ChartDirector 6.0 (Ruby Edition)

Horizontal Bar Meter




This example demonstrates the basic steps in creating a horizontal bar meter.

A horizontal bar meter can be created using the following steps:

Source Code Listing

[Ruby On Rails Version - Controller] app/controllers/hbarmeter_controller.rb
require("chartdirector")

class HbarmeterController < ApplicationController

    def index()
        @title = "Horizontal Bar Meter"
        @ctrl_file = File.expand_path(__FILE__)
        @noOfCharts = 1
        render :template => "templates/chartview"
    end

    #
    # Render and deliver the chart
    #
    def getchart()
        # The value to display on the meter
        value = 75.35

        # Create an LinearMeter object of size 260 x 66 pixels with a very light grey (0xeeeeee)
        # background, and a rounded 3-pixel thick light grey (0xaaaaaa) border
        m = ChartDirector::LinearMeter.new(260, 66, 0xeeeeee, 0xaaaaaa)
        m.setRoundedFrame(ChartDirector::Transparent)
        m.setThickFrame(3)

        # Set the scale region top-left corner at (18, 24), with size of 222 x 20 pixels. The scale
        # labels are located on the top (implies horizontal meter)
        m.setMeter(18, 24, 222, 20, ChartDirector::Top)

        # Set meter scale from 0 - 100, with a tick every 10 units
        m.setScale(0, 100, 10)

        # Add a 5-pixel thick smooth color scale to the meter at y = 48 (below the meter scale)
        smoothColorScale = [0, 0x0000ff, 25, 0x0088ff, 50, 0x00ff00, 75, 0xffff00, 100, 0xff0000]
        m.addColorScale(smoothColorScale, 48, 5)

        # Add a light blue (0x0088ff) bar from 0 to the data value with glass effect and 4 pixel
        # rounded corners
        m.addBar(0, value, 0x0088ff, ChartDirector::glassEffect(ChartDirector::NormalGlare,
            ChartDirector::Top), 4)

        # Output the chart
        send_data(m.makeChart2(ChartDirector::PNG), :type => "image/png", :disposition => "inline")

    end

end

[Ruby On Rails Version - View] app/views/templates/chartview.html.erb
<html>
<body style="margin:5px 0px 0px 5px">

<!-- Title -->
<div style="font-size:18pt; font-family:verdana; font-weight:bold">
    <%= @title %>
</div>
<hr style="border:solid 1px #000080" />

<!-- Source Code Listing Link -->
<div style="font-size:9pt; font-family:verdana; margin-bottom:1.5em">
    <%= link_to "Source Code Listing", 
        :controller => "cddemo", :action => "viewsource",
        :ctrl_file => @ctrl_file, :view_file => File.expand_path(__FILE__) %>
</div>

<!-- Create one or more IMG tags to display the demo chart(s) -->
<% 0.upto(@noOfCharts - 1) do |i| %>
    <img src="<%= url_for(:action => "getchart", :img => i) %>">
<% end %>

</body>
</html>

[Command Line Version] rubydemo/hbarmeter.rb
#!/usr/bin/env ruby
require("chartdirector")

# The value to display on the meter
value = 75.35

# Create an LinearMeter object of size 260 x 66 pixels with a very light grey (0xeeeeee) background,
# and a rounded 3-pixel thick light grey (0xaaaaaa) border
m = ChartDirector::LinearMeter.new(260, 66, 0xeeeeee, 0xaaaaaa)
m.setRoundedFrame(ChartDirector::Transparent)
m.setThickFrame(3)

# Set the scale region top-left corner at (18, 24), with size of 222 x 20 pixels. The scale labels
# are located on the top (implies horizontal meter)
m.setMeter(18, 24, 222, 20, ChartDirector::Top)

# Set meter scale from 0 - 100, with a tick every 10 units
m.setScale(0, 100, 10)

# Add a 5-pixel thick smooth color scale to the meter at y = 48 (below the meter scale)
smoothColorScale = [0, 0x0000ff, 25, 0x0088ff, 50, 0x00ff00, 75, 0xffff00, 100, 0xff0000]
m.addColorScale(smoothColorScale, 48, 5)

# Add a light blue (0x0088ff) bar from 0 to the data value with glass effect and 4 pixel rounded
# corners
m.addBar(0, value, 0x0088ff, ChartDirector::glassEffect(ChartDirector::NormalGlare,
    ChartDirector::Top), 4)

# Output the chart
m.makeChart("hbarmeter.png")