ChartDirector 6.0 (C++ Edition)

Angular Meter Pointers (1)




This example demonstrates adding multiple classical pointers of different styles to a meter.

For angular meters, classical pointers are added using BaseMeter.addPointer, while new style pointers are added using AngularMeter.addPointer2.

Comparing to new style pointers, classical angular pointers are thicker in shape. This enables them to express various shapes. They are designed to be pivoted to the center by a small pointer cap (the circle at the center). The classical pointer cap can be configured using AngularMeter.setCap.

This example demonstrates the 5 built-in classical angular pointer shapes, configured using MeterPointer.setShape. ChartDirector also supports custom shapes configured using MeterPointer.setShape2.

Source Code Listing

[The following code is available in "cppdemo/angularpointer". 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"

int main(int argc, char *argv[])
{
    // Create an AngularMeter object of size 300 x 300 pixels with transparent background
    AngularMeter *m = new AngularMeter(300, 300, Chart::Transparent);

    // Set the default text and line colors to white (0xffffff)
    m->setColor(Chart::TextColor, 0xffffff);
    m->setColor(Chart::LineColor, 0xffffff);

    // Center at (150, 150), scale radius = 128 pixels, scale angle 0 to 360 degrees
    m->setMeter(150, 150, 128, 0, 360);

    // Add a black (0x000000) circle with radius 148 pixels as background
    m->addRing(0, 148, 0x000000);

    // Add a ring between radii 139 and 147 pixels using the silver color with a light grey
    // (0xcccccc) edge as border
    m->addRing(139, 147, Chart::silverColor(), 0xcccccc);

    // Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units
    m->setScale(0, 100, 10, 5, 1);

    // Set the scale label style to 16pt Arial Italic. Set the major/minor/micro tick lengths to
    // 13/10/7 pixels pointing inwards, and their widths to 2/1/1 pixels.
    m->setLabelStyle("ariali.ttf", 16);
    m->setTickLength(-13, -10, -7);
    m->setLineWidth(0, 2, 1, 1);

    // Add a semi-transparent blue (0x7f6666ff) pointer using the default shape
    m->addPointer(25, 0x7f6666ff, 0x6666ff);

    // Add a semi-transparent red (0x7fff6666) pointer using the arrow shape
    m->addPointer(9, 0x7fff6666, 0xff6666)->setShape(Chart::ArrowPointer2);

    // Add a semi-transparent yellow (0x7fffff66) pointer using another arrow shape
    m->addPointer(51, 0x7fffff66, 0xffff66)->setShape(Chart::ArrowPointer);

    // Add a semi-transparent green (0x7f66ff66) pointer using the line shape
    m->addPointer(72, 0x7f66ff66, 0x66ff66)->setShape(Chart::LinePointer);

    // Add a semi-transparent grey (0x7fcccccc) pointer using the pencil shape
    m->addPointer(85, 0x7fcccccc, 0xcccccc)->setShape(Chart::PencilPointer);

    // Output the chart
    m->makeChart("angularpointer.png");

    //free up resources
    delete m;
    return 0;
}