add lv_slider_set_img to display an image on the knob

src/lv_objx/lv_bar.c

@@ -98,7 +98,7 @@ lv_obj_t * lv_bar_create(lv_obj_t * par, const lv_obj_t * copy)
     /*Init the new  bar object*/
     if(copy == NULL) {
         lv_obj_set_click(new_bar, false);
-        lv_obj_set_size(new_bar, LV_DPI * 2, LV_DPI / 3);
+        lv_obj_set_size(new_bar, LV_DPI * 2, LV_DPI / 4);
         lv_bar_set_value(new_bar, ext->cur_value, false);
 
         lv_theme_t * th = lv_theme_get_current();

src/lv_objx/lv_chart.c

@@ -1117,7 +1117,7 @@ static void lv_chart_draw_areas(lv_obj_t * chart, const lv_area_t * mask)
    int16_t mask_fade_id = LV_MASK_ID_INV;
    lv_draw_mask_fade_param_t mask_fade_p;
    if(ext->type & LV_CHART_TYPE_AREA_FADED) {
-       lv_draw_mask_fade_init(&mask_fade_p, &chart->coords, LV_OPA_COVER, chart->coords.y1 + (h >> 2), LV_OPA_TRANSP, chart->coords.y2 - (h >> 2));
+       lv_draw_mask_fade_init(&mask_fade_p, &chart->coords, LV_OPA_90, chart->coords.y1 + (h >> 2), LV_OPA_10, chart->coords.y2 - (h >> 2));
        mask_fade_id = lv_draw_mask_add(&mask_fade_p, NULL);
    }
 

src/lv_objx/lv_slider.c

@@ -16,6 +16,7 @@
 #include "../lv_draw/lv_draw.h"
 #include "../lv_themes/lv_theme.h"
 #include "../lv_misc/lv_math.h"
+#include "lv_img.h"
 
 /*********************
  *      DEFINES
@@ -71,6 +72,7 @@ lv_obj_t * lv_slider_create(lv_obj_t * par, const lv_obj_t * copy)
 
     /*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);
@@ -108,6 +110,22 @@ lv_obj_t * lv_slider_create(lv_obj_t * par, const lv_obj_t * copy)
  * 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
@@ -158,6 +176,20 @@ bool lv_slider_is_dragged(const lv_obj_t * 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
@@ -261,6 +293,25 @@ static lv_design_res_t lv_slider_design(lv_obj_t * slider, const lv_area_t * cli
         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) {
@@ -355,6 +406,19 @@ static lv_res_t lv_slider_signal(lv_obj_t * slider, lv_signal_t sign, void * par
         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));
 

src/lv_objx/lv_slider.h

@@ -42,6 +42,7 @@ typedef struct
     lv_bar_ext_t bar; /*Ext. of ancestor*/
     /*New data for this type */
     const lv_style_t * style_knob; /*Style of the knob*/
+    const void * knob_img;
     uint8_t dragging :1;        /*1: the slider is being dragged*/
 } lv_slider_ext_t;
 
@@ -102,6 +103,13 @@ static inline void lv_slider_set_anim_time(lv_obj_t * slider, uint16_t anim_time
     lv_bar_set_anim_time(slider, anim_time);
 }
 
+/**
+ * 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
+ */
+void lv_slider_set_knob_img(lv_obj_t * slider, const void * img_src);
+
 /**
  * Set the animation time of the slider
  * @param slider pointer to a bar object
@@ -158,6 +166,13 @@ static inline int16_t lv_slider_get_max_value(const lv_obj_t * slider)
  */
 bool lv_slider_is_dragged(const lv_obj_t * slider);
 
+/**
+ * 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);
+
 /**
  * Get the animation time of the slider
  * @param slider pointer to a slider object