Module: Gruff::Mini::Legend

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

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 5

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 5

def legend_position
  @legend_position
end

Instance Method Details

#calculate_legend_width ⇒ Object 



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# File 'lib/gruff/mini/legend.rb', line 36

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 32

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 44

def draw_vertical_legend
  return if @hide_mini_legend

  legend_square_width = 40.0 # small square with color of this item
  legend_square_margin = 10.0
  @legend_left_margin = 100.0
  legend_top_margin = 40.0

  # May fix legend drawing problem at small sizes
  @d.font = @font if @font
  @d.pointsize = @legend_font_size

  case @legend_position
  when :right then
    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

  debug { @d.line 0.0, current_y_offset, @raw_columns, current_y_offset }

  @legend_labels.each_with_index do |legend_label, index|

    # Draw label
    @d.fill = @font_color
    @d.font = @font if @font
    @d.pointsize = scale_fontsize(@legend_font_size)
    @d.stroke = 'transparent'
    @d.font_weight = Magick::NormalWeight
    @d.gravity = Magick::WestGravity
    @d = @d.annotate_scaled( @base_image,
                             @raw_columns, 1.0,
                             current_x_offset + (legend_square_width * 1.7), current_y_offset,
                             truncate_legend_label(legend_label), @scale)

    # Now draw box with color of this dataset
    @d = @d.stroke 'transparent'
    @d = @d.fill @data[index][Gruff::Base::DATA_COLOR_INDEX]
    @d = @d.rectangle(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
  @color_index = 0
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 10

def expand_canvas_for_vertical_legend
  return if @hide_mini_legend

  @legend_labels = @data.collect {|item| item[Gruff::Base::DATA_LABEL_INDEX] }

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

  @original_rows = @raw_rows
  @original_columns = @raw_columns

  case @legend_position
  when :right then
    @rows = [@rows, legend_height].max
    @columns += calculate_legend_width + @left_margin
  else
    @rows += @data.length * calculate_caps_height(scale_fontsize(@legend_font_size)) * 1.7
  end
  render_background
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 99

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