2 Creating Slides🔗ℹ

The title and layout arguments are used to combine content picts via the current_assembler parameter’s value.

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

See Using Slideshow in Rhombus 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 #'top alignment. A slide.next or slide.sync can be used in any alternative, 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 not nested slide.align constructions, which perform their own nested alignments. The ~horiz argument to slide.align determines how padding is added by default to contained elements, but nested slide.horiz constructions can change alignment.

• A value produced by slide.horiz changes alignment and potentially vertical spacing for its arguments.

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 condense mode—as are any slides for transitions in the epoch. See also nonarchival.

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 slide.left, slide.center, and slide.right functions are shorthands for slide.horiz with a specific ~horiz argument.

The default slide assembler vertically combines a title with the pict content using slide.gap space for the #'tall layout and 2*slide.gap space for the #'top layout. In #'center mode, the content pict is centered with respect to the full slide client area, and then the title is combined with overlay and #'top alignment. The #'auto mode is treated like #'tall or #'center, whichever would cause the pict to appear lower in the client area.