MotionEventgetY

The `getY` method in Android's `MotionEvent` class retrieves the vertical (Y-axis) coordinate of a touch or stylus input event. It is part of the `android.view.MotionEvent` API and is used to determine the precise position of a finger or stylus on a touchscreen or digitizer. The Y-coordinate is measured in pixels relative to the top-left corner of the view where the event occurred, with the origin (0, 0) positioned at the top-left edge of the screen.

This method is commonly employed in custom gesture detection, touch-based UI interactions, or precise input handling in Android applications. For example, developers may use `getY` alongside `getX` to calculate the exact position of a touch event within a view, enabling features like drag-and-drop, swipe gestures, or custom drawing tools. The method returns a `float` value, allowing for fractional pixel precision.

When working with multi-touch events, `getY` can be called with an index parameter to retrieve the Y-coordinate of a specific pointer (finger or stylus). If no index is provided, it defaults to the primary pointer (typically the first active touch). This flexibility is useful for applications supporting multiple simultaneous inputs, such as drawing apps or virtual keyboards.

The `getY` method is often paired with other `MotionEvent` methods like `getAction()`, `getActionIndex()`, and `getHistorySize()` to fully analyze touch events. For instance, `getAction()` helps determine whether the event represents a down, up, move, or cancel gesture, while `getHistorySize()` provides access to past positions recorded during a motion event.

Developers should note that the Y-coordinate may vary depending on the device's orientation or screen resolution, and adjustments may be necessary to ensure consistent behavior across different hardware configurations. Additionally, `getY` should be used in conjunction with `getRawY()` for absolute screen coordinates, as `getY()` provides coordinates relative to the view receiving the event.