Expresso.Presenter.Definition (expresso v0.1.0)

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Holds the types of the presenter definition, and reads the definition

A definition holds each rule of the presenter as data: modes, bindings and commands. Expresso.Presenter.Default writes the definition in the DSL of Expresso.Presenter.Extension, and presenter/0 reads it into maps. Expresso.Presenter.Program makes the program of one deck from the definition, and the interpreter in the browser runs that program. Expresso.Presenter.Interpreter is the reference interpreter in Elixir.

The modes

A mode has a condition on the state, such as [view: :present]. The interpreter uses the first mode whose condition the state matches. A mode holds:

  • bindings - each binding holds one or more events, a list of commands and its row in the list of keys.
  • each - the commands that go in front of each binding. The present, the speaker and the handout views remove the typed digits with each key. A binding with each: false does not get them.
  • any - the commands for each event of the mode. The black screen and the list of keys close at the next event, and the event does no more.
  • other - true when a key with no binding gets the each commands.
  • element - true when a click on an element runs the commands of that element, after the each commands. A page of the overview has the commands that go to its slide, and a link of Expresso.Goto has the commands that go to its step.

The events

  • {:key, key} - the value of KeyboardEvent.key, such as "j" or " ".
  • {:click, :left_third} and {:click, :right} - a click or a tap.
  • {:swipe, :left} and {:swipe, :right} - a movement of one finger.
  • :element - a click on an element that holds commands.

The commands

  • {:set, field, value} - sets a field to a value.
  • {:toggle, field} - changes a field from true to false, or from false to true.
  • {:clear, field} - sets a field to its first value, which presenter/0 declares.
  • {:assign, :selected, {:entry, :slide}} - selects the slide of the current step.
  • {:append, :digits} - adds the key to the typed digits.
  • {:step, count} - moves forward or back by a number of steps. A move past the first step or the last step makes no change.
  • {:goto, index} - goes to the step at an index in the deck.
  • {:goto_slide, slide} - goes to step 1 of a slide. With :selected, it goes to step 1 of the selected slide.
  • {:select, slide} and {:select_by, count} - select a slide in the overview, or move the selection by a number of slides. A slide outside the deck makes no change.
  • :go_typed - goes to step 1 of the slide that the typed digits give, and removes the digits.
  • {:copy, to, from} - sets a field that holds the index of a step to the value of another such field. The menu puts its cursor on the current step with {:copy, :cursor, :index}.
  • {:move, field, count} - adds a number to a field that holds the index of a step. A move past the first step or the last step makes no change.
  • {:go, field} - goes to the step at the index that a field holds.
  • {:builtin, name} - calls a built-in function of the browser: :open_speaker, :fullscreen, :reset_timer or :switch_scheme.

A definition can hold two symbols in place of a number: :last_slide and {:columns, sign}. Expresso.Presenter.Program changes each symbol into a number for the deck.

Summary

Types

binding()

A binding: its events, its commands, and its row and its group in the list of keys

command()

A command of a definition. The section "The commands" of the module documentation tells what each command does.

event()

An event of a binding

field()

A field of the state

mode()

A mode of the presenter

t()

The definition of the presenter

Functions

from(module)

Make a definition from a module that uses Expresso.Presenter.Dsl

presenter()

Return the definition of the presenter

Types

binding()

@type binding() :: %{
  on: [event()],
  commands: [command()],
  text: String.t(),
  label: String.t() | nil,
  group: String.t() | nil,
  each: boolean()
}

A binding: its events, its commands, and its row and its group in the list of keys

command()

@type command() ::
  {:set, field(), term()}
  | {:toggle, field()}
  | {:clear, field()}
  | {:assign, :selected, {:entry, :slide}}
  | {:append, :digits}
  | {:step, integer()}
  | {:goto, non_neg_integer() | :last_slide}
  | {:goto_slide, :selected | pos_integer()}
  | {:select, pos_integer() | :last_slide}
  | {:select_by, integer() | {:columns, 1 | -1}}
  | {:copy, field(), field()}
  | {:move, field(), integer()}
  | {:go, field()}
  | :go_typed
  | {:builtin, :open_speaker | :fullscreen | :reset_timer | :switch_scheme}

A command of a definition. The section "The commands" of the module documentation tells what each command does.

event()

@type event() ::
  {:key, String.t()}
  | {:click, :left_third | :right}
  | {:swipe, :left | :right}
  | :element

An event of a binding

field()

@type field() ::
  :index
  | :view
  | :blank
  | :help
  | :digits
  | :overview
  | :selected
  | :progress
  | :every
  | :undim
  | :menu
  | :cursor

A field of the state

mode()

@type mode() :: %{
  name: atom(),
  when: keyword(),
  bindings: [binding()],
  each: [command()],
  any: [command()] | nil,
  other: boolean(),
  element: boolean()
}

A mode of the presenter

t()

@type t() :: %{
  state: map(),
  sync: [field()],
  reset: [field()],
  modes: [mode()],
  project: Expresso.Presenter.Projection.t()
}

The definition of the presenter

Functions

from(module)

@spec from(module()) :: t()

Make a definition from a module that uses Expresso.Presenter.Dsl

presenter()

@spec presenter() :: t()

Return the definition of the presenter

The definition comes from Expresso.Presenter.Default. The modes come in the order that the interpreter examines them. The black screen comes first, then the list of keys, then the overview, then the views.