ChartDirector 6.0 (Ruby Edition)

Color Horizontal 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 by with different colors, different end point positions and different widths at the end points.

The title and value readout are created using BaseChart.addText. The value readout is configured to have a black background and a depressed border using Box.setBackground, and with rounded corners using Box.setRoundedCorners.

Source Code Listing

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

class ColorhlinearmeterController < ApplicationController

    def index()
        @title = "Color Horizontal 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 250 x 75 pixels with a 3-pixel thick rounded frame
        m = ChartDirector::LinearMeter.new(250, 75, bgColor[chartIndex], borderColor[chartIndex])
        m.setRoundedFrame(ChartDirector::Transparent)
        m.setThickFrame(3)

        # Set the scale region top-left corner at (14, 23), with size of 218 x 20 pixels. The scale
        # labels are located on the top (implies horizontal meter)
        m.setMeter(14, 23, 218, 20, ChartDirector::Top)

        # 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 y = 23 (top of scale) with zero width and
            # ending at y = 23 with 20 pixels width
            m.addColorScale(smoothColorScale, 23, 0, 23, 20)
        elsif chartIndex == 4
            # Add the smooth color scale starting at y = 33 (center of scale) with zero width and
            # ending at y = 23 with 20 pixels width
            m.addColorScale(smoothColorScale, 33, 0, 23, 20)
        else
            # Add the smooth color scale starting at y = 43 (bottom of scale) with zero width and
            # ending at y = 23 with 20 pixels width
            m.addColorScale(smoothColorScale, 43, 0, 23, 20)
        end

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

        # Add a label left aligned to (10, 61) using 8pt Arial Bold font
        m.addText(10, 61, "Temperature C", "arialbd.ttf", 8, ChartDirector::TextColor,
            ChartDirector::Left)

        # Add a text box right aligned to (235, 61). Display the value using white (0xffffff) 8pt
        # Arial Bold font on a black (0x000000) background with depressed rounded border.
        t = m.addText(235, 61, m.formatValue(value, "2"), "arialbd.ttf", 8, 0xffffff,
            ChartDirector::Right)
        t.setBackground(0x000000, 0x000000, -1)
        t.setRoundedCorners(3)

        # 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/colorhlinearmeter.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 250 x 75 pixels with a 3-pixel thick rounded frame
    m = ChartDirector::LinearMeter.new(250, 75, bgColor[chartIndex], borderColor[chartIndex])
    m.setRoundedFrame(ChartDirector::Transparent)
    m.setThickFrame(3)

    # Set the scale region top-left corner at (14, 23), with size of 218 x 20 pixels. The scale
    # labels are located on the top (implies horizontal meter)
    m.setMeter(14, 23, 218, 20, ChartDirector::Top)

    # 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 y = 23 (top of scale) with zero width and ending at
        # y = 23 with 20 pixels width
        m.addColorScale(smoothColorScale, 23, 0, 23, 20)
    elsif chartIndex == 4
        # Add the smooth color scale starting at y = 33 (center of scale) with zero width and ending
        # at y = 23 with 20 pixels width
        m.addColorScale(smoothColorScale, 33, 0, 23, 20)
    else
        # Add the smooth color scale starting at y = 43 (bottom of scale) with zero width and ending
        # at y = 23 with 20 pixels width
        m.addColorScale(smoothColorScale, 43, 0, 23, 20)
    end

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

    # Add a label left aligned to (10, 61) using 8pt Arial Bold font
    m.addText(10, 61, "Temperature C", "arialbd.ttf", 8, ChartDirector::TextColor,
        ChartDirector::Left)

    # Add a text box right aligned to (235, 61). Display the value using white (0xffffff) 8pt Arial
    # Bold font on a black (0x000000) background with depressed rounded border.
    t = m.addText(235, 61, m.formatValue(value, "2"), "arialbd.ttf", 8, 0xffffff,
        ChartDirector::Right)
    t.setBackground(0x000000, 0x000000, -1)
    t.setRoundedCorners(3)

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

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