ocaml-canvas 1.0.0 (latest)

Event descriptions

All event descriptions contain the canvas on which the event occured and the timestamp indicating when the event occured.

type timestamp = Int64.t

Timestamps represent the time in microseconds, from an arbitrary starting point

type 'a canvas_event = {

canvas : Canvas.t;
timestamp : timestamp;
data : 'a;

}

Generic description of events occurring on canvases

type position = int * int

A position is a pair of integers

type size = int * int

A size is a pair of integers

type key =

| KeyEscape
| KeyF1
| KeyF2
| KeyF3
| KeyF4
| KeyF5
| KeyF6
| KeyF7
| KeyF8
| KeyF9
| KeyF10
| KeyF11
| KeyF12
| KeyPrintScreen
(*
absent from Mac Keyboards
*)
| KeyScrollLock
(*
absent from Mac Keyboards
*)
| KeyPause
(*
absent from Mac Keyboards
*)
| KeyGraveTilde
| Key1Exclamation
| Key2At
| Key3Number
| Key4Dollar
| Key5Percent
| Key6Caret
| Key7Ampersand
| Key8Asterisk
| Key9LParenthesis
| Key0RParenthesis
| KeyMinusUndersclre
| KeyEqualPlus
| KeyBackspace
| KeyTab
| KeyQ
| KeyW
| KeyE
| KeyR
| KeyT
| KeyY
| KeyU
| KeyI
| KeyO
| KeyP
| KeyLBracketCurly
| KeyRBracketCurly
| KeyBackslashPipe
(*
replaced by KeyNonUSNumberTilde on ISO KB
*)
| KeyCapsLock
| KeyA
| KeyS
| KeyD
| KeyF
| KeyG
| KeyH
| KeyJ
| KeyK
| KeyL
| KeySemicolonColon
| KeyQuoteDoublequote
| KeyNonUSNumberTilde
(*
extra key left of Return on ISO KB, although generally mapped to KeyBackslashPipe instead
*)
| KeyReturn
| KeyLShift
| KeyNonUSBackslashPipe
(*
extra key right of LShift on ISO KB
*)
| KeyZ
| KeyX
| KeyC
| KeyV
| KeyB
| KeyN
| KeyM
| KeyCommaLess
| KeyPeriodGreater
| KeySlashQuestion
| KeyRShift
| KeyLControl
| KeyLMeta
(*
left Windows / Command key
*)
| KeyLAlt
| KeySpacebar
| KeyRAlt
| KeyRMeta
(*
right Windows / Command key
*)
| KeyMenu
| KeyRControl
| KeyInsert
(*
replaced by a Fn key on Mac (with a different code)
*)
| KeyHome
| KeyPageUp
| KeyDeleteForward
| KeyEend
| KeyPageDown
| KeyUpArrow
| KeyLeftArrow
| KeyDownArrow
| KeyRightArrow
| KeyPadNumlockClear
(*
on Mac, Clear replaces NumLock
*)
| KeyPadEquals
(*
on Mac keyboards only
*)
| KeyPadDivide
| KeyPadMultiply
| KeyPadMinus
| KeyPad7Home
| KeyPad8UpArrow
| KeyPad9PageUp
| KeyPadPlus
| KeyPad4LeftArrow
| KeyPad5
| KeyPad6RightArrow
| KeyPadComma
(*
specific to Brazilian keyboards
*)
| KeyPad1End
| KeyPad2DownArrow
| KeyPad3PageDown
| KeyPad0Insert
| KeyPadDecimalDelete
| KeyPadEnter
| KeyF13
| KeyF14
| KeyF15
| KeyF16
| KeyF17
| KeyF18
| KeyF19
| KeyF20
| KeyF21
| KeyF22
| KeyF23
| KeyF24
| KeyInternational1
(*
extra key left of RShift on JIS and Brazilian KB
*)
| KeyInternational2
(*
Katakana/Hiragana key right of Space on JIS KB
*)
| KeyInternational3
(*
extra key left of Backspace on JIS KB
*)
| KeyInternational4
(*
Henkan key right of Space on JIS KB
*)
| KeyInternational5
(*
Muhenkan key left of Space on JIS KB
*)
| KeyInternational6
(*
Kanma (comma) key right of KP0 on JIS KB
*)
| KeyInternational7
(*
Double-Byte/Single-Byte toggle key
*)
| KeyInternational8
(*
Undefined
*)
| KeyInternational9
(*
Undefined
*)
| KeyLang1
(*
Hangul/English toggle key (Korean)
*)
| KeyLang2
(*
Hanja conversion key (Korean)
*)
| KeyLang3
(*
Katakana key (Japanese)
*)
| KeyLang4
(*
Hiragana key (Japanese)
*)
| KeyLand5
(*
Zenkaku/Hankaku key (Japanese)
*)
| KeyHelp
| KeyMute
| KeyVolumeUp
| KeyVolumeDown
(*
A physical keyboard key, assuming an ideal "extended" QWERTY keyboard that synthetizes various layouts, including ANSI, ISO and JIS. Note that the symbol on the key may be different from the symbolic key name: this allows to refer to keys by their physical location, which can be useful for instance in games.
*)

type flags = {

flag_shift : bool;
flag_alt : bool;
flag_control : bool;
flag_meta : bool;
flag_capslock : bool;
flag_numlock : bool;
flag_dead : bool;

}

The state of various keyboard flags

type key_data = {

key : key;
(*
Physical key that was pressed/released
*)
char : Uchar.t;
(*
Equivalent Unicode character in the current layout
*)
flags : flags;
(*
State of various modifier keys when the event occured
*)

}

Describes a keyboard event

type button =

| ButtonNone
| ButtonLeft
| ButtonMiddle
| ButtonRight
| ButtonWheelUp
| ButtonWheelDown
(*
A mouse button
*)

type button_data = {

position : position;
(*
Cursor position when the event occured
*)
button : button;
(*
Button that was pressed/released
*)

}

Describes a mouse button event

val frame : unit canvas_event React.event

Occurs when the backend determines it is time to draw a new frame. A typical frequency is 60 times per second, though this varies depending on the platform.

val focus_in : unit canvas_event React.event

Occurs when the canvas becomes active as a result of being clicked or tabbed-into

val focus_out : unit canvas_event React.event

Occurs when the canvas becomes inactive as a result of another canvas being clicked or tabbed-into

val resize : size canvas_event React.event

Occurs when the canvas is resized by a user action

val move : position canvas_event React.event

Occurs when the canvas is moved by a user action

val close : unit canvas_event React.event

Occurs when the user clicks the close button

val key_down : key_data canvas_event React.event

Occurs when the user presses a key on the keyboard. The event description contains both the physical key (of type Event.key and the Unicode character corresponding to that key (if any), according to the current keyboard layout. For instance, pressing the "A" key on an AZERTY keyboard will yield a physical key Event.KeyQ and the Unicode code point for character "A".

val key_up : key_data canvas_event React.event

Occurs when the user releases a key on the keyboard

val button_down : button_data canvas_event React.event

Occurs when the user presses a mouse button

val button_up : button_data canvas_event React.event

Occurs when the user releases a mouse button

val mouse_move : size canvas_event React.event

Occurs when the user moves the mouse cursor

val event_timestamp : Int64.t React.signal

The timestamp of the last canvas event that occurred

val int_of_key : key -> int

int_of_key k returns a platform-independent integer representation of key k. This integer corresponds to the key code as defined by the USB standard for keybords.

see https://www.usb.org/sites/default/files/documents/hut1_12v2.pdf

val key_of_int : int -> key

key_of_int i returns the key corresponding to the platform-independent integer i in the range 0-255.

Exceptions:

Invalid_argument if i < 0 or i > 255

package ocaml-canvas