Class: Qt::Widget

Inherits:
Object show all
Defined in:
lib/qtext/extensions.rb

Class Method Summary collapse

Class Method Details

.construct_signal(signature, method_name = nil) ⇒ Object

add a signal with the given signature, and create a method called method_name which will emit the signal, a method called method_name_signal which will return the signal ready to be used in a connect. If method_name is not provided the method will be named as the name part of signature. Also create a handler on_method_name {|*args| }



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# File 'lib/qtext/extensions.rb', line 316

def self.construct_signal( signature, method_name = nil )
  # add the signal
  q_signal( signature )
  
  # add an accessor method that returns the result of SIGNAL
  if method_name.nil?
    md = /([\w_]+) *\(/.match( signature )
    base_method_name = md[1]
    method_name = base_method_name + '_signal'
  end
  
  # create the accessor method which returns
  # a signal ready to be connected
  define_method method_name do
    SIGNAL( signature )
  end
  
  # create the connection method
  line, st = __LINE__, <<-EOF
    def on_#{base_method_name}( &block )
      connect( #{method_name} ) do |*args|
        yield( *args )
      end
    end
  EOF
  class_eval st, __FILE__, line + 1
end

.signal(symbol) ⇒ Object

specify a signal symbol, and add the other methods, namely

  • symbol which emits the signal

  • symbol_signal which is the method added by q_signal, ie the actual Qt emitter

  • on_symbol {|*args| } which is the handler



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# File 'lib/qtext/extensions.rb', line 348

def self.signal( symbol )
  # add the signal emitter
  signature = "#{symbol.to_s}_signal( QVariant & )"
  q_signal( signature )
  
  # add an emitter
  line_number, st = __LINE__, <<-EOF
    def #{symbol.to_s}( *args )
      #~ puts "ingoing args: \#\{args.inspect\}"
      # convert args to variant(s)
      variant =
      case args.size
        when 0; Qt::Variant.new
        when 1; args[0].to_variant
        else; Qt::Variant.new( args )
      end
      #~ puts "ingoing variant: \#\{variant.inspect\}"
      emit #{symbol.to_s}_signal( variant )
    end
  EOF
  class_eval st, __FILE__, line_number + 1
  
  # create the connection method
  line_number, st = __LINE__, <<-EOF
    def on_#{symbol.to_s}( &block )
      Kernel.raise "on_#{symbol.to_s} must have a block" if block.nil?
      connect( SIGNAL( '#{signature}' ) ) do |variant|
        #~ puts "outcoming variant: \#\{variant.inspect\}"
        # convert variants to Ruby objects
        args =
        case variant.typeName
          when nil; nil
          when 'QVariantList'; variant.value.map{|x| x.value}
          else variant.value
        end
        #~ puts "outcoming args: \#\{args.inspect\}"
        yield( *args )
      end
    end
  EOF
  class_eval st, __FILE__, line_number + 1
end