ChartDirector 6.0 (Ruby Edition)

Color Vertical Linear Meters


          

This example demonstrates horizontal linear meters in various colors, with different color scales, and with title and value readout.

BaseMeter.addColorScale is used to create the color scales in the meters. The color scales are created with various colors, end point positions and widths at the end points.

The title and value readout are created as TextBox objects using BaseChart.addTitle and BaseChart.addTitle2, with the text box background set to the same color as that of the chart border.

Source Code Listing

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

class ColorvlinearmeterController < ApplicationController

    def index()
        @title = "Color Vertical Linear Meters"
        @ctrl_file = File.expand_path(__FILE__)
        @noOfCharts = 6
        render :template => "templates/chartview"
    end

    #
    # Render and deliver the chart
    #
    def getchart()
        # This script can draw different charts depending on the chartIndex
        chartIndex = (params["img"]).to_i

        # The value to display on the meter
        value = 74.25

        # The background and border colors of the meters
        bgColor = [0xbbddff, 0xccffcc, 0xffccff, 0xffffaa, 0xffdddd, 0xeeeeee]
        borderColor = [0x000088, 0x006600, 0x6600aa, 0xee6600, 0x880000, 0x666666]

        # Create a LinearMeter object of size 70 x 260 pixels with a 3-pixel thick rounded frame
        m = ChartDirector::LinearMeter.new(70, 260, bgColor[chartIndex], borderColor[chartIndex])
        m.setRoundedFrame(ChartDirector::Transparent)
        m.setThickFrame(3)

        # Set the scale region top-left corner at (28, 30), with size of 20 x 200 pixels. The scale
        # labels are located on the left (default - implies vertical meter)
        m.setMeter(28, 30, 20, 200)

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

        # Demostrate different types of color scales and putting them at different positions
        smoothColorScale = [0, 0x6666ff, 25, 0x00bbbb, 50, 0x00ff00, 75, 0xffff00, 100, 0xff0000]
        stepColorScale = [0, 0x33ff33, 50, 0xffff33, 80, 0xff3333, 100]
        highLowColorScale = [0, 0x6666ff, 70, ChartDirector::Transparent, 100, 0xff0000]

        if chartIndex == 0
            # Add the smooth color scale at the default position
            m.addColorScale(smoothColorScale)
        elsif chartIndex == 1
            # Add the step color scale at the default position
            m.addColorScale(stepColorScale)
        elsif chartIndex == 2
            # Add the high low scale at the default position
            m.addColorScale(highLowColorScale)
        elsif chartIndex == 3
            # Add the smooth color scale starting at x = 28 (left of scale) with zero width and
            # ending at x = 28 with 20 pixels width
            m.addColorScale(smoothColorScale, 28, 0, 28, 20)
        elsif chartIndex == 4
            # Add the smooth color scale starting at x = 38 (center of scale) with zero width and
            # ending at x = 28 with 20 pixels width
            m.addColorScale(smoothColorScale, 38, 0, 28, 20)
        else
            # Add the smooth color scale starting at x = 48 (right of scale) with zero width and
            # ending at x = 28 with 20 pixels width
            m.addColorScale(smoothColorScale, 48, 0, 28, 20)
        end

        # Add a blue (0x0000cc) pointer at the specified value
        m.addPointer(value, 0x0000cc)

        # Add a title using white (0xffffff) 8pt Arial Bold font with a border color background
        m.addTitle("Temp C", "arialbd.ttf", 8, 0xffffff).setBackground(borderColor[chartIndex])

        # Add a bottom title using white (0xffffff) 8pt Arial Bold font with a border color
        # background to display the value
        m.addTitle2(ChartDirector::Bottom, m.formatValue(value, "2"), "arialbd.ttf", 8, 0xffffff
            ).setBackground(borderColor[chartIndex])

        # 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/colorvlinearmeter.rb
#!/usr/bin/env ruby
require("chartdirector")

def createChart(chartIndex)

    # The value to display on the meter
    value = 74.25

    # The background and border colors of the meters
    bgColor = [0xbbddff, 0xccffcc, 0xffccff, 0xffffaa, 0xffdddd, 0xeeeeee]
    borderColor = [0x000088, 0x006600, 0x6600aa, 0xee6600, 0x880000, 0x666666]

    # Create a LinearMeter object of size 70 x 260 pixels with a 3-pixel thick rounded frame
    m = ChartDirector::LinearMeter.new(70, 260, bgColor[chartIndex], borderColor[chartIndex])
    m.setRoundedFrame(ChartDirector::Transparent)
    m.setThickFrame(3)

    # Set the scale region top-left corner at (28, 30), with size of 20 x 200 pixels. The scale
    # labels are located on the left (default - implies vertical meter)
    m.setMeter(28, 30, 20, 200)

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

    # Demostrate different types of color scales and putting them at different positions
    smoothColorScale = [0, 0x6666ff, 25, 0x00bbbb, 50, 0x00ff00, 75, 0xffff00, 100, 0xff0000]
    stepColorScale = [0, 0x33ff33, 50, 0xffff33, 80, 0xff3333, 100]
    highLowColorScale = [0, 0x6666ff, 70, ChartDirector::Transparent, 100, 0xff0000]

    if chartIndex == 0
        # Add the smooth color scale at the default position
        m.addColorScale(smoothColorScale)
    elsif chartIndex == 1
        # Add the step color scale at the default position
        m.addColorScale(stepColorScale)
    elsif chartIndex == 2
        # Add the high low scale at the default position
        m.addColorScale(highLowColorScale)
    elsif chartIndex == 3
        # Add the smooth color scale starting at x = 28 (left of scale) with zero width and ending
        # at x = 28 with 20 pixels width
        m.addColorScale(smoothColorScale, 28, 0, 28, 20)
    elsif chartIndex == 4
        # Add the smooth color scale starting at x = 38 (center of scale) with zero width and ending
        # at x = 28 with 20 pixels width
        m.addColorScale(smoothColorScale, 38, 0, 28, 20)
    else
        # Add the smooth color scale starting at x = 48 (right of scale) with zero width and ending
        # at x = 28 with 20 pixels width
        m.addColorScale(smoothColorScale, 48, 0, 28, 20)
    end

    # Add a blue (0x0000cc) pointer at the specified value
    m.addPointer(value, 0x0000cc)

    # Add a title using white (0xffffff) 8pt Arial Bold font with a border color background
    m.addTitle("Temp C", "arialbd.ttf", 8, 0xffffff).setBackground(borderColor[chartIndex])

    # Add a bottom title using white (0xffffff) 8pt Arial Bold font with a border color background
    # to display the value
    m.addTitle2(ChartDirector::Bottom, m.formatValue(value, "2"), "arialbd.ttf", 8, 0xffffff
        ).setBackground(borderColor[chartIndex])

    # Output the chart
    m.makeChart("colorvlinearmeter%s.png" % chartIndex)
end

createChart(0)
createChart(1)
createChart(2)
createChart(3)
createChart(4)
createChart(5)