Added the Gruff library to the lib/ directory of the the rails folder, and the

[selectricity-live] / lib / gruff-0.2.8 / lib / gruff / line.rb

diff --git a/lib/gruff-0.2.8/lib/gruff/line.rb b/lib/gruff-0.2.8/lib/gruff/line.rb
new file mode 100644 (file)
index 0000000..72416b2
--- /dev/null
+++ b/lib/gruff-0.2.8/lib/gruff/line.rb
@@ -0,0 +1,94 @@
+
+require File.dirname(__FILE__) + '/base'
+
+class Gruff::Line < Gruff::Base
+
+  # Draw a dashed line at the given value
+  attr_accessor :baseline_value
+       
+  # Color of the baseline
+  attr_accessor :baseline_color
+  
+  # Hide parts of the graph to fit more datapoints, or for a different appearance.
+  attr_accessor :hide_dots, :hide_lines
+
+  # Call with target pixel width of graph (800, 400, 300), and/or 'false' to omit lines (points only).
+  #
+  #  g = Gruff::Line.new(400) # 400px wide with lines
+  #
+  #  g = Gruff::Line.new(400, false) # 400px wide, no lines (for backwards compatibility)
+  #
+  #  g = Gruff::Line.new(false) # Defaults to 800px wide, no lines (for backwards compatibility)
+  # 
+  # The preferred way is to call hide_dots or hide_lines instead.
+  def initialize(*args)
+    raise ArgumentError, "Wrong number of arguments" if args.length > 2
+    if args.empty? or ((not Numeric === args.first) && (not String === args.first)) then
+      super()
+    else
+      super args.shift
+    end
+    
+    @hide_dots = @hide_lines = false
+    @baseline_color = 'red'
+    @baseline_value = nil
+  end
+
+  def draw
+    super
+
+    return unless @has_data
+    
+    # Check to see if more than one datapoint was given. NaN can result otherwise.  
+    @x_increment = (@column_count > 1) ? (@graph_width / (@column_count - 1).to_f) : @graph_width
+     
+    if (defined?(@norm_baseline)) then
+      level = @graph_top + (@graph_height - @norm_baseline * @graph_height)
+      @d = @d.push
+      @d.stroke_color @baseline_color
+      @d.fill_opacity 0.0
+      @d.stroke_dasharray(10, 20)
+      @d.stroke_width 5
+      @d.line(@graph_left, level, @graph_left + @graph_width, level)
+      @d = @d.pop
+    end
+
+    @norm_data.each do |data_row|      
+      prev_x = prev_y = nil
+
+      data_row[1].each_with_index do |data_point, index|
+        new_x = @graph_left + (@x_increment * index)
+        next if data_point.nil?
+
+        draw_label(new_x, index)
+
+        new_y = @graph_top + (@graph_height - data_point * @graph_height)
+
+        # Reset each time to avoid thin-line errors
+        @d = @d.stroke data_row[DATA_COLOR_INDEX]
+        @d = @d.fill data_row[DATA_COLOR_INDEX]
+        @d = @d.stroke_opacity 1.0
+        @d = @d.stroke_width clip_value_if_greater_than(@columns / (@norm_data.first[1].size * 4), 5.0)
+
+        if !@hide_lines and !prev_x.nil? and !prev_y.nil? then          
+          @d = @d.line(prev_x, prev_y, new_x, new_y)
+        end
+        circle_radius = clip_value_if_greater_than(@columns / (@norm_data.first[1].size * 2.5), 5.0)
+        @d = @d.circle(new_x, new_y, new_x - circle_radius, new_y) unless @hide_dots
+
+        prev_x = new_x
+        prev_y = new_y
+      end
+
+    end
+
+    @d.draw(@base_image)
+  end
+
+  def normalize
+    @maximum_value = [@maximum_value.to_f, @baseline_value.to_f].max
+    super
+    @norm_baseline = (@baseline_value.to_f / @maximum_value.to_f) if @baseline_value
+  end
+  
+end