GLUT-2.4.0.0: A binding for the OpenGL Utility Toolkit

Portability | portable
Stability | stable
Maintainer | sven.panne@aedion.de
Safe Haskell | None

Graphics.UI.GLUT.Callbacks.Window

Contents

- Redisplay callbacks
- Reshape callback
- Callbacks for visibility changes
- Window close callback
- Keyboard callback
- Special callback
- Mouse callback
- Keyboard and mouse input callback
- Mouse wheel callback
- Mouse movement callbacks
- Spaceball callback
- Dial & button box callback
- Tablet callback
- Joystick callback

Description

Synopsis

- type DisplayCallback = IO ()
- displayCallback :: SettableStateVar DisplayCallback
- overlayDisplayCallback :: SettableStateVar (Maybe DisplayCallback)
- type ReshapeCallback = Size -> IO ()
- reshapeCallback :: SettableStateVar (Maybe ReshapeCallback)
- data Visibility
  - = NotVisible
  - | Visible
- type VisibilityCallback = Visibility -> IO ()
- visibilityCallback :: SettableStateVar (Maybe VisibilityCallback)
- data WindowState
  - = Unmapped
  - | FullyRetained
  - | PartiallyRetained
  - | FullyCovered
- type WindowStateCallback = WindowState -> IO ()
- windowStateCallback :: SettableStateVar (Maybe WindowStateCallback)
- type CloseCallback = IO ()
- closeCallback :: SettableStateVar (Maybe CloseCallback)
- type KeyboardCallback = Char -> Position -> IO ()
- keyboardCallback :: SettableStateVar (Maybe KeyboardCallback)
- keyboardUpCallback :: SettableStateVar (Maybe KeyboardCallback)
- type SpecialCallback = SpecialKey -> Position -> IO ()
- specialCallback :: SettableStateVar (Maybe SpecialCallback)
- specialUpCallback :: SettableStateVar (Maybe SpecialCallback)
- type MouseCallback = MouseButton -> KeyState -> Position -> IO ()
- mouseCallback :: SettableStateVar (Maybe MouseCallback)
- data Key
  - = Char Char
  - | SpecialKey SpecialKey
  - | MouseButton MouseButton
- data SpecialKey
  - = KeyF1
  - | KeyF2
  - | KeyF3
  - | KeyF4
  - | KeyF5
  - | KeyF6
  - | KeyF7
  - | KeyF8
  - | KeyF9
  - | KeyF10
  - | KeyF11
  - | KeyF12
  - | KeyLeft
  - | KeyUp
  - | KeyRight
  - | KeyDown
  - | KeyPageUp
  - | KeyPageDown
  - | KeyHome
  - | KeyEnd
  - | KeyInsert
  - | KeyNumLock
  - | KeyBegin
  - | KeyDelete
  - | KeyUnknown Int
- data MouseButton
  - = LeftButton
  - | MiddleButton
  - | RightButton
  - | WheelUp
  - | WheelDown
  - | AdditionalButton Int
- data KeyState
  - = Down
  - | Up
- data Modifiers = Modifiers {
  - shift :: KeyState
  - ctrl :: KeyState
  - alt :: KeyState
  }
- type KeyboardMouseCallback = Key -> KeyState -> Modifiers -> Position -> IO ()
- keyboardMouseCallback :: SettableStateVar (Maybe KeyboardMouseCallback)
- type WheelNumber = Int
- type WheelDirection = Int
- type MouseWheelCallback = WheelNumber -> WheelDirection -> Position -> IO ()
- mouseWheelCallback :: SettableStateVar (Maybe MouseWheelCallback)
- type MotionCallback = Position -> IO ()
- motionCallback :: SettableStateVar (Maybe MotionCallback)
- passiveMotionCallback :: SettableStateVar (Maybe MotionCallback)
- data Crossing
  - = WindowLeft
  - | WindowEntered
- type CrossingCallback = Crossing -> IO ()
- crossingCallback :: SettableStateVar (Maybe CrossingCallback)
- type SpaceballMotion = Int
- type SpaceballRotation = Int
- type ButtonIndex = Int
- data SpaceballInput
  - = SpaceballMotion SpaceballMotion SpaceballMotion SpaceballMotion
  - | SpaceballRotation SpaceballRotation SpaceballRotation SpaceballRotation
  - | SpaceballButton ButtonIndex KeyState
- type SpaceballCallback = SpaceballInput -> IO ()
- spaceballCallback :: SettableStateVar (Maybe SpaceballCallback)
- data DialAndButtonBoxInput
  - = DialAndButtonBoxButton ButtonIndex KeyState
  - | DialAndButtonBoxDial DialIndex Int
- type DialIndex = Int
- type DialAndButtonBoxCallback = DialAndButtonBoxInput -> IO ()
- dialAndButtonBoxCallback :: SettableStateVar (Maybe DialAndButtonBoxCallback)
- data TabletPosition = TabletPosition Int Int
- data TabletInput
  - = TabletMotion
  - | TabletButton ButtonIndex KeyState
- type TabletCallback = TabletInput -> TabletPosition -> IO ()
- tabletCallback :: SettableStateVar (Maybe TabletCallback)
- data JoystickButtons = JoystickButtons {
  - joystickButtonA :: KeyState
  - joystickButtonB :: KeyState
  - joystickButtonC :: KeyState
  - joystickButtonD :: KeyState
  }
- data JoystickPosition = JoystickPosition Int Int Int
- type JoystickCallback = JoystickButtons -> JoystickPosition -> IO ()
- joystickCallback :: SettableStateVar (Maybe (JoystickCallback, PollRate))

# Redisplay callbacks

type DisplayCallback = IO ()

A display callback

displayCallback :: SettableStateVar DisplayCallback

Controls the display callback for the current window. When GLUT determines that the normal plane for the window needs to be redisplayed, the display callback for the window is called. Before the callback, the current window is set to the window needing to be redisplayed and (if no overlay display callback is registered) the layer in use is set to the normal plane. The entire normal plane region should be redisplayed in response to the callback (this includes ancillary buffers if your program depends on their state).

GLUT determines when the display callback should be triggered based on the window's redisplay state. The redisplay state for a window can be either set explicitly by calling `postRedisplay` or implicitly as the result of window damage reported by the window system. Multiple posted redisplays for a window are coalesced by GLUT to minimize the number of display callbacks called.

When an overlay is established for a window, but there is no overlay display callback registered, the display callback is used for redisplaying both the overlay and normal plane (that is, it will be called if either the redisplay state or overlay redisplay state is set). In this case, the layer in use is not implicitly changed on entry to the display callback.

See `overlayDisplayCallback` to understand how distinct callbacks for the overlay and normal plane of a window may be established.

When a window is created, no display callback exists for the window. It is the responsibility of the programmer to install a display callback for the window before the window is shown. A display callback must be registered for any window that is shown. If a window becomes displayed without a display callback being registered, a fatal error occurs. There is no way to "deregister" a display callback (though another callback routine can always be registered).

Upon return from the display callback, the normal damaged state of the window (see `damaged`) is cleared. If there is no overlay display callback registered the overlay damaged state of the window (see `damaged`) is also cleared.

overlayDisplayCallback :: SettableStateVar (Maybe DisplayCallback)

Controls the overlay display callback for the current window. The overlay display callback is functionally the same as the window's display callback except that the overlay display callback is used to redisplay the window's overlay.

When GLUT determines that the overlay plane for the window needs to be redisplayed, the overlay display callback for the window is called. Before the callback, the current window is set to the window needing to be redisplayed and the layer in use is set to the overlay. The entire overlay region should be redisplayed in response to the callback (this includes ancillary buffers if your program depends on their state).

GLUT determines when the overlay display callback should be triggered based on the window's overlay redisplay state. The overlay redisplay state for a window can be either set explicitly by calling `postOverlayRedisplay` or implicitly as the result of window damage reported by the window system. Multiple posted overlay redisplays for a window are coalesced by GLUT to minimize the number of overlay display callbacks called.

Upon return from the overlay display callback, the overlay damaged state of the window (see `damaged`) is cleared.

Initially there is no overlay display callback registered when an overlay is established. See `displayCallback` to understand how the display callback alone is used if an overlay display callback is not registered.

# Reshape callback

type ReshapeCallback = Size -> IO ()

A reshape callback

reshapeCallback :: SettableStateVar (Maybe ReshapeCallback)

Controls the reshape callback for the current window. The reshape callback is triggered when a window is reshaped. A reshape callback is also triggered immediately before a window's first display callback after a window is created or whenever an overlay for the window is established. The parameter of the callback specifies the new window size in pixels. Before the callback, the current window is set to the window that has been reshaped.

If a reshape callback is not registered for a window or `reshapeCallback` is set to `Nothing` (to deregister a previously registered callback), the default reshape callback is used. This default callback will simply call

     viewport (Position 0 0) (Size width height)

on the normal plane (and on the overlay if one exists).

If an overlay is established for the window, a single reshape callback is generated. It is the callback's responsibility to update both the normal plane and overlay for the window (changing the layer in use as necessary).

When a top-level window is reshaped, subwindows are not reshaped. It is up to the GLUT program to manage the size and positions of subwindows within a top-level window. Still, reshape callbacks will be triggered for subwindows when their size is changed using `windowSize`.

# Callbacks for visibility changes

data Visibility

The visibility state of the current window

Constructors

NotVisible | No part of the current window is visible, i.e., until the window's visibility changes, all further rendering to the window is discarded.
Visible | The current window is totally or partially visible. GLUT considers a window visible if any pixel of the window is visible or any pixel of any descendant window is visible on the screen.

Instances

Eq Visibility |
Ord Visibility |
Show Visibility |

type VisibilityCallback = Visibility -> IO ()

A visibility callback

visibilityCallback :: SettableStateVar (Maybe VisibilityCallback)

Controls the visibility callback for the current window. The visibility callback for a window is called when the visibility of a window changes.

If the visibility callback for a window is disabled and later re-enabled, the visibility status of the window is undefined; any change in window visibility will be reported, that is if you disable a visibility callback and re-enable the callback, you are guaranteed the next visibility change will be reported.

Note that you can either use `visibilityCallback` or `windowStateCallback`, but not both, because the former is implemented via the latter.

data WindowState

The window state of the current window

Constructors

Unmapped | The current window is unmapped.
FullyRetained | The current window is unobscured.
PartiallyRetained | The current window is partially obscured.
FullyCovered | The current window is fully obscured.

Instances

Eq WindowState |
Ord WindowState |
Show WindowState |

type WindowStateCallback = WindowState -> IO ()

A window state callback

windowStateCallback :: SettableStateVar (Maybe WindowStateCallback)

Controls the window state callback for the current window. The window state callback for a window is called when the window state of a window changes.

If the window state callback for a window is disabled and later re-enabled, the window state state of the window is undefined; any change in the window state will be reported, that is if you disable a window state callback and re-enable the callback, you are guaranteed the next window state change will be reported.

Note that you can either use `visibilityCallback` or `windowStateCallback`, but not both, because the former is implemented via the latter.

# Window close callback

type CloseCallback = IO ()

closeCallback :: SettableStateVar (Maybe CloseCallback)

# Keyboard callback

type KeyboardCallback = Char -> Position -> IO ()

A keyboard callback

keyboardCallback :: SettableStateVar (Maybe KeyboardCallback)

Controls the keyboard callback for the current window. This is activated only when a key is pressed.

keyboardUpCallback :: SettableStateVar (Maybe KeyboardCallback)

Controls the keyboard callback for the current window. This is activated only when a key is released.

# Special callback

type SpecialCallback = SpecialKey -> Position -> IO ()

A special key callback

specialCallback :: SettableStateVar (Maybe SpecialCallback)

Controls the special key callback for the current window. This is activated only when a special key is pressed.

specialUpCallback :: SettableStateVar (Maybe SpecialCallback)

Controls the special key callback for the current window. This is activated only when a special key is released.

# Mouse callback

type MouseCallback = MouseButton -> KeyState -> Position -> IO ()

A mouse callback

mouseCallback :: SettableStateVar (Maybe MouseCallback)

Controls the mouse callback for the current window.

# Keyboard and mouse input callback

data Key

A generalized view of keys

Constructors

Char Char |
SpecialKey SpecialKey |
MouseButton MouseButton |

Instances

Eq Key |
Ord Key |
Show Key |

data SpecialKey

Special keys

Constructors

KeyF1 |
KeyF2 |
KeyF3 |
KeyF4 |
KeyF5 |
KeyF6 |
KeyF7 |
KeyF8 |
KeyF9 |
KeyF10 |
KeyF11 |
KeyF12 |
KeyLeft |
KeyUp |
KeyRight |
KeyDown |
KeyPageUp |
KeyPageDown |
KeyHome |
KeyEnd |
KeyInsert |
KeyNumLock |
KeyBegin |
KeyDelete |
KeyUnknown Int |

Instances

Eq SpecialKey |
Ord SpecialKey |
Show SpecialKey |

data MouseButton

Mouse buttons, including a wheel

Constructors

LeftButton |
MiddleButton |
RightButton |
WheelUp |
WheelDown |
AdditionalButton Int |

Instances

Eq MouseButton |
Ord MouseButton |
Show MouseButton |

data KeyState

The current state of a key or button

Constructors

Down |
Up |

Instances

Eq KeyState |
Ord KeyState |
Show KeyState |

data Modifiers

The state of the keyboard modifiers

Constructors

Modifiers |

Fields

shift :: KeyState
ctrl :: KeyState
alt :: KeyState

Instances

Eq Modifiers |
Ord Modifiers |
Show Modifiers |

type KeyboardMouseCallback = Key -> KeyState -> Modifiers -> Position -> IO ()

A keyboard/mouse callback

keyboardMouseCallback :: SettableStateVar (Maybe KeyboardMouseCallback)

Controls the keyboard/mouse callback for the current window. The keyboard/mouse callback for a window is called when the state of a key or mouse button changes. The callback parameters indicate the new state of the key/button, the state of the keyboard modifiers, and the mouse location in window relative coordinates.

Note that this is a convenience function that should not ordinarily be used in conjunction with `keyboardCallback`, `keyboardUpCallback`, `specialCallback`, `specialUpCallback`, or `mouseCallback`.

# Mouse wheel callback

type WheelNumber = Int

type WheelDirection = Int

type MouseWheelCallback = WheelNumber -> WheelDirection -> Position -> IO ()

mouseWheelCallback :: SettableStateVar (Maybe MouseWheelCallback)

(freeglut only) Controls the mouse wheel callback for the current window. The mouse wheel callback for a window is called when a mouse wheel is used and the wheel number is greater than or equal to `numMouseButtons`.

# Mouse movement callbacks

type MotionCallback = Position -> IO ()

A motion callback

motionCallback :: SettableStateVar (Maybe MotionCallback)

Controls the motion callback for the current window. The motion callback for a window is called when the mouse moves within the window while one or more mouse buttons are pressed. The callback parameter indicates the mouse location in window relative coordinates.

passiveMotionCallback :: SettableStateVar (Maybe MotionCallback)

Controls the passive motion callback for the current window. The passive motion callback for a window is called when the mouse moves within the window while no mouse buttons are pressed. The callback parameter indicates the mouse location in window relative coordinates.

data Crossing

The relation between the mouse pointer and the current window has changed.

Constructors

WindowLeft | The mouse pointer has left the current window.
WindowEntered | The mouse pointer has entered the current window.

Instances

Eq Crossing |
Ord Crossing |
Show Crossing |

type CrossingCallback = Crossing -> IO ()

An enter/leave callback

crossingCallback :: SettableStateVar (Maybe CrossingCallback)

Controls the mouse enter/leave callback for the current window. Note that some window systems may not generate accurate enter/leave callbacks.

X Implementation Notes: An X implementation of GLUT should generate accurate enter/leave callbacks.

# Spaceball callback

type SpaceballMotion = Int

Translation of the Spaceball along one axis, normalized to be in the range of -1000 to +1000 inclusive

type SpaceballRotation = Int

Rotation of the Spaceball along one axis, normalized to be in the range of -1800 .. +1800 inclusive

type ButtonIndex = Int

The index of a specific buttons of an input device.

data SpaceballInput

The state of the Spaceball has changed.

Constructors

SpaceballMotion SpaceballMotion SpaceballMotion SpaceballMotion |
SpaceballRotation SpaceballRotation SpaceballRotation SpaceballRotation |
SpaceballButton ButtonIndex KeyState |

Instances

Eq SpaceballInput |
Ord SpaceballInput |
Show SpaceballInput |

type SpaceballCallback = SpaceballInput -> IO ()

A SpaceballButton callback

spaceballCallback :: SettableStateVar (Maybe SpaceballCallback)

Controls the Spaceball callback for the current window. The Spaceball callback for a window is called when the window has Spaceball input focus (normally, when the mouse is in the window) and the user generates Spaceball translations, rotations, or button presses. The number of available Spaceball buttons can be determined with `numSpaceballButtons`.

Registering a Spaceball callback when a Spaceball device is not available has no effect and is not an error. In this case, no Spaceball callbacks will be generated.

# Dial & button box callback

data DialAndButtonBoxInput

The dial & button box state has changed.

Constructors

DialAndButtonBoxButton ButtonIndex KeyState |
DialAndButtonBoxDial DialIndex Int |

Instances

Eq DialAndButtonBoxInput |
Ord DialAndButtonBoxInput |
Show DialAndButtonBoxInput |

type DialIndex = Int

The index of a specific dial of a dial and button box.

type DialAndButtonBoxCallback = DialAndButtonBoxInput -> IO ()

A dial & button box callback

dialAndButtonBoxCallback :: SettableStateVar (Maybe DialAndButtonBoxCallback)

Controls the dial & button box callback for the current window. The dial & button box button callback for a window is called when the window has dial & button box input focus (normally, when the mouse is in the window) and the user generates dial & button box button presses or dial changes. The number of available dial & button box buttons and dials can be determined with `numDialsAndButtons`.

Registering a dial & button box callback when a dial & button box device is not available is ineffectual and not an error. In this case, no dial & button box button will be generated.

# Tablet callback

data TabletPosition

Absolute tablet position, with coordinates normalized to be in the range of 0 to 2000 inclusive

Constructors

TabletPosition Int Int |

Instances

Eq TabletPosition |
Ord TabletPosition |
Show TabletPosition |

data TabletInput

The table state has changed.

Constructors

TabletMotion |
TabletButton ButtonIndex KeyState |

Instances

Eq TabletInput |
Ord TabletInput |
Show TabletInput |

type TabletCallback = TabletInput -> TabletPosition -> IO ()

A tablet callback

tabletCallback :: SettableStateVar (Maybe TabletCallback)

Controls the tablet callback for the current window. The tablet callback for a window is called when the window has tablet input focus (normally, when the mouse is in the window) and the user generates tablet motion or button presses. The number of available tablet buttons can be determined with `numTabletButtons`.

Registering a tablet callback when a tablet device is not available is ineffectual and not an error. In this case, no tablet callbacks will be generated.

# Joystick callback

data JoystickButtons

The state of the joystick buttons

Constructors

JoystickButtons |

Fields

joystickButtonA :: KeyState
joystickButtonB :: KeyState
joystickButtonC :: KeyState
joystickButtonD :: KeyState

Instances

Eq JoystickButtons |
Ord JoystickButtons |
Show JoystickButtons |

data JoystickPosition

Absolute joystick position, with coordinates normalized to be in the range of -1000 to 1000 inclusive. The signs of the three axes mean the following:

- negative = left, positive = right
- negative = towards player, positive = away
- if available (e.g. rudder): negative = down, positive = up

Constructors

JoystickPosition Int Int Int |

Instances

Eq JoystickPosition |
Ord JoystickPosition |
Show JoystickPosition |

type JoystickCallback = JoystickButtons -> JoystickPosition -> IO ()

A joystick callback

joystickCallback :: SettableStateVar (Maybe (JoystickCallback, PollRate))

Controls the joystick callback for the current window. The joystick callback is called either due to polling of the joystick at the uniform timer interval specified (if > 0) or in response to an explicit call of `forceJoystickCallback`.

X Implementation Notes: Currently GLUT has no joystick support for X11.