lv_wl_backend_private.h

Typedefs

typedef void *(*lv_wayland_backend_init_t)(void)

Initialize the backend context.

This function is called once when the Wayland driver is initialized to create the global backend context. The returned pointer will be passed as backend_ctx to all other backend operations.

See also

lv_wayland_backend_deinit_t

Note

This is called before any displays are created

Return:

Pointer to backend-specific context data, or NULL on failure

typedef void (*lv_wayland_backend_deinit_t)(void *backend_ctx)

Deinitialize the backend context.

This function is called when the Wayland driver is deinitialized. It must clean up all resources allocated in the init function and free the backend context.

See also

lv_wayland_backend_init_t

Note

This is called after all displays have been destroyed

Param backend_ctx:

[in] Pointer to the backend context returned by init

typedef void *(*lv_wayland_backend_init_display_t)(void *backend_ctx, lv_display_t *display, int32_t width, int32_t height)

Initialize a new display.

This function is called when creating a new LVGL display on Wayland. It should allocate and initialize per-display resources needed for rendering.

Note

The returned pointer can be retrieved later using lv_wayland_get_backend_display_data()

Note

It is expected that each display gets its own data structure in order for a backend to support multiple displays

Param backend_ctx:

[in] Pointer to the backend context

Param display:

[in] Pointer to the LVGL display object

Param width:

[in] Initial width of the display in pixels

Param height:

[in] Initial height of the display in pixels

Return:

Pointer to display-specific data, or NULL on failure

typedef void *(*lv_wayland_backend_resize_display_t)(void *backend_ctx, lv_display_t *display)

Resize or reconfigure a display.

This function is called when a display needs to be resized or when its rotation is modified. The backend should update its rendering resources accordingly.

Note

This may be called multiple times during a display's lifetime

Note

The returned pointer will replace the previous display data. It can be retrieved using lv_wayland_get_backend_display_data()

Warning

The display data is overwritten with the return value of this function

Param backend_ctx:

[in] Pointer to the backend context

Param display:

[in] Pointer to the LVGL display object being resized

Return:

Pointer to updated display-specific data, or NULL on failure

typedef void (*lv_wayland_backend_destroy_display_t)(void *backend_ctx, lv_display_t *display)

Destroy a display.

This function is called when an LVGL display is being destroyed. It must clean up all per-display resources and free the display data that was allocated in init_display.

Note

The display data associated with this display must be freed

Param backend_ctx:

[in] Pointer to the backend context

Param display:

[in] Pointer to the LVGL display object being destroyed

typedef void (*lv_wayland_backend_global_handler_t)(void *backend_ctx, struct wl_registry *registry, uint32_t name, const char *interface, uint32_t version)

Handle Wayland global objects.

This function is called for every global object advertised by the Wayland compositor. The backend can use this to bind to Wayland protocols it requires (e.g., wl_shm, EGL extensions, DMA-BUF protocols, etc.).

Note

This is called during Wayland connection setup

Note

The backend should use wl_registry_bind() to bind to needed protocols

Param backend_ctx:

[in] Pointer to the backend context

Param registry:

[in] Wayland registry object

Param name:

[in] Numeric name of the global object

Param interface:

[in] String name of the interface (e.g., "wl_shm")

Param version:

[in] Version number of the interface

Functions

void *lv_wayland_get_backend_display_data(lv_display_t *display)

Get the backend-specific display data.

Retrieves the per-display data pointer that was returned by the backend's init_display/resize_display functions. This allows the backend to access its own display-specific state and resources.

See also

lv_wayland_backend_init_display_t

Note

This returns the value that was returned by lv_wayland_backend_init_display_t or lv_wayland_backend_resize_display_t

Parameters:

display – [in] Pointer to the LVGL display object

Returns:

Pointer to backend-specific display data

struct wl_surface *lv_wayland_get_window_surface(lv_display_t *display)

Get the Wayland surface for rendering.

Retrieves the wl_surface object associated with the display window. This is the surface that the backend must use for all rendering operations (attaching buffers, committing frames, etc.).

Note

This surface is managed by the Wayland driver and must not be destroyed by the backend

Note

All rendering output should be attached to this surface

Parameters:

display – [in] Pointer to the LVGL display object

Returns:

Pointer to the Wayland surface for rendering, or NULL if not available

Variables

const lv_wayland_backend_ops_t wl_backend_ops

struct lv_wayland_backend_ops_t

#include <lv_wl_backend_private.h>

Wayland backend operations structure.

This structure defines the complete set of operations that a Wayland backend must implement. All function pointers must be non-NULL.

Lifecycle Order:

1. init() - Initialize backend context

2. global_handler() - Called for each Wayland global (may be called multiple times)

3. init_display() - Create display (may be called multiple times for multiple displays)

4. resize_display() - Resize display (called as needed)

5. deinit_display() - Destroy display (called once per display)

6. deinit() - Clean up backend context

Public Members

lv_wayland_backend_init_t init

Initialize backend context

lv_wayland_backend_global_handler_t global_handler

Handle Wayland global objects

lv_wayland_backend_init_display_t init_display

Initialize a new display

lv_wayland_backend_resize_display_t resize_display

Resize or reconfigure display

lv_wayland_backend_destroy_display_t deinit_display

Destroy a display

lv_wayland_backend_deinit_t deinit

Deinitialize backend context