gui_base.py

# ***************************************************************************
# *   (c) 2009 Yorik van Havre <yorik@uncreated.net>                        *
# *   (c) 2010 Ken Cline <cline@frii.com>                                   *
# *   (c) 2019 Eliud Cabrera Castillo <e.cabrera-castillo@tum.de>           *
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"""Provide the Base object for all Draft Gui commands."""
## @package gui_base
# \ingroup DRAFT
# \brief This module provides the Base object for all Draft Gui commands.

import FreeCAD as App
import FreeCADGui as Gui
import draftutils.todo as todo


class GuiCommandBase:
    """Generic class that is the basis of all Gui commands.

    This class should eventually replace `DraftTools.DraftTool`,
    once all functionality in that class is merged here.

    Attributes
    ----------
    commit_list : list of 2-element tuples
        Each tuple is made of a string, and a list of strings.
        ::
            commit_list = [(string1, list1), (string2, list2), ...]

        The string is a simple header, for example, a command name,
        that indicates what is being executed.

        Each string in the list of strings represents a Python instruction
        which will be executed in a delayed fashion
        by `todo.ToDo.delayCommit()`
        ::
            list1 = ["a = FreeCAD.Vector()",
                     "pl = FreeCAD.Placement()",
                     "Draft.autogroup(obj)"]

            commit_list = [("Something", list1)]

        This is used when the 3D view has event callbacks that crash
        Coin3D.
        If this is not needed, those commands could be called in the
        body of the command without problem.
        ::
            >>> a = FreeCAD.Vector()
            >>> pl = FreeCAD.Placement()
            >>> Draft.autogroup(obj)
    """

    def __init__(self):
        self.call = None
        self.commit_list = []
        self.doc = None
        App.activeDraftCommand = None
        self.view = None
        self.planetrack = None

    def IsActive(self):
        """Return True when this command should be available."""
        if App.ActiveDocument:
            return True
        else:
            return False

    def finish(self):
        """Terminate the active command by committing the list of commands.

        It also perform some other tasks like terminating
        the plane tracker and the snapper.
        """
        App.activeDraftCommand = None
        if self.planetrack:
            self.planetrack.finalize()
        if hasattr(Gui, "Snapper"):
            Gui.Snapper.off()
        if self.call:
            try:
                self.view.removeEventCallback("SoEvent", self.call)
            except RuntimeError:
                # the view has been deleted already
                pass
            self.call = None
        if self.commit_list:
            todo.ToDo.delayCommit(self.commit_list)
        self.commit_list = []

    def commit(self, name, func):
        """Store actions to be committed to the document.

        Parameters
        ----------
        name : str
            A string that indicates what is being committed.

        func : list of strings
            Each element of the list should be a Python command
            that will be executed.
        """
        self.commit_list.append((name, func))