xgbsplay: add simple graphical interface

[mmitch]

I've created a small demo implementation of an X11 gbsplay client. Now that we have the .desktop file integration, it is quite nice to just click and play a file – and even nicer when gbsplay does not spawn an extra terminal :-)

Please share your thoughts on whether this works for you, if it is a good or bad idea and if it should be merged to the master branch (and when it is, if it should be enabled or disabled by default).

how to use

Run configure --with-xgbsplay, then make, make install as usual. As both gbsplay.desktop and xgbsplay.desktop will be installed and there is no way of providing any precedence, you might have to manually switch *.gbs files from gbsplay to xgbsplay - both should be listed as supported applications.

limitations and TODOs

• I copied all of gbsplay.c into xgbsplay.c and then made some minor changes - that's a lot of duplicate code that should be refactored
• there is no real error handling for all the X11 function calls, it is still a hack in that way
• I planned to remove the usage of stdout-using plugins (iodumper, midi) as they are of little use with a graphical interface but I did not do that yet because I'd have to change or duplicate plugout_select_by_name() and plugout_list_plugins() (neither is prepared to accept a filter)
• channel mute actions (keyboard commands 1…4) are currently unsupported
• per channel and global volume bars are missing

Aaaaand the interface is plain ugly. This has multiple reasons:

• I really don't have a good idea what the interface should look like :-) (that's another reason for the missing channel mute actions - perhaps the volume bars could be used if they did exist)
• adding font support to write some text would have tripled the time I have spent in all this

[mmitch]

@ranma Care to have a look at this? I have removed most of the duplications between gbsplay.c and xgbsplay.c by moving common code to player.c. From my point of view the duplications where the biggest showstopper preventing a merge to master.

The X11 UI is still very basic, but it works. With the code deduplicated, xgbsplay in master should not lag behind gbsplay like this branch did in the last 1.5 years. Travis CI will build both gbsplay and xgbsplay, so at least compile-time problems should be caught by that. The default build configuration is still "only gbsplay", for xgbsplay you need to ./configure --with-xgsplay, so any problems with the xgbsplay code shouldn't bother anybody out there.

[codecov[bot]]

Codecov Report

Merging #22 into master will increase coverage by 0.16%. The diff coverage is 40.71%.

@@            Coverage Diff             @@
##           master      #22      +/-   ##
==========================================
+ Coverage   41.97%   42.13%   +0.16%     
==========================================
  Files          18       19       +1     
  Lines        2716     2727      +11     
==========================================
+ Hits         1140     1149       +9     
- Misses       1576     1578       +2     

Impacted Files	Coverage Δ
player.c	39.18% <39.18%> (ø)
gbsplay.c	33.33% <87.50%> (-2.50%)	:arrow_down:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update a0e5459...3fcf170. Read the comment docs.

[mmitch]

Rebased to current master, please review.

I think the missed code coverage target for the patch can be ignored – I did not even know we had coverage targets ;-)