Module Creation

Overview
Adding new modules and workbenches in FreeCAD is very easy. A module is any extension of FreeCAD, while a workbench is a special GUI configuration that groups some toolbars and menus. Usually you create a new module which contains its own workbench.

Modules can be programmed in C++ or in python, or in a mixture of both, but the module init files must be in python. Setting up a new module with those init files is easy, and can be done either manually or with the FreeCAD build tool.

Using the FreeCAD Build tool
Creating a new application module in FreeCAD is rather simple. The FreeCAD Build Tool (fcbt) does most of the heavy lifting for you. It is a Python script which can be found in the FreeCAD development tree under:

When your python interpreter is correctly installed, you can execute the script from a command line with

It will display the following menu:

At the command prompt enter CM to start the creation of a module:

You are now asked to specify a name for your new module. Lets call it TestMod for this example:

After pressing Enter, fcbt starts copying all necessary files for your module into a new folder located at

Then all files are modified with your new module name. The only thing you need to do now is to add the two new projects "appTestMod" and "appTestModGui" to your workspace (on Windows) or to your makefile targets (unix). Thats it!

Setting up a new module manually
You need two things to create a new module:


 * A new folder in the FreeCAD Mod folder (either in InstalledPath/FreeCAD/Mod or in UserPath/.FreeCAD/Mod). You can name it as you like.
 * Inside that folder, an InitGui.py file. That file will be executed automatically on FreeCAD start (it can be empty, but just to test it,, put a print("hello world") inside)

Additionally, you can also add an Init.py file. InitGui.py file is loaded only when FreeCAD runs in GUI mode, whereas the Init.py file is always loaded. Since we're creating a workbench, however, we'll put our code in InitGui.py, since workbenches are GUI-only tools.

Creating a new workbench
Inside the InitGui.py file, the first thing you will want to do is define a workbench. You can use the following example as a template:

The workbench must have all these attributes defined:
 * Icon - An XPM image. Most image software (like GIMP) can convert an image into xpm format, which is a text file. You can then paste the contents here.
 * MenuText - The workbench name as it appears in the workbenches list
 * Tooltip - Defines the tooltip text
 * Initialize - Executed when FreeCAD loads and creates all menus and toolbars that the workbench will use. If you are going to make your module in C++, you can also define your menus and toolbars inside the C++ module rather than the InitGui.py file. The important thing is that they are created now, before the module is activated.
 * Activated - Executed when the user switches to your workbench
 * Deactivated - Executed when the user switches away to another workbench or leaves FreeCAD

Creating FreeCAD commands in Python
Usually you define all your tools (called Commands in FreeCAD) in another module, then import that module before creating the toolbars and menus. Here is a simple example that can be used as a template:

Note there are three methods defined:
 * GetResources - Returns a dictionary with the visual attributes of your tool. The Accel parameter defines an optional shortcut key.
 * IsActive - Determines whether or not the command is active. Inactive commands are indicated by a greyed-out icon in the menus and toolbars.
 * Activated - Executed when the Command is called, whether through a toolbar button, menu or script API call.

Creating FreeCAD Commands in C++
To Be Documented

Links

 * Some examples how power users have extended FreeCAD with various custom external workbenches are collected in External workbenches
 * Other example in Power user hub Workbench creation
 * Creating Commands Command