By default Lazarus-IDE only opens one project at a time, and that's not always nice. In some environments it is convenient to have all projects in a group and edit/compile whatever is most convenient. For example, opening all projects in a group, and compiling all of them in one move, instead of compiling one at a time.
There is a personal recommendation, use the project manager only from version 2.2 onwards, I had some embarrassments in Lazarus 2.0.13 and I think the project manager is not cool in this version, but in Lazarus 2.2 it is working very well and replaces it with advantages the Project inspector.
If you also think so then install the Project Manager following these instructions and then watch the video that visually summarizes what will be done:
Once installed, go to Tools|Options|Environment|Project Grops and turn on options Open last group on startand also Compile and build compile target:
then go to Project|New project group to create a new group or else Project|Open project group to open an existing group. You can dock it on a side panel if you want to make it permanent.
As much as I wanted to explain, the Project Group is not that different from the Project Inspector, the difference lies in being able to clean, compile (with its different Build Modes) instead of just one project, perform this operation in several projects.
When tapping on the project group name, you will notice two options are enabled “Compile” and “Complete clean”:
These options will respectively allow you to compile all projects in the group or clean their compilation garbage.
When compiling all the projects in the group, the project manager repeats the last build mode of the project, it does not give the option to change the Build mode for all projects and this is an option that differentiates it from Delphi Project Manager. If you need the Build mode to be modified you will have to go to Project|Project Options or a mouse click on the project and then choose Properties, both lead to the same place:
The project group is a welcome option for programmers who have to change projects all the time. But for now, by not offering quick “Build mode” switching for the group, its advantage is just this.
If you are using Lazarus 2.2 or higher it is better to leave the project group instead of project inspector because at least here, it lists the files in a more coherent order, first the project file, then the datamodules and then the other files (not alphabetically):
I still don't understand if the way listed above was intentional or accidental, I hope it was intentional because it was a very good idea, but if it was accidental then I will correct this article later.