Class: Redwood::UndoManager

Inherits:
Object show all
Includes:
Singleton
Defined in:
lib/sup/undo.rb

Overview

Implements a single undo list for the Sup instance

The basic idea is to keep a list of lambdas to undo things. When an action is called (such as ‘archive’), a lambda is registered with UndoManager that will undo the archival action

Instance Method Summary collapse

Methods included from Singleton

included

Constructor Details

#initialize ⇒ UndoManager

Returns a new instance of UndoManager.



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# File 'lib/sup/undo.rb', line 13

def initialize
  @@actionlist = []
end

Instance Method Details

#clear ⇒ Object 



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# File 'lib/sup/undo.rb', line 34

def clear
  @@actionlist = []
end

#register(desc, *actions, &b) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/sup/undo.rb', line 17

def register desc, *actions, &b
  actions = [*actions.flatten]
  actions << b if b
  raise ArgumentError, "need at least one action" unless actions.length > 0
  @@actionlist.push :desc => desc, :actions => actions
end

#undo ⇒ Object 



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# File 'lib/sup/undo.rb', line 24

def undo
  unless @@actionlist.empty?
    actionset = @@actionlist.pop
    actionset[:actions].each { |action| action.call }
    BufferManager.flash "undid #{actionset[:desc]}"
  else
    BufferManager.flash "nothing more to undo!"
  end
end