4 Helpers

▼ |  | Embedded GUI: Widgets Within Editors

1 | Containers
2 | Controls
3 | Control Snips
4 | Helpers
5 | Snip Functions

On this page:

stretchable-editor-snip-mixin
stretchable-editor-snip%
new
fixed-width-label-snip
tabbable-text<%>
set-caret-owner
set-ahead
set-back
tabbable-text-mixin
set-tabbing
grey-editor-snip-mixin
grey-editor-mixin
single-line-text-mixin
cue-text-mixin
cue-text%
new
clear-cue-text

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## 4 Helpers🔗ℹ

mixin stretchable-editor-snip-mixin : (class? . -> . class?)
argument extends/implements: | editor-snip%
result implements: | stretchable-snip<%>

Extends an editor snip the stretchable-snip<%> interface, which allows it to be stretched to fit an alignment-parent<%>’s allotted width. Stretchable snips are useful as the snip of a snip-wrapper%

class stretchable-editor-snip% : class?
superclass: editor-snip%
extends: | stretchable-editor-snip-mixin
| editor-snip%

> > > constructor
> > > (new stretchable-editor-snip% |
> > > | [ | [stretchable-width stretchable-width] |
> > > |  | [stretchable-height stretchable-height]]) |
> > → (is-a?/c stretchable-editor-snip%)
> > stretchable-width : boolean? = #t
> > stretchable-height : boolean? = #t

> Creates a stretchable snip with the given initial stretchability.

> procedure (fixed-width-label-snip possible-labels) → (subclass?/c snip%)
> possible-labels : (listof string?)

Returns a subclass of snip% that takes a single initialization argument. The argument provided when instantiating the class must be a member of possible-labels; the given label is displayed by the snip, but the snip is sized to match the longest of the labels in possible-labels.

In other words, the resulting class helps align multiple GUI elements t hat are labeled from a particular set of strings.

interface tabbable-text<%> : interface?

An interface for tabbing between embedded text%s.

> > method (send a-tabbable-text set-caret-owner) → void?

> Moves the caret into the tabbable-text<%>.

> > method (send a-tabbable-text set-ahead) → void?

> Called when tabbing ahead.

> > method (send a-tabbable-text set-back) → void?

> Called when tabbing backward.

mixin tabbable-text-mixin : (class? . -> . class?)
argument extends/implements: | editor:keymap<%>
result implements: | tabbable-text<%>

Adds the tabbable-text<%> interface to an editor:text% class, where instantiation installs key bindings to tab ahead and backward

> procedure (set-tabbing a-text ...) → void?
> a-text : (is-a?/c tabbable-text<%>)

Sets the tabbing order of tabbable-text<%>s by setting each text’s set-ahead and set-back thunks to point to its neighbor in the argument list.

mixin grey-editor-snip-mixin : (class? . -> . class?)
argument extends/implements: | editor-snip%

Gives an editor-snip% a colored background indicating that is disabled. The editor is not disabled by the mixin however, and must be locked separately.

mixin grey-editor-mixin : (class? . -> . class?)
argument extends/implements: | editor<%>

Gives an editor<%> a colored background indicating that is disabled. The editor is not disabled by the mixin however, and must be locked separately.

mixin single-line-text-mixin : (class? . -> . class?)
argument extends/implements: | editor:keymap<%>

Restricts a text to one line by overriding its key bindings to do nothing on enter.

mixin cue-text-mixin : (class? . -> . class?)
argument extends/implements: | text%

Gives a text% an instantiation argument of a string that is displayed in the text% initially in grey; the text disappears when the text gets focus. This technique is useful for labeling texts without needing to take up space.

class cue-text% : class?
superclass: (cue-text-mixin text%)

> > > constructor
> > > (new cue-text% |  |  |  |
> > > | [ | [cue-text cue-text] |  |  |  |
> > > |  | [color color] |  |  |  |
> > > |  | [behavior behavior]]) |  | → |  | (is-a?/c cue-text%)
> > cue-text : string? = ""
> > color : string? = "gray"
> > | behavior |  | : |  | (listof (one-of/c 'on-focus 'on-char))
> > |  |  | = |  | '(on-focus)

> Creates an instance with the given initial content, color, and behvior for when to clear the text.

> > method (send a-cue-text clear-cue-text) → void?

> Clears the cue text, if it’s still present.

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