[pyclutter] examples: Add Clutter.Actor.bind_model() example

[Emmanuele Bassi <ebassi src gnome org>]

commit 85073e9d5b3cceb23ae1fa911dbb4f329a103551
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Sat Jul 18 14:42:40 2015 +0100

    examples: Add Clutter.Actor.bind_model() example
    
    Needs fairly bleeding edge Gio bindings.

 examples/Makefile.am    |    1 +
 examples/actor-model.py |  184 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 185 insertions(+), 0 deletions(-)
---
diff --git a/examples/Makefile.am b/examples/Makefile.am
index 86cd8ee..5d5f36d 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -1,4 +1,5 @@
 EXTRA_DIST = \
+       actor-model.py \
        basic-actor.py \
        canvas.py \
        clutter-gtk-style.py \
diff --git a/examples/actor-model.py b/examples/actor-model.py
new file mode 100644
index 0000000..cac7755
--- /dev/null
+++ b/examples/actor-model.py
@@ -0,0 +1,184 @@
+from gi.repository import Clutter
+from gi.repository import GObject
+from gi.repository import Gio
+
+class MenuItemModel(GObject.GObject):
+    def __init__(self):
+        GObject.GObject.__init__(self)
+
+    label = GObject.Property(type=str, default='')
+    selected = GObject.Property(type=bool, default=False)
+
+class MenuItemView(Clutter.Text):
+    def __init__(self):
+        Clutter.Text.__init__(self)
+
+        self._selected = False
+
+        self.props.font_name = 'Sans Bold 24px'
+        self.props.color = Clutter.Color.get_static(Clutter.StaticColor.WHITE)
+        self.props.margin_left = 12
+        self.props.margin_right = 12
+
+        self.set_pivot_point(0.5, 0.5)
+
+        group = Clutter.TransitionGroup(duration=250, progress_mode=Clutter.AnimationMode.EASE_OUT)
+
+        trans = Clutter.PropertyTransition(property_name='scale-x')
+        trans.set_from(1.0)
+        trans.set_to(3.0)
+        group.add_transition(trans)
+
+        trans = Clutter.PropertyTransition(property_name='scale-y')
+        trans.set_from(1.0)
+        trans.set_to(3.0)
+        group.add_transition(trans)
+
+        trans = Clutter.PropertyTransition(property_name='opacity')
+        trans.set_from(255)
+        trans.set_to(0)
+        group.add_transition(trans)
+
+        self.add_transition('activateTransition', group)
+        group.stop()
+
+        self.connect('transition-stopped', self._on_transition_stopped)
+
+    def _on_transition_stopped(self, actor, transition, is_finished):
+        if transition == 'activateTransition':
+            self.set_scale(1, 1)
+            self.set_opacity(255)
+
+    def set_selected(self, value):
+        self._selected = value
+        if self._selected:
+            self.props.color = Clutter.Color.get_static(Clutter.StaticColor.WHITE)
+        else:
+            self.props.color = Clutter.Color.get_static(Clutter.StaticColor.SKY_BLUE_LIGHT)
+
+    def get_selected(self):
+        return self._selected
+
+    selected = GObject.Property(type=bool, default=False, setter=set_selected, getter=get_selected)
+
+    def activate(self):
+        self.get_transition('activateTransition').start()
+
+class Menu(Clutter.Actor):
+    def __init__(self):
+        Clutter.Actor.__init__(self)
+
+        layout = Clutter.BoxLayout(orientation=Clutter.Orientation.VERTICAL, spacing=12)
+        self.props.layout_manager = layout
+
+        self.props.background_color = Clutter.Color.get_static(Clutter.StaticColor.BLACK)
+
+        self._current_idx = -1
+
+        def create_menu_item_view(item):
+            view = MenuItemView()
+            item.bind_property('label', view, 'text', GObject.BindingFlags.SYNC_CREATE)
+            item.bind_property('selected', view, 'selected', GObject.BindingFlags.SYNC_CREATE | 
GObject.BindingFlags.BIDIRECTIONAL)
+            return view
+
+        self._model = Gio.ListStore(item_type=MenuItemModel)
+        self.bind_model(self._model, create_menu_item_view)
+
+    def _on_item_selected(self, item, pspec):
+        if item.props.selected:
+            print('Item {} selected'.format(item.props.label))
+
+    def populate(self, n_items=12):
+        for i in range(1, n_items + 1):
+            item = MenuItemModel()
+            item.props.label = 'Option {0:d}'.format(i)
+
+            self._model.append(item)
+
+            item.connect('notify::selected', self._on_item_selected)
+
+        self.select_item(0)
+
+    def select_item(self, idx):
+        if self._current_idx == idx:
+            return self.get_child_at_index(self._current_idx)
+
+        item = self.get_child_at_index(self._current_idx)
+        if item is not None:
+            item.props.selected = False
+
+        self._current_idx = idx
+        if self._current_idx < 0:
+            self._current_idx = self.get_n_children()
+        elif self._current_idx >= self.get_n_children():
+            self._current_idx = 0
+
+        item = self.get_child_at_index(self._current_idx)
+        if item is not None:
+            item.props.selected = True
+
+        return item
+
+    def select_prev(self):
+        return self.select_item(self._current_idx - 1)
+
+    def select_next(self):
+        return self.select_item(self._current_idx + 1)
+
+    def activate_item(self):
+        item = self.get_child_at_index(self._current_idx)
+        if item is not None:
+            item.activate()
+
+def on_key_press_event(stage, event):
+    scroll = stage.get_first_child()
+    menu = scroll.get_first_child()
+    key = event.keyval
+
+    if key == Clutter.KEY_q:
+        Clutter.main_quit()
+        return True
+
+    if key == Clutter.KEY_Up:
+        item = menu.select_prev()
+        if item is not None:
+            pos = Clutter.Point()
+            (pos.x, pos.y) = item.get_position()
+            scroll.scroll_to_point(pos)
+            return True
+
+    if key == Clutter.KEY_Down:
+        item = menu.select_next()
+        if item is not None:
+            pos = Clutter.Point()
+            (pos.x, pos.y) = item.get_position()
+            scroll.scroll_to_point(pos)
+            return True
+
+    if key == Clutter.KEY_Return or key == Clutter.KEY_KP_Enter:
+        menu.activate_item()
+        return True
+
+    return False
+
+if __name__ == '__main__':
+    Clutter.init(None)
+
+    stage = Clutter.Stage(title='Actor Model', user_resizable=True)
+    stage.connect('destroy', Clutter.main_quit)
+    stage.connect('key-press-event', on_key_press_event)
+    stage.show()
+
+    scroll = Clutter.ScrollActor(name='scroll')
+    scroll.set_position(0, 18)
+    scroll.add_constraint(Clutter.AlignConstraint(source=stage, align_axis=Clutter.AlignAxis.X_AXIS, 
factor=0.5))
+    scroll.add_constraint(Clutter.BindConstraint(source=stage, coordinate=Clutter.BindCoordinate.HEIGHT, 
offset=-36))
+    scroll.set_scroll_mode(Clutter.ScrollMode.VERTICALLY)
+    scroll.set_easing_duration(250)
+    stage.add_child(scroll)
+
+    menu = Menu()
+    scroll.add_child(menu)
+    menu.populate()
+
+    Clutter.main()