Interface

In order to edit E-part's GUI, the Glade program is used. The interface file is stored on "data/epart.ui", in the package source tree.

The E-part program is designed for a screen only device, with touch sensing and possibly mouse left/rigth buttons capture from usb/bluetooth foot switches. Vizualization area must be optimized, the program should run maximized, preferably with no window decorations.

Whenever the user is prompted for some alphanumeric input, a simple virtual keyboard should be displayed enabling touch screen text entry.

In order to display music, the user should define playlists (programs) and select one score there for displaying it. So, there are three application screens:

1. Display
2. Config
3. File chooser

Each of them must fit in the same window: or the program is being configured or it is displaying some music score. A toggle button is used to alternate between these modes. When configuring, the user may be prompted to indicate some pdf-file, so the need for the third screen, the file-chooser.

Display mode

This is the main application screen, and it has as less controls as possible, which are concentrated in a button bar in the left. In the rigth side there is the scrolling bar with a tiny numerical display.

The button bar provides the following functions:

1. Play/pause
2. Advance to next park-position on the current score
3. Go back to previous park-position on the current score
4. Show/edit park-positions
5. Show/edit timing for park-positions
6. Go to previous score in the current program
7. Go to next score in the current program
8. Alternate between display/config modes

Editing park-positions

When paused, the user is able to edit park-positions and their timings.

To add some park-position, scroll the music score to the desired point and add define some number in the park-position button. The value entered will be rounded to an integer and inserted as needed in the ordered values already defined.

Then press the timings button to define how many time in seconds will this park-position be showed until automatic flip leads to the next one. If zero or negative value is used, automatic flip is disabled. If empty value is defined, the park-position is deleted.

Park-position information is saved in text-file, human-readable form, along with each pdf-file, using the same filename, but with ".epart" extension.

When going to config mode, all the controls from 1 to 7 become insensitive.

Config mode

The configuration screen provides two panes, one for defining the programs (playlists) and the other to show the scores for each selected program.

Both panes shares three controls: add, edit and remove, but this last one presents an extra checkbox for exclusion confirmation. The actuation of the controls depends on the selected pane, and will call functions accordingly.

When adding or editing scores, the file-chooser dialog will allow the user to browse the file system and choose an existing pdf-file as music score.

Selection on which score to display is made directly over the lists presented in each panel, they are clickable and even sortable.

The information configured here is saved in text human-readable form, one line for each program name, followed by its score paths on the following lines. The begining of paths have a ":" marker or "@" for the selected one. When no ":" or "@" is present, a new program is so defined.

This config file is usually located at: $HOME/.local/share/epart/programs.lst