Convert from cxhelp/cxcmd schemes to http scheme

[Eric Pettersen]

In order for ChimeraX web pages to have better functionality outside ChimeraX itself, we want to change from using cxhelp/cxcmd URL schemes to regular http schemes, which will also make the QtWebEngineView bug of not delegating unknown schemes moot. The first step would be to set up web servers for the http schemes, possibly:

​​http://chimerax.rbvi.ucsf.edu/exec/...
​​http://chimerax.rbvi.ucsf.edu/help/...

This first phase would be assigned to Conrad. The next step would be to convert the log and help viewer tools to recognize the schemes and to convert any HTML using the old schemes to the new schemes. This phase would be shared among Eric/Greg and Elaine.

[Conrad Huang]

We know how to support custom URL schemes in QtWebEngineView now, so we do not have to switch to using http links for executing ChimeraX commands.

The reason for switching away from cxcmd scheme is that we do not want to display a hyperlink that does not work in a non-ChimeraX browser. An alternative to this is to add some Javascript that disables links whose href uses the cxcmd scheme unless it is running in a ChimeraX browser. The latter is nice because the page will work properly even without server support. The downside is if the user disables scripts; but we already use Javascript for some stuff so those will also break if scripting is disabled.

[Eric Pettersen]

Added the http vs. Javascript issue to the developer meeting future agenda items.

[Conrad Huang]

"Fixed" in 35e6c7a.

Added Javascript to make cxcmd links display a dialog saying the link only works in ChimeraX. Quick Start Guide and Log were fixed but other pages using cxcmd links will have to include the same Javascript.

[Conrad Huang]

When the Log contents is saved as HTML, a chunk of Javascript is automatically inserted at the beginning so that "help:" and "cxcmd:" links are handled properly in non-ChimeraX HTML browsers.

[Elaine Meng]

Yes, the main missing link (so to speak) is saving all those logged commands as Chimera-executable (ticket #312) instead of links to the help for that command.