Class: Glimmer::DSL::Expression

Inherits:
Object
  • Object
show all
Defined in:
lib/glimmer/dsl/expression.rb

Overview

Represents a Glimmer DSL expression (e.g. label(:center) { … })

An expression object can interpret a keyword, args, and a block into a UI object

Expressions subclasses follow the convention of using ‘and` and `or` english versino of Ruby’s boolean operations. This allows easy DSL-like readability of the rules, and easy tagging with pd when troubleshooting.

Instance Method Summary collapse

Instance Method Details

#add_content(parent, &block) ⇒ Object

Adds block content to specified parent UI object (Optional)

Only expressions that receive a content block should implement



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# File 'lib/glimmer/dsl/expression.rb', line 26

def add_content(parent, &block)
  # No Op by default
end

#can_interpret?(parent, keyword, *args, &block) ⇒ Boolean

Checks if it can interpret parameters (subclass must override)

Returns:

  • (Boolean)

Raises:



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# File 'lib/glimmer/dsl/expression.rb', line 14

def can_interpret?(parent, keyword, *args, &block)
  raise Error, "#can_interpret? must be implemented by an Expression subclass"
end

#interpret(parent, keyword, *args, &block) ⇒ Object

Interprets parameters (subclass must override)

Raises:



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# File 'lib/glimmer/dsl/expression.rb', line 19

def interpret(parent, keyword, *args, &block)
  raise Error, "#interpret must be implemented by an Expression subclass"
end

#textual?(object) ⇒ Boolean

Checks if object is a Symbol or a String

Returns:

  • (Boolean) 


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# File 'lib/glimmer/dsl/expression.rb', line 36

def textual?(object)
  object.is_a?(Symbol) or object.is_a?(String)
end

#widget?(parent) ⇒ Boolean

Checks if parent object is a widget

Returns:

  • (Boolean) 


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# File 'lib/glimmer/dsl/expression.rb', line 31

def widget?(parent)
  parent.is_a?(SWT::WidgetProxy) or parent.is_a?(UI::CustomWidget)
end