Add basic cursor tree widget

test_scripts/test_cursor_tree_widget.py

@@ -0,0 +1,35 @@
+import datetime
+
+import urwid
+import urwid.curses_display
+
+import cheuph
+from cheuph import (AT, BasicCursorRenderer, CursorTreeRenderer,
+                    CursorTreeWidget, InMemorySupply, Message)
+
+
+def add(supply, level, text, amount=4):
+    t = datetime.datetime(2019, 5, 7, 13, 25, 6)
+    if level < 0: return
+    for i in range(amount):
+        new_text = f"{text}->{i}"
+        supply.add(Message(new_text, text or None, t, str(i), new_text))
+        add(supply, level - 1, new_text, amount=amount)
+
+def main():
+    s = InMemorySupply()
+    r = BasicCursorRenderer()
+    t = CursorTreeRenderer(s, r)
+
+    add(s, 4, "")
+
+    #screen = urwid.curses_display.Screen()
+    event_loop = urwid.AsyncioEventLoop()
+    loop = urwid.MainLoop(
+            cheuph.CursorTreeWidget(t),
+            #screen=screen,
+            event_loop=event_loop,
+    )
+    loop.run()
+
+main()