The example shows how to plot a two-dimensional intensity map as a colormap
using wrappers around qcustomplot library.
The application model contains a collection of various items to properly
separate scientific data from presentation data.
It's an item to hold buffer of double values, holding 2D data, and the
information about axis binning. Data2DItem is not intended for direct plotting
and needs ColorMapItem for that.
It's an item that contains a link to certain Data2DItem and serves as a
wrapper around scientific data. Its main purpose is to carry the additional data
for presentation purposes: the title of the graph, the gradient of a heat map,
etc. ColorMapItem is not intended for direct plotting and needs
ColorMapViewportItem for that.
It's an item that can have an arbitrary amount of ColorMapItem's on board.
Additionally, it contains items to store the data related to viewport axes:
current zoom level, axis title, color bar data, etc. ColorMapItem needs
ColorMapCanvas for plotting.
It is a widget, wrapper around QCustomPlot, provided with status string. It
shows the content of ColorMapViewportItem on the screen and establishes the
signaling between QCustomPlot and SessionModel. When the user zooms in into
QCustomPlot with the mouse wheel or drag color bar, the data of the model is
updated. Similarly, when data is updated in a model via some tree or table view,
the changes are propagated back to qcustomplot. If the user saves a project
file, all zoom levels and, possibly, other settings of qcustomplot can be
automatically preserved.