Module: Gruff::Mini::Legend

Included in:
Bar, Pie, SideBar
Defined in:
lib/gruff/mini/legend.rb

Overview

A module to handle the small legend.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#hide_mini_legend ⇒ Object

Returns the value of attribute hide_mini_legend.



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# File 'lib/gruff/mini/legend.rb', line 7

def hide_mini_legend
  @hide_mini_legend
end

#legend_position ⇒ Object

Returns the value of attribute legend_position.



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# File 'lib/gruff/mini/legend.rb', line 7

def legend_position
  @legend_position
end

Instance Method Details

#calculate_legend_width ⇒ Object 



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# File 'lib/gruff/mini/legend.rb', line 43

def calculate_legend_width
  width = @legend_labels.map { |label| calculate_width(@legend_font_size, label) }.max
  scale_fontsize(width + 40 * 1.7)
end

#calculate_line_height ⇒ Object 



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# File 'lib/gruff/mini/legend.rb', line 39

def calculate_line_height
  calculate_caps_height(@legend_font_size) * 1.7
end

#draw_vertical_legend ⇒ Object

Draw the legend beneath the existing graph.



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# File 'lib/gruff/mini/legend.rb', line 51

def draw_vertical_legend
  return if @hide_mini_legend

  legend_square_width = 40.0 # small square with color of this item
  @legend_left_margin = 100.0
  legend_top_margin = 40.0

  case @legend_position
  when :right
    current_x_offset = @original_columns + @left_margin
    current_y_offset = @top_margin + legend_top_margin
  else
    current_x_offset = @legend_left_margin
    current_y_offset = @original_rows + legend_top_margin
  end

  @legend_labels.each_with_index do |legend_label, index|
    # Draw label
    label = truncate_legend_label(legend_label)
    text_renderer = Gruff::Renderer::Text.new(label, font: @font, size: @legend_font_size, color: @font_color)
    x_offset = current_x_offset + (legend_square_width * 1.7)
    text_renderer.add_to_render_queue(@raw_columns, 1.0, x_offset, current_y_offset, Magick::WestGravity)

    # Now draw box with color of this dataset
    rect_renderer = Gruff::Renderer::Rectangle.new(color: store.data[index].color)
    rect_renderer.render(current_x_offset,
                         current_y_offset - legend_square_width / 2.0,
                         current_x_offset + legend_square_width,
                         current_y_offset + legend_square_width / 2.0)

    current_y_offset += calculate_line_height
  end
end

#expand_canvas_for_vertical_legend ⇒ Object

The canvas needs to be bigger so we can put the legend beneath it.



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# File 'lib/gruff/mini/legend.rb', line 18

def expand_canvas_for_vertical_legend
  return if @hide_mini_legend

  @legend_labels = store.data.map(&:label)

  legend_height = scale_fontsize(store.length * calculate_line_height + @top_margin + @bottom_margin)

  @original_rows = @raw_rows
  @original_columns = @raw_columns

  case @legend_position
  when :right
    @rows = [@rows, legend_height].max
    @columns += calculate_legend_width + @left_margin
  else
    @rows += store.length * calculate_caps_height(scale_fontsize(@legend_font_size)) * 1.7
  end

  Gruff::Renderer.setup(@columns, @rows, @font, @scale, @theme_options)
end

#initialize ⇒ Object 



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# File 'lib/gruff/mini/legend.rb', line 9

def initialize(*)
  @hide_mini_legend = false
  @legend_position = nil
  super
end

#truncate_legend_label(label) ⇒ Object

Shorten long labels so they will fit on the canvas.

Department of Hu...



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# File 'lib/gruff/mini/legend.rb', line 90

def truncate_legend_label(label)
  truncated_label = label.to_s

  font_size = scale_fontsize(@legend_font_size)
  max_width = @columns - @legend_left_margin - @right_margin
  while calculate_width(font_size, truncated_label) > max_width && truncated_label.length > 1
    truncated_label = truncated_label[0..truncated_label.length - 2]
  end
  truncated_label + (truncated_label.length < label.to_s.length ? '...' : '')
end