Merge pull request #143 from nucleic/feature-dock-area-save

Make enamldef objects pickable

enaml/core/enamldef_meta.py

@@ -5,7 +5,29 @@
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #------------------------------------------------------------------------------
-from .declarative import DeclarativeMeta
+from .declarative_meta import DeclarativeMeta
+
+
+def __enamldef_newobj__(cls, *args):
+    """ An enamldef pickler function.
+
+    This function is not part of the public Enaml api.
+
+    """
+    instance = cls.__new__(cls, *args)
+    cls.__node__(instance)
+    return instance
+
+
+def __reduce_ex__(self, proto):
+    """ An implementation of the reduce protocol.
+
+    This method creates a reduction tuple for enamldef instances. It
+    is not part of the public Enaml api.
+
+    """
+    args = (type(self),) + self.__getnewargs__()
+    return (__enamldef_newobj__, args, self.__getstate__())
 
 
 class EnamlDefMeta(DeclarativeMeta):
@@ -17,6 +39,18 @@ class EnamlDefMeta(DeclarativeMeta):
     #: be modified by user code.
     __node__ = None
 
+    def __new__(meta, name, bases, dct):
+        """ Create a new enamldef subclass.
+
+        This method overrides the default Atom pickle reducer with one
+        which invokes the Enaml compiler node during unpickling.
+
+        """
+        cls = DeclarativeMeta.__new__(meta, name, bases, dct)
+        if cls.__reduce_ex__ is not __reduce_ex__:
+            cls.__reduce_ex__ = __reduce_ex__
+        return cls
+
     def __repr__(cls):
         """ A nice repr for a type created by the `enamldef` keyword.
 

examples/workbench/persistent_view.enaml

@@ -0,0 +1,160 @@
+#------------------------------------------------------------------------------
+# Copyright (c) 2013, Nucleic Development Team.
+#
+# Distributed under the terms of the Modified BSD License.
+#
+# The full license is in the file COPYING.txt, distributed with this software.
+#------------------------------------------------------------------------------
+from enaml.layout.api import HSplitLayout, InsertItem
+from enaml.widgets.api import Container, DockArea, DockItem, Html
+from enaml.workbench.api import Extension, PluginManifest
+from enaml.workbench.core.api import Command
+from enaml.workbench.ui.api import ActionItem, MenuItem
+
+
+print 'Imported Persistent View!'
+
+
+class PickableDockItem(DockItem):
+    """ A custom pickable dock item class.
+
+    """
+    def __getstate__(self):
+        """ Get the pickle state for the dock item.
+
+        This method saves the necessary state for the dock items used
+        in this example. Different applications will have different
+        state saving requirements.
+
+        The default __setstate__ method provided on the Atom base class
+        provides sufficient unpickling behavior.
+
+        """
+        return {'name': self.name, 'title': self.title}
+
+
+class PickableDockArea(DockArea):
+    """ A custom pickable dock area class.
+
+    """
+    def get_save_items(self):
+        """ Get the list of dock items to save with this dock area.
+
+        """
+        return [c for c in self.children if isinstance(c, PickableDockItem)]
+
+    def __getstate__(self):
+        """ Get the pickle state for the dock area.
+
+        This method saves the necessary state for the dock area used
+        in this example. Different applications will have different
+        state saving requirements.
+
+        """
+        state = {
+            'name': self.name,
+            'layout': self.save_layout(),
+            'items': self.get_save_items(),
+        }
+        return state
+
+    def __setstate__(self, state):
+        """ Restore the state of the dock area.
+
+        """
+        self.name = state['name']
+        self.layout = state['layout']
+        self.insert_children(None, state['items'])
+
+
+enamldef Pane(PickableDockItem):
+    """ A pickable dock item with default Html content.
+
+    """
+    Container:
+        Html:
+            source = '<h1><center>%s</center></h1>' % title
+
+
+def create_new_area():
+    """ Create a new pickable dock area with two child panes.
+
+    """
+    area = PickableDockArea(name='the_dock_area')
+    Pane(area, name='first', title='Pane 0')
+    Pane(area, name='second', title='Pane 1')
+    area.layout = HSplitLayout('first', 'second')
+    return area
+
+
+def new_item(event):
+    """ The handler for the 'sample.persistent.new_item' command.
+
+    """
+    ui = event.workbench.get_plugin('enaml.workbench.ui')
+    area = ui.workspace.content.find('the_dock_area')
+    count = len(area.dock_items())
+    name = '_pane_%d' % count
+    title = 'Pane %d' % count
+    item = Pane(area, name=name, title=title)
+    area.update_layout(InsertItem(item=item.name))
+
+
+def destroy_items(event):
+    """ The handler for the 'sample.persistent.destroy_items' command.
+
+    """
+    ui = event.workbench.get_plugin('enaml.workbench.ui')
+    area = ui.workspace.content.find('the_dock_area')
+    for item in area.dock_items():
+        item.destroy()
+
+
+enamldef PersistentManifest(PluginManifest):
+    """ The manifest which is registered when the view is loaded.
+
+    This manifest contributes extra menu items to the menu bar and
+    new commands for manipulating the dock area items.
+
+    """
+    id = 'sample.persistent'
+    Extension:
+        id = 'commands'
+        point = 'enaml.workbench.core.commands'
+        Command:
+            id = 'sample.persistent.new_item'
+            handler = new_item
+        Command:
+            id = 'sample.persistent.destroy_items'
+            handler = destroy_items
+    Extension:
+        id = 'actions'
+        point = 'enaml.workbench.ui.actions'
+        MenuItem:
+            path = '/debug'
+            label = 'Debug'
+            after = 'file'
+        MenuItem:
+            path = '/options'
+            label = 'Options'
+        MenuItem:
+            path = '/tools'
+            label = 'Tools'
+            before = 'workspace'
+        ActionItem:
+            path = '/debug/something'
+            label = 'Something'
+        ActionItem:
+            path = '/options/something_else'
+            label = 'Something Else'
+        ActionItem:
+            path = '/tools/destroy_items'
+            label = 'Destroy Items'
+            shortcut = 'Ctrl+X'
+            command = 'sample.persistent.destroy_items'
+        ActionItem:
+            path = '/file/new'
+            label = 'New'
+            shortcut = 'Ctrl+N'
+            group = 'user'
+            command = 'sample.persistent.new_item'

examples/workbench/persistent_workspace.py

@@ -0,0 +1,74 @@
+#------------------------------------------------------------------------------
+# Copyright (c) 2013, Nucleic Development Team.
+#
+# Distributed under the terms of the Modified BSD License.
+#
+# The full license is in the file COPYING.txt, distributed with this software.
+#------------------------------------------------------------------------------
+import cPickle
+
+from atom.api import Unicode
+
+from enaml.widgets.api import Container
+from enaml.workbench.ui.api import Workspace
+
+import enaml
+with enaml.imports():
+    from persistent_view import PersistentManifest, create_new_area
+
+
+print 'Imported Persistent Workspace!'
+
+
+#: Storage for the pickled dock area. This would be saved
+#: to some persistent storage media in a real application.
+PICKLED_DOCK_AREA = None
+
+
+class PersistentWorkspace(Workspace):
+    """ A custom Workspace class for the crash course example.
+
+    """
+    #: Storage for the plugin manifest's id.
+    _manifest_id = Unicode()
+
+    def start(self):
+        """ Start the workspace instance.
+
+        This method will create the container content and register the
+        provided plugin with the workbench.
+
+        """
+        self.content = Container(padding=0)
+        self.load_area()
+        manifest = PersistentManifest()
+        self._manifest_id = manifest.id
+        self.workbench.register(manifest)
+
+    def stop(self):
+        """ Stop the workspace instance.
+
+        This method will unregister the workspace's plugin that was
+        registered on start.
+
+        """
+        self.save_area()
+        self.workbench.unregister(self._manifest_id)
+
+    def save_area(self):
+        """ Save the dock area for the workspace.
+
+        """
+        global PICKLED_DOCK_AREA
+        area = self.content.find('the_dock_area')
+        PICKLED_DOCK_AREA = cPickle.dumps(area, -1)
+
+    def load_area(self):
+        """ Load the dock area into the workspace content.
+
+        """
+        if PICKLED_DOCK_AREA is not None:
+            area = cPickle.loads(PICKLED_DOCK_AREA)
+        else:
+            area = create_new_area()
+        area.set_parent(self.content)

examples/workbench/sample_plugin.enaml

@@ -37,17 +37,10 @@ def second_view_factory(workbench):
     return space
 
 
-def third_view_factory(workbench):
-    from sample_workspace import SampleWorkspace
-
-    import enaml
-    with enaml.imports():
-        from third_view import ThirdView, ThirdManifest
-
-    space = SampleWorkspace()
-    space.window_title = 'Third View'
-    space.content_def = ThirdView
-    space.manifest_def = ThirdManifest
+def persistent_view_factory(workbench):
+    from persistent_workspace import PersistentWorkspace
+    space = PersistentWorkspace()
+    space.window_title = 'Persistent View'
     return space
 
 
@@ -98,12 +91,12 @@ enamldef SampleManifest(PluginManifest):
             command = 'enaml.workbench.ui.select_workspace'
             parameters = {'workspace': 'sample.second_view'}
         ActionItem:
-            path = '/workspace/third'
-            label = 'Third'
+            path = '/workspace/persistent'
+            label = 'Persistent'
             shortcut = 'Ctrl+3'
             group = 'spaces'
             command = 'enaml.workbench.ui.select_workspace'
-            parameters = {'workspace': 'sample.third_view'}
+            parameters = {'workspace': 'sample.persistent_view'}
         ActionItem:
             path = '/workspace/close'
             label = 'Close Workspace'
@@ -118,6 +111,6 @@ enamldef SampleManifest(PluginManifest):
         point = 'enaml.workbench.ui.workspaces'
         factory = second_view_factory
     Extension:
-        id = 'third_view'
+        id = 'persistent_view'
         point = 'enaml.workbench.ui.workspaces'
-        factory = third_view_factory
+        factory = persistent_view_factory