AG_GRAPH(3)

NAME
AG_Graph - agar graph view widget

SYNOPSIS

    #include <agar/core.h>
    #include <agar/gui.h>

DESCRIPTION
The AG_Graph widget displays a graph. A graph is composed of vertices (or ‘nodes’) and edges that connect pairs of vertices.

Edges may be either directed or undirected. Labels and colors can be associated with edges or vertices.

The AG_Graph widget will attempt to position the vertices in the view in order to minimize the number of edges crossing each other, but this is a NP-complete problem. The user can also move vertices manually, or they can be placed programmatically.

INHERITANCE HIERARCHY
AG_Object(3) -> AG_Widget(3) -> AG_Graph.

INITIALIZATION
AG_Graph * AG_GraphNew(AG_Widget *parent, Uint flags)

void AG_GraphSizeHint(AG_Graph *graph, Uint width, Uint height)

The AG_GraphNew() function allocates, initializes, and attaches a new AG_Graph widget. Acceptable flags include:

AG_GRAPH_NO_MOVE
    User cannot move vertices.

AG_GRAPH_NO_SELECT
    User cannot select vertices.

AG_GRAPH_NO_MENUS
    Disable popup menus.

AG_GRAPH_READONLY
    Implies AG_GRAPH_NO_MOVE, AG_GRAPH_NO_SELECT and AG_GRAPH_NO_MENUS.

AG_GRAPH_HFILL
    Expand horizontally in parent (equivalent to invoking AG_ExpandHoriz(3)).

AG_GRAPH_VFILL
    Expand vertically in parent (equivalent to invoking AG_ExpandVert(3)).

AG_GRAPH_EXPAND
    Shorthand for AG_GRAPH_HFILL|AG_GRAPH_VFILL.

The AG_GraphSizeHint() function requests an initial widget size in pixels.

VERTICES
AG_GraphVertex * AG_GraphVertexNew(AG_Graph *graph, void *userPtr)

AG_GraphVertex * AG_GraphVertexFind(AG_Graph *graph, void *userPtr)

void AG_GraphVertexLabel(AG_GraphVertex *vertex, const char *format, ...)

void AG_GraphVertexLabelS(AG_GraphVertex *vertex, const char *text)

void AG_GraphVertexColorLabel(AG_GraphVertex *vertex, Uint8 r, Uint8 g, Uint8 b)

void AG_GraphVertexColorBG(AG_GraphVertex *vertex, Uint8 r, Uint8 g, Uint8 b)

void AG_GraphVertexSize(AG_GraphVertex *vertex, Uint width, Uint height)

void AG_GraphVertexPosition(AG_GraphVertex *vertex, int x, int y)

void AG_GraphVertexPopupMenu(AG_GraphVertex *vertex, AG_PopupMenu *pm)

The AG_GraphVertexNew() function creates a new vertex in the specified graph. userPtr is an optional user pointer to associate with the vertex.

AG_GraphVertexFind() returns the vertex matching the specified user pointer, or NULL if no match exists.

AG_GraphVertexLabel() sets the text label associated with a vertex.

AG_GraphVertexColorLabel() sets the color of the text label. AG_GraphVertexColorBG() sets the background color for the node item.

AG_GraphVertexSize() changes the default size of the node item.

AG_GraphVertexPosition() moves the node item to the given position in the view.

AG_GraphVertexPopupMenu() arranges for the given popup menu to be displayed when the user right clicks on the vertex.

EDGES
AG_GraphEdge * AG_GraphEdgeNew(AG_Graph *graph, AG_GraphVertex *v1, AG_GraphVertex *v2, void *userPtr)

AG_GraphEdge * AG_GraphEdgeFind(AG_Graph *graph, void *userPtr)

void AG_GraphEdgeLabel(AG_GraphEdge *edge, const char *format, ...)

void AG_GraphEdgeLabelS(AG_GraphEdge *edge, const char *text)

void AG_GraphEdgeColorLabel(AG_GraphEdge *edge, Uint8 r, Uint8 g, Uint8 b)

void AG_GraphEdgeColor(AG_GraphEdge *edge, Uint8 r, Uint8 g, Uint8 b)

void AG_GraphEdgePopupMenu(AG_GraphEdge *edge, AG_PopupMenu *menu)

The AG_GraphEdgeNew() function creates a new edge connecting vertices v1 and v2. If the two vertices are already connected by an edge, the function fails and returns NULL. userPtr is an optional user pointer to associated with the edge.

AG_GraphEdgeFind() returns the vertex matching the specified user pointer, or NULL if no match exists.

The AG_GraphEdgeLabel() sets the text label to display along the given edge.

AG_GraphEdgeColorLabel() sets the color of the text label. AG_GraphEdgeColor() sets the color of the line representing the edge. AG_GraphEdgePopupMenu() arranges for the given popup menu to be displayed when the user right clicks on the edge.

EVENTS
The AG_Graph widget generates the following events:

graph-vertex-selected(AG_GraphVertex *vtx)
    The specified vertex is now selected.
graph-vertex-unselected(AG_GraphVertex *vtx)
    The specified vertex is no longer selected.
graph-edge-selected(AG_GraphEdge *edge)
    The specified edge is now selected.
graph-edge-unselected(AG_GraphEdge *edge)
    The specified edge is no longer selected.

STRUCTURE DATA
For the AG_Graph object:

int xOffs, yOffs
    Display offset in pixels.
Uint nvertices
    Vertex count (read-only).
Uint nedges
    Edge count (read-only)
TAILQ vertices
    List of AG_GraphVertex items (read-only)
TAILQ edges
    List of AG_GraphEdge items (read-only).

For the AG_GraphVertex structure:

int x, y
    Pixel coordinates of vertex in the graph.
Uint w, h
    Bounding box for graphical representation of the vertex.
void *userPtr
    Generic user pointer.
TAILQ edges
    List of AG_GraphEdge(3) objects connected to this vertex.

For the AG_GraphEdge structure:

AG_GraphVertex *v1, *v2
    Vertices connected by edge
void *userPtr
    User pointer

SEE ALSO
AG_Intro(3), AG_Menu(3), AG_Widget(3), AG_Window(3)

HISTORY
The AG_Graph widget first appeared in Agar 1.3.