canvas.cpp

wxGTK 是 wxWidgets 的 linux GTK+ (>2.2.3)版本。wxWidgets 是一个跨平台的 GUI 框架

        m_dragState = StartDraggingLeft;
        m_firstDragX = x;
        m_firstDragY = y;
      }
      else if (event.LeftUp())
      {
        // N.B. Only register a click if the same object was
        // identified for down *and* up.
        if (nearest_object == m_draggedShape)
          nearest_object->GetEventHandler()->OnLeftClick((double)x, (double)y, keys, attachment);

        m_draggedShape = NULL;
        m_dragState = NoDragging;
      }
      else if (event.LeftDClick())
      {
        nearest_object->GetEventHandler()->OnLeftDoubleClick((double)x, (double)y, keys, attachment);

        m_draggedShape = NULL;
        m_dragState = NoDragging;
      }
      else if (event.RightDown())
      {
        m_draggedShape = nearest_object;
        m_draggedAttachment = attachment;
        m_dragState = StartDraggingRight;
        m_firstDragX = x;
        m_firstDragY = y;
      }
      else if (event.RightUp())
      {
        if (nearest_object == m_draggedShape)
          nearest_object->GetEventHandler()->OnRightClick((double)x, (double)y, keys, attachment);

        m_draggedShape = NULL;
        m_dragState = NoDragging;
      }
    }
    else // Canvas event (no nearest object)
    {
      if (event.LeftDown())
      {
        m_draggedShape = NULL;
        m_dragState = StartDraggingLeft;
        m_firstDragX = x;
        m_firstDragY = y;
      }
      else if (event.LeftUp())
      {
        OnLeftClick((double)x, (double)y, keys);

        m_draggedShape = NULL;
        m_dragState = NoDragging;
      }
      else if (event.RightDown())
      {
        m_draggedShape = NULL;
        m_dragState = StartDraggingRight;
        m_firstDragX = x;
        m_firstDragY = y;
      }
      else if (event.RightUp())
      {
        OnRightClick((double)x, (double)y, keys);

        m_draggedShape = NULL;
        m_dragState = NoDragging;
      }
    }
  }
}

/*
 * Try to find a sensitive object, working up the hierarchy of composites.
 *
 */
wxShape *wxShapeCanvas::FindFirstSensitiveShape(double x, double y, int *new_attachment, int op)
{
  wxShape *image = FindShape(x, y, new_attachment);
  if (!image) return NULL;

  wxShape *actualImage = FindFirstSensitiveShape1(image, op);
  if (actualImage)
  {
    double dist;
    // Find actual attachment
    actualImage->HitTest(x, y, new_attachment, &dist);
  }
  return actualImage;
}

wxShape *wxShapeCanvas::FindFirstSensitiveShape1(wxShape *image, int op)
{
  if (image->GetSensitivityFilter() & op)
    return image;
  if (image->GetParent())
    return FindFirstSensitiveShape1(image->GetParent(), op);
  return NULL;
}

// Helper function: true if 'contains' wholly contains 'contained'.
static bool WhollyContains(wxShape *contains, wxShape *contained)
{
  double xp1, yp1, xp2, yp2;
  double w1, h1, w2, h2;
  double left1, top1, right1, bottom1, left2, top2, right2, bottom2;

  xp1 = contains->GetX(); yp1 = contains->GetY(); xp2 = contained->GetX(); yp2 = contained->GetY();
  contains->GetBoundingBoxMax(&w1, &h1);
  contained->GetBoundingBoxMax(&w2, &h2);

  left1 = (double)(xp1 - (w1 / 2.0));
  top1 = (double)(yp1 - (h1 / 2.0));
  right1 = (double)(xp1 + (w1 / 2.0));
  bottom1 = (double)(yp1 + (h1 / 2.0));

  left2 = (double)(xp2 - (w2 / 2.0));
  top2 = (double)(yp2 - (h2 / 2.0));
  right2 = (double)(xp2 + (w2 / 2.0));
  bottom2 = (double)(yp2 + (h2 / 2.0));

  return ((left1 <= left2) && (top1 <= top2) && (right1 >= right2) && (bottom1 >= bottom2));
}

wxShape *wxShapeCanvas::FindShape(double x, double y, int *attachment, wxClassInfo *info, wxShape *notObject)
{
  double nearest = 100000.0;
  int nearest_attachment = 0;
  wxShape *nearest_object = NULL;

  // Go backward through the object list, since we want:
  // (a) to have the control points drawn LAST to overlay
  //     the other objects
  // (b) to find the control points FIRST if they exist

  wxObjectList::compatibility_iterator current = GetDiagram()->GetShapeList()->GetLast();
  while (current)
  {
    wxShape *object = (wxShape *)current->GetData();

    double dist;
    int temp_attachment;

    // First pass for lines, which might be inside a container, so we
    // want lines to take priority over containers. This first loop
    // could fail if we clickout side a line, so then we'll
    // try other shapes.
    if (object->IsShown() &&
        object->IsKindOf(CLASSINFO(wxLineShape)) &&
        object->HitTest(x, y, &temp_attachment, &dist) &&
        ((info == NULL) || object->IsKindOf(info)) &&
        (!notObject || !notObject->HasDescendant(object)))
    {
      // A line is trickier to spot than a normal object.
      // For a line, since it's the diagonal of the box
      // we use for the hit test, we may have several
      // lines in the box and therefore we need to be able
      // to specify the nearest point to the centre of the line
      // as our hit criterion, to give the user some room for
      // manouevre.
      if (dist < nearest)
      {
        nearest = dist;
        nearest_object = object;
        nearest_attachment = temp_attachment;
      }
    }
    if (current)
      current = current->GetPrevious();
  }

  current = GetDiagram()->GetShapeList()->GetLast();
  while (current)
  {
    wxShape *object = (wxShape *)current->GetData();
    double dist;
    int temp_attachment;

    // On second pass, only ever consider non-composites or divisions. If children want to pass
    // up control to the composite, that's up to them.
    if (object->IsShown() && (object->IsKindOf(CLASSINFO(wxDivisionShape)) || !object->IsKindOf(CLASSINFO(wxCompositeShape)))
        && object->HitTest(x, y, &temp_attachment, &dist) && ((info == NULL) || object->IsKindOf(info)) &&
        (!notObject || !notObject->HasDescendant(object)))
    {
      if (!object->IsKindOf(CLASSINFO(wxLineShape)))
      {
        // If we've hit a container, and we have already found a line in the
        // first pass, then ignore the container in case the line is in the container.
        // Check for division in case line straddles divisions (i.e. is not wholly contained).
        if (!nearest_object || !(object->IsKindOf(CLASSINFO(wxDivisionShape)) || WhollyContains(object, nearest_object)))
        {
          nearest_object = object;
          nearest_attachment = temp_attachment;
          current = GetDiagram()->GetShapeList()->GetFirst()->GetPrevious(); // finish loop
        }
      }
    }
    if (current)
      current = current->GetPrevious();
  }

  *attachment = nearest_attachment;
  return nearest_object;
}

/*
 * Higher-level events called by OnEvent
 *
 */

void wxShapeCanvas::OnLeftClick(double WXUNUSED(x), double WXUNUSED(y), int WXUNUSED(keys))
{
}

void wxShapeCanvas::OnRightClick(double WXUNUSED(x), double WXUNUSED(y), int WXUNUSED(keys))
{
}

void wxShapeCanvas::OnDragLeft(bool WXUNUSED(draw), double WXUNUSED(x), double WXUNUSED(y), int WXUNUSED(keys))
{
}

void wxShapeCanvas::OnBeginDragLeft(double WXUNUSED(x), double WXUNUSED(y), int WXUNUSED(keys))
{
}

void wxShapeCanvas::OnEndDragLeft(double WXUNUSED(x), double WXUNUSED(y), int WXUNUSED(keys))
{
}

void wxShapeCanvas::OnDragRight(bool WXUNUSED(draw), double WXUNUSED(x), double WXUNUSED(y), int WXUNUSED(keys))
{
}

void wxShapeCanvas::OnBeginDragRight(double WXUNUSED(x), double WXUNUSED(y), int WXUNUSED(keys))
{
}

void wxShapeCanvas::OnEndDragRight(double WXUNUSED(x), double WXUNUSED(y), int WXUNUSED(keys))
{
}

void wxShapeCanvas::AddShape(wxShape *object, wxShape *addAfter)
 { GetDiagram()->AddShape(object, addAfter); }
void wxShapeCanvas::InsertShape(wxShape *object)
 { GetDiagram()->InsertShape(object); }
void wxShapeCanvas::RemoveShape(wxShape *object)
 { GetDiagram()->RemoveShape(object); }
bool wxShapeCanvas::GetQuickEditMode()
 { return GetDiagram()->GetQuickEditMode(); }
void wxShapeCanvas::Redraw(wxDC& dc)
 { GetDiagram()->Redraw(dc); }
void wxShapeCanvas::Snap(double *x, double *y)
 { GetDiagram()->Snap(x, y); }