Module: Glimmer::SWT::Observer
- Included in:
- ListSelectionBinding, ModelBinding, Glimmer::SWT::ObservableModel::Notifier, Proc, TableItemsBinding, TreeItemsBinding, WidgetBinding
- Defined in:
- lib/glimmer/swt/observer.rb
Overview
Mixin representing Observer trait from Observer Design Pattern Allows classes to include without interfering with their inheritance hierarchy.
Includes a default implementation that can receive an observer block Example: Observer.proc {|new_value| puts new_value} Subclasses may override
Defined Under Namespace
Classes: Proc
Class Method Summary collapse
Instance Method Summary collapse
-
#add_dependent(parent_to_dependent_hash) ⇒ Object
add dependent observer to unregister when unregistering observer.
- #call(new_value) ⇒ Object
-
#dependents ⇒ Object
mapping of registrations to dependents property] => [[dependent, dependent_observable, dependent_property], …].
- #dependents_for(registration) ⇒ Object
-
#register(observable, property = nil) ⇒ Object
(also: #observe)
registers observer in an observable on a property (optional) observer maintains registration list to unregister later.
- #registrations ⇒ Object
- #registrations_for(observable, property = nil) ⇒ Object
- #remove_dependent(parent_to_dependent_hash) ⇒ Object
- #unregister(observable, property = nil) ⇒ Object (also: #unobserve)
-
#unregister_all_observables ⇒ Object
(also: #unobserve_all_observables)
cleans up all registrations in observables.
- #unregister_dependents_with_observable(registration, dependent_observable) ⇒ Object
Class Method Details
Instance Method Details
#add_dependent(parent_to_dependent_hash) ⇒ Object
add dependent observer to unregister when unregistering observer
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# File 'lib/glimmer/swt/observer.rb', line 100 def add_dependent(parent_to_dependent_hash) observable, property = registration = parent_to_dependent_hash.keys.first dependent_observer, dependent_observable, dependent_property = dependent = parent_to_dependent_hash.values.first dependents_for(registration) << dependent end |
#call(new_value) ⇒ Object
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# File 'lib/glimmer/swt/observer.rb', line 112 def call(new_value) raise 'Not implemented!' end |
#dependents ⇒ Object
mapping of registrations to dependents property] => [[dependent, dependent_observable, dependent_property], …]
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# File 'lib/glimmer/swt/observer.rb', line 44 def dependents @dependents ||= Hash.new end |
#dependents_for(registration) ⇒ Object
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# File 'lib/glimmer/swt/observer.rb', line 48 def dependents_for(registration) dependents[registration] ||= Set.new end |
#register(observable, property = nil) ⇒ Object Also known as: observe
registers observer in an observable on a property (optional) observer maintains registration list to unregister later
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# File 'lib/glimmer/swt/observer.rb', line 54 def register(observable, property = nil) unless observable.is_a?(Observable) # TODO refactor code to be more smart/polymorphic/automated and honor open/closed principle if observable.is_a?(Array) observable.extend(ObservableArray) else observable.extend(ObservableModel) end end observable.add_observer(*[self, property].compact) [observable, property].tap do |registration| self.registrations << registration end end |
#registrations ⇒ Object
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# File 'lib/glimmer/swt/observer.rb', line 34 def registrations @registrations ||= Set.new end |
#registrations_for(observable, property = nil) ⇒ Object
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# File 'lib/glimmer/swt/observer.rb', line 38 def registrations_for(observable, property = nil) registrations.select {|o, p| o == observable && p == property} end |
#remove_dependent(parent_to_dependent_hash) ⇒ Object
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# File 'lib/glimmer/swt/observer.rb', line 106 def remove_dependent(parent_to_dependent_hash) observable, property = registration = parent_to_dependent_hash.keys.first dependent_observer, dependent_observable, dependent_property = dependent = parent_to_dependent_hash.values.first dependents_for(registration).delete(dependent) end |
#unregister(observable, property = nil) ⇒ Object Also known as: unobserve
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# File 'lib/glimmer/swt/observer.rb', line 70 def unregister(observable, property = nil) observable.remove_observer(*[self, property].compact) registration = [observable, property] dependents_for(registration).each do |dependent| dependent_observer, dependent_observable, dependent_property = dependent dependent_observer.unregister(dependent_observable, dependent_property) remove_dependent(registration => dependent) end registrations.delete(registration) end |
#unregister_all_observables ⇒ Object Also known as: unobserve_all_observables
cleans up all registrations in observables
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# File 'lib/glimmer/swt/observer.rb', line 92 def unregister_all_observables registrations.each do |observable, property| unregister(observable, property) end end |
#unregister_dependents_with_observable(registration, dependent_observable) ⇒ Object
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# File 'lib/glimmer/swt/observer.rb', line 82 def unregister_dependents_with_observable(registration, dependent_observable) thedependents = dependents_for(registration).select do |d_observer, d_observable, d_property| d_observable == dependent_observable end thedependents.each do |d_observer, d_observable, d_property| d_observer.unregister(d_observable, d_property) end end |