I just looked into the events with my DisplayEvents-plugin, and I see it being triggered.
Here is a snippet of the log, if a workspace with two projects is loaded, each project has several targets (win, linux, debug, release ...)
No files are opened.
16:29:19,888 => cbEVT_APP_ACTIVATED
16:29:19,891 => cbEVT_EDITOR_SWITCHED
16:29:19,891 => cbEVT_EDITOR_ACTIVATED
16:29:21,481 => cbEVT_WORKSPACE_CHANGED
16:29:21,507 => cbEVT_EDITOR_CLOSE
Loading workspace "/home/jens/src/src/SPS_Log.workspace"
Loading project file...
Parsing project file...
16:29:21,512 => cbEVT_PROJECT_RENAMED
16:29:21,512 => cbEVT_PROJECT_TARGETS_MODIFIED
16:29:21,513 => cbEVT_BUILDTARGET_ADDED
16:29:21,513 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target Debug
16:29:21,513 => cbEVT_BUILDTARGET_ADDED
16:29:21,514 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target Release
16:29:21,516 => cbEVT_BUILDTARGET_ADDED
16:29:21,516 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target WinRelease
16:29:21,517 => cbEVT_BUILDTARGET_ADDED
16:29:21,517 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target WinDebug
16:29:21,518 => cbEVT_BUILDTARGET_ADDED
16:29:21,518 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target Release gcc-4.4
16:29:21,518 => cbEVT_BUILDTARGET_ADDED
16:29:21,519 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target clang++ Debug
Loading project files...
16:29:21,519 => cbEVT_PROJECT_BEGIN_ADD_FILES
16:29:21,520 => cbEVT_PROJECT_END_ADD_FILES
2 files loaded
Done loading project in 10ms
Project's base path: /home/jens/src/src/libbeckhoff/
Project's common toplevel path: /home/jens/src/src/libbeckhoff/
16:29:21,522 => cbEVT_BUILDTARGET_SELECTED
Loading project file...
Parsing project file...
16:29:21,524 => cbEVT_PROJECT_RENAMED
16:29:21,525 => cbEVT_PROJECT_TARGETS_MODIFIED
16:29:21,525 => cbEVT_BUILDTARGET_ADDED
16:29:21,525 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target Debug
16:29:21,526 => cbEVT_BUILDTARGET_ADDED
16:29:21,526 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target Release
16:29:21,526 => cbEVT_BUILDTARGET_ADDED
16:29:21,527 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target WinRelease
16:29:21,527 => cbEVT_BUILDTARGET_ADDED
16:29:21,527 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target WinDebug
16:29:21,528 => cbEVT_BUILDTARGET_ADDED
16:29:21,528 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target Release gcc-4.4
16:29:21,529 => cbEVT_BUILDTARGET_ADDED
16:29:21,529 => cbEVT_PROJECT_TARGETS_MODIFIED
Loading target clang++ Debug
Loading project files...
16:29:21,530 => cbEVT_PROJECT_BEGIN_ADD_FILES
16:29:21,531 => cbEVT_PROJECT_END_ADD_FILES
13 files loaded
Done loading project in 9ms
Project's base path: /home/jens/src/src/
Project's common toplevel path: /home/jens/src/src/
16:29:21,533 => cbEVT_BUILDTARGET_SELECTED
SPS_Log now depends on libbeckhoff (1 deps)
16:29:21,538 => cbEVT_PROJECT_ACTIVATE
16:29:21,539 => cbEVT_COMPILER_SET_BUILD_OPTIONS
16:29:21,541 => cbEVT_COMPILER_SET_BUILD_OPTIONS
16:29:21,541 => cbEVT_COMPILER_SET_BUILD_OPTIONS
16:29:21,542 => cbEVT_COMPILER_SET_BUILD_OPTIONS
16:29:21,542 => cbEVT_COMPILER_SET_BUILD_OPTIONS
16:29:21,548 => cbEVT_PROJECT_OPEN
16:29:21,548 => cbEVT_PROJECT_OPEN
16:29:21,549 => cbEVT_WORKSPACE_CHANGED
Passing list of files to batch-parser.
Header to parse with priority: '/usr/include/c++/4.6/cstddef'
Header to parse with priority: '/usr/include/wx-2.8/wx/defs.h'
Header to parse with priority: '/usr/include/wx-2.8/wx/dlimpexp.h'
Header to parse with priority: '/usr/include/wx-2.8/wx/toplevel.h'
Header to parse with priority: '/usr/include/boost/config.hpp'
Header to parse with priority: '/usr/include/boost/filesystem/config.hpp'
Add 6 priority parsing file(s) for project 'SPS_Log'...
Added 9 file(s) for project 'SPS_Log' to batch-parser...
Create new parser for project 'SPS_Log'
Starting batch parsing for project 'SPS_Log'...
Project 'SPS_Log' parsing stage done!
Project 'SPS_Log' parsing stage done (512 total parsed files, 26463 tokens in 0 minute(s), 2.260 seconds).
Updating class browser...
Class browser updated.
16:29:24,607 => cbEVT_COMPILER_SET_BUILD_OPTIONS
16:29:24,609 => cbEVT_COMPILER_SET_BUILD_OPTIONS
16:29:24,610 => cbEVT_COMPILER_SET_BUILD_OPTIONS
16:29:24,610 => cbEVT_COMPILER_SET_BUILD_OPTIONS
16:29:24,611 => cbEVT_COMPILER_SET_BUILD_OPTIONS
16:29:24,612 => cbEVT_COMPILER_SET_BUILD_OPTIONS
Add project (libbeckhoff) to parser
Done adding 1 files of project (libbeckhoff) to parser.
Add next project to parser.
Starting batch parsing for project 'libbeckhoff'...
Project 'libbeckhoff' parsing stage done!
Project 'libbeckhoff' parsing stage done (513 total parsed files, 26463 tokens in 0 minute(s), 0.021 seconds).
Updating class browser...
Class browser updated.