Class: Presently::PresentationController

Inherits:
Object
  • Object
show all
Defined in:
lib/presently/presentation_controller.rb

Overview

Manages the mutable state of a presentation: current slide, clock, and listeners.

Wraps an immutable Presentation and provides navigation, timing, and listener notification. Multiple views (display, presenter) can register as listeners to receive updates.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(presentation, state: nil) ⇒ PresentationController

Initialize a new controller for the given presentation.



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# File 'lib/presently/presentation_controller.rb', line 19

def initialize(presentation, state: nil)
	@presentation = presentation
	@current_index = 0
	@clock = Clock.new
	@listeners = []
	@state = state
	
	@state&.restore(self)
end

Instance Attribute Details

#clock ⇒ Object (readonly)

Returns the value of attribute clock.



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# File 'lib/presently/presentation_controller.rb', line 36

def clock
  @clock
end

#current_index ⇒ Object (readonly)

Returns the value of attribute current_index.



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# File 'lib/presently/presentation_controller.rb', line 33

def current_index
  @current_index
end

#presentation ⇒ Object (readonly)

Returns the value of attribute presentation.



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# File 'lib/presently/presentation_controller.rb', line 30

def presentation
  @presentation
end

#The index of the current slide.(indexofthecurrentslide.) ⇒ Object (readonly) 



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# File 'lib/presently/presentation_controller.rb', line 33

attr :current_index

#The underlying presentation data.(underlyingpresentationdata.) ⇒ Object (readonly) 



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# File 'lib/presently/presentation_controller.rb', line 30

attr :presentation

Instance Method Details

#add_listener(listener) ⇒ Object

Register a listener to be notified when the slide changes. The listener must respond to ‘#slide_changed!`.



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# File 'lib/presently/presentation_controller.rb', line 149

def add_listener(listener)
	@listeners << listener
end

#advance! ⇒ Object

Advance to the next slide.



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# File 'lib/presently/presentation_controller.rb', line 137

def advance!
	go_to(@current_index + 1)
end

#current_slide ⇒ Object

The currently displayed slide.



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# File 'lib/presently/presentation_controller.rb', line 52

def current_slide
	@presentation.slides[@current_index]
end

#go_to(index) ⇒ Object

Navigate to a specific slide by index. Ignores out-of-bounds indices. Notifies listeners on change.



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# File 'lib/presently/presentation_controller.rb', line 129

def go_to(index)
	return if index < 0 || index >= slide_count
	
	@current_index = index
	notify_listeners!
end

#next_slide ⇒ Object

The slide following the current one.



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# File 'lib/presently/presentation_controller.rb', line 58

def next_slide
	@presentation.slides[@current_index + 1]
end

#pacing ⇒ Object

The current pacing status relative to the slide timing.



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# File 'lib/presently/presentation_controller.rb', line 100

def pacing
	return :on_time unless @clock.started?
	
	elapsed = @clock.elapsed
	slide_start = @presentation.expected_time_at(@current_index)
	slide_end = @presentation.expected_time_at(@current_index + 1)
	
	if elapsed > slide_end
		:behind
	elsif elapsed < slide_start
		:ahead
	else
		:on_time
	end
end

#previous_slide ⇒ Object

The slide preceding the current one.



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# File 'lib/presently/presentation_controller.rb', line 64

def previous_slide
	@presentation.slides[@current_index - 1] if @current_index > 0
end

#reload! ⇒ Object

Reload slides from disk and notify listeners.



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# File 'lib/presently/presentation_controller.rb', line 160

def reload!
	@presentation = @presentation.reload
	notify_listeners!
end

#remove_listener(listener) ⇒ Object

Remove a previously registered listener.



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# File 'lib/presently/presentation_controller.rb', line 155

def remove_listener(listener)
	@listeners.delete(listener)
end

#reset_timer! ⇒ Object

Reset the timer so that elapsed time matches the expected time for the current slide.



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# File 'lib/presently/presentation_controller.rb', line 93

def reset_timer!
	@clock.reset!(@presentation.expected_time_at(@current_index))
	notify_listeners!
end

#retreat! ⇒ Object

Go back to the previous slide.



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# File 'lib/presently/presentation_controller.rb', line 142

def retreat!
	go_to(@current_index - 1)
end

#save_state! ⇒ Object

Persist the current state to disk.



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# File 'lib/presently/presentation_controller.rb', line 166

def save_state!
	@state&.save(self)
end

#slide_count ⇒ Object

The total number of slides.



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# File 'lib/presently/presentation_controller.rb', line 70

def slide_count
	@presentation.slide_count
end

#slide_progress ⇒ Object

The progress through the current slide’s allocated time.



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# File 'lib/presently/presentation_controller.rb', line 82

def slide_progress
	return 0.0 unless @clock.started?
	
	slide = current_slide
	return 0.0 unless slide
	
	time_into_slide = @clock.elapsed - @presentation.expected_time_at(@current_index)
	(time_into_slide / slide.duration).clamp(0.0, 1.0)
end

#slides ⇒ Object

The ordered list of slides, delegated to the presentation.



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# File 'lib/presently/presentation_controller.rb', line 46

def slides
	@presentation.slides
end

#templates ⇒ Object

The template resolver, delegated to the presentation.



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# File 'lib/presently/presentation_controller.rb', line 40

def templates
	@presentation.templates
end

#The presentation timer.=(presentationtimer. = (value)) ⇒ Object 



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# File 'lib/presently/presentation_controller.rb', line 36

attr :clock

#time_remaining ⇒ Object

The estimated time remaining in the presentation.



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# File 'lib/presently/presentation_controller.rb', line 118

def time_remaining
	return total_duration unless @clock.started?
	
	expected_remaining = @presentation.expected_time_at(slide_count) - @clock.elapsed
	
	[expected_remaining, 0].max
end

#total_duration ⇒ Object

The total expected duration of the presentation.



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# File 'lib/presently/presentation_controller.rb', line 76

def total_duration
	@presentation.total_duration
end