/// <summary>
/// Adds a given <see cref="AGraphNode"/> instance node to this scene
/// and returns the index at which it was added. If the given node is
/// already in this scene, its current index is returned. Otherwise,
/// the last index is returned as it is the last node added.
/// </summary>
/// <param name="node">The <see cref="AGraphNode"/> instance
/// to be added to this scene, if it isn't already in the scene.</param>
/// <returns>The index at which the given <see cref="AGraphNode"/>
/// instance is added to this scene, which is the last index unless
/// it's already in this scene, where its current index is returned.
/// </returns>
/// <remarks>The function basically doubles as an IndexOf function if
/// the code invoking it is aware that the given <see cref="AGraphNode"/>
/// instance is already present in this scene.</remarks>
public int AddNode(AGraphNode node)
{
if (this.mNodeCount == 0)
{
if (this.mNodes.Length == 0)
{
this.mNodes = new AGraphNode[4];
}
}
else
{
for (int i = 0; i < this.mNodeCount; i++)
{
if (this.mNodes[i] == node)
{
return(i);
}
}
if (this.mNodes.Length == this.mNodeCount)
{
AGraphNode[] nodes = new AGraphNode[2 * this.mNodeCount];
Array.Copy(this.mNodes, 0, nodes, 0, this.mNodeCount);
this.mNodes = nodes;
}
}
this.mNodes[this.mNodeCount++] = node;
return(this.mNodeCount - 1);
}
/// <summary>
/// Removes the given <see cref="AGraphNode"/> instance from this scene,
/// and returns true if it was successfully or false if it wasn't in
/// this scene to begin with.
/// </summary>
/// <param name="node">The <see cref="AGraphNode"/> instance
/// to remove from the scene.</param>
/// <returns>true if the given <see cref="AGraphNode"/> instance is
/// successfully removed from this scene, or false if it wasn't in
/// this scene to begin with.</returns>
public bool RemoveNode(AGraphNode node)
{
if (this.mNodeCount == 0)
{
return(false);
}
int i;
for (i = 0; i < this.mNodeCount; i++)
{
if (this.mNodes[i] == node)
{
break;
}
}
if (i == this.mNodeCount)
{
return(false);
}
this.mNodeCount--;
if (i < this.mNodeCount)
{
Array.Copy(this.mNodes, i + 1, this.mNodes, i,
this.mNodeCount - i);
}
this.mNodes[this.mNodeCount] = null;
return(true);
}
/// <summary>
/// Invoked whenever a <see cref="AGraphNode"/> instance that has been "grabbed"
/// by the mouse during a previous MouseDown event is being moved by the mouse,
/// which allows classes descended from <see cref="AGraphNodeScene"/> to take
/// appropriate actions pertaining to the node being moved and implement any
/// effects it may have on other nodes in the scene and the scene itself.
/// </summary>
/// <param name="node"></param>
protected virtual void OnNodeMovedByMouse(AGraphNode node)
{
}
