wlr_layer_shell_unstable_v1

• # zwlr_layer_shell_v1

  Clients can use this interface to assign the surface_layer role to wl_surfaces. Such surfaces are assigned to a "layer" of the output and rendered with a defined z-depth respective to each other. They may also be anchored to the edges and corners of a screen and specify input handling semantics. This interface should be suitable for the implementation of many desktop shell components, and a broad number of other applications that interact with the desktop.

  Requests

  • #

    get_layer_surface

    create a layer_surface from a surface
    struct zwlr_layer_surface_v1* zwlr_layer_shell_v1_get_layer_surface(

    struct zwlr_layer_shell_v1* zwlr_layer_shell_v1,

    struct wl_surface* surface,

    struct wl_output* output,

    uint32_t layer, /* layer to add this surface to */

    const char* namespace /* namespace for the layer surface */

    )
    Create a layer surface for an existing surface. This assigns the role of layer_surface, or raises a protocol error if another role is already assigned. Creating a layer surface from a wl_surface which has a buffer attached or committed is a client error, and any attempts by a client to attach or manipulate a buffer prior to the first layer_surface.configure call must also be treated as errors. After creating a layer_surface object and setting it up, the client must perform an initial commit without any buffer attached. The compositor will reply with a layer_surface.configure event. The client must acknowledge it and is then allowed to attach a buffer to map the surface. You may pass NULL for output to allow the compositor to decide which output to use. Generally this will be the one that the user most recently interacted with. Clients can specify a namespace that defines the purpose of the layer surface.
  • #

    destroy

    destroy the layer_shell object
    void zwlr_layer_shell_v1_destroy(

    struct zwlr_layer_shell_v1* zwlr_layer_shell_v1

    )
    This request indicates that the client will not use the layer_shell object any more. Objects that have been created through this instance are not affected.

  Enums

  • #

    error
    ZWLR_LAYER_SHELL_V1_ERROR_ROLE /* wl_surface has another role */
    ZWLR_LAYER_SHELL_V1_ERROR_INVALID_LAYER /* layer value is invalid */
    ZWLR_LAYER_SHELL_V1_ERROR_ALREADY_CONSTRUCTED /* wl_surface has a buffer attached or committed */
  • #

    layer

    available layers for surfaces
    ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND
    ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM
    ZWLR_LAYER_SHELL_V1_LAYER_TOP
    ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY
    These values indicate which layers a surface can be rendered in. They are ordered by z depth, bottom-most first. Traditional shell surfaces will typically be rendered between the bottom and top layers. Fullscreen shell surfaces are typically rendered at the top layer. Multiple surfaces can share a single layer, and ordering within a single layer is undefined.

• # zwlr_layer_surface_v1

  An interface that may be implemented by a wl_surface, for surfaces that are designed to be rendered as a layer of a stacked desktop-like environment. Layer surface state (layer, size, anchor, exclusive zone, margin, interactivity) is double-buffered, and will be applied at the time wl_surface.commit of the corresponding wl_surface is called. Attaching a null buffer to a layer surface unmaps it. Unmapping a layer_surface means that the surface cannot be shown by the compositor until it is explicitly mapped again. The layer_surface returns to the state it had right after layer_shell.get_layer_surface. The client can re-map the surface by performing a commit without any buffer attached, waiting for a configure event and handling it as usual.

  Requests

  • #

    set_size

    sets the size of the surface
    void zwlr_layer_surface_v1_set_size(

    struct zwlr_layer_surface_v1* zwlr_layer_surface_v1,

    uint32_t width,

    uint32_t height

    )
    Sets the size of the surface in surface-local coordinates. The compositor will display the surface centered with respect to its anchors. If you pass 0 for either value, the compositor will assign it and inform you of the assignment in the configure event. You must set your anchor to opposite edges in the dimensions you omit; not doing so is a protocol error. Both values are 0 by default. Size is double-buffered, see wl_surface.commit.
  • #

    set_anchor

    configures the anchor point of the surface
    void zwlr_layer_surface_v1_set_anchor(

    struct zwlr_layer_surface_v1* zwlr_layer_surface_v1,

    uint32_t anchor

    )
    Requests that the compositor anchor the surface to the specified edges and corners. If two orthogonal edges are specified (e.g. 'top' and 'left'), then the anchor point will be the intersection of the edges (e.g. the top left corner of the output); otherwise the anchor point will be centered on that edge, or in the center if none is specified. Anchor is double-buffered, see wl_surface.commit.
  • #

    set_exclusive_zone

    configures the exclusive geometry of this surface
    void zwlr_layer_surface_v1_set_exclusive_zone(

    struct zwlr_layer_surface_v1* zwlr_layer_surface_v1,

    int32_t zone

    )
    Requests that the compositor avoids occluding an area with other surfaces. The compositor's use of this information is implementation-dependent - do not assume that this region will not actually be occluded. A positive value is only meaningful if the surface is anchored to one edge or an edge and both perpendicular edges. If the surface is not anchored, anchored to only two perpendicular edges (a corner), anchored to only two parallel edges or anchored to all edges, a positive value will be treated the same as zero. A positive zone is the distance from the edge in surface-local coordinates to consider exclusive. Surfaces that do not wish to have an exclusive zone may instead specify how they should interact with surfaces that do. If set to zero, the surface indicates that it would like to be moved to avoid occluding surfaces with a positive exclusive zone. If set to -1, the surface indicates that it would not like to be moved to accommodate for other surfaces, and the compositor should extend it all the way to the edges it is anchored to. For example, a panel might set its exclusive zone to 10, so that maximized shell surfaces are not shown on top of it. A notification might set its exclusive zone to 0, so that it is moved to avoid occluding the panel, but shell surfaces are shown underneath it. A wallpaper or lock screen might set their exclusive zone to -1, so that they stretch below or over the panel. The default value is 0. Exclusive zone is double-buffered, see wl_surface.commit.
  • #

    set_margin

    sets a margin from the anchor point
    void zwlr_layer_surface_v1_set_margin(

    struct zwlr_layer_surface_v1* zwlr_layer_surface_v1,

    int32_t top,

    int32_t right,

    int32_t bottom,

    int32_t left

    )
    Requests that the surface be placed some distance away from the anchor point on the output, in surface-local coordinates. Setting this value for edges you are not anchored to has no effect. The exclusive zone includes the margin. Margin is double-buffered, see wl_surface.commit.
  • #

    set_keyboard_interactivity

    requests keyboard events
    void zwlr_layer_surface_v1_set_keyboard_interactivity(

    struct zwlr_layer_surface_v1* zwlr_layer_surface_v1,

    uint32_t keyboard_interactivity

    )
    Set how keyboard events are delivered to this surface. By default, layer shell surfaces do not receive keyboard events; this request can be used to change this. This setting is inherited by child surfaces set by the get_popup request. Layer surfaces receive pointer, touch, and tablet events normally. If you do not want to receive them, set the input region on your surface to an empty region. Keyboard interactivity is double-buffered, see wl_surface.commit.
  • #

    get_popup

    assign this layer_surface as an xdg_popup parent
    void zwlr_layer_surface_v1_get_popup(

    struct zwlr_layer_surface_v1* zwlr_layer_surface_v1,

    struct xdg_popup* popup

    )
    This assigns an xdg_popup's parent to this layer_surface. This popup should have been created via xdg_surface::get_popup with the parent set to NULL, and this request must be invoked before committing the popup's initial state. See the documentation of xdg_popup for more details about what an xdg_popup is and how it is used.
  • #

    ack_configure

    ack a configure event
    void zwlr_layer_surface_v1_ack_configure(

    struct zwlr_layer_surface_v1* zwlr_layer_surface_v1,

    uint32_t serial /* the serial from the configure event */

    )
    When a configure event is received, if a client commits the surface in response to the configure event, then the client must make an ack_configure request sometime before the commit request, passing along the serial of the configure event. If the client receives multiple configure events before it can respond to one, it only has to ack the last configure event. A client is not required to commit immediately after sending an ack_configure request - it may even ack_configure several times before its next surface commit. A client may send multiple ack_configure requests before committing, but only the last request sent before a commit indicates which configure event the client really is responding to.
  • #

    destroy

    destroy the layer_surface
    void zwlr_layer_surface_v1_destroy(

    struct zwlr_layer_surface_v1* zwlr_layer_surface_v1

    )
    This request destroys the layer surface.
  • #

    set_layer

    change the layer of the surface
    void zwlr_layer_surface_v1_set_layer(

    struct zwlr_layer_surface_v1* zwlr_layer_surface_v1,

    uint32_t layer /* layer to move this surface to */

    )
    Change the layer that the surface is rendered on. Layer is double-buffered, see wl_surface.commit.

  Events

  • #

    configure

    suggest a surface change
    uint32_t serial
    uint32_t width
    uint32_t height
    The configure event asks the client to resize its surface. Clients should arrange their surface for the new states, and then send an ack_configure request with the serial sent in this configure event at some point before committing the new surface. The client is free to dismiss all but the last configure event it received. The width and height arguments specify the size of the window in surface-local coordinates. The size is a hint, in the sense that the client is free to ignore it if it doesn't resize, pick a smaller size (to satisfy aspect ratio or resize in steps of NxM pixels). If the client picks a smaller size and is anchored to two opposite anchors (e.g. 'top' and 'bottom'), the surface will be centered on this axis. If the width or height arguments are zero, it means the client should decide its own window dimension.
  • #

    closed

    surface should be closed
    The closed event is sent by the compositor when the surface will no longer be shown. The output may have been destroyed or the user may have asked for it to be removed. Further changes to the surface will be ignored. The client should destroy the resource after receiving this event, and create a new surface if they so choose.

  Enums

  • #

    keyboard_interactivity

    types of keyboard interaction possible for a layer shell surface
    ZWLR_LAYER_SURFACE_V1_KEYBOARD_INTERACTIVITY_NONE
    ZWLR_LAYER_SURFACE_V1_KEYBOARD_INTERACTIVITY_EXCLUSIVE
    ZWLR_LAYER_SURFACE_V1_KEYBOARD_INTERACTIVITY_ON_DEMAND
    Types of keyboard interaction possible for layer shell surfaces. The rationale for this is twofold: (1) some applications are not interested in keyboard events and not allowing them to be focused can improve the desktop experience; (2) some applications will want to take exclusive keyboard focus.
  • #

    error
    ZWLR_LAYER_SURFACE_V1_ERROR_INVALID_SURFACE_STATE /* provided surface state is invalid */
    ZWLR_LAYER_SURFACE_V1_ERROR_INVALID_SIZE /* size is invalid */
    ZWLR_LAYER_SURFACE_V1_ERROR_INVALID_ANCHOR /* anchor bitfield is invalid */
    ZWLR_LAYER_SURFACE_V1_ERROR_INVALID_KEYBOARD_INTERACTIVITY /* keyboard interactivity is invalid */
  • #

    anchor
    ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP /* the top edge of the anchor rectangle */
    ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM /* the bottom edge of the anchor rectangle */
    ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT /* the left edge of the anchor rectangle */
    ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT /* the right edge of the anchor rectangle */

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