Class: Context::Context

Inherits:
Object show all
Defined in:
lib/Context/Context.rb

Overview

The Context is the Presenter in the Model, View, Presentor (MVP) model. It is an object that holds the logic for the UI scenario that the application is currently in. Context is an abstract class.

A Context is made up of views, model objects and other sub-contexts. One of the views should be a UI widget container that contains all of the views for the Context. The concrete classes should define the logic for the Context that is either called by enter() or called from one of the contained views.

Note that views are usually only instantiated in createViews, which is called on enter(), not on Context creation. However, there is no requirement for this.

Direct Known Subclasses

Gtk::App

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(viewBridge) ⇒ Context

Create a new Context. Takes a Bridge that is used to create the View s in using the correct namespace.



26
27
28
29
30
31
32
 
# File 'lib/Context/Context.rb', line 26

def initialize(viewBridge)
	@parent = nil
	@mainView = nil
	@viewBridge = viewBridge
	@keyMap = KeyMap.new
	@entered = false
end

Instance Attribute Details

#mainView ⇒ Object

Returns the value of attribute mainView.



21
22
23
 
# File 'lib/Context/Context.rb', line 21

def mainView
  @mainView
end

#parent ⇒ Object (readonly)

Returns the value of attribute parent.



21
22
23
 
# File 'lib/Context/Context.rb', line 21

def parent
  @parent
end

Instance Method Details

#addView(view) ⇒ Object

Adds a view to the mainView Since the mainView is intended to be a UI container that contains all the views, this method is called by a sub-context’s enter() method to allow the parent’s mainView to contain the sub-context’s views.



72
73
74
 
# File 'lib/Context/Context.rb', line 72

def addView(view)
	@mainView.addView(view) unless @mainView.nil?
end

#createViews ⇒ Object

This method should be overriden by the concrete class. It should instantiate all the views and set @mainView



38
39
40
 
# File 'lib/Context/Context.rb', line 38

def createViews
    # Nothing to do here
end

#destroyViews ⇒ Object

This method should be overriden by the concrete class. It should destroy all the views and set @mainView to nil



63
64
65
 
# File 'lib/Context/Context.rb', line 63

def destroyViews
    @mainView = nil
end

#enter(parent) ⇒ Object

Enters the Context. After it is called, the Context is then active and can be interacted with. This method automatically calls createViews() and adds the mainView to the parent’s view.

Usually this method will be overriden by the concrete class. However, it should be careful to call super() in the appropriate place.



83
84
85
86
87
88
89
90
 
# File 'lib/Context/Context.rb', line 83

def enter(parent)
	@parent = parent
	if (@parent != nil)
	    @entered = true
	    setupViews
		parent.addView(@mainView) unless @mainView.nil?
	end
end

#exit ⇒ Object

Exits the Context. After it is called, the context is no longer active and can’t be interacted with. This method automatically removes the mainView from the parent’s view and calls destroyViews().

Usually this method will be overriden by the concrete class. However, it should be careful to call super() in the appropriate place.



106
107
108
109
110
111
112
 
# File 'lib/Context/Context.rb', line 106

def exit()
    @entered = false
          if !@parent.nil? && !@parent.mainView.nil?
              @parent.mainView.removeView(@mainView) unless @mainView.nil?
          end
          destroyViews
end

#getKeyBinding(key) ⇒ Object

Returns the existing binding for a key.

Warning: This key binding mechanism is likely to be depracated, or at least heavily modified soon.



131
132
133
134
 
# File 'lib/Context/Context.rb', line 131

def getKeyBinding(key)
    a = @keyMap.findKey(key)
    a.unless_nil.action
end

#isEntered? ⇒ Boolean

Returns true if the context has been entered, but not exited. Returns false if the context has never been entered, or if it has been entered and then exited.

Returns:

  • (Boolean) 


95
96
97
 
# File 'lib/Context/Context.rb', line 95

def isEntered?
    @entered
end

#notifyKey(view, key) ⇒ Object

Called by the view to indicated that a key has been pressed. Runs the binding in the keymap, or returns nil if there isn’t one.

Warning: This key binding mechanism is likely to be depracated, or at least heavily modified soon.



142
143
144
 
# File 'lib/Context/Context.rb', line 142

def notifyKey(view, key)
    @keyMap.unless_nil do press(key) end
end

#peekAtView ⇒ Object

Creates views and returns the main View. This is intended to be used by test code where entering the context executes code and you need to know what the view will be ahead of time. I can think of no reason to use this in production code.



54
55
56
57
 
# File 'lib/Context/Context.rb', line 54

def peekAtView
    setupViews
    @mainView
end

#setKeyBinding(key, &binding) ⇒ Object

Sets a binding for a key. Whenever a key is pressed, the context is notified. This sets up a binding between the key and the block passed in. After that point, the block will be called everytime the key is pressed.

Warning: This key binding mechanism is likely to be depracated, or at least heavily modified soon.



122
123
124
125
 
# File 'lib/Context/Context.rb', line 122

def setKeyBinding(key, &binding)
    a = KeyAssignment.new(key, &binding)
    @keyMap.add(a)
end

#setupViews ⇒ Object

This is intended to be private (how do I do that again?) Just so that it doesn’t create a view if it is already created



44
45
46
47
48
 
# File 'lib/Context/Context.rb', line 44

def setupViews
    if @mainView.nil?
        createViews
    end
end