Class: Vedeu::Buffers::Buffer

Inherits:
Object
  • Object
show all
Includes:
Repositories::Model
Defined in:
lib/vedeu/buffers/buffer.rb,
lib/vedeu/buffers/repository.rb

Overview

Repository

Instance Attribute Summary collapse

Attributes included from Repositories::Model

#repository

Instance Method Summary collapse

Methods included from Repositories::Model

included, #store

Methods included from Common

#absent?, #array?, #boolean, #boolean?, #empty_value?, #escape?, #falsy?, #hash?, #line_model?, #numeric?, #positionable?, #present?, #snake_case, #stream_model?, #string?, #symbol?, #truthy?, #view_model?

Constructor Details

#initialize(attributes = {}) ⇒ Vedeu::Buffers::Buffer

Return a new instance of Buffer. Generally a Buffer is initialized with only a ‘name’ and ‘back’ parameter.

Parameters:

  • attributes (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (attributes):



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# File 'lib/vedeu/buffers/buffer.rb', line 49

def initialize(attributes = {})
  defaults.merge!(attributes).each do |key, value|
    instance_variable_set("@#{key}", value)
  end
end

Instance Attribute Details

#back ⇒ Vedeu::Views::View

The next buffer to be displayed; contains the content which will be shown on next refresh.

Returns:



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# File 'lib/vedeu/buffers/buffer.rb', line 19

def back
  @back
end

#front ⇒ Vedeu::Views::View

The currently displayed buffer, contains the content which was last output.

Returns:



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# File 'lib/vedeu/buffers/buffer.rb', line 26

def front
  @front
end

#name ⇒ String|Symbol (readonly)

Returns:

  • (String|Symbol) 


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# File 'lib/vedeu/buffers/buffer.rb', line 37

def name
  @name
end

#previous ⇒ Vedeu::Views::View

The previous buffer which was displayed; contains the content that was shown before ‘front’.

Returns:



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# File 'lib/vedeu/buffers/buffer.rb', line 33

def previous
  @previous
end

Instance Method Details

#add(view, refresh = false) ⇒ Boolean

Add the view to the back buffer, then update the repository. Returns boolean indicating that the repository was updated.

Parameters:

  • view (Vedeu::Views::View)
  • refresh (Boolean) (defaults to: false) —

    Should the view be refreshed once stored? Default: false.

Returns:



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# File 'lib/vedeu/buffers/buffer.rb', line 62

def add(view, refresh = false)
  @back = view

  store

  Vedeu.trigger(:_refresh_view_, view.name) if boolean(refresh)

  true
end

#back? ⇒ Boolean

Return a boolean indicating content presence on the buffer type.

Returns:

  • (Boolean) —

    Whether the buffer targetted has content.



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# File 'lib/vedeu/buffers/buffer.rb', line 76

def back?
  (back.nil? || back.lines.empty?) ? false : true
end

#cursor_visible? ⇒ Boolean

Return a boolean indicating whether the cursor should be visible for this view.

On a per-view (and per-interface) basis, the cursor can be set to be visible or not visible.

  • If the cursor is visible, then refresh actions or events involving the cursor will act as normal; hiding and showing as the view is rendered or as events are triggered to change the visibility state.

  • If the cursor is not visible, then refresh actions and events involving the cursor will be ignored- the cursor is not shown, so do no work.

Returns:



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# File 'lib/vedeu/buffers/buffer.rb', line 95

def cursor_visible?
  if front?
    front.cursor_visible?

  elsif previous?
    previous.cursor_visible?

  else
    interface.cursor_visible?

  end
end

#defaults ⇒ Hash<Symbol => void> (private)

The default options/attributes for a new instance of this class.

Returns:

  • (Hash<Symbol => void>) 


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# File 'lib/vedeu/buffers/buffer.rb', line 178

def defaults
  {
    back:       nil,
    front:      nil,
    name:       '',
    previous:   nil,
    repository: Vedeu.buffers,
  }
end

#front? ⇒ Boolean

Return a boolean indicating content presence on the buffer type.

Returns:

  • (Boolean) —

    Whether the buffer targetted has content.



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# File 'lib/vedeu/buffers/buffer.rb', line 112

def front?
  (front.nil? || front.lines.empty?) ? false : true
end

#interface ⇒ Vedeu::Interfaces::Interface (private)

Returns:



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# File 'lib/vedeu/buffers/buffer.rb', line 189

def interface
  Vedeu.interfaces.by_name(name)
end

#previous? ⇒ Boolean

Return a boolean indicating content presence on the buffer type.

Returns:

  • (Boolean) —

    Whether the buffer targetted has content.



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# File 'lib/vedeu/buffers/buffer.rb', line 120

def previous?
  (previous.nil? || previous.lines.empty?) ? false : true
end

#render ⇒ Array<Array<Array<Vedeu::Cells::Char>>>

Retrieve the latest content from the buffer.

  • If we have new content (i.e. content on ‘back’) to be shown, we first clear the area occupied by the previous content, then clear the area for the new content, and then finally render the new content.

  • If there is no new content (i.e. ‘back’ is empty), check the ‘front’ buffer and display that.

  • If there is no new content, and the front buffer is empty, display the ‘previous’ buffer.

  • If the ‘previous’ buffer is empty, return an empty collection.

Returns:



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# File 'lib/vedeu/buffers/buffer.rb', line 138

def render
  current = if back?
              swap

              front

            elsif front?
              front

            elsif previous?
              previous

            end

  Vedeu::Output::Viewport.render(current) unless current.nil?
end

#size ⇒ Fixnum

Returns the number of lines of content for the buffer or 0 if the buffer is empty.

Returns:

  • (Fixnum) 


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# File 'lib/vedeu/buffers/buffer.rb', line 159

def size
  if back?
    back.lines.size

  elsif front?
    front.lines.size

  elsif previous?
    previous.lines.size

  else
    0

  end
end

#swap ⇒ Boolean (private)

Return a boolean indicating content was swapped between buffers.

Returns:



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# File 'lib/vedeu/buffers/buffer.rb', line 197

def swap
  Vedeu.log(type: :buffer, message: "Buffer swapping: '#{name}'")

  @previous = front
  @front    = back
  @back     = nil

  store

  true
end