Package limn.backend

@NullMarked package limn.backend

The service-provider interface a native platform implements: Backend runs the event loop and creates NativeWindows. Beside it sit the contracts a platform must supply: the GpuRenderer widgets draw through, WindowInput, Clipboard, Cursors, FileDialogs and Crashes reporting. Come here to write a backend, or to see exactly what one owes the toolkit; an application constructs one at startup and otherwise programs against the modules above, which never name a windowing library.

Related Packages

Package	Description
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.
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).

Class	Description
AccessibilityBridge	What a backend gives a window so that a platform's assistive technology can read it.
AccessibilityBridge.Host	What the scene gives a bridge: the three ways to ask for a tree, and the one way to act.
Backend	Service-provider interface for a native platform backend (windows, input, GPU rendering, clipboard).
Clipboard	The system clipboard: what the user last copied, in this application or another, in every format it was offered in.
ClosePolicy	What a user's close of a window does once it is allowed: set with NativeWindow.setClosePolicy(limn.backend.ClosePolicy), ClosePolicy.DISPOSE by default.
CloseRequest	One question to a window's CloseRequestHandler: may this window close? Answered exactly once, with CloseRequest.allow() or CloseRequest.refuse(), now or later: a handler that shows a dialog keeps the request and answers from the dialog's result.
CloseRequest.Reason	Why the window is asked.
CloseRequestHandler	Decides whether a window may close, set with NativeWindow.setCloseRequestHandler(limn.backend.CloseRequestHandler).
Crashes	Crash containment registry: one process-wide CrashHandler (default: log and continue) that the toolkit and backend notify whenever application code throws inside the event loop.
Crashes.ShutdownRequested	Unwinds the event loop when a CrashHandler returned false; containment sites let it pass through instead of re-dispatching, so the HANDLER.current() sees each crash once.
CrashHandler	Application hook for crashes the toolkit caught in the event loop.
CrashPhase	Where application code was executing when a contained crash was caught.
Cursor	A standard mouse-cursor shape a widget can request while hovered: the OS's native pointer, so it looks and feels exactly like every other application.
Display	A monitor/screen, normalized so every part of the toolkit reads display information the same way instead of each class poking at the platform: its identity (Display.id()/Display.name()), the mode currently set (Display.currentResolution()), all supported modes (Display.availableResolutions()), the full Display.bounds(), the usable Display.workArea() (minus taskbar/dock), and the DPI Display.contentScale().
FileDialogs	The platform's own file and folder choosers, owned by a window: NativeWindow.fileDialogs().
FileDialogs.Filter	A file-name filter: a human-readable description plus glob patterns, e.g.
GraphicsInfo	Which graphics context a backend actually obtained, and which of the optional capabilities the toolkit uses are present on it.
ImageCursor	A custom mouse cursor built from an Image (a themed crosshair, a brush outline, a spell-target reticle), where the ten stock Cursor shapes are not enough.
Launcher	Hands an address or a file to the system the window is on: a web page to the browser, a mailto: to the mail program, a file to the program registered for its type, or a file to the file manager, shown selected in its folder.
LoopEnd	Why Backend.runEventLoop() returned.
LoopLifetime	How long Backend.runEventLoop() runs: set with Backend.setLoopLifetime(limn.backend.LoopLifetime), LoopLifetime.UNTIL_LAST_WINDOW by default.
NativeWindow	A top-level native window.
NativeWindow.ContentScaleListener	Notified when the window moves to a monitor with a different content scale.
Platform	The operating system and processor architecture this JVM runs on, answered once and from one place.
Platform.Os	The operating system families the toolkit tells apart.
PointerMode	How the window treats the mouse pointer: visibility and capture.
Printer	What prints a PDF through the system's own print dialog, owned by a window: reached from NativeWindow.printer().
PrintResult	What became of a print asked of the system through Printer.
QuitHandler	Decides whether the application may end, for what belongs to no window (a download still running): set with Backend.setQuitHandler(limn.backend.QuitHandler).
QuitRequest	The application-wide question Backend.requestQuit() asks first, to the QuitHandler, before any window is asked: may the application end? Answered exactly once, now or later.
RenderStats	A snapshot of GPU resources the renderer is holding: currently the number of GL textures resident (glyph-atlas pages + cached image textures) and their estimated size in bytes.
Resolution	An immutable screen mode: a size and refresh rate.
ScreenRect	A rectangle in native screen coordinates: a Display's full bounds or its usable work area (the monitor minus OS chrome like the taskbar/dock/menu bar).
SizeLimits	The bounds a window's size is kept within while the user resizes it, in logical points.
WindowConfig	Initial configuration for a NativeWindow: start from WindowConfig.of(java.lang.String, int, int), then change what differs from a plain window with a wither.
WindowState	Where a window is, how large and in which state, as one value: what NativeWindow.state() answers and what NativeWindow.observeState(java.util.function.Consumer<limn.backend.WindowState>) hands a listener each time any part of it changes.
WindowStyle	Visual framing of a window.