A kitten to demo mouse handling

kittens/mouse_demo/main.py

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+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+# License: GPLv3 Copyright: 2021, Kovid Goyal <kovid at kovidgoyal.net>
+
+import sys
+from typing import List, Optional
+
+from ..show_key.kitty_mode import format_mods
+from ..tui.handler import Handler
+from ..tui.loop import Loop, MouseEvent
+from ..tui.operations import MouseTracking
+
+
+class Mouse(Handler):
+    mouse_tracking = MouseTracking.full
+
+    def __init__(self) -> None:
+        self.current_mouse_event: Optional[MouseEvent] = None
+
+    def initialize(self) -> None:
+        self.cmd.set_cursor_visible(False)
+        self.draw_screen()
+
+    def finalize(self) -> None:
+        self.cmd.set_cursor_visible(True)
+
+    def on_mouse(self, ev: MouseEvent) -> None:
+        self.current_mouse_event = ev
+        self.draw_screen()
+
+    @Handler.atomic_update
+    def draw_screen(self) -> None:
+        self.cmd.clear_screen()
+        ev = self.current_mouse_event
+        if ev is None:
+            self.print('Move the mouse or click to see mouse events')
+            return
+        self.print(f'Position: {ev.pixel_x}, {ev.pixel_y}')
+        self.print(f'Cell: {ev.cell_x}, {ev.cell_y}')
+        self.print(f'{ev.type}')
+        if ev.buttons:
+            self.print(ev.buttons)
+        if ev.mods:
+            self.print(f'Modifiers: {format_mods(ev.mods)}')
+
+
+def main(args: List[str]) -> None:
+    loop = Loop()
+    handler = Mouse()
+    loop.loop(handler)
+
+
+if __name__ == '__main__':
+    main(sys.argv)