42.4 Slideshow Presentations

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42 | GUI libraries

▼ | 42 | GUI libraries

42.1 | Dr Racket Language Levels
42.2 | Notify-boxes
42.3 | Preferences
42.4 | Slideshow Presentations
42.5 | GUI Widgets

► | 42.4 | Slideshow Presentations

42.4.1 | Text Formatting
42.4.2 | Pict Colors
42.4.3 | Pict Manipulation
42.4.4 | Staged Slides
42.4.5 | Tables
42.4.6 | Multiple Columns

On this page:

42.4.1`` Text Formatting
with-size
with-scale
big
small
with-font
with-style
bold
italic
subscript
superscript
caps
42.4.2`` Pict Colors
color
red
orange
yellow
green
blue
purple
black
brown
gray
white
cyan
magenta
light
dark
color/ c
42.4.3`` Pict Manipulation
fill
42.4.3.1`` Conditional Manipulations
show
hide
strike
shade
42.4.3.2`` Conditional Combinations
pict-if
pict-cond
pict-case
pict-match
pict-combine
with-pict-combine
42.4.4`` Staged Slides
staged
stage
stage-name
slide/ staged
42.4.5`` Tables
tabular
42.4.6`` Multiple Columns
two-columns
mini-slide
columns
column
column-size
ellipse/ border
circle/ border
rectangle/ border
rounded-rectangle/ border
blank-line
pin-label-line
pin-arrow-label-line
pin-arrows-label-line

Version: 5.0.1.5
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#### 42.4`` Slideshow Presentations

( require unstable/gui/slideshow)

##### 42.4.1`` Text Formatting

( with-size size expr)

Sets current-font-size to size while running expr.

( with-scale scale expr)

Multiplies current-font-size by scale while running expr.

( big text)

( small text)

Scale current-font-size by 3/2 or 2/3, respectively, while running text.

( with-font font expr)

Sets current-main-font to font while running expr.

( with-style style expr)

Adds style to current-main-font (via cons) while running expr.

( bold text)

( italic text)

( subscript text)

( superscript text)

( caps text)

Adds the attributes for bold, italic, superscript, subscript, or small caps text, respectively, to current-main-font while running text.

##### 42.4.2`` Pict Colors

( color c p) → pict?
c : color/c
p : pict?

Applies color c to picture p. Equivalent to ( colorize p c).

( red pict) → pict?
pict : pict?

( orange pict) → pict?
pict : pict?

( yellow pict) → pict?
pict : pict?

( green pict) → pict?
pict : pict?

( blue pict) → pict?
pict : pict?

( purple pict) → pict?
pict : pict?

( black pict) → pict?
pict : pict?

( brown pict) → pict?
pict : pict?

( gray pict) → pict?
pict : pict?

( white pict) → pict?
pict : pict?

( cyan pict) → pict?
pict : pict?

( magenta pict) → pict?
pict : pict?

These functions apply appropriate colors to picture p.

( light color) → color/c
color : color/c

( dark color) → color/c
color : color/c

These functions produce ligher or darker versions of a color.

color/c : flat-contract?

This contract recognizes color strings, color% instances, and RGB color lists.

##### 42.4.3`` Pict Manipulation

( fill pict width height) → pict?
pict : pict?
width : ( or/c real? #f)
height : ( or/c real? #f)

Extends pict’s bounding box to a minimum width and/or height, placing the original picture in the middle of the space.

##### 42.4.3.1`` Conditional Manipulations

These pict transformers all take boolean arguments that determine whether to transform the pict or leave it unchanged. These transformations can be useful for staged slides, as the resulting pict always has the same size and shape, and its contents always appear at the same position, but changing the boolean argument between slides can control when the transformation occurs.

( show pict [show?]) → pict?
pict : pict?
show? : truth/c = #t

( hide pict [hide?]) → pict?
pict : pict?
hide? : truth/c = #t

These functions conditionally show or hide an image, essentially choosing between pict and ( ghost pict). The only difference between the two is the default behavior and the opposite meaning of the show? and hide? booleans. Both functions are provided for mnemonic purposes.

( strike pict [strike?]) → pict?
pict : pict?
strike? : truth/c = #t

Displays a strikethrough image by putting a line through the middle of pict if strike? is true; produces pict unchanged otherwise.

( shade pict [shade? #:ratio ratio]) → pict?
pict : pict?
shade? : truth/c = #t
ratio : ( real-in 0 1) = 1/2

Shades pict to show with ratio of its normal opacity; if ratio is 1 or shade? is #f, shows pict unchanged.

##### 42.4.3.2`` Conditional Combinations

These pict control flow operators decide which pict of several to use. All branches are evaluated; the resulting pict is a combination of the pict chosen by normal conditional flow with ghost applied to all the other picts. The result is a picture large enough to accomodate each alternative, but showing only the chosen one. This is useful for staged slides, as the pict chosen may change with each slide but its size and position will not.

( pict-if maybe-combine test-expr then-expr else-expr)

maybe-combine

=

|  | | |  | #:combine combine-expr

Chooses either then-expr or else-expr based on test-expr, similarly to if. Combines the chosen, visible image with the other, invisible image using combine-expr, defaulting to pict-combine.

( pict-cond maybe-combine [test-expr pict-expr] ...)

maybe-combine

=

|  | | |  | #:combine combine-expr

Chooses a pict-expr based on the first successful test-expr, similarly to cond. Combines the chosen, visible image with the other, invisible images using combine-expr, defaulting to pict-combine.

( pict-case test-expr maybe-combine [literals pict-expr] ...)

maybe-combine

=

|  | | |  | #:combine combine-expr

Chooses a pict-expr based on test-expr and each list of literals, similarly to case. Combines the chosen, visible image with the other, invisible images using combine-expr, defaulting to pict-combine.

( pict-match test-expr maybe-combine [pattern pict-expr] ...)

maybe-combine

=

|  | | |  | #:combine combine-expr

Chooses a pict-expr based on test-expr and each pattern, similarly to match. Combines the chosen, visible image with the other, invisible images using combine-expr, defaulting to pict-combine.

pict-combine

This syntax parameter determines the default pict combining form used by the above macros. It defaults to lbl-superimpose.

( with-pict-combine combine-id body ...)

Sets pict-combine to refer to combine-id within each of the body terms, which are spliced into the containing context.

##### 42.4.4`` Staged Slides

( staged [name ...] body ...)

Executes the body terms once for each stage name. The terms may include expressions and mutually recursive definitions. Within the body, each name is bound to a number from 1 to the number of stages in order. Furthermore, during execution stage is bound to the number of the current stage and stage-name is bound to a symbol representing the name of the current stage. By comparing stage to the numeric value of each name, or stage-name to quoted symbols of the form 'name, the user may compute based on the progression of the stages.

stage

stage-name

These keywords are bound during the execution of staged and should not be used otherwise.

( slide/staged [name ...] arg ...)

Creates a staged slide. Equivalent to ( staged [name ...] ( slide arg ...)).

Within a staged slide, the boolean arguments to hide, show, strike, and shade can be used to determine in which stages to perform a transformation. The macros pict-if, pict-cond, pict-case, and pict-match may also be used to create images which change naturally between stages.

##### 42.4.5`` Tables

( tabular |  | row |  |  |  |
|  | ... |  |  |  |
| [ | #:gap gap |  |  |  |
|  | #:hgap hgap |  |  |  |
|  | #:vgap vgap |  |  |  |
|  | #:align align |  |  |  |
|  | #:halign halign |  |  |  |
|  | #:valign valign]) |  | → |  | pict?

row : ( listof ( or/c string? pict?))
gap : natural-number/c = gap-size
hgap : natural-number/c = gap
vgap : natural-number/c = gap

| align |  | : |  | (->* [] [] #:rest ( listof pict?) pict?)
|  |  | = |  | lbl-superimpose

halign : (->* [] [] #:rest ( listof pict?) pict?) = align
valign : (->* [] [] #:rest ( listof pict?) pict?) = align

Constructs a table containing the given rows, all of which must be of the same length. Applies t to each string in a row to construct a pict. The hgap, vgap, halign, and valign are used to determine the horizontal and vertical gaps and alignments as in table (except that every row and column is uniform).

##### 42.4.6`` Multiple Columns

( two-columns one two)

Constructs a two-column pict using one and two as the two columns. Sets current-para-width appropriately in each column.

( mini-slide pict ...) → pict?
pict : pict?

Appends each pict vertically with space between them, similarly to the slide function.

( columns pict ...) → pict?
pict : pict?

Combines each pict horizontally, aligned at the top, with space in between.

( column width body ...)

Sets current-para-width to width during execution of the body expressions.

( column-size n [r]) → real?
n : exact-positive-integer?
r : real? = (/ n)

Computes the width of one column out of n that takes up a ratio of r of the available space (according to current-para-width).

> > > The subsequent bindings were added by Vincent St-Amour.

( ellipse/border |  | w |  |  |  |
|  | h |  |  |  |
|  | #:color color |  |  |  |
|  | #:border-color border-color |  |  |  |
|  | #:border-width border-width) |  | → |  | pict?

w : real?
h : real?
color : color/c
border-color : color/c
border-width : real?

( circle/border |  | diameter |  |  |  |
|  | #:color color |  |  |  |
|  | #:border-color border-color |  |  |  |
|  | #:border-width border-width) |  | → |  | pict?

diameter : real?
color : color/c
border-color : color/c
border-width : real?

( rectangle/border |  | w |  |  |  |
|  | h |  |  |  |
|  | #:color color |  |  |  |
|  | #:border-color border-color |  |  |  |
|  | #:border-width border-width) |  | → |  | pict?

w : real?
h : real?
color : color/c
border-color : color/c
border-width : real?

( rounded-rectangle/border |  | w |  |  |  |
|  | h |  |  |  |
|  | #:color color |  |  |  |
|  | #:border-color border-color |  |  |  |
|  | #:border-width border-width) |  | → |  | pict?

w : real?
h : real?
color : color/c
border-color : color/c
border-width : real?

These functions create shapes with border of the given color and width.

> > > The subsequent bindings were added by Scott Owens.

( blank-line) → pict?

Adds a blank line of the current font size’s height.

( pin-label-line |  | label |  |  |  |
|  | pict |  |  |  |
|  | src-pict |  |  |  |
|  | src-coord-fn |  |  |  |
|  | dest-pict |  |  |  |
|  | dest-coord-fn |  |  |  |
|  | #:start-angle start-angle |  |  |  |
|  | #:end-angle end-angle |  |  |  |
|  | #:start-pull start-pull |  |  |  |
|  | #:end-pull end-pull |  |  |  |
|  | #:line-width line-width |  |  |  |
|  | #:color color |  |  |  |
|  | #:under? under? |  |  |  |
|  | #:x-adjust x-adjust |  |  |  |
|  | #:y-adjust y-adjust) |  | → |  | pict?

label : pict?
pict : pict?
src-pict : pict-path?
src-coord-fn : (-> pict-path? ( values real? real?))
dest-pict : pict-path?
dest-coord-fn : (-> pict-path? ( values real? real?))
start-angle : ( or/c real? #f)
end-angle : ( or/c real? #f)
start-pull : real?
end-pull : real?
line-width : ( or/c real? #f)
color : ( or/c #f string? ( is-a?/c color%))
under? : any/c
x-adjust : real?
y-adjust : real?

( pin-arrow-label-line |  | label |
|  | arrow-size |
|  | pict |
|  | src-pict |
|  | src-coord-fn |
|  | dest-pict |
|  | dest-coord-fn |
|  | #:start-angle start-angle |
|  | #:end-angle end-angle |
|  | #:start-pull start-pull |
|  | #:end-pull end-pull |
|  | #:line-width line-width |
|  | #:color color |
|  | #:under? under? |
|  | #:hide-arrowhead? hide-arrowhead? |
|  | #:x-adjust x-adjust |
|  | #:y-adjust y-adjust) |

→ pict?
label : pict?
arrow-size : real?
pict : pict?
src-pict : pict-path?
src-coord-fn : (-> pict-path? ( values real? real?))
dest-pict : pict-path?
dest-coord-fn : (-> pict-path? ( values real? real?))
start-angle : ( or/c real? #f)
end-angle : ( or/c real? #f)
start-pull : real?
end-pull : real?
line-width : ( or/c real? #f)
color : ( or/c #f string? ( is-a?/c color%))
under? : any/c
hide-arrowhead? : any/c
x-adjust : real?
y-adjust : real?

( pin-arrows-label-line |  | label |
|  | arrow-size |
|  | pict |
|  | src-pict |
|  | src-coord-fn |
|  | dest-pict |
|  | dest-coord-fn |
|  | #:start-angle start-angle |
|  | #:end-angle end-angle |
|  | #:start-pull start-pull |
|  | #:end-pull end-pull |
|  | #:line-width line-width |
|  | #:color color |
|  | #:under? under? |
|  | #:hide-arrowhead? hide-arrowhead? |
|  | #:x-adjust x-adjust |
|  | #:y-adjust y-adjust) |

→ pict?
label : pict?
arrow-size : real?
pict : pict?
src-pict : pict-path?
src-coord-fn : (-> pict-path? ( values real? real?))
dest-pict : pict-path?
dest-coord-fn : (-> pict-path? ( values real? real?))
start-angle : ( or/c real? #f)
end-angle : ( or/c real? #f)
start-pull : real?
end-pull : real?
line-width : ( or/c real? #f)
color : ( or/c #f string? ( is-a?/c color%))
under? : any/c
hide-arrowhead? : any/c
x-adjust : real?
y-adjust : real?

These functions behave like pin-line, pin-arrow-line and pin-arrows-line with the addition of a label attached to the line.
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