To edit the panel and its underlying scripting, right-click the ApplicatorMacro module and select Related Files → ApplicatorMacro.script to open the file in the in-built text editor MATE. Since we just defined this macro module, the script file is basically empty except for some placeholders.

Figure 10.8. ApplicatorMacro.script in MATE

	Tip
	MATE comes with some special features like autocompletion, syntax highlighting, indentation, etc. for MDL, Python and help files. For an extensive list, see the MeVisLab Reference Manual, chapter “MATE”.

We want three sections in the .script file:

Note

The window section of the GUI could also be implemented in the .def file. If you want to implement an enhanced GUI and add more fields that only exist for scripting, use the .script file and reference that from your .def file. The advantage of splitting the GUI definition from the module announcement is a faster MeVisLab startup (because only the .def file is read). Further information on this subject can be found in the MDL Reference.

First we will define the interface. As no inputs are needed, keep this line as it is. For the output, we address the output of the SoGroup module named Applicator. The following lines will result in an output field that will "deliver" the applicator.

Interface {
  Inputs = ""
  Outputs {
      Field Scene { internalName = "Applicator.self" }
  }
  Parameters = ""
}

Enter the lines in MATE and save the script file.

Then reload the module by right-clicking the macro module and selecting Reload Definition to apply the changes. The ApplicatorMacro module now shows an Open Inventor output connector.

Figure 10.9. ApplicatorMacro Module with Output Connector

The internal network of the macro shows the output placeholder. In the mouse-over, the output field name is displayed.

Figure 10.10. Internal Network of the ApplicatorMacro Module

As next step, we will define the parameters for our interface. In this example, we want to have two parameters:

These two parameters need to be added to the Interface part of the script file. Besides setting the parameter type (type) and the default value (value), you can also add a minimum and a maximum value to limit the range to sensible values.

Interface {
  Inputs = ""
  Outputs {
    Field Scene { internalName = "Applicator.self" }
  }

  Parameters {
    Field length {
      type  = float
      value = 20
      min   =  1
      max   = 50
    }
    Field diameter {
      type  = float
      value =  3
      min   =  0.1
      max   = 10
    }
  }
}

Once again, save the script and reload the macro module.

Open the automatic panel, either by double-clicking the module, by holding ALT and double-clicking the module, or by right-clicking the module and selecting Show Window → Automatic Panel from the context menu. The new parameters are visible in the automatic panel. They can also be edited there by clicking on each value field and editing the value.

Figure 10.11. Automatic Panel of the ApplicatorMacro Module

In principle, this would be enough to enter the values. However, usually a more user-friendly panel should be offered. In the panel, values can be sorted by correlation or importance and distributed on various tabs. It is also possible to leave rarely used parameters out of the panel to make it slimmer; as the automatic panel of a module is always available, the user can always view and edit all parameters there.

To create a panel for the two parameters, the new section Window is added at the end of the script file. Besides defining the fields in Category, you can also add a step value which will regulate how large the step is when moving through the values with the spin box arrows or the mouse wheel (with the mouse cursor over the field). As the diameter is smaller than the length, it makes sense to set a smaller step size here.

Interface {
  Inputs = ""
  Outputs {
    Field Scene { internalName = "Applicator.self" }
  }

  Parameters {
    Field length {
      type  = float
      value = 20
      min   =  1
      max   = 50
    }
    Field diameter {
      type  = float
      value =  3
      min   =  0.1
      max   = 10
    }
  }
}

Commands {

}


Window {
  Category {
    Field length   { step = 1   }
    Field diameter { step = 0.1 }
  }
}

Save the script and reload the macro module.

Now open the panel, either by double-clicking the module (because the panel is the new default panel) or by right-clicking the module and selecting Show Window → Panel from the context menu. The new parameters are visible in the panel and can be edited manually (or by using the spin arrows or the mouse wheel).

Figure 10.12. Panel of the ApplicatorMacro Module

All parameters are defined and the panel is ready for entering values — however, we still do not have any interaction. So the last section Command needs to be added, in which the respective scripting file (a Python file) and the fields this scripting file should “look at” need to be entered

The source will be a local file which we will add manually, with the name ApplicatorMacro.py by convention.

To relate to the scripting, we need two field listeners that listen to fields and call the script command given in the command tag when the field changes. The functions AdjustLength and AdjustDiameter used in the code do not exist yet but will be defined by us in the Python file.

Interface {
  Inputs = ""
  Outputs {
    Field Scene { internalName = "Applicator.self" }
  }

  Parameters {
    Field length {
      type  = float
      value = 20
      min   =  1
      max   = 50
    }
    Field diameter {
      type  = float
      value =  3
      min   =  0.1
      max   = 10
    }
  }
}

Commands {
  source = $(LOCAL)/ApplicatorMacro.py

  FieldListener  length   { command = AdjustLength   }
  FieldListener  diameter { command = AdjustDiameter }
}

Window {
  Category {
    Field length   { step = 1   }
    Field diameter { step = 0.1 }
  }
}

Save the script and reload the macro module. If the Python file or the scripting commands do not exist yet, errors messages will appear in the Debug Output of MATE. Do not be concerned — we will add everything we need for real interactivity in the next section.

	Tip
	Panels can have a more complex design; for the possibilities, see the MDL Reference and the MDL panel example modules in MeVisLab (search for modules starting with “Test...”).