class Demo::CairoTextExtents

Constants

TEXT

Public Class Methods

new() click to toggle source
Calls superclass method
# File gtk2/sample/gtk-demo/cairo-text-extents.rb, line 17
def initialize
  super('cairo text')
end

Public Instance Methods

draw(cr) click to toggle source
# File gtk2/sample/gtk-demo/cairo-text-extents.rb, line 21
def draw(cr)
  cr.select_font_face("Sans",
                          Cairo::FONT_SLANT_NORMAL,
                          Cairo::FONT_WEIGHT_NORMAL)
  
  cr.set_font_size(0.3)
  extents = cr.text_extents(TEXT)
  
  x = 0.1
  y = 0.6
  
  cr.move_to(x, y)
  cr.show_text(TEXT)
  
  # draw helping lines
  cr.set_source_rgba(1, 0.2, 0.2, 0.6)
  cr.arc(x, y, 0.05, 0, 2 * Math::PI)
  cr.fill
  cr.move_to(x, y)
  cr.rel_line_to(0, -extents.height)
  cr.rel_line_to(extents.width, 0)
  cr.rel_line_to(extents.x_bearing, -extents.y_bearing)
  cr.stroke
end