Resource Limits and Configuration

PixelUI trades fixed capacity for predictable memory use. “What happens when this is full?” is part of the API contract.

Public setting	Default	Effect
`PIXELUI_MAX_ANIMATION_COUNT`	35	Inline animation slots
`PIXELUI_MAX_APP_NUM`	12	AppManager registrations
`PIXELUI_MAX_VIEW_DEPTH`	8	Live App depth and metadata
`PIXELUI_APPLICATION_ARENA_SIZE`	4096 B	Shared storage for all live Apps
`PIXELUI_APPLICATION_ARENA_MAX_ALIGNMENT`	64	Maximum App alignment
`PIXELUI_CALLBACK_STORAGE_SIZE`	32 B	ETL inline lambda capacity
`PIXELUI_MAX_ICONVIEW_ITEMS`	11	IconView items
`PIXELUI_MAX_LISTVIEW_DEPTH`	6	Submenu history depth
`PIXELUI_MAX_POPUP_NUM`	3	Active plus pending Popups
`PIXELUI_MAX_ONSCREEN_WIDGET_NUM`	6	FocusManager root nodes
`PIXELUI_MAX_INT_FIXED_WIDTH`	6	Maximum PopupValueDigits width
`PIXELUI_MAX_COROUTINE_NUM`	10	CoroutineScheduler capacity
`PIXELUI_MAX_TEXT_LENGTH`	30	Inline text and keyboard draft capacity
`PIXELUI_MAX_LISTITEM_NAME_NUM`	30	ListItem title buffer size

Feature switches and fonts

PIXELUI_USE_ANIMATION, PIXELUI_USE_POPUP, PIXELUI_USE_COROUTINE, and PIXELUI_USE_FOCUS control whether core modules are compiled. PIXELUI_USE_LABEL_SCROLL controls automatic scrolling for Label and menu titles. Info, Progress, ValueDigits, and Keyboard Popups can also be disabled independently. PIXELUI_USE_POPUP_KEYBOARD requires Focus to be enabled.

PIXELUI_FONT_TEXT/SMALL/TINY/NUMERIC/CHART define font roles used by Widgets. The default body font contains GB2312 glyphs. Replacing it can significantly reduce flash use when Chinese text is not needed.

External configuration

Define PIXELUI_CONFIG_PATH consistently across the library and firmware to point to one complete configuration file. Different translation units must not see different capacities or switches, because that creates ABI and ODR violations.

Tuning order

Count peak simultaneously live Apps, Animations, Popups, and root Widgets.
Leave headroom and handle false or LaunchResult failures.
Measure sizeof, alignment, and the linker map again with the target compiler.
Change one capacity category at a time and compare .bss and .data.

ViewManager, the App arena, and the other managers are inline members of PixelUI. Raising limits directly increases fixed RAM use even before those slots are occupied.