v8.0.0 is released

v8.0 brings many new features like simplified and more powerful scrolling, new layouts inspired by CSS Flexbox and Grid, simplified and improved widgets, more powerful events, hookable drawing, and more.

v8 is a major change and therefore it’s not backward compatible with v7.

Directory structure

• The lv_ prefix is removed from the folder names
• The docs is moved to the lvgl repository
• The examples are moved to the lvgl repository
• Create an src/extra folder for complex widgets:
  • It makes the core LVGL leaner
  • In extra we can have a lot and specific widgets
  • Good place for contributions

Widget changes

• lv_cont removed, layout features are moved to lv_obj
• lv_page removed, scroll features are moved to lv_obj
• lv_objmask the same can be achieved by events
• lv_meter added as the unioin of lv_linemeter and lv_gauge
• lv_span new widget mimicing HTML <span>
• lv_animing new widget for simple slideshow animations
• + many minor changes and improvements

New scrolling

• Support “elastic” scrolling when scrolled in
• Support scroll chaining among any objects types (not only lv_pagess)
• Remove lv_drag. Similar effect can be achieved by setting the position in LV_EVENT_PRESSING
• Add snapping
• Add snap stop to scroll max 1 snap point

New layouts

• CSS Grid-like layout support
• CSS Flexbox-like layout support

Styles

• Optimize and simplify styles
• State is saved in the object instead of the style property
• Object size and position can be set in styles too

Events

• Allow adding multiple events to an object
• A user_data can be attached to the added events

Driver changes

• lv_disp_drv_t, lv_indev_drv_t, lv_fs_drv_t needs to be static
• ...disp_buf... is renamed to draw_buf. See an initialization example here.
• No partial update if two screen sized buffers are set
• disp_drv->full_refresh = 1 makes always the whole display redraw.
• hor_res and ver_res need to be set in disp_drv
• indev_read_cb returns void. To indicate that there is more that to read set data->continue_reading = 1 in the read_cb

Other changes

• Remove the copy parameter from create functions
• Simplified File system interface API
• Use a more generic inheritance
• The built-in themes are reworked
• lv_obj_align now saved the alignment and realigns the object automatically but can’t be used to align to other than the parent
• lv_obj_align_to can align to an object but doesn’t save the alignment
• lv_pct(x) can be used to set the size and position in percentage
• There are many other changes in widgets that are not detailed here. Please refer to the documentation of the widgets.

New release policy

• We will follow Release branches with GitLab flow
• Minor releases are expected in every 3-4 month
• master will always contain the latest changes

Migrating from v7 to v8

• First and foremost, create a new lv_conf.h based on lv_conf_template.h.
• To try the new version it’s recommended to use a simulator project and see the examples.
• When migrating your project to v8
  • Update the drivers are described above
  • Update the styles
  • Update the events
  • Use the new layouts instead of lv_cont features
  • Use lv_obj instead of lv_page
  • The other parts are mainly minor renames and refactoring. See the functions’ documentation for descriptions.