Add show_touch_trace method for touch visualization (#1156)

* Add show_touch_trace method for touch visualization

Added a method to show touch trace on the device screen with options for pointer location and visual feedback.

* docs(readme): add usage example for show_touch_trace()

* adjust the format

---------

Co-authored-by: zeros.zhou <zeros.zhou@nothing.tech>

Author: Zeros2619

README.md

@@ -476,6 +476,15 @@ Note: click, swipe, drag operations support percentage position values. Example:
     d.open_quick_settings()
     ```
 
+* Show touch trace on device screen
+
+    ```python
+    # show touch trace on device screen
+    d.show_touch_trace()
+    # hide touch trace
+    d.show_touch_trace(pointer_location=False, show_touches=False)
+    ```
+
 ### Selector
 
 Selector is a handy mechanism to identify a specific UI object in the current window.

uiautomator2/__init__.py

@@ -51,6 +51,17 @@ class _Device(_BaseClient):
         (0, "natural", "n", 0), (1, "left", "l", 90),
         (2, "upsidedown", "u", 180), (3, "right", "r", 270))
 
+    def show_touch_trace(self, pointer_location: bool = True, show_touches: bool = True):
+        """
+        Show touch trace on device screen
+
+        Args:
+            pointer_location (bool): screen overlay showing current touch data
+            show_touches (bool): show visual feedback for taps
+        """
+        self.shell(f"settings put system pointer_location {int(pointer_location)}")
+        self.shell(f"settings put system show_touches {int(show_touches)}")
+
     def window_size(self):
         """ return (width, height) """
         w, h = self._dev.window_size()