lvgl/src/lv_objx/lv_slider.c

/**
 * @file lv_slider.c
 *
 */

/*********************
 *      INCLUDES
 *********************/
#include "lv_slider.h"
#if LV_USE_SLIDER != 0

#include "../lv_core/lv_debug.h"
#include "../lv_core/lv_group.h"
#include "../lv_core/lv_indev.h"
#include "../lv_draw/lv_draw.h"
#include "../lv_themes/lv_theme.h"
#include "../lv_misc/lv_math.h"
#include "lv_img.h"

/*********************
 *      DEFINES
 *********************/
#define LV_OBJX_NAME "lv_slider"

/**********************
 *      TYPEDEFS
 **********************/

/**********************
 *  STATIC PROTOTYPES
 **********************/
static lv_design_res_t lv_slider_design(lv_obj_t * slider, const lv_area_t * clip_area, lv_design_mode_t mode);
static lv_res_t lv_slider_signal(lv_obj_t * slider, lv_signal_t sign, void * param);

/**********************
 *  STATIC VARIABLES
 **********************/
static lv_design_cb_t ancestor_design_f;
static lv_signal_cb_t ancestor_signal;

/**********************
 *      MACROS
 **********************/

/**********************
 *   GLOBAL FUNCTIONS
 **********************/

/**
 * Create a slider objects
 * @param par pointer to an object, it will be the parent of the new slider
 * @param copy pointer to a slider object, if not NULL then the new object will be copied from it
 * @return pointer to the created slider
 */
lv_obj_t * lv_slider_create(lv_obj_t * par, const lv_obj_t * copy)
{
    LV_LOG_TRACE("slider create started");

    /*Create the ancestor slider*/
    lv_obj_t * new_slider = lv_bar_create(par, copy);
    LV_ASSERT_MEM(new_slider);
    if(new_slider == NULL) return NULL;

    if(ancestor_design_f == NULL) ancestor_design_f = lv_obj_get_design_cb(new_slider);
    if(ancestor_signal == NULL) ancestor_signal = lv_obj_get_signal_cb(new_slider);

    /*Allocate the slider type specific extended data*/
    lv_slider_ext_t * ext = lv_obj_allocate_ext_attr(new_slider, sizeof(lv_slider_ext_t));
    LV_ASSERT_MEM(ext);
    if(ext == NULL) return NULL;

    /*Initialize the allocated 'ext' */
    ext->style_knob = &lv_style_pretty;
    ext->knob_img = NULL;

    /*The signal and design functions are not copied so set them here*/
    lv_obj_set_signal_cb(new_slider, lv_slider_signal);
    lv_obj_set_design_cb(new_slider, lv_slider_design);

    /*Init the new slider slider*/
    if(copy == NULL) {
        lv_obj_set_click(new_slider, true);
        lv_obj_set_protect(new_slider, LV_PROTECT_PRESS_LOST);

        /*Set the default styles*/
        lv_theme_t * th = lv_theme_get_current();
        if(th) {
            lv_slider_set_style(new_slider, LV_SLIDER_STYLE_BG, th->style.slider.bg);
            lv_slider_set_style(new_slider, LV_SLIDER_STYLE_INDIC, th->style.slider.indic);
            lv_slider_set_style(new_slider, LV_SLIDER_STYLE_KNOB, th->style.slider.knob);
        } else {
            lv_slider_set_style(new_slider, LV_SLIDER_STYLE_KNOB, ext->style_knob);
        }
    }
    /*Copy an existing slider*/
    else {
        lv_slider_ext_t * copy_ext = lv_obj_get_ext_attr(copy);
        ext->style_knob            = copy_ext->style_knob;
        /*Refresh the style with new signal function*/
        lv_obj_refresh_style(new_slider);
    }

    LV_LOG_INFO("slider created");

    return new_slider;
}

/*=====================
 * Setter functions
 *====================*/

/**
 * Set an image to display on the knob of the slider
 * @param slider pointer to a slider object
 * @param img_src pointer to an `lv_img_dsc_t` variable or a path to an image  (not an `lv_img` object)
 */
void lv_slider_set_knob_img(lv_obj_t * slider, const void * img_src)
{
    LV_ASSERT_OBJ(slider, LV_OBJX_NAME);

    lv_slider_ext_t * ext = lv_obj_get_ext_attr(slider);

    ext->knob_img = img_src;
    lv_obj_refresh_ext_draw_pad(slider);
    lv_obj_invalidate(slider);
}

/**
 * Set a style of a slider
 * @param slider pointer to a slider object
 * @param type which style should be set
 * @param style pointer to a style
 */
void lv_slider_set_style(lv_obj_t * slider, lv_slider_style_t type, const lv_style_t * style)
{
    LV_ASSERT_OBJ(slider, LV_OBJX_NAME);

    lv_slider_ext_t * ext = lv_obj_get_ext_attr(slider);

    switch(type) {
        case LV_SLIDER_STYLE_BG: lv_bar_set_style(slider, LV_BAR_STYLE_BG, style); break;
        case LV_SLIDER_STYLE_INDIC: lv_bar_set_style(slider, LV_BAR_STYLE_INDIC, style); break;
        case LV_SLIDER_STYLE_KNOB:
            ext->style_knob = style;
            lv_obj_refresh_ext_draw_pad(slider);
            break;
    }
}

/*=====================
 * Getter functions
 *====================*/

/**
 * Get the value of a slider
 * @param slider pointer to a slider object
 * @return the value of the slider
 */
int16_t lv_slider_get_value(const lv_obj_t * slider)
{
    LV_ASSERT_OBJ(slider, LV_OBJX_NAME);
    return lv_bar_get_value(slider);
}

/**
 * Give the slider is being dragged or not
 * @param slider pointer to a slider object
 * @return true: drag in progress false: not dragged
 */
bool lv_slider_is_dragged(const lv_obj_t * slider)
{
    LV_ASSERT_OBJ(slider, LV_OBJX_NAME);

    lv_slider_ext_t * ext = lv_obj_get_ext_attr(slider);
    return ext->dragging ? true : false;
}

/**
 * Get an image to display on the knob of the slider
 * @param slider pointer to a slider object
 * @return the image source: pointer to an `lv_img_dsc_t` variable or a path to an image  (not an `lv_img` object)
 */
const void * lv_slider_get_knob_img(lv_obj_t * slider, const void * img_src)
{
    LV_ASSERT_OBJ(slider, LV_OBJX_NAME);

    lv_slider_ext_t * ext = lv_obj_get_ext_attr(slider);

    return ext->knob_img;
}

/**
 * Get a style of a slider
 * @param slider pointer to a slider object
 * @param type which style should be get
 * @return style pointer to a style
 */
const lv_style_t * lv_slider_get_style(const lv_obj_t * slider, lv_slider_style_t type)
{
    LV_ASSERT_OBJ(slider, LV_OBJX_NAME);

    const lv_style_t * style = NULL;
    lv_slider_ext_t * ext    = lv_obj_get_ext_attr(slider);

    switch(type) {
        case LV_SLIDER_STYLE_BG: style = lv_bar_get_style(slider, LV_BAR_STYLE_BG); break;
        case LV_SLIDER_STYLE_INDIC: style = lv_bar_get_style(slider, LV_BAR_STYLE_INDIC); break;
        case LV_SLIDER_STYLE_KNOB: style = ext->style_knob; break;
        default: style = NULL; break;
    }

    return style;
}

/**********************
 *   STATIC FUNCTIONS
 **********************/

/**
 * Handle the drawing related tasks of the sliders
 * @param slider pointer to an object
 * @param clip_area the object will be drawn only in this area
 * @param mode LV_DESIGN_COVER_CHK: only check if the object fully covers the 'mask_p' area
 *                                  (return 'true' if yes)
 *             LV_DESIGN_DRAW: draw the object (always return 'true')
 *             LV_DESIGN_DRAW_POST: drawing after every children are drawn
 * @param return an element of `lv_design_res_t`
 */
static lv_design_res_t lv_slider_design(lv_obj_t * slider, const lv_area_t * clip_area, lv_design_mode_t mode)
{
    /*Return false if the object is not covers the mask_p area*/
    if(mode == LV_DESIGN_COVER_CHK) {
        return LV_DESIGN_RES_NOT_COVER;
    }
    /*Draw the object*/
    else if(mode == LV_DESIGN_DRAW_MAIN) {

        /*The ancestor design function will draw the background and the indicator.
         * It also sets ext->bar.indic_area*/
        ancestor_design_f(slider, clip_area, mode);

        lv_slider_ext_t * ext = lv_obj_get_ext_attr(slider);
        const lv_style_t * style_knob  = lv_slider_get_style(slider, LV_SLIDER_STYLE_KNOB);
        lv_opa_t opa_scale = lv_obj_get_opa_scale(slider);

        lv_coord_t objw = lv_obj_get_width(slider);
        lv_coord_t objh = lv_obj_get_height(slider);
        bool hor = objw >= objh ? true : false;
        lv_coord_t knob_size = hor ? objh : objw;
        bool sym = false;
        if(ext->bar.sym && ext->bar.min_value < 0 && ext->bar.max_value > 0) sym = true;

        lv_area_t knob_area;

        /*Horizontal*/
        if(hor) {
            if(!sym) {
                knob_area.x1 = ext->bar.indic_area.x2;
            } else {
                if(ext->bar.cur_value >= 0) {
                    knob_area.x1 = ext->bar.indic_area.x2;
                } else {
                    knob_area.x1 = ext->bar.indic_area.x1;
                }
            }
            knob_area.x1 -= (knob_size >> 1);
            knob_area.x2 = knob_area.x1 + knob_size;
            knob_area.y1 = slider->coords.y1;
            knob_area.y2 = slider->coords.y2;
        }
        /*Vertical*/
        else {
            if(!sym) {
               knob_area.y1 = ext->bar.indic_area.y1;
           } else {
               if(ext->bar.cur_value >= 0) {
                   knob_area.y1 = ext->bar.indic_area.y1;
               } else {
                   knob_area.y1 = ext->bar.indic_area.y2;
               }
           }
           knob_area.y1 -= (knob_size >> 1);
           knob_area.y2 = knob_area.y1 + knob_size;
           knob_area.x1 = slider->coords.x1;
           knob_area.x2 = slider->coords.x2;
        }

        /*Apply the paddings on the knob area*/
        knob_area.x1 -= style_knob->body.padding.left;
        knob_area.x2 += style_knob->body.padding.right;
        knob_area.y1 -= style_knob->body.padding.top;
        knob_area.y2 += style_knob->body.padding.bottom;

        lv_draw_rect(&knob_area, clip_area, style_knob, opa_scale);

        if(ext->knob_img) {
            lv_res_t res;
            lv_img_header_t info;
            res = lv_img_decoder_get_info(ext->knob_img, &info);
            if(res == LV_RES_OK) {
                lv_coord_t x_ofs = knob_area.x1 + (lv_area_get_width(&knob_area) - info.w) / 2;
                lv_coord_t y_ofs = knob_area.y1 + (lv_area_get_height(&knob_area) - info.h) / 2;
                lv_area_t a;
                a.x1 = x_ofs;
                a.y1 = y_ofs;
                a.x2 = info.w - 1 + x_ofs;
                a.y2 = info.h - 1 + y_ofs;

                lv_draw_img(&a, clip_area, ext->knob_img, style_knob, 0, LV_IMG_ZOOM_NONE, false, opa_scale);
            } else {
                LV_LOG_WARN("lv_slider_design: can't get knob image info")
            }
        }
    }
    /*Post draw when the children are drawn*/
    else if(mode == LV_DESIGN_DRAW_POST) {
        return ancestor_design_f(slider, clip_area, mode);
    }

    return LV_DESIGN_RES_OK;
}

/**
 * Signal function of the slider
 * @param slider pointer to a slider object
 * @param sign a signal type from lv_signal_t enum
 * @param param pointer to a signal specific variable
 * @return LV_RES_OK: the object is not deleted in the function; LV_RES_INV: the object is deleted
 */
static lv_res_t lv_slider_signal(lv_obj_t * slider, lv_signal_t sign, void * param)
{
    lv_res_t res;

    /* Include the ancient signal function */
    res = ancestor_signal(slider, sign, param);
    if(res != LV_RES_OK) return res;
    if(sign == LV_SIGNAL_GET_TYPE) return lv_obj_handle_get_type_signal(param, LV_OBJX_NAME);

    lv_slider_ext_t * ext = lv_obj_get_ext_attr(slider);
    lv_point_t p;

    if(sign == LV_SIGNAL_PRESSED) {
        ext->dragging = true;
    } else if(sign == LV_SIGNAL_PRESSING) {
        lv_indev_get_point(param, &p);

        lv_coord_t w = lv_obj_get_width(slider);
        lv_coord_t h = lv_obj_get_height(slider);
        const lv_style_t * indic_style = lv_slider_get_style(slider, LV_SLIDER_STYLE_INDIC);
        int32_t range = ext->bar.max_value - ext->bar.min_value;
        int16_t new_value = 0;
        if(w >= h) {
            lv_coord_t indic_w = w - indic_style->body.padding.left - indic_style->body.padding.right;
            new_value = p.x - (slider->coords.x1 + indic_style->body.padding.left); /*Make the point relative to the indicator*/
            new_value = (new_value * range) / indic_w;
            new_value += ext->bar.min_value;
        } else {
            lv_coord_t indic_h = h - indic_style->body.padding.bottom - indic_style->body.padding.top;
            new_value = p.y - (slider->coords.y2 + indic_style->body.padding.bottom); /*Make the point relative to the indicator*/
            new_value = (-new_value * range) / indic_h;
            new_value += ext->bar.min_value;

        }

        if(new_value < ext->bar.min_value) new_value = ext->bar.min_value;
        else if(new_value > ext->bar.max_value) new_value = ext->bar.max_value;

        if(new_value != ext->bar.cur_value) {
            ext->bar.cur_value = new_value;
            lv_obj_invalidate(slider);
            res = lv_event_send(slider, LV_EVENT_VALUE_CHANGED, NULL);
            if(res != LV_RES_OK) return res;
        }
    } else if(sign == LV_SIGNAL_RELEASED || sign == LV_SIGNAL_PRESS_LOST) {
        ext->dragging = false;

#if LV_USE_GROUP
        /*Leave edit mode if released. (No need to wait for LONG_PRESS) */
        lv_group_t * g             = lv_obj_get_group(slider);
        bool editing               = lv_group_get_editing(g);
        lv_indev_type_t indev_type = lv_indev_get_type(lv_indev_get_act());
        if(indev_type == LV_INDEV_TYPE_ENCODER) {
            if(editing) lv_group_set_editing(g, false);
        }
#endif

    } else if(sign == LV_SIGNAL_CORD_CHG) {
        /* The knob size depends on slider size.
         * During the drawing method the ext. size is used by the knob so refresh the ext. size.*/
        if(lv_obj_get_width(slider) != lv_area_get_width(param) ||
           lv_obj_get_height(slider) != lv_area_get_height(param)) {
            slider->signal_cb(slider, LV_SIGNAL_REFR_EXT_DRAW_PAD, NULL);
        }
    } else if(sign == LV_SIGNAL_REFR_EXT_DRAW_PAD) {
        const lv_style_t * bg_style      = lv_slider_get_style(slider, LV_SLIDER_STYLE_BG);
        const lv_style_t * indic_style      = lv_slider_get_style(slider, LV_SLIDER_STYLE_INDIC);
        const lv_style_t * knob_style = lv_slider_get_style(slider, LV_SLIDER_STYLE_KNOB);

        /* The smaller size is the knob diameter*/
        lv_coord_t knob_size = LV_MATH_MIN(lv_obj_get_width(slider), lv_obj_get_height(slider)) >> 1;
        knob_size += LV_MATH_MAX(
                        LV_MATH_MAX(knob_style->body.padding.left, knob_style->body.padding.right),
                        LV_MATH_MAX(knob_style->body.padding.bottom,knob_style->body.padding.top));

        knob_size += knob_style->body.shadow.width + knob_style->body.shadow.spread;
        knob_size += LV_MATH_MAX(LV_MATH_ABS(knob_style->body.shadow.offset.x), LV_MATH_ABS(knob_style->body.shadow.offset.y));

        if(ext->knob_img) {
            lv_img_header_t info;
            lv_res_t res;
            res = lv_img_decoder_get_info(ext->knob_img, &info);
            if(res == LV_RES_OK) {
                knob_size = LV_MATH_MAX(knob_size, info.w);
                knob_size = LV_MATH_MAX(knob_size, info.h);
            } else {
                LV_LOG_WARN("slider signal (LV_SIGNAL_REFR_EXT_DRAW_PAD): can't get knob image info")
            }
        }


        lv_coord_t bg_size = bg_style->body.shadow.width + bg_style->body.shadow.spread;
        bg_size += LV_MATH_MAX(LV_MATH_ABS(bg_style->body.shadow.offset.x), LV_MATH_ABS(bg_style->body.shadow.offset.y));

        lv_coord_t indic_size = indic_style->body.shadow.width + indic_style->body.shadow.spread;
        indic_size += LV_MATH_MAX(LV_MATH_ABS(indic_style->body.shadow.offset.x), LV_MATH_ABS(indic_style->body.shadow.offset.y));

        slider->ext_draw_pad = LV_MATH_MAX(slider->ext_draw_pad, knob_size);
        slider->ext_draw_pad = LV_MATH_MAX(slider->ext_draw_pad, indic_size);
        slider->ext_draw_pad = LV_MATH_MAX(slider->ext_draw_pad, bg_size);

    } else if(sign == LV_SIGNAL_CONTROL) {
        char c = *((char *)param);

        if(c == LV_KEY_RIGHT || c == LV_KEY_UP) {
            lv_slider_set_value(slider, lv_slider_get_value(slider) + 1, true);
            res = lv_event_send(slider, LV_EVENT_VALUE_CHANGED, NULL);
            if(res != LV_RES_OK) return res;
        } else if(c == LV_KEY_LEFT || c == LV_KEY_DOWN) {
            lv_slider_set_value(slider, lv_slider_get_value(slider) - 1, true);
            res = lv_event_send(slider, LV_EVENT_VALUE_CHANGED, NULL);
            if(res != LV_RES_OK) return res;
        }
    } else if(sign == LV_SIGNAL_GET_EDITABLE) {
        bool * editable = (bool *)param;
        *editable       = true;
    }

    return res;
}
#endif