1366711 - Provide a way for nsIProcess to launch an application on Windows without it being visible

Status: RESOLVED FIXED

(Core :: XPCOM, enhancement)

Description

[Gabriele Svelto [:gsvelto]]

This is needed for both bug 1359326 and bug 1364673. In both cases we either have a console window that pops up (when the application is built as a console application) or the mouse throbber that appears (if it's a GUI application). I've tried multiple workarounds in the application themselves to avoid this but couldn't find a satisfying solution.

I've thought for a while about the best way to expose this. I didn't want to add another parameter to run()/runw()/runAsync()/runwAsync() because that would require adjusting a dozen C++ call sites and the same applies to adding a parameter to init(). I also didn't want to add an attribute because it made no sense to flip it after the application was launched. So I've settled on adding a new initialization method initHidden() that sets the appropriate state; I hope it's a good enough solution.

Comment 1

[Gabriele Svelto [:gsvelto]]

Attachment: Bug 1366711 - Make it possible to hide applications launched with nsIProcess;

Review commit: https://reviewboard.mozilla.org/r/141522/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/141522/

Comment 2

[Benjamin Smedberg]

Comment on attachment 8869974 [details]
Bug 1366711 - Make it possible to hide applications launched with nsIProcess;

https://reviewboard.mozilla.org/r/141522/#review146232

::: xpcom/threads/nsIProcess.idl:27
(Diff revision 1)
> +   * window and will run hidden. This currently affects the Windows platform
> +   * alone.
> +   *
> +   * @param executable The executable to run.
> +   */
> +  void initHidden(in nsIFile executable);

Having a separate initHidden method is complex API. I can think of two ways to do this more extensibly:

 init(nsIFile executable, [optional] unsigned int flags)

OR

 process.startHidden = true
 process.init(file)

Comment 3

[Gabriele Svelto [:gsvelto]]

OK, thanks, I'll go for the latter then because the former would require changing quite a few unrelated C++ call sites.

Comment 4

[Gabriele Svelto [:gsvelto]]

Comment on attachment 8869974 [details]
Bug 1366711 - Make it possible to hide applications launched with nsIProcess;

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/141522/diff/1-2/

Comment 5

[Benjamin Smedberg]

Comment on attachment 8869974 [details]
Bug 1366711 - Make it possible to hide applications launched with nsIProcess;

https://reviewboard.mozilla.org/r/141522/#review146978

I don't think it should require changing callsites, because of the [optional] ? But this is fine.

Comment 6

[Gabriele Svelto [:gsvelto]]

(In reply to Benjamin Smedberg [:bsmedberg] from comment #5)
> Comment on attachment 8869974 [details]
> Bug 1366711 - Make it possible to hide applications launched with nsIProcess;
> 
> https://reviewboard.mozilla.org/r/141522/#review146978
> 
> I don't think it should require changing callsites, because of the
> [optional] ? But this is fine.

I tried that but there doesn't seem to be a way to provide a default parameter to the C++ interface, so the argument isn't really optional in C++. Anyway, thanks for the review!

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1df25c9d3299
Make it possible to hide applications launched with nsIProcess; r=bsmedberg

Comment 8

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/1df25c9d3299