Added a way to use DTE to add new files directly into VS without having to generate projects
This avoids the annoying "Do you want to reload?" dialog that appears in VS when projects are externally changed, and also saves us the cost/time of having to run UBT to generate projects.
[CL 2435515 by Matthew Griffin in Main branch]
TTP# 331398 - EDITOR: Logspam when opening Visual Studio
Deferring a VS file open request used to use a deferred command to wait until VS had finished opening before opening the requested files, however, this command was essentially simulating a Tick, as if the command was not yet ready to be processed it was simply deferred again, leading to spammed output.
Rather than do this, I've added a Tick function which will attempt to open the entire list of pending files as a single call, rather than try each file individually like the command would.
ReviewedBy Thomas.Sarkanen, Chris.Wood, Max.Preussner
[CL 2058815 by Jamie Dale in Main branch]
#ttp 330039 EDITOR: Platform-agnostic editor code depends on Windows-only VSAccessor headers
#detail Source code access is now extensible via plugins, so any new editors can be easily added.
#add Added SourceCodeAccess module that routes access via plugins.
#change Moved much of the old VSAccessor code into a new VisualStudioSourceCodeAccess plugin.
#add Added a counterpart XCode plugin & migrated the code from FSourceCodeNavigation (Applescript etc.) into there.
#remove Removed applescript for XCode access (it is now done via code).
#remove Removed source code access functionality from platform layer.
#add Added details customization for source code access settings, so users can choose their own accessor.
#remove Removed dependencies on VSAccessor.
#change Changed API in SWidget to not require building a string to be parsed, instead this acesses and forwards filenames & line numbers.
#extra Tested on Mac by Mark S.
reviewed by Andrew.Brown
[CL 2048697 by Thomas Sarkanen in Main branch]
