pulp::view::web Namespace Reference

Classes
struct	ViewportMapping
	Maps CSS pixels — the unit every browser pointer event reports — to root-view coordinates. More...
struct	BackingStore
	Canvas backing-store size and the scale factor handed to the Skia surface. More...
struct	BrowserModifiers
struct	BrowserPointerEvent
struct	BrowserWheelEvent
struct	BrowserKeyEvent
class	WebInputRouter
	Routes translated browser events into a live View tree. More...

Enumerations
enum class	BrowserPointerPhase : uint8_t { down , move , up , cancel }
	W3C PointerEvent phase. More...
enum class	BrowserPointerType : uint8_t { mouse , touch , pen }
	W3C PointerEvent.pointerType. More...
enum class	BrowserDeltaMode : uint8_t { pixel = 0 , line = 1 , page = 2 }
	W3C WheelEvent.deltaMode. More...

Functions
Point	css_to_root (const ViewportMapping &mapping, Point css)
	CSS-pixel point → root-view point. Identity without a design viewport.
Point	root_to_css (const ViewportMapping &mapping, Point root)
	Root-view point → CSS-pixel point. The exact inverse of css_to_root().
BackingStore	compute_backing_store (float css_width, float css_height, float device_pixel_ratio)
	The one place the HiDPI factor is applied.
uint16_t	translate_modifiers (const BrowserModifiers &mods)
	metaKey is Command on a Mac browser and the Super/Windows key elsewhere, so it sets both kModMeta and kModCmd.
MouseButton	translate_button (int w3c_button)
PointerType	translate_pointer_type (BrowserPointerType type)
MouseEvent	translate_pointer (const BrowserPointerEvent &event, const ViewportMapping &mapping)
	Browser pointer event → Pulp MouseEvent in ROOT coordinates.
MouseEvent	translate_wheel (const BrowserWheelEvent &event, const ViewportMapping &mapping)
	Browser wheel event → Pulp wheel MouseEvent in ROOT coordinates.
KeyCode	translate_key_code (const std::string &key)
	KeyboardEvent.key → KeyCode.
KeyEvent	translate_key (const BrowserKeyEvent &event)
std::string	text_for_key (const BrowserKeyEvent &event)
	The text a key-down should also deliver as a TextInputEvent, or "" when the key produces no character.
void	install_browser_window_host (std::string canvas_selector="#canvas")
	Register the Emscripten BrowserWindowHost factory so WindowHost::create() returns a canvas-backed host.
void	install_web_input_listeners (const std::string &canvas_selector, WebInputRouter &router)
	Attach/detach the DOM listeners (pointer, wheel, key, resize) that feed router.
void	remove_web_input_listeners (const std::string &canvas_selector)
void	notify_browser_host_resized (float css_width, float css_height)
	The canvas element's CSS size changed.
bool	browser_host_gpu_available ()
	Is the live browser host's GPU surface renderable RIGHT NOW?
float	device_pixel_ratio ()
	Current devicePixelRatio, and the canvas element's CSS size. Emscripten only.
bool	canvas_css_size (const std::string &canvas_selector, float &css_width, float &css_height)
void	set_canvas_size (const std::string &canvas_selector, const BackingStore &backing, float css_width, float css_height)
	Size the canvas element: backing store in device pixels, CSS box in CSS pixels.
void	set_canvas_visible (const std::string &canvas_selector, bool visible)
	Show/hide the canvas element (style.display). Emscripten only.

Variables
constexpr float	kWheelLinePixels = 16.0f
	A wheel line is one text line; a wheel page falls back to this when the mapping carries no CSS height.
constexpr float	kWheelPageFallbackPixels = 400.0f

Enumeration Type Documentation

BrowserDeltaMode

enum class pulp::view::web::BrowserDeltaMode : uint8_t

strong

W3C WheelEvent.deltaMode.

Enumerator
pixel
line
page

BrowserPointerPhase

enum class pulp::view::web::BrowserPointerPhase : uint8_t

strong

W3C PointerEvent phase.

Enumerator
down
move
up
cancel

BrowserPointerType

enum class pulp::view::web::BrowserPointerType : uint8_t

strong

W3C PointerEvent.pointerType.

Enumerator
mouse
touch
pen

Function Documentation

browser_host_gpu_available()

bool pulp::view::web::browser_host_gpu_available

(

)

Is the live browser host's GPU surface renderable RIGHT NOW?

False while the WebGL context is lost — the browser can revoke it at any time (context-cap eviction, GPU-process crash, backgrounded mobile tab), and the Ganesh surface then abandons its Skia context and refuses to paint until webglcontextrestored arrives. Exposed so a host page (and the browser pixel fixture) can observe and assert that recovery instead of guessing from a frozen canvas. False when no host is installed. Emscripten only.

canvas_css_size()

bool pulp::view::web::canvas_css_size	(	const std::string &	canvas_selector,
		float &	css_width,
		float &	css_height )

compute_backing_store()

BackingStore pulp::view::web::compute_backing_store ( float css_width, float css_height, float device_pixel_ratio )

inline

The one place the HiDPI factor is applied.

canvas.style.{width,height} stay at the CSS size, canvas.{width,height} become the returned device size, and scale_factor is the ratio — so paint scales up while input coordinates stay in CSS pixels.

css_to_root()

Point pulp::view::web::css_to_root ( const ViewportMapping & mapping, Point css )

inline

CSS-pixel point → root-view point. Identity without a design viewport.

device_pixel_ratio()

float pulp::view::web::device_pixel_ratio

(

)

Current devicePixelRatio, and the canvas element's CSS size. Emscripten only.

install_browser_window_host()

void pulp::view::web::install_browser_window_host

(

std::string

canvas_selector = "#canvas"

)

Register the Emscripten BrowserWindowHost factory so WindowHost::create() returns a canvas-backed host.

canvas_selector is a CSS selector for the target HTMLCanvasElement. Defined in platform/web/window_host_web.cpp, which is compiled only for Emscripten targets.

install_web_input_listeners()

void pulp::view::web::install_web_input_listeners	(	const std::string &	canvas_selector,
		WebInputRouter &	router )

Attach/detach the DOM listeners (pointer, wheel, key, resize) that feed router.

Defined in platform/web/web_input.cpp — Emscripten only.

notify_browser_host_resized()

void pulp::view::web::notify_browser_host_resized	(	float	css_width,
		float	css_height )

The canvas element's CSS size changed.

Called by the resize listener in web_input.cpp; handled by the live host in window_host_web.cpp.

remove_web_input_listeners()

void pulp::view::web::remove_web_input_listeners

(

const std::string &

canvas_selector

)

root_to_css()

Point pulp::view::web::root_to_css ( const ViewportMapping & mapping, Point root )

inline

Root-view point → CSS-pixel point. The exact inverse of css_to_root().

set_canvas_size()

void pulp::view::web::set_canvas_size	(	const std::string &	canvas_selector,
		const BackingStore &	backing,
		float	css_width,
		float	css_height )

Size the canvas element: backing store in device pixels, CSS box in CSS pixels.

Emscripten only.

set_canvas_visible()

void pulp::view::web::set_canvas_visible	(	const std::string &	canvas_selector,
		bool	visible )

Show/hide the canvas element (style.display). Emscripten only.

text_for_key()

std::string pulp::view::web::text_for_key ( const BrowserKeyEvent & event )

inline

The text a key-down should also deliver as a TextInputEvent, or "" when the key produces no character.

KeyboardEvent.key is the printable character itself for character keys and a multi-character NAME ("Enter", "ArrowLeft") otherwise; a non-ASCII character is a multi-byte UTF-8 string whose first byte has the high bit set, which is how it stays distinguishable from a name. Ctrl/Meta chords are commands, not text.

translate_button()

MouseButton pulp::view::web::translate_button ( int w3c_button )

inline

translate_key()

KeyEvent pulp::view::web::translate_key ( const BrowserKeyEvent & event )

inline

translate_key_code()

KeyCode pulp::view::web::translate_key_code ( const std::string & key )

inline

KeyboardEvent.key → KeyCode.

Unmapped names (modifier keys, media keys, …) return KeyCode::unknown, which still reaches the view tree as a KeyEvent so a widget can observe the modifier state.

translate_modifiers()

uint16_t pulp::view::web::translate_modifiers ( const BrowserModifiers & mods )

inline

metaKey is Command on a Mac browser and the Super/Windows key elsewhere, so it sets both kModMeta and kModCmd.

A wasm build is not __APPLE__, so is_main_modifier() resolves to Ctrl there — a shortcut that must follow the host OS reads isCmdDown()/isCtrlDown() explicitly.

translate_pointer()

MouseEvent pulp::view::web::translate_pointer ( const BrowserPointerEvent & event, const ViewportMapping & mapping )

inline

Browser pointer event → Pulp MouseEvent in ROOT coordinates.

Both position and window_position carry the root point. The host overwrites position with the hit view's local coordinates before dispatch (the macOS host's convention), which it can only do once hit-testing has picked a target.

translate_pointer_type()

PointerType pulp::view::web::translate_pointer_type ( BrowserPointerType type )

inline

translate_wheel()

MouseEvent pulp::view::web::translate_wheel ( const BrowserWheelEvent & event, const ViewportMapping & mapping )

inline

Browser wheel event → Pulp wheel MouseEvent in ROOT coordinates.

Sign is preserved: WheelEvent.deltaY is positive when the content scrolls DOWN, and Pulp's scroll_delta_y is positive-is-down too (ScrollView adds it straight onto its scroll offset). Non-pixel delta modes are normalized to CSS pixels.

Variable Documentation

kWheelLinePixels

float pulp::view::web::kWheelLinePixels = 16.0f

inlineconstexpr

A wheel line is one text line; a wheel page falls back to this when the mapping carries no CSS height.

kWheelPageFallbackPixels

float pulp::view::web::kWheelPageFallbackPixels = 400.0f

inlineconstexpr