Changelog

v9.0.0

Migration guide

As v9 is a major version it contains API breaking changes too. Most of the conceptual changes in v9 were internal, however the API was affected some widgets reword and refactoring as well.

IMPORTANT

If you are updating a v8 project to v9, special care must be taken as some parts

  • will not result in compiler error, but LVGL might not work due to related issues

  • will result in hard to understand compiler errors

So pay extra attention to these:

  • lv_display_set_buffers(display, buf1, buf2, buf_size_byte, mode)() is more or less the equivalent of lv_disp_draw_buf_init(&draw_buf_dsc, buf1, buf2, buf_size_px) from v8, however in v9 the buffer size is set in bytes.

  • In v9 lv_color_t is always RGB888 regardless of LV_COLOR_DEPTH.

  • lv_conf.h has been changed a lot, so don't forget to update it from lv_conf_template.h

  • Be sure <stdint.h> is not included in lv_conf.h. In v9 we have some assembly parts for even better performance and a random include there would mess up the assembly part.

  • The online image converter in not updated yet. Until that use LVGLImage.py .

Main new features

  • Run time display color format adjustment with RGB888 support

  • Built-in support pthread, FreeRTOS and other (RT)OSes which are used during rendering

  • Built-in support LVGL's, C library, and other ``stdlib``s

  • Better parallel rendering architecture. See the details here

  • Built in display and touch driver: SDL, Linux Frame buffer, NuttX LCD and touch drivers, ST7789 and ILI9341 driver are available and more will come soon

  • Observer allows to bind data to UI elements and create a uniform and easy to maintain API

  • GitHub CodeSpace integration makes possible to run LVGL in an Online VSCode editor with 3 click. See more here

  • Add vector graphics support via ThorVG. It can be used to draw vector graphics to a Canvas

  • lv_image.h supports aligning, stretching or tiling the image source if the widget is larger or smaller.

General API changes

Although lv_api_map.h address most of the refactoring we encourage you to use the latest API directly.

  • lv_disp_... is renamed to lv_display_...

  • btn_... is renamed to button_...

  • btnmatrix_... is renamed to buttonmatrix_...

  • img_... is renamed to image_...

  • zoom is renamed to scale

  • angle is renamed to rotation

  • scr is renamed to screen

  • act is renamed to active

  • del is renamed to delete

  • col is renamed to column

  • lv_obj_clear_flag is renamed to lv_obj_remove_flag

  • lv_obj_clear_state is renamed to lv_obj_remove_state

  • lv_coord_t was removed and replaced by int32_t

New color format management

  • LV_IMG_CF_... was replaced by LV_COLOR_FORMAT_...

  • LV_COLOR_DEPTH 24 is supported for RGB888 rendering

  • lv_color_t always means RGB888

Display API

  • lv_disp_drv_t and lv_disp_draw_buf_t was removed

  • To create a display and set it up:

lv_display_t * disp = lv_display_create(hor_res, ver_res)
lv_display_set_flush_cb(disp, flush_cb);
lv_display_set_buffers(disp, buf1, buf2, buf_size_in_bytes, mode);

  • Note that now buf size is in bytes and not pixels

  • mode can be:

    • LV_DISPLAY_RENDER_MODE_PARTIAL This way the buffers can be smaller then the display to save RAM. At least 1/10 screen sized buffer(s) are recommended.

    • LV_DISPLAY_RENDER_MODE_DIRECT The buffer(s) has to be screen sized and LVGL will render into the correct location of the buffer. This way the buffer always contain the whole image. With 2 buffers the buffers’ content are kept in sync automatically. (Old v7 behavior)

    • LV_DISPLAY_RENDER_MODE_FULL Just always redraw the whole screen. With 2 buffers is a standard double buffering.

  • Similarly to the widgets, now you can attach events to the display too, using lv_display_add_event()

  • monitor_cb is removed and LV_EVENT_RENDER_READY event is fired instead

  • Instead of having display background color and image, lv_layer_bottom() is added where any color can be set or any widget can be created.

  • The target color format can be adjusted in the display in runtime by calling lv_display_set_color_format(disp, LV_COLOR_FORMAT_...)

  • LV_COLOR_16_SWAP is removed and lv_draw_sw_rgb565_swap() can be called manually in the flush_cb if needed to swap the in-place.

  • disp_drv.scr_transp was removed and lv_display_set_color_format(disp, LV_COLOR_FORMAT_NATIVE_ALPHA) can be used instead

  • set_px_cb is removed. You can can convert the rendered image in the flush_cb.

  • For more details check out the docs `here /porting/display>`__ and `here /overview/display>`__.

Indev API

  • Similarly to the display lv_indev_drv_t was removed and an input device can be created like this:

  • Similarly to the widgets, now you can attach events to the indevs too, using lv_indev_add_event()

  • The feedback_cb was removed, instead LV_EVENT_PRESSED/CLICKED/etc events are sent to the input device

lv_indev_t * indev = lv_indev_create();
lv_indev_set_type(indev, LV_INDEV_TYPE_...);
lv_indev_set_read_cb(indev, read_cb);

Others

  • lv_msg is removed and replaced by lv_observer

  • lv_chart ticks support was removed, lv_scale can be used instead

  • lv_msgbox is update to be more flexible. It uses normal button instead of button matrix

  • lv_tabview was updated to user real button instead of a button matrix

v8.3

For Other v8.3.x releases visit the Changelog in the release/v8.3 branch .