2 Creating Slides🔗ℹ

The title, layout, and aspect arguments are used to combine content picts via the current_assembler parameter’s value. See also slide_pict, which performs that combination without registering a slide.

Besides immediate picts, the content values can produce descriptions of slides to construct using lists, slide.next, slide.sync, and slide.alts (or one of its shorthands: slide.horiz, slide.left, slide.center, or slide.right):

See Overview for an introduction to this slide staging and alignment sublanguage.

• Nested lists are flattened and spliced.

• A slide.next creates two picts: one with everything before the slide.next, and one with everything after. The two picts are then made sequential with sequential before combining them with stack. The sequential function is used with its default duration mode, so it sustains the first pict. The first pict is also marked as nonarchival for its pre-sustained duration. Note that slide.next might be used in the part before this use, after this use, or both, creating a multi-epoch pict wherever it’s used.

• A slide.sync is similar to slide.next, but it combines a snapshot of the pict from after slide.sync for all but the last epoch of the pict before slide.sync, and it shifts the time box of the pict after slide.sync by one less (so that the last epoch of the pict before and the first epoch of the pict after are the same).

• A value produced by slide.alts creates one pict for each argument to slide.alts, and the picts are sequentialized and then combined with overlay. (That’s similar to using switch, but the bounding boxes for all alternatives are preserved for the combined duration.)

  The overlay combination uses the vertical alignment that is supplied to slide.alts, while its horizontal alignment and vertical spacing depends on an enclosing slide.align (or one of the slide.left, slide.horiz, slide.center, or slide.right aliases). Spacing and alignment default to slide.gap and #'center, respectively, if slide.align or slide.horiz is enclosing.

  A slide.next or slide.sync can be used in any alternative with slide.alts, and slide.alts can be nested. In either of those cases, the corresponding alternative will itself be a multi-epoch pict.

• A value produced by slide.align causes all picts as arguments to slide.align to get the same width by padding on the left, right, or both. This padding applies to picts in nested slide.alts alternatives as well as nested slide.horiz constructions—but for nested slide.align constructions with local alignment (which is the case unless ~local: #false is provided), padding applies only after the nested slide.align applies it own padding.

  The ~horiz argument to slide.align determines how padding is added by default to contained elements, but nested slide.align constructions can change alignment. Supplying #'inherit for the ~sep or ~horiz argument to slide.align means that vertical spacing and alignment are determined by an enclosing slide.align or slide.horiz, defaulting to slide.gap and #'left is none is enclosing.

When a pict representing a slide has the #'nonarchival key mapped to a true value in its metadata for some epoch, then the slide for that epoch is skipped in condensed mode—as are any slides for transitions in the epoch. See also nonarchival.

When a pict representing a slide has the #'continued key mapped to a true value in its metadata for some epoch, then the slide for that epoch does not increment the page number that the slideshow viewer or printer displays.

Changed in version 1.1 of package rhombus-slideshow-lib: Added #'continued support.

If full is a true value, then the resulting pict represents a slide including its title as combined via current_assembler. Otherwise, current_assembler is not used, and the resulting pict is just the result of combining the content values.

The last epoch of the pict created for the step before slide.next or slide.sync is suppressed for condensed mode (including printing) via nonarchival. The slide.Next.continued method creates a variant of slide.next or slide.sync that also suppresses a new page number for the last epoch by using continued.

Changed in version 1.1 of package rhombus-slideshow-lib: Added slide.Next and the slide.Next.continued method.

The slide.Alts.continued method produces an adjusted description that suppress a new page number of the last epoch of all but the last alternative pict in content by using continued.

Changed in version 1.1 of package rhombus-slideshow-lib: Added slide.Alts and the slide.Alts.continued method.

The slide.horiz functions is a shorthand for slide.align with ~local: #false.

The slide.left, slide.center, and slide.right functions are shorthands for slide.pict with a specific ~horiz argument and with the ~local argument defaulting to #false instead of #true.

The StaticPict for the previous slide corresponds to a snapshot at the end of the last epoch for the previous slide. The Pict for the new slide can be animated with multiple epochs, reflecting the case that a single call to slide generates a animated or multi-epoch Pict. Both the StaticPict and Pict are assembled in the sense that they have been combined along with their titles, if any, as by slide_pict.

The Map argument to transition provides additional information through the following keys (with more potentially added in the future):

• #'prev_name: The name (defaults to the title) for the previous slide.

• #'name: The name (defaults to the title) that will be used for the new slide.

• #'lead_in: The value of the ~lead_in argument for the slide call that triggered a new slide.

• #'prev_aspect: An aspect ration as an Aspect for the previous slide.

• #'aspect: An aspect ration as an Aspect for the new slide.

A transition function can call slide and/or slide_transition. If it calls slide, then newly created slides will appear before the result of transition. If it calls slide_transition, then the registered function is invoked on the next call to slide and not to the result of the transition function.

Added in version 1.1 of package rhombus-slideshow-lib.