This directory serves as an example on how to build applications using Qt and EPICS. Three directories are present, with each representing a more complicated and complete implementation of the build.
The end goal is to produce an application that monitors pvRecords hosted on a V4 database. It's GUI will be implemented using Qt. The GUI will facilitate the monitoring of multiple records in its final state.
Getting up and running. This is a simple application that requests data from a record and then displays it in a text box. The GUI implements a tab mechanism, allowing multiple records' data to be viewed at once.
The moc_put.cpp file is the output of the Qt 'moc' program. 'moc' means Meta Object Comiler. This file is generated, and does not have to be written.
Beta builds on alpha by splitting the code up into a model/view relationship. The model uses EPICS, and the view uses Qt. In this way the model can be dislocated from the GUI and used for other purposes.
Gamma represents the final product and the largest leap from version to version. It implements multithreading in the model to allow monitoring of multiple records. This is necessary becuase the monitor will block the current thread as it waits for changes in the record's data. The GUI also changes some, as it needs to make use of the model's monitoring functionality. This is done by adding a timer that updates the local data to match that retrieved by the monitor. The polling rate set by the timer is currently 250 milliseconds. The performace of the application at this rate is acceptable. Higher polling rates have not been experimented with. Though it is doubtful it would cause any real performace issue, the effects of higher polling rates are unknown.