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.

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 (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 local (DOM content) coordinates.
MouseEvent.clientY Read only: The Y coordinate of the mouse pointer in local (DOM content) coordinates.
MouseEvent.ctrlKey Read only: Returns true if the control key was down when the mouse event was fired.
MouseEvent.layerX Non-Standard Read only: Returns the horizontal coordinate of the event relative to the current layer.
MouseEvent.layerY Non-Standard 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 mousemove event.
MouseEvent.movementY Read only: The Y coordinate of the mouse pointer relative to the position of the last mousemove event.
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.region Read only: Returns the id of the hit region affected by the event. If no hit region is affected, null is returned.
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 global (screen) coordinates.
MouseEvent.screenY Read only: The Y coordinate of the mouse pointer in global (screen) coordinates.
MouseEvent.shiftKey Read only: Returns true if the shift key was down when the mouse event was fired.
MouseEvent.mozPressure Non-Standard Deprecated Read only: The amount of pressure applied to a touch or tablet device when generating the event; this value ranges between 0.0 (minimum pressure) and 1.0 (maximum pressure). Instead of using this deprecated (and non-standard) property, you should use PointerEvent and look at its pressure property.
MouseEvent.mozInputSource Non-Standard 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 Non-Standard 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

Constants

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

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() Deprecated: Initializes the value of a MouseEvent created. If the event has already being 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

<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);

Result

Specifications

Specification
UI Events # interface-mouseevent
CSSOM View Module # extensions-to-the-mouseevent-interface
Pointer Lock 2.0 # extensions-to-the-mouseevent-interface

Browser compatibility

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