display doc in embedded browser

[guiv42]

to remove dependency to external web browser
Specific use case for Ubuntu, where distro's web browser cannot access local resources
see #153

Limitations:

• pom files updated for all configurations, but only tested with Linux/JFX, Linux/SWT, Win10/SWT
• no embedded controls for navigation (e.g. back, forward)

The method "openUrl" of application object is now unused, but I did not remove it: it can be used in future versions to link to an external website for online help

[helge17]

Linux SWT, help not starting; error:
org.herac.tuxguitar.action.TGActionException: No more handles because there is no underlying browser available.
Please ensure that WebKit with its GTK 3.x bindings is installed (WebKit2 API level is preferred). Additionally, please note that GTK4 does not currently have Browser support.

FreeBSD JFX: Does not build.

Probably some dependency problems, I have to investigate...

[guiv42]

Linux SWT: I have "libwebkit2gtk-4_0-37" installed on my system, this might be the required dependency?

[helge17]

Indeed, libwebkit2gtk-4.0-37 is needed. I only had libwebkit2gtk-4.1-0 install, this does not work.

[guiv42]

Okay, so at the end it boils down to a dependency issue: where do we expect to find a working web engine?

• before PR: constraint exported to the OS, fails in Ubuntu context
• after PR: manage constraint internally, fails in some other situations

I don't know exactly how to handle this. At least for all runtime errors, a simple modification could be implemented when user types F1:

• try to display doc in embedded browser
• if it fails, catch exception and fallback to historical behavior (start external web browser).

For Linux, this could end up in a "recommended" package in deb/rpm package.

For build-time errors (FreeBSD)... I have no idea

[guiv42]

Indeed, libwebkit2gtk-4.0-37 is needed. I only had libwebkit2gtk-4.1-0 install, this does not work.

If I try to uninstall it, my package manager tells me it also needs to uninstall TuxGuitar 1.6.0 (OpenSuse rpm version). In fact, TuxGuitar 1.6.0 rpm has "eclipse sw >= 4.13" as an explicit dependency. And the version of eclipse-swt installed in my system (4.15-11.2) has an explicit dependency to libwebkit2gtk-4.0.so.37...

I see you already added the dependency in the deb package. Just 2 questions:

• any idea how to solve this in Linux standalone version? (tgz)
• what do you think of adding this dependency in deb/rpm only as a "recommended" package? (see my proposal to fallback to previous behavior in case embedded browser isn't available)