lvgl/docs/ROADMAP.md

Roadmap

Planned for v9

Naming and API

• lv_style_set_size() should have separate width and height parameters
• lv_img_set_src() use "type-aware" parameter. See here
• Reconsider image color formats.
• More consistent names:remove/clear/delete/del, offset/ofs, add/create/register, id/idx/index, middle/mid/center, img/image, txt/text, opa/opacity/alpha, scr/screen, disp, display, finished/complete/completed/ready, buf/buffer, ..._cb, angle, rotation, zoom, scale`
• Reconsider the use of has, is, enable "action" keywords
• Update canvas API (https://github.com/lvgl/lvgl/issues/3393)
• LV_STYLE_PROP_INHERIT -> LV_STYLE_PROP_FLAG_INHERITABLE LINK
• Replace disp_drv->direct_mode/full_refresh with enum.
• Consider flat directory structure. E.g. extra/widgets to widgets
• Use uint32_t and int32_t in APIs where possible. Consider hardcoding lv_coord_t as int32_t.
• To define a new stdlib API use defines LV_USE_CUSTO_... and let the user implement lv_... functions somewhere (instead of defining the name of the custom functions)

Architecture

• Consider merging lv_disp_t, lv_disp_t, lv_disp_draw_buf_t, lv_draw_ctx_t, and structs from the new driver API (or only some of them)
• Better way to reset global variables in lv_deinit() #3385
• New driver architecture #2720
• draw_ctx->buffer_convert? See here. Also remove 16 SWAPPED color format? See here.
• Reconsider masks. There should be a generic high level mask API whic is independent of the drawing engine.
• get_glyph_bitmap should return an a8 bitmap that can be blended immediately.
• Reconsider how themes should work. See here.
• Make LVGL render independent areas in parallel.
• Introduce a pipeline in renderer to support multi-GPUs/Accelerators, such as 2D-capable-DMAs, 2D GPUs, dedicated processor cores for 2D tasks etc.
• More conscious <std*.h> wrapper API
• Drop lv_mem_buf_get as tlsf should be fast enough for normal allocations too. Fragmentation is also lower if processes can completely clean up after themselves.
• lv_array: replace linked lists with array where possible (arrays are faster and uses less memory)
• Reconsider how to handle UTF-8 characters (allow different encoding too) and Bidi. Maybe create an abstraction for typesetting.
• Generic lv_date_t and lv_time_t?
• More color formats: 24 bit, ARGB1555, ARGB4444 etc
• Unified caching #3116 #3415
• Make layouts with an lv_layout_dsc_t instead of registering an ID+callback. See here
• Condider using lv_color32_t on APIs to support e.g. alpha gradient.

Styles

• Make style_bg_img support 9patch images
• non-uniform scale of images: scale width and height differently
• Scroll anim settings should come from styles to allow customization

Widgets

• lv_img: Reconsider image sizing models (when the image size is not content): center, top-left, zoom, tile, other?
• lv_tabview Replace button matrix with real buttons for more flexibility
• lv_label reconsider label long modes. (support min/max-width/height too) #3420
• lv_roller make it more flexible #4009
• Universal scale widget/support (see here and #4043)
• Improve lv_label_align_t #1656
• Disabled widgets should absorb indev actions without sending events. #3860

Drawing and rendering

• Automatically recalculate the layout if a coordinte is get with lv_obj_get_width/height/x/y/etc

Animations

• Consider anim events to replace many callbacks with one
• lv_anim_time_to_speed should work differently to remove style_anim_speed. E.g. on large values of anim time store the speed. Besides all widgets should use the style_anim property. anim should clamp the time if it's calculated from speed, e.g lv_clamp(200, t, 2000). (maybe a->min_time/max_time).
• Use dedicated lv_anim_custom_exec_cb_t. See here.

Planned in general

CI

• Plaform independent bechmarking # 3443
• Run static analyzer
• Release script
• Unit test for all widgets #2337
• CI test for flash/RAM usage #3127

Architecture

• C++ binding: https://github.com/lvgl/lv_binding_cpp
• Markup language #2428

Styles

• Hover
• Global states in selectors. E.g. LV_STATE_PRESSED | SMALL_SCREEN like media quarry in CSS

Drawing and rendering

• Different radius on each corner #2800
• gradient to border/outline/shadow
• multiple shadow/border
• perspective
• text shadow
• innter shadow
• ARGB image stroke/grow on the alpha map
• real time blur
• gradient with alpha

Widgets

• lv_bar, lv_arc: handle max < min for fill direction swapping #4039

Others

• More grid features. E.g. repeat(auto-fill, minmax( px, 1fr))
• Named grid cells to allow updating layouts without touching the children (like CSS grid-template-areas)
• Scene support. See this comment
• Circle layout. #2871
• Variable binding. I.e create properties which can be bound to objects and those obejcts are notified on value change. Maybe based on lv_msg?
• Consider stagger animations.

Ideas

• Consider direct binary font format support
• Improve groups. Discussion. Reconsider focusing logic. Allow having no widget selected (on web it's possible). Keep editing state in lv_obj_t (See here). Support slider left knob focusing (see here)
• lv_mem_alloc_aligned(size, align)
• Speed up font decompression
• Support larger images: add support for large image #1892
• Functional programming support, pure view? See here
• Style components. See this comment
• SVG support: integrate an SVG render library
• Support dot_begin and dot_middle long modes for labels
• Allow matrix input for image transformation?
• Radial/skew/conic gradient
• Somehow let children inherit the parent's state
• text on path