GFXprim

Choice widget

A choice widget is a class of widgets that allows to select exactly one choice from a given set.

There are two different choices application APIs, the choices can either be static initialized by an string array, or dynamic backed by an structure with callbacks.

The widget class allows to get values and modify widget state by an unified API.

Choice class API functions

void gp_widget_choice_sel_set(gp_widget *self, size_t sel);

size_t gp_widget_choice_sel_get(gp_widget *self);

size_t gp_widget_choice_prev_sel_get(gp_widget *self);

size_t gp_widget_choice_cnt_get(gp_widget *self);

const char *gp_widget_choice_name_get(gp_widget *self, size_t idx);

Functions to get and set the selected choice, the choices count and particular choice name and the choice widget class constructor.

The gp_widget_choice_prev_sel_get() can be used to query previously selected choice inside of the widget event handler.

Choice class ops and array constructors

enum gp_widget_choice_flags {
        GP_WIDGET_CHOICE_COPY = 1,
};

gp_widget *gp_widget_choice_new(unsigned int widget_type,
                                const char *choices[],
                                size_t cnt, size_t sel);

gp_widget *gp_widget_choice_ops_new(unsigned int widget_type,
                                    const struct gp_widget_choice_ops *ops);

gp_widget *gp_widget_choice_arr_new(unsigned int widget_type, const void *array,
                                    size_t memb_cnt, uint16_t memb_size,
                                    uint16_t memb_off, size_t sel, int flags);

Creates a choice widget from a static array. The array choices can either be compied when GP_WIDGET_CHOICE_COPY is passed in the flags, or the base pointer is stored and dereferenced each time widget is repainted.

See choice array API example.

Choices callback API

enum gp_widget_choice_op {
        GP_WIDGET_CHOICE_OP_SEL,
        GP_WIDGET_CHOICE_OP_CNT,
};

struct gp_widget_choice_ops {
        const char *(*get_choice)(gp_widget *self, size_t idx);
        size_t (*get)(gp_widget *self, enum gp_widget_choice_op op);
        void (*set)(gp_widget *self, size_t val);
};

void gp_widget_choice_refresh(gp_widget *self);

The ops structure implements callbacks to get choice count and selected choice, set selected choice and get choice name.

The refresh function must be called by the application every time the choices do change since the widget will cache some of the data returned by these callbacks. The refresh function will re-read the data and also check if the widget needs to be resized.

See choice ops API example.

Spinbutton

gp_widget *gp_widget_spinbutton_new(const char *choices[],
                                    unsigned int choice_cnt,
                                    unsigned int selected);

gp_widget *gp_widget_spinbutton_ops_new(const struct gp_widget_choice_ops *ops);

gp_widget *gp_widget_spinbutton_arr_new(const void *array,
                                        size_t memb_cnt, uint16_t memb_size,
                                        uint16_t memb_off, size_t sel, int flags);

Spinbutton is parsed from JSON with when type equals to "spinbutton".

Spinbutton

Radiobutton

gp_widget *gp_widget_radiobutton_new(const char *choices[],
                                     unsigned int choice_cnt,
                                     unsigned int selected);

gp_widget *gp_widget_radiobutton_ops_new(const struct gp_widget_choice_ops *ops);

gp_widget *gp_widget_radiobutton_arr_new(const void *array,
                                         size_t memb_cnt, uint16_t memb_size,
                                         uint16_t memb_off, size_t sel, int flags);

Radiobutton is parsed from JSON with when type equals to "radiobutton".

Radiobutton

Table 1. Choice class JSON attributes
Attribute	Type	Default	Description
`choices`	string array		List of choices
`ops`	string		The ops structure id
`selected`	uint	string	0

Table 2. Choice class widget events
Widget event value	Description
0	Emitted on selection change.