Package limn.backend.spi

@NullMarked package limn.backend.spi

What a backend implements and the toolkit calls, below the application's view of limn.backend: the input a window delivers to its scene (WindowInput), the frame it asks the scene to draw (FrameCallback, FrameInfo, GpuRenderer), the services it installs (BackendServices), and the modality rules every backend shares (ModalStack).

Incubating. The 1.0 contract freezes the application's layer, limn.backend; this layer may change in a minor release while a second backend is still possible, and every change is listed in the CHANGELOG with its migration. An application does not need it.

Related Packages

Package	Description
limn.backend	The service-provider interface a native platform implements: Backend runs the event loop and creates NativeWindows.
limn.backend.lwjgl	The shipped backend: GLFW windows and input, an OpenGL 3.3 core renderer that batches the 2D canvas and hosts the 3D provider, OpenAL audio, and stb for font rasterization and image decoding.

Class	Description
BackendPeer	What the toolkit asks of a backend below the application's view of it: the modal stack, and windows it can reach as peers.
BackendPeer.SceneModalHandle	Handle to an in-scene modal (see BackendPeer.pushSceneModal(limn.backend.NativeWindow, boolean)); BackendPeer.SceneModalHandle.release() it on close.
BackendServices	Everything a Backend provides to the toolkit besides its windows, named in one place and installed by one call.
DragRequest	A drag the scene hands to the system: what it carries, what may be done with it, the picture the system shows under the pointer, and who hears the end.
FrameCallback	Renders one frame of a window.
FrameInfo	Immutable per-frame metrics handed to a FrameCallback.
GlyphOutlines	The outlines of the glyphs a ShapedText names, for a writer that draws text as text rather than as pixels: a PDF page keeps each glyph as its outline and maps it back to the characters it stands for.
GlyphOutlines.Glyph	A glyph drawn in place of a character.
GlyphOutlines.Picture	A picture drawn in place of a character: a colour emoji's strike.
GlyphOutlines.Piece	One thing a glyphless cluster draws.
GpuRenderer	GPU rendering entry point for one window.
Installed<T>	The one slot a backend fills for a service the toolkit offers statically: the image decoder, the audio engine, the text ruler, the 3D provider, the crash handler, the UI runtime.
LauncherPeer	What a backend does for Launcher: hand an address or a file to the system its window is on.
MenuBarHost	What a backend asks and tells of a menu bar the system shows.
MenuBarReading	A menu bar as a backend is handed it for the system's own bar: what the application declared, already sorted into the places a system that keeps the bar outside the window has for it.
MenuBarReading.Kind	What a menu of the bar is to the system.
MenuBarReading.Top	One menu of the bar.
MenuRow	One row of a menu the system draws (a tray's, a menu bar's) as a backend is handed it: what the three systems can draw of a menu's item, and a number to say back when the user chooses it.
MenuRow.Kind	What a row is.
ModalStack	Modality bookkeeping for a backend: a stack of active modals and the decision of whether a given window's input is blocked.
ModalStack.Active	One active modal, for a backend's own rule over them.
PrinterPeer	What a backend's window implements so that Printer can print through it: the system's own print dialog, owned by the window, and the hand-over of a PDF to the system once the dialog is confirmed.
PrintJob	What a PrinterPeer hands the system: a PDF, the job's name, and the paper the document was laid out on, which the system's dialog starts from.
SystemMenuBar	The menu bar a system keeps outside the windows, one for the application, as a backend offers it to the toolkit.
SystemMenuLabels	The words the toolkit writes in a system's menu bar for the items that are not the application's: those of the application's own menu and of a Window menu given to an application that named none.
TextInput	What text a window asks the platform for, set with WindowPeer.setTextInput(limn.backend.spi.TextInput).
TrayHost	What a tray's backend asks of the toolkit and tells it.
TrayPeer	What a backend does for Tray: keep one icon in the system's place for one.
TrayPicture	A tray icon's picture at whatever size a system asks for: the application's icon, and the dot that says attention when it has one.
TrayState	What a tray shows, whole: a backend is handed a new one whenever any part changes and shows the difference.
WindowInput	Receives a window's translated native input on the UI thread, in logical points.
WindowPeer	What the toolkit asks of a window below the application's view of it: the input it delivers, the frames it asks for, the input method, the popups it owns and whether it is a modal.
WindowPeer.PopupKind	What a registered child window is, which decides whether a modal over the owner leaves it usable.