docs add meter

docs/widgets/extra/meter.md

@@ -1 +1,90 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/widgets/extra/meter.md
+```
 # Meter (lv_meter)
+
+## Overview
+The Meter widget can visualize data in very flexible ways. In can show arcs, needles, ticks lines and labels.
+
+## Parts and Styles
+- `LV_PART_MAIN` The background of the Meter and it uses the typical background properties. 
+- `LV_PART_TICK` The tick lines a labels using the *line* and *text* style properties.
+- `LV_PART_INDICATOR` The needle line or image using the *line* and *img* style properties, plus the background properties to draw a square (or circle) on the pivot of the needles. Padding makes the square larger.
+- `LV_PART_ITEMS` The arcs using the *arc* properties.
+
+## Usage
+
+### Add a scale
+
+For first a *Scale* needs to be added to the Meter with `lv_meter_scale_t * scale = lv_meter_add_scale(meter)`. 
+The Scale has minor and major ticks and labels on the major tick. Later indicators (needles, arcs, tick modifiers) can be added to the meter
+
+Any number of scaled can be added to Meter.
+
+The minor tick lines can be configured with: `lv_meter_set_scale_ticks(meter, scale, tick_count, line_width, tick_length, ctick_olor)`.
+
+To add major tick lines use `lv_meter_set_scale_major_ticks(meter, scale, nth_major, tick_width, tick_length, tick_color, label_gap)`. `nth_major` tells how many minor ticks to skip to draw a major tick.
+
+Labels are added automatically on major ticks with `label_gap` distance from the ticks with text proportionally to the values of the tick line.
+
+`lv_meter_set_scale_range(meter, scale, min, max, angle_range, rotation)` sets the value and angle range of the scale.
+
+### Add indicators
+
+Indicators needs to be added to a Scale and their value is interpreted in the range of the Scale.
+
+#### Needle line
+
+`lv_meter_indicator_t * indic = lv_meter_add_needle_line(meter, scale, line_width, line_color, r_mod)` adds a needle line to a Scale. By default the length of the line is the same as the scale's radius but `r_mod` changes the length.
+
+`lv_meter_set_indicator_value(meter, inidicator, value)` sets the value of the indicator.
+
+#### Needle image
+
+`lv_meter_indicator_t * indicator = lv_meter_add_needle_img(meter, scale, img_src, pivot_x, pivot_y)` sets an image that will be used as a needle. `img_src` should be a needle pointing to the right like this `-O--->`.
+`pivot_x` and `pivot_y` sets the pivot point of the rotation relative to the top left corner of the image. 
+
+`lv_meter_set_indicator_value(meter, inidicator, value)` sets the value of the indicator.
+
+#### Arc
+`lv_meter_indicator_t * indicator = lv_meter_add_arc(meter, scale, arc_width, arc_color, r_mod)` adds and arc indicator. . By default the radius of the arc is the same as the scale's radius but `r_mod` changes the radius.
+
+`lv_meter_set_indicator_start_value(meter, inidicator, value)` and `lv_meter_set_indicator_end_value(meter, inidicator, value)` sets the value of the indicator. 
+
+#### Scale lines (ticks)
+`lv_meter_indicator_t * indicator = lv_meter_add_scale_lines(meter, scale, color_start, color_end, bool local, width_mod)` adds an indicator that modifies the ticks lines. 
+If `local` is `true` the ticks' color will be faded from `color_start` to `color_end` in the indicator's  start and end value range. 
+If `local` is `false` `color_start` and `color_end` is mapped to the start and end value of the scale and only a "slice" of that color gradient will be visible in the indicator's start and end value range.
+`width_mod` modifies the width of the tick lines.
+
+`lv_meter_set_indicator_start_value(meter, inidicator, value)` and `lv_meter_set_indicator_end_value(meter, inidicator, value)` sets the value of the indicator. 
+
+## Events
+- `LV_EVENT_DRAW_PART_BEGIN` and `LV_EVENT_DRAW_PART_END` is sent for the tick labels to allow overwriting the texts. The following fields of `lv_obj_draw_part_dsc_t` is set:
+`clip_area`, `part` (to `LV_PART_TICK`), `id` (the index of the major tick line), `value` (the value of the tick line), `label_dsc`, `text` (value converted to decimal)
+
+Learn more about [Events](/overview/event).
+
+## Keys
+Keys have effect on the close button and button matrix. You can add them manually to a group if required.
+
+Learn more about [Keys](/overview/indev).
+
+
+## Example
+
+```eval_rst
+
+.. include:: ../../../examples/widgets/meter/index.rst
+
+```
+
+## API 
+
+```eval_rst
+
+.. doxygenfile:: lv_meter.h
+  :project: lvgl
+        
+```

examples/widgets/btnmatrix/lv_example_btnmatrix_2.c

@@ -12,7 +12,7 @@ static void event_cb(lv_event_t * e)
         /*Change the draw descriptor the 2nd button*/
         if(dsc->id == 1) {
             dsc->rect_dsc->radius = 0;
-            if(lv_btnmatrix_get_selected_btn(obj) == dsc->id)  dsc->rect_dsc->bg_color = lv_palette_darken(LV_PALETTE_GREY, 3);
+            if(lv_btnmatrix_get_selected_btn(obj) == dsc->id)  dsc->rect_dsc->bg_color = lv_palette_darken(LV_PALETTE_BLUE, 3);
             else dsc->rect_dsc->bg_color = lv_palette_main(LV_PALETTE_BLUE);
 
             dsc->rect_dsc->shadow_width = 6;

examples/widgets/meter/index.rst

@@ -4,7 +4,28 @@ C
 Simple meter
 """""""""""""""""""""""
 
-.. lv_example:: lv_ex_widgets/lv_ex_meter/lv_ex_meter_1
+.. lv_example:: widgets/meter/lv_example_meter_1
+  :language: c
+
+
+A meter with multiple arcs
+"""""""""""""""""""""""""
+
+.. lv_example:: widgets/meter/lv_example_meter_2
+  :language: c
+
+
+ A clock from a meter
+"""""""""""""""""""""""
+
+.. lv_example:: widgets/meter/lv_example_meter_3
+  :language: c
+
+
+Pie chart
+"""""""""""""""""""""""
+
+.. lv_example:: widgets/meter/lv_example_meter_4
   :language: c
 
 MicroPython

examples/widgets/meter/lv_example_meter_1.c

@@ -19,8 +19,8 @@ void lv_example_meter_1(void)
 
     /*Add a scale first*/
     lv_meter_scale_t * scale = lv_meter_add_scale(meter);
-    lv_meter_set_scale_ticks(meter, scale, 51, 2, 10, lv_palette_main(LV_PALETTE_GREY));
-    lv_meter_set_scale_major_ticks(meter, scale, 10, 4, 15, lv_color_black(), 10);
+    lv_meter_set_scale_ticks(meter, scale, 41, 2, 10, lv_palette_main(LV_PALETTE_GREY));
+    lv_meter_set_scale_major_ticks(meter, scale, 8, 4, 15, lv_color_black(), 10);
 
     lv_meter_indicator_t * indic;
 

src/extra/widgets/meter/lv_meter.c

@@ -499,7 +499,8 @@ static void draw_ticks_and_labels(lv_obj_t * obj, const lv_area_t * clip_area, c
                 lv_draw_label_dsc_t label_dsc_tmp;
                 lv_memcpy(&label_dsc_tmp, &label_dsc, sizeof(label_dsc_tmp));
 
-                dsc.id = value_of_line;
+                dsc.id = i / scale->tick_major_nth;
+                dsc.value = value_of_line;
                 dsc.label_dsc = &label_dsc_tmp;
                 lv_snprintf(dsc.text, sizeof(dsc.text), "%d", value_of_line);
                 lv_event_send(obj, LV_EVENT_DRAW_PART_BEGIN, &dsc);
@@ -515,6 +516,7 @@ static void draw_ticks_and_labels(lv_obj_t * obj, const lv_area_t * clip_area, c
                 label_cord.y2 = label_cord.y1 + label_size.y;
 
                 lv_draw_label(&label_cord, clip_area, &label_dsc, dsc.text, NULL);
+                lv_event_send(obj, LV_EVENT_DRAW_PART_END, &dsc);
 
 #if LV_DRAW_COMPLEX
                 outer_mask_id = lv_draw_mask_add(&outer_mask, NULL);