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

HISTORY

The AG_Graph widget first appeared in Agar 1.3.