LVGL v5.2 - New Objects, Drawing Features, and More

LVGL v5.2 brings substantial improvements to the graphics library with new object types, enhanced drawing capabilities, expanded image format support, and numerous object-specific features.

New Objects#

This release introduces four new widgets:

• Image button - Buttons with custom image states
• Calendar - Date picker and display widget
• Arc - Curved progress indicators and controls
• Preloader - Animated loading indicators

Drawing and Rendering#

Major improvements to the graphics rendering engine:

• Line draw algorithm improved to support perpendicular line endings
• Arc drawing - native support for curved shapes
• Shadow drawing enhancements for better visual quality
• Custom VDB write function can be registered in the display driver to support non-standard color formats, allowing VDB content to be directly flushed to the display
• RGB565 swap to swap the two bytes of RGB565 colors, making it possible to send pixel data via an 8-bit serial interface (e.g., SPI). Enable in lv_conf.h with LV_COLOR_16_SWAP
• VDB address can be set at runtime with lv_vdb_set_adr(), useful for DMA-based display drivers where VDB needs specific memory allocation
• New image formats supporting indexed and grayscale formats to save memory
• Image decoder interface to add support for any image format like PNG
• Dithering support in Online image converter

New Object Features#

lv_obj#

• Opacity scale attribute added to scale the current opacity of an object and its children, useful for fading in/out groups of objects

lv_label#

• LV_LABEL_ALIGN_RIGHT added to enable right alignment of text
• LV_LABEL_LONG_CROP long mode to simply crop text outside the label's bounds

lv_btn#

• Ink effect feature added to play an animation effect when a button is clicked and released. Configure with lv_btn_set_ink_in_time(), lv_btn_set_ink_wait_time(), lv_btn_set_ink_out_time() (requires LV_BTN_INK_EFFECT enabled in lv_conf.h)

lv_page, lv_win, lv_ta#

• Scrolling added on LV_GROUP_KEY_UP/DOWN/LEFT/RIGHT for keyboard/encoder navigation
• lv_page: Temporal scrollbar hide option added (LV_SB_MODE_HIDE)
• lv_ta: max_length and accepted_chars attributes added
• lv_ta: Action callbacks can be added with lv_ta_set_action()

Other New Features#

• SYMBOL_DUMMY: If added before a string, lv_img will display text instead of an image, allowing text to be used where icons are expected
• Monospace font support (set the width in the Online converter)
• LV_FONT_CUSTOM define added in lv_conf.h to enumerate custom fonts and make them global
• LV_CONF_INCLUDE_SIMPLE: define as a compiler symbol to include lv_conf.h as #include "lv_conf.h" instead of using relative paths
• Click focus: objects in a group can be focused when clicked by a pointer input device (mouse or touchpad)
• LV_GROUP_KEY_DEL key added
• Log system added to print debug information
• Uniscii monospace font added as built-in font
• Edit/Navigate mode for objects in a group, useful for encoder-based navigation
• Character encoding interface simplified for adding encodings beyond built-in UTF-8
• LV_INDEV_TYPE_ENCODER: New encoder input device type (Left/Right/Push)
• Option to use your existing tick handler instead of lv_tick_inc (see lv_conf_templ.h)
• Themes can be changed at runtime (set LV_THEME_LIVE_UPDATE in lv_conf.h)
• New theme: Nemo
• lv_fs_trunc and lv_fs_rename added to filesystem interface