Class: CTioga2::Graphics::Styles::StyleSheet

Inherits:
Object
  • Object
show all
Defined in:
lib/ctioga2/graphics/styles/sheet.rb

Overview

This is a style sheet, is a storage place for style objects. It has two related functions:

  • first, store the user-specified preferences

  • second, provide the appropriate default style for any given object, most probably at construction time (although that may get hard some times)

The style are cascading and scoped. A scope should begin in each plot.

Cascades happen in two ways:

  • more specific styles inherit from less specific (axis -> yaxis -> left)

  • children style inherit from parent style

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(par = nil) ⇒ StyleSheet

Returns a new instance of StyleSheet.



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 53

def initialize(par = nil)
  @parent = par
  @own_styles = {}
end

Instance Attribute Details

#own_styles ⇒ Object

The styles, in form of a style class -> style name -> style object nested hash

The style object is actually a hash ready to be fed to the BasicStyle#set_from_hash



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 51

def own_styles
  @own_styles
end

#parent ⇒ Object

The parent of the style sheet, or nil if this is the top one.



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 44

def parent
  @parent
end

Class Method Details

.current_sheet ⇒ Object 



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 152

def self.current_sheet()
  return @sheet
end

.enter_scope ⇒ Object 



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 140

def self.enter_scope()
  @sheet = StyleSheet.new(@sheet)
end

.get_parent(cls, style) ⇒ Object

Returns the parent style for the style (or nil should the style have no parent)

All styles (but base) derive from the corresponding “base” style.



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 75

def self.get_parent(cls, style)
  @style_parent[cls] ||= {}
  stl = @style_parent[cls][style]
  if (! stl) and (! (style == 'base'))
    return 'base'
  end
  return stl
end

.leave_scope ⇒ Object 



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 144

def self.leave_scope()
  if @sheet.parent
    @sheet = @sheet.parent
  else
    warn { "Trying to leave top-level stylesheet scope" }
  end
end

.set_parent(cls, style, parent) ⇒ Object

Sets the parent for the given style



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 65

def self.set_parent(cls, style, parent)
  @style_parent[cls] ||= {}
  @style_parent[cls][style] = parent
end

.style_for(cls, name, *args) ⇒ Object

Returns a suitable style object for the given style name, or crashes if the name isn’t known.

Additional arguments are passed to the constructor



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 134

def self.style_for(cls, name, *args)
  a = cls.new(*args)
  a.set_from_hash(@sheet.get_style_hash_for(cls, name))
  return a
end

.update_style(cls, what, values) ⇒ Object

Updates the style sheet concerning the what of class cls with the given values



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 159

def self.update_style(cls, what, values)
  StyleSheet.current_sheet.own_styles[cls] ||= {}
  StyleSheet.current_sheet.own_styles[cls][what] ||= {}
  StyleSheet.current_sheet.own_styles[cls][what].merge!(values)
end

Instance Method Details

#get_style_hash_for(cls, name) ⇒ Object

The style for the given name, including all cascading



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 115

def get_style_hash_for(cls, name)
  ps = {}
  if @parent
    ps = @parent.get_style_hash_for(cls, name);
  end
  style = own_style_hash_for(cls, name)
  style.merge!(ps) { |key, v1, v2| v1 }
  return style
end

#own_style_hash_for(cls, name) ⇒ Object

This returns the style we have in this object for the given name. Inner cascading should take place (ie object hierarchy, but not scope hierarchy).

This returns a hash that can be modified.



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# File 'lib/ctioga2/graphics/styles/sheet.rb', line 98

def own_style_hash_for(cls, name)
  p = self.class.get_parent(cls, name)
  base = {}
  if p
    base = own_style_hash_for(cls, p)
  end
  @own_styles[cls] ||= {}
  style = @own_styles[cls][name]
  if ! style
    return base
  end
  style = style.dup
  style.merge!(base) { |key, v1, v2| v1 }
  return style
end