Mainly I use Lazarus on Windows, I would need to know if, from the Project Inspector, there was a way to open the project folder in a Windows File Explorer.You can open it from source editor's status bar. Mouse right-click on the file name opens a popup menu with "Open folder ...". Just open the project main file or any file in the project directory and there you go.
If not, how to add a button to the Project Inspector to achieve this?Currently there is no API to extend it. If you add a popup item in the Files section for this task and create a patch, it will surely be accepted.
I managed to test the change in Windows 10 64bit. Everything works correctly apart from the fact that the button does not yet have the image. I attached the modified "projectinspector.pas" file in case it was useful to someone, the changes are preceded by a comment line containing the string "Modified by Otto" and terminated with an empty comment line.Good. You studied lots of code.
I used the "Tools > Build Lazarus" command to recompile the IDE. Previously I also tried to recompile the project using the project "lazarus-ide-lazarus.lpi", in an attempt to obtain an independent test IDE, but the build failed.Yes, that was the right way to build. Project lazarus.lpi can now be used only for debugging.
Creating a patch requires the use of the trunk/development version of Lazarus, is it correct to use fpcupdeluxe (https://github.com/LongDirtyAnimAlf/fpcupdeluxe/releases/) to get it?You can use fpcupdeluxe also for installing Lazarus but it is not really needed.
Do I have to use the FPC trunk to build?No. Lazarus trunk supports at least FPC 3.0.x and development branches 3.2 and trunk.
set path=C:\FPC\3.0.4\bin\i386-win32\;where the path must point to a valid FPC installation
make bigide
FYI, I got excited with this open folder idea in a popup menu of both project inspector and package editor so I implemented it in r62656 (trunk).
I used OpenDocument() but I guess OpenURL() works, too.
Please test.
FYI, I have other ideas for extending The features of Lazarus, but I have yet to verify them.No if you modify the code of Lazarus IDE itself. Then you must build the IDE and see how it behaves.
Could I use the IDE Window: External Tool to speed up the verification process?
A better way then is to add DebugLn() lines to your code and read their output. DebugLn has nice overloads with variant parameters. Search Lazarus source for examples.