► |  | GUI: Racket Graphics Toolkit

1 | Overview
2 | Reference
3 | Configuration
4 | Dynamic Loading
| Bibliography
| Index

► | 2 | Reference

2.1 | Windowing Classes
2.2 | Windowing Functions
2.3 | Drawing Classes
2.4 | Drawing Functions
2.5 | Editor Classes
2.6 | Editor Functions
2.7 | WXME Decoding

▼ | 2.1 | Windowing Classes

2.1.1 | area<%>
2.1.2 | area-container<%>
2.1.3 | area-container-window<%>
2.1.4 | button%
2.1.5 | canvas<%>
2.1.6 | canvas%
2.1.7 | check-box%
2.1.8 | checkable-menu-item%
2.1.9 | choice%
2.1.10 | clipboard-client%
2.1.11 | clipboard<%>
2.1.12 | combo-field%
2.1.13 | control<%>
2.1.14 | control-event%
2.1.15 | cursor%
2.1.16 | dialog%
2.1.17 | event%
2.1.18 | frame%
2.1.19 | gauge%
2.1.20 | group-box-panel%
2.1.21 | grow-box-spacer-pane%
2.1.22 | horizontal-pane%
2.1.23 | horizontal-panel%
2.1.24 | key-event%
2.1.25 | labelled-menu-item<%>
2.1.26 | list-box%
2.1.27 | list-control<%>
2.1.28 | menu%
2.1.29 | menu-bar%
2.1.30 | menu-item<%>
2.1.31 | menu-item%
2.1.32 | menu-item-container<%>
2.1.33 | message%
2.1.34 | mouse-event%
2.1.35 | pane%
2.1.36 | panel%
2.1.37 | popup-menu%
2.1.38 | radio-box%
2.1.39 | selectable-menu-item<%>
2.1.40 | separator-menu-item%
2.1.41 | scroll-event%
2.1.42 | slider%
2.1.43 | subarea<%>
2.1.44 | subwindow<%>
2.1.45 | tab-panel%
2.1.46 | text-field%
2.1.47 | timer%
2.1.48 | top-level-window<%>
2.1.49 | vertical-pane%
2.1.50 | vertical-panel%
2.1.51 | window<%>

On this page:

get-direction
get-event-type
get-position
set-direction
set-event-type
set-position

Inherited methods:
from event%
get-time-stamp
set-time-stamp

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scroll-event% : class?
superclass: event%

A scroll-event% object contains information about a scroll event. An instance of scroll-event% is always provided to on-scroll.

See get-event-type for a list of the scroll event types.

( new scroll-event% | [ | [event-type event-type] |
|  | [direction direction] |
|  | [position position] |
|  | [time-stamp time-stamp]]) |

→ ( is-a?/c scroll-event% )

event-type

:

( one-of/c 'top 'bottom 'line-up 'line-down
'page-up 'page-down 'thumb)

|  |  | = |  | 'thumb

direction : ( one-of/c 'horizontal 'vertical) = 'vertical
position : ( integer-in 0 10000) = 0
time-stamp : exact-integer? = 0

See the corresponding get- and set- methods for information about event-type, direction, position, and time-stamp.

( send a-scroll-event get-direction )
→ ( one-of/c 'horizontal 'vertical)

Gets the identity of the scrollbar that was modified by the event, either the horizontal scrollbar or the vertical scrollbar, as 'horizontal or 'vertical, respectively. See also set-direction.

( send a-scroll-event get-event-type )
→ ( one-of/c 'top 'bottom 'line-up 'line-down 'page-up 'page-down 'thumb)

Returns the type of the event, one of the following:

- 'top – user clicked a scroll-to-top button

- 'bottom – user clicked a scroll-to-bottom button

- 'line-up – user clicked an arrow to scroll up or left one step

- 'line-down – user clicked an arrow to scroll down or right one step

- 'page-up – user clicked an arrow to scroll up or left one page

- 'page-down – user clicked an arrow to scroll down or right one page

- 'thumb – user dragged the scroll position indicator

( send a-scroll-event get-position ) → ( integer-in 0 10000)

Returns the position of the scrollbar after the action triggering the event. See also set-position.

( send a-scroll-event set-direction direction) → void?
direction : ( one-of/c 'horizontal 'vertical)

Sets the identity of the scrollbar that was modified by the event, either the horizontal scrollbar or the vertical scrollbar, as 'horizontal or 'vertical, respectively. See also get-direction.

( send a-scroll-event set-event-type type) → void?

type

:

( one-of/c 'top 'bottom 'line-up 'line-down
'page-up 'page-down 'thumb)

Sets the type of the event. See get-event-type for information about each event type.

( send a-scroll-event set-position position) → void?
position : ( integer-in 0 10000)

Records the position of the scrollbar after the action triggering the event. (The scrollbar itself is unaffected). See also get-position.
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