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Grid is now rendered in background
ShowElementMenu event can now be used to show context sensitive menus for nodes, node elements etc. or to show a menu when nothing is clicked on
1 parent e265097 commit 00124c6

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5 files changed

+227
-15
lines changed

5 files changed

+227
-15
lines changed

‎Graph/GraphControl.cs

Lines changed: 153 additions & 15 deletions
Original file line numberDiff line numberDiff line change
@@ -34,6 +34,8 @@
3434

3535
namespace Graph
3636
{
37+
public delegate bool AcceptElement(IElement element);
38+
3739
public partial class GraphControl : Control
3840
{
3941
#region Constructor
@@ -49,11 +51,30 @@ public GraphControl()
4951
public event EventHandler<AcceptNodeEventArgs> NodeAdded;
5052
public event EventHandler<AcceptNodeEventArgs> NodeRemoving;
5153
public event EventHandler<NodeEventArgs> NodeRemoved;
54+
public event EventHandler<AcceptElementLocationEventArgs> ShowElementMenu;
5255
public event EventHandler<AcceptNodeConnectionEventArgs> ConnectionAdding;
5356
public event EventHandler<AcceptNodeConnectionEventArgs> ConnectionAdded;
5457
public event EventHandler<AcceptNodeConnectionEventArgs> ConnectionRemoving;
5558
public event EventHandler<NodeConnectionEventArgs> ConnectionRemoved;
5659

60+
#region Grid
61+
public bool ShowGrid = true;
62+
public float GridStep = 16.0f;
63+
private Color internalGridColor = Color.LightGray;
64+
private Pen GridPen = new Pen(Color.LightGray);
65+
public Color GridColor
66+
{
67+
get { return internalGridColor; }
68+
set
69+
{
70+
if (internalGridColor == value)
71+
return;
72+
73+
internalGridColor = value;
74+
GridPen = new Pen(internalGridColor);
75+
}
76+
}
77+
#endregion
5778

5879
#region DragElement
5980
IElement internalDragElement;
@@ -762,6 +783,62 @@ IElement FindElementAt(PointF location)
762783
}
763784
#endregion
764785

786+
#region FindElementAt
787+
IElement FindElementAt(PointF location, AcceptElement acceptElement)
788+
{
789+
foreach (var node in graphNodes)
790+
{
791+
var inputConnector = FindInputConnectorAt(node, location);
792+
if (inputConnector != null && acceptElement(inputConnector))
793+
return inputConnector;
794+
795+
var outputConnector = FindOutputConnectorAt(node, location);
796+
if (outputConnector != null && acceptElement(outputConnector))
797+
return outputConnector;
798+
799+
if (node.bounds.Contains(location))
800+
{
801+
var item = FindNodeItemAt(node, location);
802+
if (item != null && acceptElement(item))
803+
return item;
804+
if (acceptElement(node))
805+
return node;
806+
else
807+
return null;
808+
}
809+
}
810+
811+
var skipConnections = new HashSet<NodeConnection>();
812+
var foundConnections = new List<NodeConnection>();
813+
foreach (var node in graphNodes)
814+
{
815+
foreach (var connection in node.connections)
816+
{
817+
if (skipConnections.Add(connection)) // if we can add it, we haven't checked it yet
818+
{
819+
if (connection.bounds.Contains(location))
820+
foundConnections.Insert(0, connection);
821+
}
822+
}
823+
}
824+
foreach (var connection in foundConnections)
825+
{
826+
if (connection.textBounds.Contains(location) && acceptElement(connection))
827+
return connection;
828+
}
829+
foreach (var connection in foundConnections)
830+
{
831+
using (var region = GraphRenderer.GetConnectionRegion(connection))
832+
{
833+
if (region.IsVisible(location) && acceptElement(connection))
834+
return connection;
835+
}
836+
}
837+
838+
return null;
839+
}
840+
#endregion
841+
765842
#region GetTransformedLocation
766843
PointF GetTransformedLocation()
767844
{
@@ -800,23 +877,24 @@ protected override void OnPaint(PaintEventArgs e)
800877

801878
if (e.Graphics == null)
802879
return;
880+
803881

804-
e.Graphics.Clear(Color.White);
805-
806-
if (this.graphNodes.Count == 0)
807-
return;
808-
809-
UpdateMatrices();
810-
e.Graphics.PageUnit = GraphicsUnit.Pixel;
882+
e.Graphics.PageUnit = GraphicsUnit.Pixel;
811883
e.Graphics.CompositingQuality = CompositingQuality.GammaCorrected;
812-
e.Graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
813-
e.Graphics.SmoothingMode = SmoothingMode.HighQuality;
814884
e.Graphics.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;
815885
e.Graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
816-
817-
886+
e.Graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
887+
888+
UpdateMatrices();
818889
e.Graphics.Transform = transformation;
819890

891+
OnDrawBackground(e);
892+
893+
e.Graphics.SmoothingMode = SmoothingMode.HighQuality;
894+
895+
if (this.graphNodes.Count == 0)
896+
return;
897+
820898

821899
var transformed_location = GetTransformedLocation();
822900
if (command == CommandMode.MarqueSelection)
@@ -857,6 +935,41 @@ protected override void OnPaint(PaintEventArgs e)
857935
}
858936
#endregion
859937

938+
#region OnDrawBackground
939+
virtual protected void OnDrawBackground(PaintEventArgs e)
940+
{
941+
e.Graphics.Clear(Color.White);
942+
943+
if (!ShowGrid)
944+
return;
945+
946+
var points = new PointF[]{
947+
new PointF(e.ClipRectangle.Left , e.ClipRectangle.Top),
948+
new PointF(e.ClipRectangle.Right, e.ClipRectangle.Bottom)
949+
};
950+
951+
inverse_transformation.TransformPoints(points);
952+
953+
var left = points[0].X;
954+
var right = points[1].X;
955+
var top = points[0].Y;
956+
var bottom = points[1].Y;
957+
var stepScaled = GridStep;
958+
959+
var xOffset = ((float)Math.Round(left / stepScaled) * stepScaled);
960+
var yOffset = ((float)Math.Round(top / stepScaled) * stepScaled);
961+
962+
if (stepScaled > 3)
963+
{
964+
for (float x = xOffset; x < right; x += stepScaled)
965+
e.Graphics.DrawLine(GridPen, x, top, x, bottom);
966+
967+
for (float y = yOffset; y < bottom; y += stepScaled)
968+
e.Graphics.DrawLine(GridPen, left, y, right, y);
969+
}
970+
}
971+
#endregion
972+
860973

861974

862975
#region OnMouseWheel
@@ -1436,7 +1549,7 @@ private bool ConnectionIsAllowed(NodeConnector from, NodeConnector to)
14361549
if (!CompatibilityStrategy.CanConnect(from, to))
14371550
return false;
14381551
}
1439-
1552+
14401553
// If someone has subscribed to the ConnectionAdding event,
14411554
// give them a chance to interrupt this connection attempt.
14421555
if (null != ConnectionAdding)
@@ -1663,8 +1776,8 @@ protected override void OnDoubleClick(EventArgs e)
16631776
}
16641777
#endregion
16651778

1666-
#region OnClick
1667-
protected override void OnClick(EventArgs e)
1779+
#region OnMouseClick
1780+
protected override void OnMouseClick(MouseEventArgs e)
16681781
{
16691782
try
16701783
{
@@ -1676,6 +1789,31 @@ protected override void OnClick(EventArgs e)
16761789
inverse_transformation.TransformPoints(points);
16771790
var transformed_location = points[0];
16781791

1792+
if (e.Button == MouseButtons.Right)
1793+
{
1794+
if (null != ShowElementMenu)
1795+
{
1796+
// See if we clicked on an element and give our owner the chance to show a menu
1797+
var result = FindElementAt(transformed_location, delegate(IElement el)
1798+
{
1799+
// Fire the event and see if someone cancels it.
1800+
var eventArgs = new AcceptElementLocationEventArgs(el, this.PointToScreen(lastLocation));
1801+
// Give our owner the chance to show a menu for this element ...
1802+
ShowElementMenu(this, eventArgs);
1803+
// If the owner declines (cancel == true) then we'll continue looking up the hierarchy ..
1804+
return !eventArgs.Cancel;
1805+
});
1806+
// If we haven't found anything to click on we'll just return the event with a null pointer ..
1807+
// allowing our owner to show a generic menu
1808+
if (result == null)
1809+
{
1810+
var eventArgs = new AcceptElementLocationEventArgs(null, this.PointToScreen(lastLocation));
1811+
ShowElementMenu(this, eventArgs);
1812+
}
1813+
return;
1814+
}
1815+
}
1816+
16791817
var element = FindElementAt(transformed_location);
16801818
if (element == null)
16811819
{
@@ -1705,7 +1843,7 @@ protected override void OnClick(EventArgs e)
17051843
}
17061844
finally
17071845
{
1708-
base.OnClick(e);
1846+
base.OnMouseClick(e);
17091847
}
17101848
}
17111849
#endregion

‎Graph/Node.cs

Lines changed: 8 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -49,6 +49,14 @@ public sealed class AcceptNodeEventArgs : CancelEventArgs
4949
public Node Node { get; private set; }
5050
}
5151

52+
public sealed class AcceptElementLocationEventArgs : CancelEventArgs
53+
{
54+
public AcceptElementLocationEventArgs(IElement element, Point position) { Element = element; Position = position; }
55+
public AcceptElementLocationEventArgs(IElement element, Point position, bool cancel) : base(cancel) { Element = element; Position = position; }
56+
public IElement Element { get; private set; }
57+
public Point Position { get; private set; }
58+
}
59+
5260
public class Node : IElement
5361
{
5462
public string Title { get { return titleItem.Title; } set { titleItem.Title = value; } }

‎GraphExample/ExampleForm.Designer.cs

Lines changed: 29 additions & 0 deletions
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‎GraphExample/ExampleForm.cs

Lines changed: 31 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -66,6 +66,7 @@ public ExampleForm()
6666
graphControl.ConnectionAdded += new EventHandler<AcceptNodeConnectionEventArgs>(OnConnectionAdded);
6767
graphControl.ConnectionAdding += new EventHandler<AcceptNodeConnectionEventArgs>(OnConnectionAdding);
6868
graphControl.ConnectionRemoving += new EventHandler<AcceptNodeConnectionEventArgs>(OnConnectionRemoved);
69+
graphControl.ShowElementMenu += new EventHandler<AcceptElementLocationEventArgs>(OnShowElementMenu);
6970

7071
graphControl.Connect(colorItem, check1Item);
7172
}
@@ -85,6 +86,36 @@ void OnConnectionRemoved(object sender, AcceptNodeConnectionEventArgs e)
8586
//e.Cancel = true;
8687
}
8788

89+
void OnShowElementMenu(object sender, AcceptElementLocationEventArgs e)
90+
{
91+
if (e.Element == null)
92+
{
93+
// Show a test menu for when you click on nothing
94+
testMenuItem.Text = "(clicked on nothing)";
95+
nodeMenu.Show(e.Position);
96+
e.Cancel = false;
97+
} else
98+
if (e.Element is Node)
99+
{
100+
// Show a test menu for a node
101+
testMenuItem.Text = ((Node)e.Element).Title;
102+
nodeMenu.Show(e.Position);
103+
e.Cancel = false;
104+
} else
105+
if (e.Element is NodeItem)
106+
{
107+
// Show a test menu for a nodeItem
108+
testMenuItem.Text = e.Element.GetType().Name;
109+
nodeMenu.Show(e.Position);
110+
e.Cancel = false;
111+
} else
112+
{
113+
// if you don't want to show a menu for this item (but perhaps show a menu for something more higher up)
114+
// then you can cancel the event
115+
e.Cancel = true;
116+
}
117+
}
118+
88119
void OnConnectionAdding(object sender, AcceptNodeConnectionEventArgs e)
89120
{
90121
//e.Cancel = true;

‎GraphExample/ExampleForm.resx

Lines changed: 6 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -117,4 +117,10 @@
117117
<resheader name="writer">
118118
<value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
119119
</resheader>
120+
<metadata name="nodeMenu.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
121+
<value>17, 17</value>
122+
</metadata>
123+
<metadata name="nodeToolTip.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
124+
<value>128, 17</value>
125+
</metadata>
120126
</root>

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