MouseEvent

The MouseEvent interface represents events that occur due to the user interacting with a pointing device (such as a mouse). Common events using this interface include click, dblclick, mouseup, mousedown.

MouseEvent derives from UIEvent, which in turn derives from Event. Though the MouseEvent.initMouseEvent() method is kept for backward compatibility, creating of a MouseEvent object should be done using the MouseEvent() constructor.

Several more specific events are based on MouseEvent, including WheelEvent, DragEvent, and PointerEvent.

Constructor

MouseEvent(): Creates a MouseEvent object.

Static properties

MouseEvent.WEBKIT_FORCE_AT_MOUSE_DOWN Read only: Minimum force necessary for a normal click.
MouseEvent.WEBKIT_FORCE_AT_FORCE_MOUSE_DOWN Read only: Minimum force necessary for a force click.

Instance properties

This interface also inherits properties of its parents, UIEvent and Event.

MouseEvent.altKey Read only: Returns true if the alt key was down when the mouse event was fired.
MouseEvent.button Read only: The button number that was pressed or released (if applicable) when the mouse event was fired.
MouseEvent.buttons Read only: The buttons being pressed (if any) when the mouse event was fired.
MouseEvent.clientX Read only: The X coordinate of the mouse pointer in viewport coordinates.
MouseEvent.clientY Read only: The Y coordinate of the mouse pointer in viewport coordinates.
MouseEvent.ctrlKey Read only: Returns true if the control key was down when the mouse event was fired.
MouseEvent.layerX Read only: Returns the horizontal coordinate of the event relative to the current layer.
MouseEvent.layerY Read only: Returns the vertical coordinate of the event relative to the current layer.
MouseEvent.metaKey Read only: Returns true if the meta key was down when the mouse event was fired.
MouseEvent.movementX Read only: The X coordinate of the mouse pointer relative to the position of the last move event of the same type (a mousemove, pointermove, or pointerrawupdate).
MouseEvent.movementY Read only: The Y coordinate of the mouse pointer relative to the position of the last move event of the same type (a mousemove, pointermove, or pointerrawupdate).
MouseEvent.offsetX Read only: The X coordinate of the mouse pointer relative to the position of the padding edge of the target node.
MouseEvent.offsetY Read only: The Y coordinate of the mouse pointer relative to the position of the padding edge of the target node.
MouseEvent.pageX Read only: The X coordinate of the mouse pointer relative to the whole document.
MouseEvent.pageY Read only: The Y coordinate of the mouse pointer relative to the whole document.
MouseEvent.relatedTarget Read only: The secondary target for the event, if there is one.
MouseEvent.screenX Read only: The X coordinate of the mouse pointer in screen coordinates.
MouseEvent.screenY Read only: The Y coordinate of the mouse pointer in screen coordinates.
MouseEvent.shiftKey Read only: Returns true if the shift key was down when the mouse event was fired.
MouseEvent.mozInputSource Read only: The type of device that generated the event (one of the MOZ_SOURCE_* constants). This lets you, for example, determine whether a mouse event was generated by an actual mouse or by a touch event (which might affect the degree of accuracy with which you interpret the coordinates associated with the event).
MouseEvent.webkitForce Read only: The amount of pressure applied when clicking.
MouseEvent.x Read only: Alias for MouseEvent.clientX.
MouseEvent.y Read only: Alias for MouseEvent.clientY.

Instance methods

This interface also inherits methods of its parents, UIEvent and Event.

MouseEvent.getModifierState(): Returns the current state of the specified modifier key. See KeyboardEvent.getModifierState() for details.
MouseEvent.initMouseEvent(): Initializes the value of a MouseEvent created. If the event has already been dispatched, this method does nothing.

Example

This example demonstrates simulating a click (programmatically generating a click event) on a checkbox using DOM methods. Event state (canceled or not) is then determined with the return value of method EventTarget.dispatchEvent().

HTML

html

<p>
  <label><input type="checkbox" id="checkbox" /> Checked</label>
</p>
<p>
  <button id="button">Click me to send a MouseEvent to the checkbox</button>
</p>

JavaScript

function simulateClick() {
  // Get the element to send a click event
  const cb = document.getElementById("checkbox");

  // Create a synthetic click MouseEvent
  let evt = new MouseEvent("click", {
    bubbles: true,
    cancelable: true,
    view: window,
  });

  // Send the event to the checkbox element
  cb.dispatchEvent(evt);
}
document.getElementById("button").addEventListener("click", simulateClick);