//*************************************************************************
// Method: OnMouseDownLeft()
//
/// <summary>
/// Handles the MouseDown event for the left mouse button.
/// </summary>
///
/// <param name="e">
/// The MouseButtonEventArgs that contains the event data.
/// </param>
///
/// <param name="oMouseLocation">
/// Mouse location, relative to the control.
/// </param>
///
/// <param name="oClickedVertex">
/// The vertex that was clicked, or null if an empty area of the graph was
/// clicked.
/// </param>
//*************************************************************************
protected void OnMouseDownLeft(
MouseButtonEventArgs e,
Point oMouseLocation,
IVertex oClickedVertex
)
{
AssertValid();
if ( m_eMouseMode == MouseMode.Translate ||
Keyboard.IsKeyDown(Key.Space) )
{
// The user might want to translate the zoomed graph by dragging
// with the mouse.
StartTranslationDrag(oMouseLocation);
return;
}
if (m_eMouseMode == MouseMode.ZoomIn)
{
ZoomViaMouse(e, MouseLeftClickZoomFactor);
return;
}
if (m_eMouseMode == MouseMode.ZoomOut)
{
ZoomViaMouse(e, 1.0 / MouseLeftClickZoomFactor);
return;
}
if (oClickedVertex == null)
{
// The user clicked on part of the graph not covered by a vertex.
m_oDoubleClickedVertexInfo = null;
if (m_eMouseMode == MouseMode.Select)
{
DeselectAll();
}
if (this.Graph.Vertices.Count > 0)
{
// The user might want to drag a marquee. Save the mouse
// location for use within the MouseMove event.
m_oMarqueeBeingDragged = new DraggedMarquee(oMouseLocation,
this.GraphRectangle, m_oAsyncLayout.Margin);
this.Cursor = GetCursorForMarqueeDrag();
Mouse.Capture(this);
}
return;
}
// If the control key is pressed, clicking a vertex should invert its
// selected state. Otherwise...
//
// In Select mode, clicking an unselected vertex should clear the
// selection and then select the vertex. Clicking a selected vertex
// should leave the vertex selected.
//
// In AddToSelection mode, clicking a vertex should select it.
//
// In SubtractFromSelection mode, clicking a vertex should deselect
// it.
Boolean bClickedVertexIsSelected = VertexOrEdgeIsSelected(
oClickedVertex);
Boolean bSelectClickedVertex = true;
if ( (Keyboard.Modifiers & ModifierKeys.Control) != 0 )
{
bSelectClickedVertex = !bClickedVertexIsSelected;
}
else if (m_eMouseMode == MouseMode.Select)
{
if (!bClickedVertexIsSelected)
{
SetAllVerticesSelected(false);
SetAllEdgesSelected(false);
}
}
else if (m_eMouseMode == MouseMode.SubtractFromSelection)
{
bSelectClickedVertex = false;
}
SetVertexSelected(oClickedVertex, bSelectClickedVertex,
m_bMouseAlsoSelectsIncidentEdges);
// In Select and AddToSelection mode, double-clicking a vertex provides
// special behavior.
if (
Keyboard.Modifiers != 0
||
(m_eMouseMode != MouseMode.Select &&
m_eMouseMode != MouseMode.AddToSelection)
)
{
m_oDoubleClickedVertexInfo = null;
}
else if (e.ClickCount == 2)
{
OnVertexDoubleClickLeft(oClickedVertex);
}
else if (m_oDoubleClickedVertexInfo != null &&
m_oDoubleClickedVertexInfo.Vertex != oClickedVertex)
{
// (The above "else if" test is required because double-clicking a
// vertex results in this method being called twice: once with
// e.ClickCount = 1, and again with e.ClickCount = 2. We don't
// want to clear m_oDoubleClickedVertexInfo unnecessarily during
// this sequence.)
m_oDoubleClickedVertexInfo = null;
}
if (
m_bAllowVertexDrag
&&
(m_eMouseMode == MouseMode.Select ||
m_eMouseMode == MouseMode.AddToSelection)
&&
m_oSelectedVertices.Count > 0
)
{
// The user might want to drag the selected vertices. Save the
// mouse location for use within the MouseMove event.
m_oVerticesBeingDragged = new DraggedVertices(
m_oSelectedVertices.ToArray(), oMouseLocation,
this.GraphRectangle, m_oAsyncLayout.Margin);
this.Cursor = Cursors.ScrollAll;
Mouse.Capture(this);
}
}
//*************************************************************************
// Constructor: NodeXLControl()
//
/// <summary>
/// Initializes a new instance of the <see cref="NodeXLControl" /> class.
/// </summary>
//*************************************************************************
public NodeXLControl()
{
m_oGraph = new Graph();
m_oGraphDrawer = new GraphDrawer(this);
m_oAsyncLayout = new FruchtermanReingoldLayout();
OnNewLayout(m_oAsyncLayout);
m_oLastLayoutContext =
new LayoutContext(System.Drawing.Rectangle.Empty);
m_oLastGraphDrawingContext = null;
m_eLayoutState = LayoutState.Stable;
m_eMouseMode = MouseMode.Select;
m_bMouseAlsoSelectsIncidentEdges = true;
m_bAllowVertexDrag = true;
m_oVerticesBeingDragged = null;
m_oMarqueeBeingDragged = null;
m_oTranslationBeingDragged = null;
m_oSelectedVertices = new HashSet<IVertex>();
m_oSelectedEdges = new HashSet<IEdge>();
m_oCollapsedGroups = new Dictionary<String, IVertex>();
m_oDoubleClickedVertexInfo = null;
m_bShowVertexToolTips = false;
m_oLastMouseMoveLocation = new Point(-1, -1);
// Create a helper object for displaying vertex tooltips.
CreateVertexToolTipTracker();
m_oVertexToolTip = null;
m_bGraphZoomCentered = false;
this.AddLogicalChild(m_oGraphDrawer.VisualCollection);
CreateTransforms();
// Prevent a focus rectangle from being drawn around the control when
// it captures keyboard focus. The focus rectangle does not behave
// properly when the layout and render transforms are applied --
// sometimes the rectangle disappears, and sometimes it gets magnified
// by the render layout.
this.FocusVisualStyle = null;
// AssertValid();
}
//*************************************************************************
// Method: CheckForMarqueeDragOnMouseUp()
//
/// <summary>
/// Checks for a marquee drag operation during the MouseUp event.
/// </summary>
///
/// <param name="oMouseEventArgs">
/// Standard mouse event arguments.
/// </param>
//*************************************************************************
protected void CheckForMarqueeDragOnMouseUp(
MouseEventArgs oMouseEventArgs
)
{
Debug.Assert(oMouseEventArgs != null);
AssertValid();
if ( m_oMarqueeBeingDragged != null &&
m_oMarqueeBeingDragged.OnMouseUp() )
{
// Remove from the top of the graph any marquee drawn during the
// previous MouseMove event.
RemoveVisualFromTopOfGraph(m_oMarqueeBeingDragged);
if ( !this.EscapeKeyIsPressed() )
{
// Select or deselect the marqueed vertices.
SelectMarqueedVertices();
}
}
m_oMarqueeBeingDragged = null;
}