using decorators to avoid code replication

[andrea-bistacchi]

Avoiding code replication is generally achieved by using classes. However, this solution is not optimal when dealing with functions, simply defined as:

def(self, some_arguments)
    ...

In this case we might consider using decorators following this pattern:

def a_decorator(func):

    def wrapper(self, *args, **kwargs):
        # do something here, the same for all wrapped functions
        ...
        # the wrapped function goes here
        return func(self, *args, **kwargs)
        # do something here, the same for all wrapped functions
        ...

    return wrapper


@a_decorator
def a_wrapped_function(self, some_argument):
    # do something here, specific to the wrapped function
    ...
    return some_output

I will test this to unify freezing and unfreezing the GUI in functions of two_d_lines.py.

[andrea-bistacchi]

In 92dc29b I introduced the @freeze_gui decorator.

The decorator itself can be found at:

PZero/pzero/helpers/helper_functions.py

Line 286 in 92dc29b

def freeze_gui(func):

The first usage of this decorator can be found at:

PZero/pzero/two_d_lines.py

Line 208 in 92dc29b

@freeze_gui

@r-monti14 please go ahead using the decorator in all functions in two_d_lines.py and three_d_surfaces.py, following the same pattern as above.

In addition to avoiding code repetition, this will solve #114 and similar issues.

[waqashussain117]

After adding the decorater and removing the functions that are already described in the decorater, the error is still there. The window freezes.

[r-monti14]

The decorator works with those tools that do not need a final input to interrupt the function.
Tools such as "Edit line", "Draw line" and "Split line-point", after being enhanced with the decorator, do not block the window.

[andrea-bistacchi]

With 7a98c74 I have updated both resample_line_distance and resample_line_number_points functions.

@r-monti14 please use these as a reference for all other functions in two_d_lines.py and three_d_surfaces.py.

We will think about the interactive tools Edit line, Draw line and Split line-point later on.

[r-monti14]

With f6d562f I have added the decorators at all the functions in two_d_lines.py (except Draw line, Edit line, Split line-point, Extend line and Measure).

[andrea-bistacchi]

Great! Have you tested all of them?

[r-monti14]

I did a quick test with all of them. I am not sure if the Snap line works correctly, but I will test everything again in detail.
Should I also add the decorators in three_d_surfaces.py even if the functions have no code for freezing?

[andrea-bistacchi]

Yes thanks. Actually I think it would be a good idea to use freezing everywhere, also in functions used to open or import data.