Wayland-Protocols 1.35 release

The wayland-protocols 1.35 package has been released, containing a set of protocols and extensions that complement the capabilities of the base Wayland protocol and provide the capabilities necessary for building composite servers and user environments.

All protocols consistently go through three phases - development, testing and stabilization. After completion of the development stage ("unstable" category), the protocol is placed in the "staging" branch and officially included in the wayland-protocols set, and after testing is completed, it is moved to the stable category. Protocols from the "staging" category can already be used in composite servers and clients where the functionality associated with them is required. Unlike the “unstable” category, in “staging” it is forbidden to make changes that violate compatibility, but if problems and flaws are identified during testing, replacement with a new significant version of the protocol or another Wayland extension is not ruled out.

In the new version:

• The tablet-v2 protocol, which provides tools for organizing input from graphics tablets, has been transferred to the stable category.
• A new alpha-modifier protocol has been added to the “staging” category, allowing clients to change the level of surface transparency and outsource transparency operations to the composite server, which in turn can forward these operations to KMS.
• A recommendation has been added to the xdg-shell protocol not to display decoration outside the geometric boundaries of the window when using a tiled window layout.

Wayland-protocols currently includes the following stable protocols that are backward compatible:

• "viewporter" - allows the client to perform scaling and cropping actions on the edges of the surface on the server side.
• "presentation-time" - provides video display.
• “xdg-shell” is an interface for creating and interacting with surfaces like windows, which allows them to be moved around the screen, minimized, maximized, resized, etc.
• “linux-dmabuf” - provides sharing of several video cards using DMA-BUF technology (allows you to create a wl_buffer based on DMA-BUF).
• "tablet" - organization of input from graphic tablets.

Protocols tested in the "staging" branch:

• drm-lease - provides the resources necessary to form a stereo image with different buffers for the left and right eyes when displayed on virtual reality helmets.
• "ext-session-lock" - defines the means of locking the session, for example, during the operation of the screen saver or the output of the authentication dialog.
• "single-pixel-buffer" - allows you to create single-pixel buffers that include four 32-bit RGBA values.
• "xdg-activation" - allows you to transfer focus between different surfaces of the first level (for example, using xdg-activation, one application can switch focus to another).
• content-type - Allows clients to pass information about the rendered content to the composite server, which can be used to optimize content-aware behavior, such as setting DRM-specific properties such as "content type". Support for the following content types is declared: none (there is no information about the data type), photo (output of digital photos that requires minimal processing), video (video or animation, more precise synchronization is required to eliminate stuttering) and game (starting games, output from minimum delay).
• ext-idle-notify - Allows composite servers to send user inactivity notifications to clients, which can be used to activate additional power saving modes after a certain amount of inactivity.
• tearing-control - allows you to disable vertical sync (VSync) with vertical blanking pulse in full-screen applications, which is used to protect against tearing in the output (tearing). In multimedia applications, the appearance of artifacts due to tearing is an undesirable effect, but in game programs, artifacts can be tolerated if dealing with them leads to additional delays.
• ext-foreign-toplevel-list - Retrieves information about surfaces placed at the top level, which allow you to organize windows to dock on top of other content, for example, to attach your own panels and window switches.
• security-context - allows you to identify clients using sandbox isolation. A client can register a new connection to a Wayland-based composite server and attach a security context to it, after which the composite manager will limit the capabilities available to the established connection based on the specified security context.
• cursor-shape is an alternative way to customize the appearance of the cursor, based on passing a series of images of the cursor instead of snapping to a surface (wl_surface).
• “ext-transient-seat” - designed to create temporary independent sessions (seats) designed for use with virtual input devices. For example, when implementing the ability to connect to a remote desktop, the protocol allows you to create a separate session for each user with a virtual keyboard and mouse.
• "xdg-toplevel-drag" - extends the "drag & drop" mechanism with the ability to attach top-level windows to a drag operation, which can be used, for example, to organize dragging of toolbars or browser tabs with the mouse. The new protocol allows you to create detachable parts of a window that, when dragged from that window, become new windows and can be moved on top of the existing window before being re-attached.
• "xdg-dialog" - allows you to assign dialog-specific attributes to top-level surfaces, for example, you can create modal dialogs that block user interaction with the rest of the interface.
• "linux-drm-syncobj" - Provides tools for explicitly synchronizing buffers using DRM (Direct Rendering Manager) synchronization objects. It is assumed that in the context of synchronization when drawing to a buffer, the proposed protocol will improve work with drivers based on the Vulkan and OpenGL graphics APIs (the implementation is based on handlers in the drivers). The new protocol makes it possible to ensure that a render operation to a buffer is completed before the composite manager renders the buffer.

Protocols being developed in the "unstable" branch:

• "fullscreen-shell" - control work in full screen mode.
• "input-method" - processing of input methods.
• "idle-inhibit" - blocking the launch of the screensaver (screen saver).
• "input-timestamps" - timestamps for input events.
• "keyboard-shortcuts-inhibit" - Controls the attachment of keyboard shortcuts and hotkeys.
• "linux-explicit-synchronization" is a Linux-specific mechanism for synchronizing buffers in relation to a surface.
• "pointer-gestures" - control from touch screens.
• "pointer constraints" - pointer constraints (blocking).
• "primary-selection" - by analogy with X11, it provides the primary clipboard (primary selection), the insertion of information from which is usually done with the middle mouse button.
• "relative pointer events" - relative pointer events.
• "text-input" - organization of text input.
• "xdg-foreign" is an interface for interacting with the surfaces of a "neighboring" client.
• "xdg-decoration" - rendering window decorations on the server side.
• "xdg-output" - additional information about the video output (used for fractional scaling).
• "xwayland-keyboard-grab" - Capture input in XWayland applications.

Source: opennet.ru