== Main components

Gst-qa is composed of 3 parts: the monitors, the runner and the reports.

= Monitors
The monitors are used to wrap around pipeline (and elements and pads) and
attach to its data flow handling functions to be able to intercept the data
and compare it with the expected behaviors. There are 3 types of monitors:

  * GstQaElementMonitor
  * GstQaBinMonitor
  * GstQaPadMonitor

All 3 inherit from the base GstQaMonitor class. Their name suggest what they
monitor and they have a relationship to their children and parents. A bin
monitor has, possibly, child element monitors and element monitors have child
pad monitors. The monitors are responsible for listenning to new childs added
to their monitored object and creating monitors for them. For example, element
monitors listen to element's pad-added signal and create pad monitors whenever
a new pad is added.

Most (if not all) the checks are implemented at the GstQaPadMonitor, as it is
where the data flow happens.

= Runner
The GstQaRunner is the point of communication for the app to gst-qa
monitoring. It provides an API to start monitoring a pipeline and then to
access the results.

= Reports
The GstQaReports are created when a check fails, it is posted to the runner
with information about the element that found the problem, along with details
about it.