Add support for building snaps

[popey]

Attempt to build a snap of touchegg. Not currently working.

To build, on Ubuntu, locally:

Setup:

snap install snapcraft
snap install lxd
sudo lxd init --auto

Clone this repo, then from within it:
snapcraft --use-lxd

To build remotely in the ☁️

(requires launchpad.net account)
snap install snapcraft
Clone this repo then from within it:
snapcraft remote-build

Install the snap:

snap install touchegg_2.0.3-6-*_amd64.snap --dangerous

To check logs:

snap logs touchegg

Current issue:

$ snap logs touchegg 
2020-11-19T09:55:18Z touchegg.touchegg[1984594]: terminate called after throwing an instance of 'std::runtime_error'
2020-11-19T09:55:18Z touchegg.touchegg[1984594]:   what():  File /usr/share/touchegg/touchegg.conf not found.
2020-11-19T09:55:18Z touchegg.touchegg[1984594]: Reinstall Touchégg to solve this issue
2020-11-19T09:55:19Z systemd[1]: snap.touchegg.touchegg.service: Main process exited, code=dumped, status=6/ABRT
2020-11-19T09:55:19Z systemd[1]: snap.touchegg.touchegg.service: Failed with result 'core-dump'.
2020-11-19T09:55:19Z systemd[1]: snap.touchegg.touchegg.service: Scheduled restart job, restart counter is at 5.
2020-11-19T09:55:19Z systemd[1]: Stopped Service for snap application touchegg.touchegg.
2020-11-19T09:55:19Z systemd[1]: snap.touchegg.touchegg.service: Start request repeated too quickly.
2020-11-19T09:55:19Z systemd[1]: snap.touchegg.touchegg.service: Failed with result 'core-dump'.
2020-11-19T09:55:19Z systemd[1]: Failed to start Service for snap application touchegg.touchegg.

Other issues:
It would be nice to use the gnome-3-34 extension rather than bundle all the stage-packages but when I built with the extension (and omitted the entire stage-packages stanza) it fails to build with:

[ 94%] Building CXX object CMakeFiles/touchegg.dir/src/window-system/x11-cairo-surface.cpp.o                                                                                                                                                                             
[ 97%] Building CXX object CMakeFiles/touchegg.dir/src/window-system/x11.cpp.o                                                                                                                                                                                           
[100%] Linking CXX executable touchegg                                                                                                                                                                                                                                   
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0: undefined reference to `hb_ot_layout_script_select_language'                                                                                                                            
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0: undefined reference to `pango_font_get_hb_font'                                                                                                                                         
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0: undefined reference to `pango_font_description_set_variations'                                                                                                                          
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0: undefined reference to `hb_blob_create_from_file'                                                                                                                                       
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libatk-bridge-2.0.so.0: undefined reference to `atk_text_scroll_substring_to'                                                                                                                                 
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0: undefined reference to `hb_ot_var_named_instance_get_design_coords'                                                                                                                     
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0: undefined reference to `pango_coverage_get_type'                                                                                                                                        
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0: undefined reference to `pango_font_description_get_variations'                                                                                                                          
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libatk-bridge-2.0.so.0: undefined reference to `atk_component_scroll_to'                                                                                                                                      
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0: undefined reference to `hb_ot_tags_from_script_and_language'                                                                                                                            
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libatk-bridge-2.0.so.0: undefined reference to `atk_component_scroll_to_point'                                                                                                                                
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libatk-bridge-2.0.so.0: undefined reference to `atk_object_get_accessible_id'                                                                                                                                 
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0: undefined reference to `hb_ot_var_get_axis_infos'                                                                                                                                       
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libatk-bridge-2.0.so.0: undefined reference to `atk_text_scroll_substring_to_point'                                                                                                                           
/snap/gnome-3-34-1804-sdk/current/usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0: undefined reference to `hb_ot_metrics_get_position'                                                                                                                                     
collect2: error: ld returned 1 exit status                                                                                                                                                                                                                               
CMakeFiles/touchegg.dir/build.make:1004: recipe for target 'touchegg' failed                                                                                                                                                                                             
make[2]: *** [touchegg] Error 1                                                                                                                                                                                                                                          
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/touchegg.dir/all' failed                                                                                                                                                                                          
make[1]: *** [CMakeFiles/touchegg.dir/all] Error 2                                                                                                                                                                                                                       
Makefile:151: recipe for target 'all' failed                                                                                                                                                                                                                             
make: *** [all] Error 2    

[popey]

Given the snap is confined, I think it's expected not to be able to get to the configuration in /usr/share/touchegg. It might be useful for touchegg to gain a --config option so we can point to /var/snap/touchegg/common for example in which to store the config and be writable.

[kenvandine]

Given the snap is confined, I think it's expected not to be able to get to the configuration in /usr/share/touchegg. It might be useful for touchegg to gain a --config option so we can point to /var/snap/touchegg/common for example in which to store the config and be writable.

You could probably use a layout to map $SNAP/usr/share/touchegg to /usr/share/touchegg

[popey]

@kenvandine as per your suggestion, I removed all build-packages except - libpugixml-dev and added the extension back in, now it refuses to link..

Skipping pull gnome-3-34-extension (already ran)                                                                                                          
Skipping pull touchegg (already ran)                                                                                                                      
Skipping build gnome-3-34-extension (already ran)                                                                                                         
Building touchegg                                                                                                                                         
cmake /root/parts/touchegg/src -DCMAKE_INSTALL_PREFIX= -DCMAKE_BUILD_TYPE=Release                                                                         
-- Configuring done                                                                                                                                       
-- Generating done                                                                                                                                        
-- Build files have been written to: /root/parts/touchegg/build                                                                                           
cmake --build . -- -j8                                                                                                                                    
[  2%] Linking CXX executable touchegg                                                                                                                    
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -ludev                                                                                          
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -linput                                                                                         
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lcairo                                                                                         
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lX11                                                                                           
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lXtst                                                                                          
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lXrandr                                                                                                                                                                                                                                                   
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lXi                                                                                            
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lgtk-3                                                                                                                                                                                                                                                    
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lgdk-3                                                                                         
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lz                                                                                             
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lpangocairo-1.0                                                                                
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lpango-1.0                                                                                     
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lharfbuzz                                                                                      
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -latk-1.0                                                                                       
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lcairo-gobject                                                                                 
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lcairo                                                                                                                                                                                                                                                    
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lgdk_pixbuf-2.0                                                                                                                                                                                                                                           
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lgio-2.0                                                                                       
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lgobject-2.0                                                                                                                                                                                                                                              
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lglib-2.0                                                                                      
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lX11                                                                                           
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lXtst                                                                                                                                                                                                                                                     
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lXrandr                                                                                                                                                                                                                                                   
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lXi                                                                                                                                                                                                                                                       
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lgtk-3                                                                                                                                                                                                                                                    
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lgdk-3                                                                                                                                                                                                                                                    
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lz                                                                                                                                                                                                                                                        
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lpangocairo-1.0                                                                                
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lpango-1.0                                                                                                                                                                                                                                                
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lharfbuzz                                                                                                                                                                                                                                                 
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -latk-1.0                                                                                                                                                                                                                                                  
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lcairo-gobject                                                                                                                                                                                                                                            
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lgdk_pixbuf-2.0                                                                                                                                                                                                                                           
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lgio-2.0                                                                                                                                                                                                                                                  
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lgobject-2.0                                                                                                                                                                                                                                              
/snap/gnome-3-34-1804-sdk/current/usr/bin/ld: cannot find -lglib-2.0                                                                                                                                                                                                                                                 
collect2: error: ld returned 1 exit status                                                                                                                                                                                                                                                                           
CMakeFiles/touchegg.dir/build.make:1004: recipe for target 'touchegg' failed                                                                                                                                                                                                                                         
make[2]: *** [touchegg] Error 1                                                                                                                           
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/touchegg.dir/all' failed                                                                           
make[1]: *** [CMakeFiles/touchegg.dir/all] Error 2                                                                                                        
Makefile:151: recipe for target 'all' failed                                                                                                              
make: *** [all] Error 2                                                                                        

Any ideas?

[JoseExposito]

Thank you so much for the work you are putting in this PR @popey. This is going to make distributing updates so much easier 😄

Since I have a opportunity to chat with someone working at Canonical... Do you know who I can ping to update this as well?
https://launchpad.net/touchegg
Unfortunately the GEIS project is discontinued and the mailing list for MOTU and Kubuntu (the original maintainers) is inactive.

Cheers!

[popey]

Sure, I have access to fix that. Want me to change the description to point at this project?

[JoseExposito]

Yes please, that'll be great!!!

It looks like the trunk branch is still trying to import code from Google Code. Once the code gets imported from GitHub, do I need to make any change upstream so the latest version gets publish in the universe repo?

Thanks a lot!