndex;
Document doc = view.Document;
// get screen location of the caret
pt = view.GetVirPosFromIndex(doc.CaretIndex);
// calculate next location
pt.X = view.GetDesiredColumn();
pt.Y += view.LineSpacing;
/* NOT NEEDED because View.GetIndexFromVirPos handles this case.
* if( view.Height - view.LineSpacing < pt.Y )
* {
* return doc.CaretIndex; // no lines below. don't move.
* }*/
newIndex = view.GetIndexFromVirPos(pt);
// In line selection mode,
// moving caret across the line which contains the anchor position
// should select the line and a line below.
// To select a line below, calculate index of the char at one more line below.
if (doc.SelectionMode == TextDataType.Line &&
view.IsLineHeadIndex(newIndex))
{
Point pt2 = new Point(pt.X, pt.Y + view.LineSpacing);
int skippedNewIndex = view.GetIndexFromVirPos(pt2);
if (skippedNewIndex == doc.AnchorIndex)
{
newIndex = skippedNewIndex;
}
}
return(newIndex);
}
void SetSelection_Line(int anchor, int caret, IViewInternal view)
{
int toLineIndex;
// get line index of the lines where selection starts and ends
toLineIndex = view.GetLineIndexFromCharIndex(caret);
if (ViewParam.LineSelectionAnchor1 < 0 ||
(anchor != ViewParam.LineSelectionAnchor1 && anchor != ViewParam.LineSelectionAnchor2))
{
//-- line selection anchor changed or did not exists --
// select between head of the line and end of the line
int fromLineIndex = view.GetLineIndexFromCharIndex(anchor);
anchor = view.GetLineHeadIndex(fromLineIndex);
if (fromLineIndex + 1 < view.LineCount)
{
caret = view.GetLineHeadIndex(fromLineIndex + 1);
}
else
{
caret = _Document.Length;
}
ViewParam.LineSelectionAnchor1 = anchor;
ViewParam.LineSelectionAnchor2 = anchor;
}
else if (ViewParam.LineSelectionAnchor1 < caret)
{
//-- selecting to the line (or after) where selection started --
// select between head of the starting line and the end of the destination line
anchor = view.GetLineHeadIndexFromCharIndex(ViewParam.LineSelectionAnchor1);
if (view.IsLineHeadIndex(caret) == false)
{
toLineIndex = view.GetLineIndexFromCharIndex(caret);
if (toLineIndex + 1 < view.LineCount)
{
caret = view.GetLineHeadIndex(toLineIndex + 1);
}
else
{
caret = _Document.Length;
}
}
}
else // if( caret < LineSelectionAnchor )
{
//-- selecting to foregoing lines where selection started --
// select between head of the destination line and end of the starting line
int anchorLineIndex;
caret = view.GetLineHeadIndex(toLineIndex);
anchorLineIndex = view.GetLineIndexFromCharIndex(ViewParam.LineSelectionAnchor1);
if (anchorLineIndex + 1 < view.LineCount)
{
anchor = view.GetLineHeadIndex(anchorLineIndex + 1);
}
else
{
anchor = _Document.Length;
}
//DO_NOT//ViewParam.LineSelectionAnchor1 = anchor;
ViewParam.LineSelectionAnchor2 = anchor;
}
// apply new selection
SetSelection_Normal(anchor, caret);
}