docs(canvas) update to v8

docs/widgets/canvas.md

@@ -7,12 +7,13 @@
 
 ## Overview
 
-A Canvas inherites from [Image](/widgets/img) where the user can draw anything. Rectangles, texts, images, lines arcs can be drawn here using lvgl's drawing engine. 
+A Canvas inherites from [Image](/widgets/img) where the user can draw anything. 
+Rectangles, texts, images, lines, arcs can be drawn here using lvgl's drawing engine. 
 Besides some "effects" can be applied as well like rotation, zoom and blur.
 
 
 ## Parts and Styles
-The Canvas has on one main part called `LV_CANVAS_PART_MAIN` and only the *image_recolor* property is used to give a color to `LV_IMG_CF_ALPHA_1/2/4/8BIT` images.
+`LV_PART_MAIN` Uses the typical rectangle style properties and image style properties.
 
 ## Usage
 
@@ -21,38 +22,42 @@ The Canvas needs a buffer which stores the drawn image.
 To assign a buffer to a Canvas, use `lv_canvas_set_buffer(canvas, buffer, width, height, LV_IMG_CF_...)`. 
 Where  `buffer` is a static buffer (not just a local variable) to hold the image of the canvas.
 For example,
-`static lv_color_t buffer[LV_CANVAS_BUF_SIZE_TRUE_COLOR(width, height)]`. `LV_CANVAS_BUF_SIZE_...` macros help to determine the size of the buffer with different color formats.
+`static lv_color_t buffer[LV_CANVAS_BUF_SIZE_TRUE_COLOR(width, height)]`. 
+`LV_CANVAS_BUF_SIZE_...` macros help to determine the size of the buffer with different color formats.
 
 The canvas supports all the built-in color formats like `LV_IMG_CF_TRUE_COLOR` or `LV_IMG_CF_INDEXED_2BIT`. 
 See the full list in the [Color formats](/overview/image.html#color-formats) section.
 
-### Palette
-For `LV_IMG_CF_INDEXED_...` color formats, a palette needs to be initialized with  `lv_canvas_set_palette(canvas, 3, LV_COLOR_RED)`. It sets pixels with *index=3* to red.
-
+### Indexed colors
+For `LV_IMG_CF_INDEXED_1/2/4/8` color formats a palette needs to be 
+initialized with  `lv_canvas_set_palette(canvas, 3, LV_COLOR_RED)`. It sets pixels with *index=3* to red.
 
 ### Drawing
 To set a pixel on the canvas, use `lv_canvas_set_px(canvas, x, y, LV_COLOR_RED)`.
-With `LV_IMG_CF_INDEXED_...` or `LV_IMG_CF_ALPHA_...`, the index of the color or the alpha value needs to be passed as color. E.g. `lv_color_t c; c.full = 3;`
+With `LV_IMG_CF_INDEXED_...` or `LV_IMG_CF_ALPHA_...`, the index of the color or the alpha value needs to be passed as color. 
+E.g. `lv_color_t c; c.full = 3;`
 
-`lv_canvas_fill_bg(canvas, LV_COLOR_BLUE, LV_OPA_50)` fills the whole canvas to blue with 50% opacity. Note that, if the current color format doesn't support colors (e.g. `LV_IMG_CF_ALPHA_2BIT`) teh color will be ignored. 
+`lv_canvas_fill_bg(canvas, LV_COLOR_BLUE, LV_OPA_50)` fills the whole canvas to blue with 50% opacity. Note that, if the current color format doesn't support colors (e.g. `LV_IMG_CF_ALPHA_2BIT`) the color will be ignored. 
 Similarly, if opacity is not supported (e.g. `LV_IMG_CF_TRUE_COLOR`) it will be ignored.
 
-An array of pixels can be copied to the canvas with `lv_canvas_copy_buf(canvas, buffer_to_copy, x, y, width, height)`. The color format of the buffer and the canvas need to match.
+An array of pixels can be copied to the canvas with `lv_canvas_copy_buf(canvas, buffer_to_copy, x, y, width, height)`. 
+The color format of the buffer and the canvas need to match.
 
 To draw something to the canvas use
 - `lv_canvas_draw_rect(canvas, x, y, width, heigth, &draw_dsc)`
-- `lv_canvas_draw_text(canvas, x, y, max_width, &draw_dsc, txt, LV_LABEL_ALIGN_LEFT/CENTER/RIGHT)`
+- `lv_canvas_draw_text(canvas, x, y, max_width, &draw_dsc, txt)`
 - `lv_canvas_draw_img(canvas, x, y, &img_src, &draw_dsc)`
 - `lv_canvas_draw_line(canvas, point_array, point_cnt, &draw_dsc)`
 - `lv_canvas_draw_polygon(canvas, points_array, point_cnt, &draw_dsc)`
 - `lv_canvas_draw_arc(canvas, x, y, radius, start_angle, end_angle, &draw_dsc)`
 
-`draw_dsc` is a `lv_draw_rect/label/img/line_dsc_t` variable which should be first initialized with `lv_draw_rect/label/img/line_dsc_init()` function and then it's filed should be modified with the desired colors and other values.
+`draw_dsc` is a `lv_draw_rect/label/img/line/arc_dsc_t` variable which should be first initialized with `lv_draw_rect/label/img/line/arc_dsc_init()` function and then it's filed should be modified with the desired colors and other values.
 
 The draw function can draw to any color format. For example, it's possible to draw a text to an `LV_IMG_VF_ALPHA_8BIT` canvas and use the result image as a mask in [lv_objmask](/widgets/objmask) later.
 
 ### Transformations
-`lv_canvas_transform()` can be used to rotate and/or scale the image of an image and store the result on the canvas. The function needs the following parameters:
+`lv_canvas_transform()` can be used to rotate and/or scale the image of an image and store the result on the canvas. 
+The function needs the following parameters:
 - `canvas` pointer to a canvas object to store the result of the transformation.
 - `img pointer` to an image descriptor to transform. Can be the image descriptor of an other canvas too (`lv_canvas_get_img()`).
 - `angle` the angle of rotation (0..3600), 0.1 deg resolution
@@ -65,14 +70,12 @@ The draw function can draw to any color format. For example, it's possible to dr
  
 Note that a canvas can't be rotated on itself.  You need a source and destination canvas or image.
 
-## Blur
-A given area of the canvas can be blurred horizontally with `lv_canvas_blur_hor(canvas, &area, r)` to vertically with `lv_canvas_blur_ver(canvas, &area, r)`. 
+### Blur
+A given area of the canvas can be blurred horizontally with `lv_canvas_blur_hor(canvas, &area, r)` or vertically with `lv_canvas_blur_ver(canvas, &area, r)`. 
 `r` is the radius of the blur (greater value means more intensive burring). `area` is the area where the blur should be applied (interpreted relative to the canvas)
 
 ## Events
-As default the clicking of a canvas is disabled (inherited by [Image](/widgets/img)) and therefore no events are generated.
-
-If clicking is enabled (`lv_obj_set_click(canvas, true)`) only the [Generic events](../overview/event.html#generic-events) are sent by the object type.
+The same events are sent than for the [Images](/widgets/img).
 
 Learn more about [Events](/overview/event).