3.34 message%

► |  | The Racket Graphical Interface Toolkit

1 | Windowing
2 | Widget Gallery
3 | Windowing Classes
4 | Windowing Functions
5 | Editors
6 | Snip and Style Classes
7 | Editor Classes
8 | Editor Functions
9 | WXME Decoding
10 | Preferences
11 | Dynamic Loading
12 | Startup Actions
13 | Init Libraries
14 | Platform Dependencies
| Index

▼ | 3 | Windowing Classes

3.1 | area<%>
3.2 | area-container<%>
3.3 | area-container-window<%>
3.4 | button%
3.5 | canvas<%>
3.6 | canvas%
3.7 | check-box%
3.8 | checkable-menu-item%
3.9 | choice%
3.10 | clipboard-client%
3.11 | clipboard<%>
3.12 | combo-field%
3.13 | control<%>
3.14 | column-control-event%
3.15 | control-event%
3.16 | cursor%
3.17 | dialog%
3.18 | event%
3.19 | frame%
3.20 | gauge%
3.21 | group-box-panel%
3.22 | grow-box-spacer-pane%
3.23 | horizontal-pane%
3.24 | horizontal-panel%
3.25 | key-event%
3.26 | labelled-menu-item<%>
3.27 | list-box%
3.28 | list-control<%>
3.29 | menu%
3.30 | menu-bar%
3.31 | menu-item<%>
3.32 | menu-item%
3.33 | menu-item-container<%>
3.34 | message%
3.35 | mouse-event%
3.36 | pane%
3.37 | panel%
3.38 | popup-menu%
3.39 | printer-dc%
3.40 | radio-box%
3.41 | selectable-menu-item<%>
3.42 | separator-menu-item%
3.43 | scroll-event%
3.44 | slider%
3.45 | subarea<%>
3.46 | subwindow<%>
3.47 | tab-panel%
3.48 | text-field%
3.49 | timer%
3.50 | top-level-window<%>
3.51 | vertical-pane%
3.52 | vertical-panel%
3.53 | window<%>

On this page:

new
auto-resize
set-label
set-color
get-color

Inherited methods:
from control<%>
command
from subwindow<%>
reparent
from window<%>
accept-drop-files
client->screen
enable
focus
get-client-handle
get-client-size
get-cursor
get-handle
get-height
get-label
get-plain-label
get-size
get-width
get-x
get-y
has-focus?
is-enabled?
is-shown?
on-drop-file
on-focus
on-move
on-size
on-subwindow-char
on-subwindow-event
on-subwindow-focus
on-superwindow-activate
on-superwindow-enable
on-superwindow-show
popup-menu
refresh
screen->client
set-cursor
show
warp-pointer
wheel-event-mode
from area<%>
get-graphical-min-size
get-parent
get-top-level-window
min-height
min-width
stretchable-height
stretchable-width
from subarea<%>
horiz-margin
vert-margin

Racket
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class message% : class?
superclass: object%
extends: | control<%>

A message control is a static line of text or a static bitmap. The text or bitmap corresponds to the message’s label (see set-label).

> > constructor
> > (new message% |
> > |  | [label label] |
> > |  | [parent parent] |
> > | [ | [style style] |
> > |  | [font font] |
> > |  | [color color] |
> > |  | [enabled enabled] |
> > |  | [vert-margin vert-margin] |
> > |  | [horiz-margin horiz-margin] |
> > |  | [min-width min-width] |
> > |  | [min-height min-height] |
> > |  | [stretchable-width stretchable-width] |
> > |  | [stretchable-height stretchable-height] |
> > |  | [auto-resize auto-resize]]) |
> → (is-a?/c message%)
> | label |  | : |  |
> (or/c label-string? (is-a?/c bitmap%)
> (or/c 'app 'caution 'stop))
> | parent |  | : |  |
> (or/c (is-a?/c frame%) (is-a?/c dialog%)
> (is-a?/c panel%) (is-a?/c pane%))
> style : (listof (or/c 'deleted)) = null
> font : (is-a?/c font%) = normal-control-font
> color : (or/c #f string? (is-a?/c color%)) = #f
> enabled : any/c = #t
> vert-margin : spacing-integer? = 2
> horiz-margin : spacing-integer? = 2
> min-width : (or/c dimension-integer? #f) = #f
> min-height : (or/c dimension-integer? #f) = #f
> stretchable-width : any/c = #f
> stretchable-height : any/c = #f
> auto-resize : any/c = #f

Creates a string or bitmap message initially showing label. If label is a bitmap, and if the bitmap has a mask (see get-loaded-mask in bitmap%) that is the same size as the bitmap, then the mask is used for the label. Modifying a bitmap while it is used as a label has an unspecified effect on the displayed label. An 'app, 'caution, or 'stop symbol for label indicates an icon; 'app is the application icon (Windows and Mac OS) or a generic “info” icon (X), 'caution is a caution-sign icon, and 'stop is a stop-sign icon.

If & occurs in label, it is specially parsed; under Windows and X, the character following & is underlined in the displayed control to indicate a keyboard mnemonic. (Under Mac OS, mnemonic underlines are not shown.) The mnemonic is meaningless for a message (as far as on-traverse-char in top-level-window<%> is concerned), but it is supported for consistency with other control types. A programmer may assign a meaning to the mnemonic (e.g., by overriding on-traverse-char).

If style includes 'deleted, then the message is created as hidden, and it does not affect its parent’s geometry; the message can be made active later by calling parent’s add-child method.

The font argument determines the font for the control. For information about the enabled argument, see window<%>. For information about the horiz-margin and vert-margin arguments, see subarea<%>. For information about the min-width, min-height, stretchable-width, and stretchable-height arguments, see area<%>.

The color argument determines the color of the text label. It has no effect on symbol and bitmap labels. If it is #f, the system default text color is used. If it is a string, then the color is looked up in the-color-database.

If auto-resize is not #f, then automatic resizing is initially enabled (see auto-resize), and the message% object’s graphical minimum size is as small as possible.

Changed in version 1.58 of package gui-lib: Added the color argument.

> method (send a-message auto-resize) → boolean?
> (send a-message auto-resize on?) → void?
> on? : any/c

Reports or sets whether the message%’s min-width and min-height are automatically set when the label is changed via set-label.

> method (send a-message set-label label) → void?
> label : (or/c label-string? (is-a?/c bitmap%))

Overrides set-label in window<%>.
The same as set-label in window<%> when label is a string.

Otherwise, sets the bitmap label for a bitmap message. Since label is a bitmap, if the bitmap has a mask (see get-loaded-mask in bitmap%) that is the same size as the bitmap, then the mask is used for the label. Modifying a bitmap while it is used as a label has an unspecified effect on the displayed label. The bitmap label is installed only if the control was originally created with a bitmap label.

> method (send a-message set-color color) → void?
> color : (or/c #f (is-a?/c color%))
> (send a-message set-color color-name) → void?
> color-name : string?

Sets the label’s text color. When color is #f, sets the label’s text color to the platform default. This method has no effect if the label is a symbol or a bitmap.

Added in version 1.58 of package gui-lib.
Changed in version 1.71: Added support for setting the color to the system default.

> method (send a-message get-color) → (or/c #f (is-a?/c color%))

Returns the current user-specified label color or #f if the system default is used.

Added in version 1.58 of package gui-lib.

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