Replace .config rather than reconstructing plugins, drivers, and UIs.

[hooke.git] / hooke / command_stack.py

diff --git a/hooke/command_stack.py b/hooke/command_stack.py
index cebf0b9b6e89113a613e4baf2d9fa429e08c83f4..dcf2ce2a64a58e0794f282b20aed55c859fdc359 100644 (file)
--- a/hooke/command_stack.py
+++ b/hooke/command_stack.py
@@ -16,11 +16,83 @@
 # License along with Hooke.  If not, see
 # <http://www.gnu.org/licenses/>.
 
-"""The ``command_stack`` module provides tools for managing stacks of
-:class:`~hooke.engine.CommandMessage`\s and applying those stacks to
-:class:`~hooke.curve.Curve`\s.
+"""The ``command_stack`` module provides tools for managing and
+executing stacks of :class:`~hooke.engine.CommandMessage`\s.
 """
 
-from .command import Command, Argument, Failure
-from .engine import CommandMessage
-from .playlist import NoteIndexList
+
+class CommandStack (list):
+    """Store a stack of commands.
+
+    Examples
+    --------
+    >>> from .engine import CommandMessage
+    >>> c = CommandStack([CommandMessage('CommandA', {'param':'A'})])
+    >>> c.append(CommandMessage('CommandB', {'param':'B'}))
+    >>> c.append(CommandMessage('CommandA', {'param':'C'}))
+    >>> c.append(CommandMessage('CommandB', {'param':'D'}))
+
+    Implement a dummy :meth:`execute_command` for testing.
+    
+    >>> def execute_cmd(hooke, command_message):
+    ...     cm = command_message
+    ...     print 'EXECUTE', cm.command, cm.arguments
+    >>> c.execute_command = execute_cmd
+
+    >>> c.execute(hooke=None)  # doctest: +ELLIPSIS
+    EXECUTE CommandA {'param': 'A'}
+    EXECUTE CommandB {'param': 'B'}
+    EXECUTE CommandA {'param': 'C'}
+    EXECUTE CommandB {'param': 'D'}
+
+    :meth:`filter` allows you to select which commands get executed.
+    If, for example, you are applying a set of commands to the current
+    :class:`~hooke.curve.Curve`, you may only want to execute
+    instances of :class:`~hooke.plugin.curve.CurveCommand`.  Here we
+    only execute commands named `CommandB`.
+    
+    >>> def filter(hooke, command_message):
+    ...     return command_message.command == 'CommandB'
+    >>> c.filter = filter
+
+    Apply the stack to the current curve.
+
+    >>> c.execute(hooke=None)  # doctest: +ELLIPSIS
+    EXECUTE CommandB {'param': 'B'}
+    EXECUTE CommandB {'param': 'D'}
+
+    Execute a new command and add it to the stack.
+
+    >>> cm = CommandMessage('CommandC', {'param':'E'})
+    >>> c.execute_command(hooke=None, command_message=cm)
+    EXECUTE CommandC {'param': 'E'}
+    >>> c.append(cm)
+    >>> print [repr(cm) for cm in c]  # doctest: +NORMALIZE_WHITESPACE
+    ["<CommandMessage CommandA {'param': 'A'}>",
+     "<CommandMessage CommandB {'param': 'B'}>",
+     "<CommandMessage CommandA {'param': 'C'}>",
+     "<CommandMessage CommandB {'param': 'D'}>",
+     "<CommandMessage CommandC {'param': 'E'}>"]
+    """
+    def execute(self, hooke):
+        """Execute a stack of commands.
+
+        See Also
+        --------
+        _execute, filter
+        """
+        for command_message in self:
+            if self.filter(hooke, command_message) == True:
+                self.execute_command(
+                    hooke=hooke, command_message=command_message)
+
+    def filter(self, hooke, command_message):
+        """Return `True` to execute `command_message`, `False` otherwise.
+
+        The default implementation always returns `True`.
+        """
+        return True
+
+    def execute_command(self, hooke, command_message):
+        hooke.run_command(command=command_message.command,
+                          arguments=command_message.arguments)