ChartDirector 6.0 (C++ 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

[The following code is available in "cppdemo/colorhlinearmeter". A MFC version of the code is available in "mfcdemo/mfcdemo" (Windows edition only). A QT version of the code is available in "qtdemo/qtdemo".]
#include "chartdir.h"

void createChart(int chartIndex, const char *filename)
{
    // The value to display on the meter
    double value = 74.25;

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

    // Create a LinearMeter object of size 250 x 75 pixels with a 3-pixel thick rounded frame
    LinearMeter *m = new LinearMeter(250, 75, bgColor[chartIndex], borderColor[chartIndex]);
    m->setRoundedFrame(Chart::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, Chart::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
    double smoothColorScale[] = {0, 0x6666ff, 25, 0x00bbbb, 50, 0x00ff00, 75, 0xffff00, 100,
        0xff0000};
    double stepColorScale[] = {0, 0x33ff33, 50, 0xffff33, 80, 0xff3333, 100};
    double highLowColorScale[] = {0, 0x6666ff, 70, Chart::Transparent, 100, 0xff0000};

    if (chartIndex == 0) {
        // Add the smooth color scale at the default position
        m->addColorScale(DoubleArray(smoothColorScale, (int)(sizeof(smoothColorScale) / sizeof(
            smoothColorScale[0]))));
    } else if (chartIndex == 1) {
        // Add the step color scale at the default position
        m->addColorScale(DoubleArray(stepColorScale, (int)(sizeof(stepColorScale) / sizeof(
            stepColorScale[0]))));
    } else if (chartIndex == 2) {
        // Add the high low scale at the default position
        m->addColorScale(DoubleArray(highLowColorScale, (int)(sizeof(highLowColorScale) / sizeof(
            highLowColorScale[0]))));
    } else if (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(DoubleArray(smoothColorScale, (int)(sizeof(smoothColorScale) / sizeof(
            smoothColorScale[0]))), 23, 0, 23, 20);
    } else if (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(DoubleArray(smoothColorScale, (int)(sizeof(smoothColorScale) / sizeof(
            smoothColorScale[0]))), 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(DoubleArray(smoothColorScale, (int)(sizeof(smoothColorScale) / sizeof(
            smoothColorScale[0]))), 43, 0, 23, 20);
    }

    // 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, Chart::TextColor, Chart::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.
    TextBox *t = m->addText(235, 61, m->formatValue(value, "2"), "arialbd.ttf", 8, 0xffffff,
        Chart::Right);
    t->setBackground(0x000000, 0x000000, -1);
    t->setRoundedCorners(3);

    // Output the chart
    m->makeChart(filename);

    //free up resources
    delete m;
}

int main(int argc, char *argv[])
{
    createChart(0, "colorhlinearmeter0.png");
    createChart(1, "colorhlinearmeter1.png");
    createChart(2, "colorhlinearmeter2.png");
    createChart(3, "colorhlinearmeter3.png");
    createChart(4, "colorhlinearmeter4.png");
    createChart(5, "colorhlinearmeter5.png");
    return 0;
}