7 typedef struct graph_label * graph_label_t;
9 #define GRAPH_DEFAULT_FONT "Sans 12"
11 struct graph *graph_new(unsigned int xdim, unsigned int ydim, const char *font);
12 /* graph_new() Returns a new graph structure of the given dimensions and font */
13 void graph_set_size(struct graph *g, unsigned int xdim, unsigned int ydim);
14 /* graph_set_size() Changes the size of a graph to the given dimensions. */
15 void graph_set_position(struct graph *g, double xoffset, double yoffset);
16 /* graph_set_position() sets the x- and y-offset to translate the graph */
17 void bar_graph_draw(struct graph *g, cairo_t *cr);
18 /* bar_graph_draw() draws the given graph as a bar graph */
19 void line_graph_draw(struct graph *g, cairo_t *cr);
20 /* line_graph_draw draws the given graph as a line graph */
21 void line_graph_set_data_count_limit(struct graph *g, int per_label_limit);
22 /* line_graph_set_data_count_limit() limits the amount of data which can
23 * be added to a line graph. Once the limit is reached, the oldest data
24 * is discarded as new data is added
26 void graph_set_font(struct graph *g, const char *font);
27 void graph_title(struct graph *g, const char *title);
28 /* graph_title() sets the main title of the graph to the given string */
29 void graph_x_title(struct graph *g, const char *title);
30 /* graph_x_title() sets the title of the x axis to the given string */
31 void graph_y_title(struct graph *g, const char *title);
32 /* graph_y_title() sets the title of the y axis to the given string */
33 graph_label_t graph_add_label(struct graph *g, const char *label);
34 /* graph_add_label() adds a new "stream" of data to be graphed.
35 * For line charts, each label is a separate line on the graph.
36 * For bar charts, each label is a grouping of columns on the x-axis
42 * | *x **** | ** ** **
43 * | xxxx* ***** | ** xx ** xx **
44 * | x ** | ** xx ** xx ** xx
45 * | x | ** xx ** xx ** xx
46 * ----------------------- -------------------------
49 * For a line graph, the 'x's For a bar graph,
50 * would be on one "label", and 'A', 'B', and 'C'
51 * the '*'s would be on another are the labels.
55 int graph_add_data(struct graph *g, graph_label_t label, const double value);
56 /* graph_add_data() is used to add data to the labels of a bar graph */
57 int graph_add_xy_data(struct graph *g, graph_label_t label,
58 const double x, const double y, const char *tooltip);
59 /* graph_add_xy_data is used to add data to the labels of a line graph */
61 void graph_set_color(struct graph *g, graph_label_t label,
62 double red, double green, double blue);
63 #define INVISIBLE_COLOR (-1.0)
64 /* graph_set_color is used to set the color used to plot the data in
65 * a line graph. INVISIBLE_COLOR can be used to plot the data invisibly.
66 * Invisible data will have the same effect on the scaling of the axes
70 void graph_free(struct graph *bg);
71 /* free a graph allocated by graph_new() */
73 typedef void (*graph_axis_unit_change_callback)(struct graph *g, int power_of_ten);
74 void graph_x_axis_unit_change_notify(struct graph *g, graph_axis_unit_change_callback f);
75 void graph_y_axis_unit_change_notify(struct graph *g, graph_axis_unit_change_callback f);
76 /* The labels used on the x and y axes may be shortened. You can register for callbacks
77 * so that you can know how the labels are shorted, typically used to adjust the axis
78 * titles to display the proper units. The power_of_ten parameter indicates what power
79 * of ten the labels have been divided by (9, 6, 3, or 0, corresponding to billions,
80 * millions, thousands and ones.
83 void graph_add_extra_space(struct graph *g, double left_percent, double right_percent,
84 double top_percent, double bottom_percent);
85 /* graph_add_extra_space() adds extra space to edges of the the graph
86 * so that the data doesn't go to the very edges.
89 extern int graph_has_tooltips(struct graph *g);
90 extern const char *graph_find_tooltip(struct graph *g, int x, int y);
91 extern int graph_contains_xy(struct graph *p, int x, int y);
93 extern void graph_set_base_offset(struct graph *g, unsigned int base_offset);
94 extern void graph_set_graph_all_zeroes(struct graph *g, unsigned int set);
96 extern void graph_clear_values(struct graph *g);