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 and DragEvent.

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 depressed (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.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 This is an experimental API that should not be used in production code.
The X coordinate of the mouse pointer relative to the position of the padding edge of the target node.
MouseEvent.offsetY Read only This is an experimental API that should not be used in production code.
The Y coordinate of the mouse pointer relative to the position of the padding edge of the target node.
MouseEvent.pageX Read only This is an experimental API that should not be used in production code.
The X coordinate of the mouse pointer relative to the whole document.
MouseEvent.pageY Read only This is an experimental API that should not be used in production code.
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.which This API has not been standardized. Read only
The button being pressed when the mouse event was fired.
MouseEvent.mozPressure This API has not been standardized. This deprecated API should no longer be used, but will probably still work. 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 instead use PointerEvent and look at its pressure property.
MouseEvent.mozInputSource This API has not been standardized. Read only
The type of device that generated the event (one of the MOZ_SOURCE_* constants listed below). 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 This API has not been standardized. Read only
The amount of pressure applied when clicking
MouseEvent.x This is an experimental API that should not be used in production code. Read only
Alias for MouseEvent.clientX.
MouseEvent.y This is an experimental API that should not be used in production code. Read only
Alias for MouseEvent.clientY

Constants

MouseEvent.WEBKIT_FORCE_AT_MOUSE_DOWN This API has not been standardized. Read only
Minimum force necessary for a normal click
MouseEvent.WEBKIT_FORCE_AT_FORCE_MOUSE_DOWN This API has not been standardized. 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() This deprecated API should no longer be used, but will probably still work.
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><button id="button">Click me</button>

JavaScript

function simulateClick() {
  var evt = new MouseEvent("click", {
    bubbles: true,
    cancelable: true,
    view: window
  });
  var cb = document.getElementById("checkbox"); //element to click on
  var canceled = !cb.dispatchEvent(evt);
  if(canceled) {
    // A handler called preventDefault
    alert("canceled");
  } else {
    // None of the handlers called preventDefault
    alert("not canceled");
  }
}
document.getElementById("button").addEventListener('click', simulateClick);

Result

Specifications

Specification Status Comment
CSS Object Model (CSSOM) View Module
The definition of 'MouseEvent' in that specification.
Working Draft Redefines MouseEvent from long to double. This means that a PointerEvent whose pointerType is mouse will be a double.
Pointer Lock
The definition of 'MouseEvent' in that specification.
Candidate Recommendation From Document Object Model (DOM) Level 3 Events Specification, added movementX and movementY properties.
CSS Object Model (CSSOM) View Module
The definition of 'MouseEvent' in that specification.
Working Draft From Document Object Model (DOM) Level 3 Events Specification, added offsetX and offsetY, pageX and pageY, x, and y properties. Redefined screen, page, client, and coordinate (x and y) properties as double from long.
UI Events
The definition of 'MouseEvent' in that specification.
Working Draft
Document Object Model (DOM) Level 3 Events Specification
The definition of 'MouseEvent' in that specification.
Obsolete From Document Object Model (DOM) Level 2 Events Specification, added the MouseEvent() constructor, the getModifierState() method and the buttons property.
Document Object Model (DOM) Level 2 Events Specification
The definition of 'MouseEvent' in that specification.
Obsolete Initial definition.

Browser compatibility

BCD tables only load in the browser

See also