/// <summary>
/// Handles the drawing and updating of the graph.
/// </summary>
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
// calculate the mouse position in the graph
PointF graphMousePos= _nodeLayoutManager.ViewToGraph(_lastMousePosition);
// when the layout was changed it needs to be recalculated
bool layoutChanged= _nodeLayoutManager.LayoutChanged;
if(layoutChanged)
_nodeLayoutManager.UpdateLayout(e.Graphics);
// centre the root behaviour if requested
if(_pendingCentreBehavior)
{
_pendingCentreBehavior= false;
CenterNode(_rootNode);
}
// select the pending node
if(_selectedNodePending !=null)
{
SelectedNode= _selectedNodePendingParent.GetChild(_selectedNodePending);
_selectedNodePending= null;
_selectedNodePendingParent= null;
if(ClickNode !=null)
ClickNode(_selectedNode);
}
// check if we must keep the original position of the mouse
if(_maintainMousePosition)
{
_maintainMousePosition= false;
// move the graph so that _graphOrigin is at the same position in the view as it was before
float mouseX= (graphMousePos.X - _graphOrigin.X) * _nodeLayoutManager.Scale + _nodeLayoutManager.Offset.X;
float mouseY= (graphMousePos.Y - _graphOrigin.Y) * _nodeLayoutManager.Scale + _nodeLayoutManager.Offset.Y;
_nodeLayoutManager.Offset= new PointF(mouseX, mouseY);
}
// check if we must keep the original position of _maintainNodePosition
else if(_maintainNodePosition !=null)
{
// move the graph so that _graphOrigin is at the same position in the view as it was before
RectangleF bbox= _maintainNodePosition.BoundingBox;
PointF viewpos= new PointF(bbox.Location.X * _nodeLayoutManager.Scale, bbox.Location.Y * _nodeLayoutManager.Scale);
_nodeLayoutManager.Offset= new PointF(_graphOrigin.X - viewpos.X, _graphOrigin.Y - viewpos.Y);
}
// reset the node whose position we want to keep
_maintainNodePosition= null;
// draw the graph to the view
_nodeLayoutManager.DrawGraph(e.Graphics, _currentNode, _selectedNode, graphMousePos);
// check if we are currently dragging a node and we must draw additional data
if(_dragTargetNode !=null && _dragTargetNode.Node !=_movedNode)
{
if(_dragAttachMode == NodeAttachMode.Event)
{
// we could draw some stuff for events here
}
else
{
// draw the arrows for the attach modes
// get the bounding box of the node
RectangleF bbox= _dragTargetNode.BoundingBox;
// get the bounding box of the connector
_dragTargetConnector= null;
// the depth of the area for the mouse
const float offset= 20.0f;
// the distance of the arrow from the border and its height
const float innerOffset= 6.0f;
// the horizintal middle of the node
float centerX= bbox.Left + bbox.Width *0.5f;
// the half width of the arrow depending of the node's height
float arrowHalfWidth= (bbox.Height - innerOffset - innerOffset) *0.5f;
// calculate the mouse areas for the different attach modes
RectangleF top= new RectangleF(bbox.X + offset, bbox.Top, bbox.Width - offset - offset, offset);
RectangleF bottom= new RectangleF(bbox.X + offset, bbox.Bottom - offset, bbox.Width - offset - offset, offset);
RectangleF left= new RectangleF(bbox.X, bbox.Y, offset, bbox.Height);
// update for dragging in a new node
BehaviorNode behavior= _dragNodeDefaults as BehaviorNode;
if(behavior !=null && behavior.FileManager ==null)
behavior= null;
bool hasParentBehavior= _dragTargetNode.HasParentBehavior(behavior);
bool parentHasParentBehavior= _dragTargetNode.Parent !=null && _dragTargetNode.Parent.HasParentBehavior(behavior);
bool mayTop= _dragTargetNode.Node.Parent !=null && !parentHasParentBehavior && _dragTargetNode.Node.ParentConnector.AcceptsChildren(1);
bool mayBottom= _dragTargetNode.Node.Parent !=null && !parentHasParentBehavior && _dragTargetNode.Node.ParentConnector.AcceptsChildren(1);
bool mayLeft= _dragTargetNode.Parent !=null && !parentHasParentBehavior && !hasParentBehavior &&
!_dragTargetNode.Node.ParentConnector.IsReadOnly &&
_dragNodeDefaults is Node &&
((Node)_dragNodeDefaults).CanAdoptNode(_dragTargetNode.Node) &&
!(_dragNodeDefaults.GetType() is BehaviorNode);
// update for moving an existing node
bool dragTargetHasParentMovedNode= false;
if(_movedNode !=null)
{
dragTargetHasParentMovedNode= _keyShiftIsDown && _dragTargetNode.HasParent(_movedNode);
// a node may not dragged on itself and may not dragged on one of its own children
if(_dragTargetNode.Node ==_movedNode || dragTargetHasParentMovedNode)
{
mayTop= false;
mayBottom= false;
mayLeft= false;
}
else
{
// a dragged node cannot be placed in the same position again
mayTop= mayTop && _dragTargetNode.Node.PreviousNode !=_movedNode;
mayBottom= mayBottom && _dragTargetNode.Node.NextNode !=_movedNode;
mayLeft= mayLeft && _movedNode.CanAdoptChildren(_dragTargetNode.Node) && (!_keyShiftIsDown || _movedNode.Children.Count ==0);
}
}
else if(_copiedNode !=null)
{
mayLeft= mayLeft && _copiedNode.CanAdoptChildren(_dragTargetNode.Node) && (!_keyShiftIsDown || _copiedNode.Children.Count ==0);
}
// reset the attach mode
_dragAttachMode= NodeAttachMode.None;
// the vertices needed to draw the arrows
PointF[] vertices= new PointF[3];
// draw the top arrow if this action is allowed
if(mayTop)
{
vertices[0]= new PointF(centerX - arrowHalfWidth, top.Bottom - innerOffset);
vertices[1]= new PointF(centerX, top.Top + innerOffset);
vertices[2]= new PointF(centerX + arrowHalfWidth, top.Bottom - innerOffset);
if(top.Contains(graphMousePos))
{
_dragAttachMode= NodeAttachMode.Top;
e.Graphics.FillPolygon(Brushes.White, vertices);
}
else e.Graphics.FillPolygon(Brushes.Black, vertices);
}
// draw the bottom arrow if this action is allowed
if(mayBottom)
{
vertices[0]= new PointF(centerX - arrowHalfWidth, bottom.Top + innerOffset);
vertices[1]= new PointF(centerX + arrowHalfWidth, bottom.Top + innerOffset);
vertices[2]= new PointF(centerX, bottom.Bottom - innerOffset);
if(_dragAttachMode ==NodeAttachMode.None && bottom.Contains(graphMousePos))
{
_dragAttachMode= NodeAttachMode.Bottom;
e.Graphics.FillPolygon(Brushes.White, vertices);
}
else e.Graphics.FillPolygon(Brushes.Black, vertices);
}
// draw the left arrow if this action is allowed
if(mayLeft)
{
vertices[0]= new PointF(left.Right - innerOffset, left.Top + innerOffset);
vertices[1]= new PointF(left.Right - innerOffset, left.Bottom - innerOffset);
vertices[2]= new PointF(left.Left + innerOffset, left.Top + left.Height *0.5f);
if(_dragAttachMode ==NodeAttachMode.None && left.Contains(graphMousePos))
{
_dragAttachMode= NodeAttachMode.Left;
e.Graphics.FillPolygon(Brushes.White, vertices);
}
else e.Graphics.FillPolygon(Brushes.Black, vertices);
}
// draw the right arrow if this action is allowed
foreach(Node.Connector connector in _dragTargetNode.Node.Connectors)
{
RectangleF bboxConnector= _dragTargetNode.Node.GetConnectorBoundingBox(bbox, connector);
//e.Graphics.DrawRectangle(Pens.Red, bboxConnector.X, bboxConnector.Y, bboxConnector.Width, bboxConnector.Height);
RectangleF right= new RectangleF(bboxConnector.Right - offset, bboxConnector.Y, offset, bboxConnector.Height);
bool mayRight= !dragTargetHasParentMovedNode && !hasParentBehavior && connector.AcceptsChildren(1);
if(mayRight && _movedNode !=null && connector ==_movedNode.ParentConnector)
mayRight= false;
if(mayRight)
{
float inOffset= bboxConnector.Height >innerOffset *4.0f ? innerOffset : 3.0f;
vertices[0]= new PointF(right.Left + inOffset, right.Top + inOffset);
vertices[1]= new PointF(right.Right - inOffset, right.Top + right.Height *0.5f);
vertices[2]= new PointF(right.Left + inOffset, right.Bottom - inOffset);
if(_dragAttachMode ==NodeAttachMode.None && right.Contains(graphMousePos))
{
_dragTargetConnector= connector;
_dragAttachMode= NodeAttachMode.Right;
e.Graphics.FillPolygon(Brushes.White, vertices);
}
else e.Graphics.FillPolygon(Brushes.Black, vertices);
}
}
}
}
// draw last mouse pos
//e.Graphics.DrawRectangle(Pens.Red, graphMousePos.X -1.0f, graphMousePos.Y -1.0f, 2.0f, 2.0f);
//when we are dragging an existing node we draw a small graph representing it
if(_movedNodeGraph !=null)
{
// update the layout for the graph. This happens only once inside the function.
_movedNodeGraph.UpdateLayout(e.Graphics);
// offset the graph to the mouse position
_movedNodeGraph.Offset= new PointF(_nodeLayoutManager.Offset.X + graphMousePos.X * _nodeLayoutManager.Scale,
_nodeLayoutManager.Offset.Y + graphMousePos.Y * _nodeLayoutManager.Scale - _movedNodeGraph.RootNodeLayout.LayoutRectangle.Height *0.5f * _movedNodeGraph.Scale);
// draw the graph
_movedNodeGraph.DrawGraph(e.Graphics, null, null, graphMousePos);
}
//if(_currentNode !=null && _currentNode.SubItems.Count >0)
// Invalidate();
}