Introduction to the GUI
***********************

GUI Elements
============

Treeview Browser
----------------
The treeview browser is the left panel of 
VDAT. Each night of observation in the `redux/` directory
is displayed. Underneath you can select different calibration 
(arc and flat), science or bias (zero) images. Which is 
selected is then used as the target of all the other VDAT 
commands. You can also click on the tick box next the calibration
and bias directories, to select that directory to be used as 
calibration for the rest of the reduction. 


Main Panel
----------
The main panel is the central panel of VDAT that
displays an image of the focal plane. What is displayed
depends on the type of file selected in the treeview
browser. When there are OFU widgets in this panel
they can be hovered over, to display the IFUID and IFUSLOTID.
IFUs can be selected and deselected by left clicking. Any
commands clicked on the buttons menu only act on the
selected IFUs. The IFU widgets can lso be double clicked to
load an IFU viewer.

IFU Viewer
----------
The IFU viewer is window that displays detailed information
about a particular IFU. It is loaded when an IFU widget in
the main panel is double-clicked


GUI Advanced Configuration
==========================

Tabs Config File
----------------
The ``tabs.yml`` file in the configuration directory controls
what is displayed in the IFU viewer and the main panel. This configuration is 
written in `YAML <http://yaml.org/>`_. Note that YAML is sensitive to 
the indentation. What configuration is used depends on the type of selected
folder, the different configurations are under the heading
``zro, cal, sci``.


Configuring the IFU viewer
--------------------------
The IFU viewer that pops up when you double click an IFU is configured
using the `ifu_viewer` subsection under each of the ``zro, cal, sci``
directory types. The section `header_keys` gives a list of header
keys to display in the bottom panel of the IFU viewer, these header
keys are extracted from the header of the currently in focus file.
The ``tabs`` section descibes each of the tabs on the IFU viewer. The format
is::

    tabs: &fcommon
        raw: #  name of the tab 
            regex: '[0-9]*_{ihmpid}{channel}{amp}_*.fits' # regular expression used to find the files
            channel: ['L', 'R'] # channels to loop over
            amp: ['U', 'L'] # amplifiers to loop over 
            #order of channel and amp determines position in window

The IFU viewer creates a tab and fills it with a grid of `Ginga <http://ginga.readthedocs.org/en/latest/index.html>`_ fits viewers. 
The grid dimensions depend on which channels and amps are present (if any), i.e is you have L, R 
channels and U, L amps like in the example above, you get a 2x2 grid.

You can have different tabs for different types of directory simply by have different configurations in the `tabs:` section.

Configuring the main panel
--------------------------
The configuration for the main panel for each type can be found under
the `main:` subsections of the YAML file.