public static Action <TextEditorData> VisualSelectionFromMoveAction(Action <TextEditorData> moveAction)
{
return(delegate(TextEditorData data) {
//get info about the old selection state
DocumentLocation oldCaret = data.Caret.Location, oldAnchor = oldCaret, oldLead = oldCaret;
if (data.IsSomethingSelected)
{
oldLead = data.MainSelection.Lead;
oldAnchor = data.MainSelection.Anchor;
}
//do the action, preserving selection
SelectionActions.StartSelection(data);
moveAction(data);
SelectionActions.EndSelection(data);
DocumentLocation newCaret = data.Caret.Location, newAnchor = newCaret, newLead = newCaret;
if (data.IsSomethingSelected)
{
newLead = data.MainSelection.Lead;
newAnchor = data.MainSelection.Anchor;
}
//Console.WriteLine ("oc{0}:{1} oa{2}:{3} ol{4}:{5}", oldCaret.Line, oldCaret.Column, oldAnchor.Line, oldAnchor.Column, oldLead.Line, oldLead.Column);
//Console.WriteLine ("nc{0}:{1} na{2}:{3} nl{4}:{5}", newCaret.Line, newCaret.Line, newAnchor.Line, newAnchor.Column, newLead.Line, newLead.Column);
//pivot the anchor around the anchor character
if (oldAnchor < oldLead && newAnchor >= newLead)
{
data.SetSelection(new DocumentLocation(newAnchor.Line, newAnchor.Column + 1), newLead);
}
else if (oldAnchor > oldLead && newAnchor <= newLead)
{
data.SetSelection(new DocumentLocation(newAnchor.Line, newAnchor.Column - 1), newLead);
}
//pivot the lead about the anchor character
if (newAnchor == newLead)
{
if (oldAnchor < oldLead)
{
SelectionActions.FromMoveAction(Left) (data);
}
else
{
SelectionActions.FromMoveAction(Right) (data);
}
}
//pivot around the anchor line
else
{
if (oldAnchor < oldLead && newAnchor > newLead && (
(newLead.Line == newAnchor.Line && oldLead.Line == oldAnchor.Line + 1) ||
(newLead.Line == newAnchor.Line - 1 && oldLead.Line == oldAnchor.Line)))
{
SelectionActions.FromMoveAction(Left) (data);
}
else if (oldAnchor > oldLead && newAnchor < newLead && (
(newLead.Line == newAnchor.Line && oldLead.Line == oldAnchor.Line - 1) ||
(newLead.Line == newAnchor.Line + 1 && oldLead.Line == oldAnchor.Line)))
{
SelectionActions.FromMoveAction(Right) (data);
}
}
});
}