Simple Gantt Chart

This example demonstrates a simple gantt chart.

This chart is created by using a horizontal box-whisker layer, in which only the "box" part of the box-whisker layer is used. Date/time values are used as box data, resulting in a gantt chart.

The key features demonstrated in this example are:

Create the box-whisker layer using XYChart.addBoxWhiskerLayer, in which the data arrays are dates.
Swap the x-axis and y-axis using XYChart.swapXY, so the chart is using a horizontal orientation.
Use XYChart.setYAxisOnRight to move the y-axis to the opposite side of the plot area, so that the y-axis is at the top of the plot area. (Note: the "right" word on setYAxisOnRight means the "right" side before "swapXY" rotation. After rotation, the right side will become to top side.)
Use Axis.setReverse to reverse the direction of the x-axis, so that the x-axis is vertical from top to bottom (instead of from bottom to top).
Set the y-axis to date scale using Axis.setDateScale.
Set multi-format axis labels for the y-axis using Axis.setMultiFormat. Note that the labels for the first week of the month are in bold, with the month name shown. The other labels just show the day.
Use alternative background colors for the plot area by providing two background colors when calling XYChart.setPlotArea.

The following is the command line version of the code in "cppdemo/gantt". The MFC version of the code is in "mfcdemo/mfcdemo". The Qt Widgets version of the code is in "qtdemo/qtdemo". The QML/Qt Quick version of the code is in "qmldemo/qmldemo".

#include "chartdir.h"

int main(int argc, char *argv[])
{
    // data for the gantt chart, representing the start date, end date and names for various
    // activities
    double startDate[] = {Chart::chartTime(2004, 8, 16), Chart::chartTime(2004, 8, 30),
        Chart::chartTime(2004, 9, 13), Chart::chartTime(2004, 9, 20), Chart::chartTime(2004, 9, 27),
        Chart::chartTime(2004, 10, 4), Chart::chartTime(2004, 10, 25), Chart::chartTime(2004, 11, 1
        ), Chart::chartTime(2004, 11, 8)};
    const int startDate_size = (int)(sizeof(startDate)/sizeof(*startDate));
    double endDate[] = {Chart::chartTime(2004, 8, 30), Chart::chartTime(2004, 9, 13),
        Chart::chartTime(2004, 9, 27), Chart::chartTime(2004, 10, 4), Chart::chartTime(2004, 10, 11
        ), Chart::chartTime(2004, 11, 8), Chart::chartTime(2004, 11, 8), Chart::chartTime(2004, 11,
        22), Chart::chartTime(2004, 11, 22)};
    const int endDate_size = (int)(sizeof(endDate)/sizeof(*endDate));
    const char* labels[] = {"Market Research", "Define Specifications", "Overall Archiecture",
        "Project Planning", "Detail Design", "Software Development", "Test Plan", "Testing and QA",
        "User Documentation"};
    const int labels_size = (int)(sizeof(labels)/sizeof(*labels));

    // Create a XYChart object of size 620 x 280 pixels. Set background color to light blue
    // (ccccff), with 1 pixel 3D border effect.
    XYChart* c = new XYChart(620, 280, 0xccccff, 0x000000, 1);

    // Add a title to the chart using 15 points Times Bold Itatic font, with white (ffffff) text on
    // a deep blue (000080) background
    c->addTitle("Simple Gantt Chart Demo", "Times New Roman Bold Italic", 15, 0xffffff
        )->setBackground(0x000080);

    // Set the plotarea at (140, 55) and of size 460 x 200 pixels. Use alternative white/grey
    // background. Enable both horizontal and vertical grids by setting their colors to grey
    // (c0c0c0). Set vertical major grid (represents month boundaries) 2 pixels in width
    c->setPlotArea(140, 55, 460, 200, 0xffffff, 0xeeeeee, Chart::LineColor, 0xc0c0c0, 0xc0c0c0
        )->setGridWidth(2, 1, 1, 1);

    // swap the x and y axes to create a horziontal box-whisker chart
    c->swapXY();

    // Set the y-axis scale to be date scale from Aug 16, 2004 to Nov 22, 2004, with ticks every 7
    // days (1 week)
    c->yAxis()->setDateScale(Chart::chartTime(2004, 8, 16), Chart::chartTime(2004, 11, 22), 86400 *
        7);

    // Set multi-style axis label formatting. Month labels are in Arial Bold font in "mmm d" format.
    // Weekly labels just show the day of month and use minor tick (by using '-' as first character
    // of format string).
    c->yAxis()->setMultiFormat(Chart::StartOfMonthFilter(), "<*font=Arial Bold*>{value|mmm d}",
        Chart::StartOfDayFilter(), "-{value|d}");

    // Set the y-axis to shown on the top (right + swapXY = top)
    c->setYAxisOnRight();

    // Set the labels on the x axis
    c->xAxis()->setLabels(StringArray(labels, labels_size));

    // Reverse the x-axis scale so that it points downwards.
    c->xAxis()->setReverse();

    // Set the horizontal ticks and grid lines to be between the bars
    c->xAxis()->setTickOffset(0.5);

    // Add a green (33ff33) box-whisker layer showing the box only.
    c->addBoxWhiskerLayer(DoubleArray(startDate, startDate_size), DoubleArray(endDate, endDate_size
        ), DoubleArray(), DoubleArray(), DoubleArray(), 0x00cc00, Chart::SameAsMainColor,
        Chart::SameAsMainColor);

    // Output the chart
    c->makeChart("gantt.png");

    //free up resources
    delete c;

    return 0;
}