private void Render()
{
if (TracePoints != null && TracePoints.Count > 2)
{
PointF[] polygon = CreateSelectionPolygon();
if (polygon.Length > 2)
{
DocumentWorkspace.ResetOutlineWhiteOpacity();
NewSelectionRenderer.ResetOutlineWhiteOpacity();
Selection.SetContinuation(polygon, SelectionMode);
CombineMode cm;
if (SelectionMode == CombineMode.Replace)
{
cm = CombineMode.Replace;
}
else
{
cm = CombineMode.Xor;
}
NewSelection.SetContinuation(polygon, cm);
Update();
}
}
}
private void Done()
{
if (Tracking)
{
// Truth table for what we should do based on three flags:
// append | moved | tooQuick | result | optimized expression to yield true
// ---------+-------+----------+-----------------------------------------------------------------------
// F | T | T | clear selection | !append && (!moved || tooQuick)
// F | T | F | emit new selected area | !append && moved && !tooQuick
// F | F | T | clear selection | !append && (!moved || tooQuick)
// F | F | F | clear selection | !append && (!moved || tooQuick)
// T | T | T | append to selection | append && moved
// T | T | F | append to selection | append && moved
// T | F | T | reset selection | append && !moved
// T | F | F | reset selection | append && !moved
//
// append --> If the user was holding control, then true. Else false.
// moved --> If they never moved the mouse, false. Else true.
// tooQuick --> If they held the mouse button down for more than 50ms, false. Else true.
//
// "Clear selection" means to result in no selected area. If the selection area was previously empty,
// then no HistoryMemento is emitted. Otherwise a Deselect HistoryMemento is emitted.
//
// "Reset selection" means to reset the selected area to how it was before interaction with the tool,
// without a HistoryMemento.
PointF[] polygon = CreateSelectionPolygon();
HasMoved &= (polygon.Length > 1);
// They were "too quick" if they weren't doing a selection for more than 50ms
// This takes care of the case where someone wants to click to deselect, but accidentally moves
// the mouse. This happens VERY frequently.
bool tooQuick = Utility.TicksToMs((DateTime.Now - StartTime).Ticks) <= 50;
// If their selection was completedly out of bounds, it will be clipped
bool clipped = (polygon.Length == 0);
// What the user drew had no effect on the selection, e.g. subtraction where there was nothing in the first place
bool noEffect = false;
WhatToDo whatToDo;
// If their selection gets completely clipped (i.e. outside the image canvas),
// then result in a no-op
if (Append)
{
if (!HasMoved || clipped || noEffect)
{
whatToDo = WhatToDo.Reset;
}
else
{
whatToDo = WhatToDo.Emit;
}
}
else
{
if (HasMoved && !tooQuick && !clipped && !noEffect)
{
whatToDo = WhatToDo.Emit;
}
else
{
whatToDo = WhatToDo.Clear;
}
}
switch (whatToDo)
{
case WhatToDo.Clear:
if (WasNotEmpty)
{
// emit a deselect history action
UndoAction.Name = DeselectFunction.StaticName;
UndoAction.Image = DeselectFunction.StaticImage;
HistoryStack.PushNewMemento(UndoAction);
}
Selection.Reset();
break;
case WhatToDo.Emit:
// emit newly selected area
UndoAction.Name = Name;
HistoryStack.PushNewMemento(UndoAction);
Selection.CommitContinuation();
break;
case WhatToDo.Reset:
// reset selection, no HistoryMemento
Selection.ResetContinuation();
break;
}
DocumentWorkspace.ResetOutlineWhiteOpacity();
NewSelectionRenderer.ResetOutlineWhiteOpacity();
NewSelection.Reset();
NewSelectionRenderer.Visible = false;
Tracking = false;
DocumentWorkspace.EnableSelectionOutline = true;
DocumentWorkspace.InvalidateSurface(Utility.RoundRectangle(DocumentWorkspace.VisibleDocumentRectangleF));
}
}
protected override void OnMouseDown(MouseEventArgs e)
{
base.OnMouseDown(e);
Cursor = GetCursor();
if (Tracking)
{
MoveOriginMode = true;
LastPoint = new Point(e.X, e.Y);
OnMouseMove(e);
}
else if ((e.Button & MouseButtons.Left) == MouseButtons.Left ||
(e.Button & MouseButtons.Right) == MouseButtons.Right)
{
Tracking = true;
HasMoved = false;
StartTime = DateTime.Now;
TracePoints = new List <Point>
{
new Point(e.X, e.Y)
};
UndoAction = new SelectionHistoryMemento("sentinel", Image, DocumentWorkspace);
WasNotEmpty = !Selection.IsEmpty;
// Determine this.combineMode
if ((ModifierKeys & Keys.Control) != 0 && e.Button == MouseButtons.Left)
{
SelectionMode = CombineMode.Union;
}
else if ((ModifierKeys & Keys.Alt) != 0 && e.Button == MouseButtons.Left)
{
SelectionMode = CombineMode.Exclude;
}
else if ((ModifierKeys & Keys.Control) != 0 && e.Button == MouseButtons.Right)
{
SelectionMode = CombineMode.Xor;
}
else if ((ModifierKeys & Keys.Alt) != 0 && e.Button == MouseButtons.Right)
{
SelectionMode = CombineMode.Intersect;
}
else
{
SelectionMode = AppEnvironment.SelectionCombineMode;
}
DocumentWorkspace.EnableSelectionOutline = false;
NewSelection.Reset();
PdnGraphicsPath basePath = Selection.CreatePath();
NewSelection.SetContinuation(basePath, CombineMode.Replace, true);
NewSelection.CommitContinuation();
bool newSelectionRendererVisible = true;
// Act on this.combineMode
switch (SelectionMode)
{
case CombineMode.Xor:
Append = true;
Selection.ResetContinuation();
break;
case CombineMode.Union:
Append = true;
Selection.ResetContinuation();
break;
case CombineMode.Exclude:
Append = true;
Selection.ResetContinuation();
break;
case CombineMode.Replace:
Append = false;
Selection.Reset();
break;
case CombineMode.Intersect:
Append = true;
Selection.ResetContinuation();
break;
default:
throw new InvalidEnumArgumentException();
}
NewSelectionRenderer.Visible = newSelectionRendererVisible;
}
}
