Port 'Drop Down' demo to Python

demos/Drop Down/main.py

@@ -0,0 +1,76 @@
+import gi
+
+from gi.repository import GObject, Gio, Gtk
+import workbench
+
+drop_down = workbench.builder.get_object("drop_down")
+advanced_drop_down = workbench.builder.get_object("advanced_drop_down")
+
+
+def on_selected_item(_drop_down, _selected_item):
+    selected_item = drop_down.get_selected_item().get_string()
+    print(selected_item)
+
+
+def on_advanced_selected_item(_drop_down, _selected_item):
+    selected_item = advanced_drop_down.get_selected_item()
+    if selected_item:
+        print(selected_item.key)
+
+
+drop_down.connect("notify::selected-item", on_selected_item)
+
+expression = Gtk.ClosureExpression.new(
+    GObject.TYPE_STRING,
+    lambda obj: obj.get_string(),
+    None,
+)
+
+drop_down.set_expression(expression)
+
+
+class KeyValuePair(GObject.Object):
+    key = GObject.Property(type=str, flags=GObject.ParamFlags.READWRITE, default="")
+    value = GObject.Property(
+        type=str,
+        nick="Value",
+        blurb="Value",
+        flags=GObject.ParamFlags.READWRITE,
+        default="",
+    )
+
+
+model = Gio.ListStore(item_type=KeyValuePair)
+
+model.splice(
+    0,
+    0,
+    [
+        KeyValuePair(key="lion", value="Lion"),
+        KeyValuePair(key="tiger", value="Tiger"),
+        KeyValuePair(key="leopard", value="Leopard"),
+        KeyValuePair(key="elephant", value="Elephant"),
+        KeyValuePair(key="giraffe", value="Giraffe"),
+        KeyValuePair(key="cheetah", value="Cheetah"),
+        KeyValuePair(key="zebra", value="Zebra"),
+        KeyValuePair(key="panda", value="Panda"),
+        KeyValuePair(key="koala", value="Koala"),
+        KeyValuePair(key="crocodile", value="Crocodile"),
+        KeyValuePair(key="hippo", value="Hippopotamus"),
+        KeyValuePair(key="monkey", value="Monkey"),
+        KeyValuePair(key="rhino", value="Rhinoceros"),
+        KeyValuePair(key="kangaroo", value="Kangaroo"),
+        KeyValuePair(key="dolphin", value="Dolphin"),
+    ],
+)
+
+list_store_expression = Gtk.PropertyExpression.new(
+    KeyValuePair,
+    None,
+    "value",
+)
+
+advanced_drop_down.set_expression(list_store_expression)
+advanced_drop_down.set_model(model)
+
+advanced_drop_down.connect("notify::selected-item", on_advanced_selected_item)