ai-agent-book/chapter9/browser-use-rpa/browser-use/browser_use/actor/mouse.py

"""Mouse class for mouse operations."""

from typing import TYPE_CHECKING

if TYPE_CHECKING:
	from cdp_use.cdp.input.commands import DispatchMouseEventParameters, SynthesizeScrollGestureParameters
	from cdp_use.cdp.input.types import MouseButton

	from browser_use.browser.session import BrowserSession


class Mouse:
	"""Mouse operations for a target."""

	def __init__(self, browser_session: 'BrowserSession', session_id: str | None = None, target_id: str | None = None):
		self._browser_session = browser_session
		self._client = browser_session.cdp_client
		self._session_id = session_id
		self._target_id = target_id

	async def click(self, x: int, y: int, button: 'MouseButton' = 'left', click_count: int = 1) -> None:
		"""Click at the specified coordinates."""
		# Mouse press
		press_params: 'DispatchMouseEventParameters' = {
			'type': 'mousePressed',
			'x': x,
			'y': y,
			'button': button,
			'clickCount': click_count,
		}
		await self._client.send.Input.dispatchMouseEvent(
			press_params,
			session_id=self._session_id,
		)

		# Mouse release
		release_params: 'DispatchMouseEventParameters' = {
			'type': 'mouseReleased',
			'x': x,
			'y': y,
			'button': button,
			'clickCount': click_count,
		}
		await self._client.send.Input.dispatchMouseEvent(
			release_params,
			session_id=self._session_id,
		)

	async def down(self, button: 'MouseButton' = 'left', click_count: int = 1) -> None:
		"""Press mouse button down."""
		params: 'DispatchMouseEventParameters' = {
			'type': 'mousePressed',
			'x': 0,  # Will use last mouse position
			'y': 0,
			'button': button,
			'clickCount': click_count,
		}
		await self._client.send.Input.dispatchMouseEvent(
			params,
			session_id=self._session_id,
		)

	async def up(self, button: 'MouseButton' = 'left', click_count: int = 1) -> None:
		"""Release mouse button."""
		params: 'DispatchMouseEventParameters' = {
			'type': 'mouseReleased',
			'x': 0,  # Will use last mouse position
			'y': 0,
			'button': button,
			'clickCount': click_count,
		}
		await self._client.send.Input.dispatchMouseEvent(
			params,
			session_id=self._session_id,
		)

	async def move(self, x: int, y: int, steps: int = 1) -> None:
		"""Move mouse to the specified coordinates."""
		# TODO: Implement smooth movement with multiple steps if needed
		_ = steps  # Acknowledge parameter for future use

		params: 'DispatchMouseEventParameters' = {'type': 'mouseMoved', 'x': x, 'y': y}
		await self._client.send.Input.dispatchMouseEvent(params, session_id=self._session_id)

	async def scroll(self, x: int = 0, y: int = 0, delta_x: int | None = None, delta_y: int | None = None) -> None:
		"""Scroll the page using robust CDP methods."""
		if not self._session_id:
			raise RuntimeError('Session ID is required for scroll operations')

		# Activate the target first (critical for CDP calls to work)
		if self._target_id:
			try:
				await self._client.send.Target.activateTarget(params={'targetId': self._target_id})
			except Exception:
				pass

		# Method 1: Try mouse wheel event (most reliable)
		try:
			# Get viewport dimensions
			layout_metrics = await self._client.send.Page.getLayoutMetrics(session_id=self._session_id)
			viewport_width = layout_metrics['layoutViewport']['clientWidth']
			viewport_height = layout_metrics['layoutViewport']['clientHeight']

			# Use provided coordinates or center of viewport
			scroll_x = x if x > 0 else viewport_width / 2
			scroll_y = y if y > 0 else viewport_height / 2

			# Calculate scroll deltas (positive = down/right)
			scroll_delta_x = delta_x or 0
			scroll_delta_y = delta_y or 0

			# Dispatch mouse wheel event
			await self._client.send.Input.dispatchMouseEvent(
				params={
					'type': 'mouseWheel',
					'x': scroll_x,
					'y': scroll_y,
					'deltaX': scroll_delta_x,
					'deltaY': scroll_delta_y,
				},
				session_id=self._session_id,
			)
			return

		except Exception:
			pass

		# Method 2: Fallback to synthesizeScrollGesture
		try:
			params: 'SynthesizeScrollGestureParameters' = {'x': x, 'y': y, 'xDistance': delta_x or 0, 'yDistance': delta_y or 0}
			await self._client.send.Input.synthesizeScrollGesture(
				params,
				session_id=self._session_id,
			)
		except Exception:
			# Method 3: JavaScript fallback
			scroll_js = f'window.scrollBy({delta_x or 0}, {delta_y or 0})'
			await self._client.send.Runtime.evaluate(
				params={'expression': scroll_js, 'returnByValue': True},
				session_id=self._session_id,
			)