function onCanvasKeyPress( event ) {
    var canvasKeyPressEventArgs = {
      originalEvent: event.originalEvent,
    };

    /**
     * Raised when a keyboard key is pressed and the focus is on the {@link OpenSeadragon.Viewer#canvas} element.
     *
     * @event canvas-key-press
     * @memberof OpenSeadragon.Viewer
     * @type {object}
     * @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised this event.
     * @property {Object} originalEvent - The original DOM event.
     * @property {?Object} userData - Arbitrary subscriber-defined object.
     */

    this.raiseEvent('canvas-key-press', canvasKeyPressEventArgs);
}
Raised when a keyboard key is pressed and the focus is on the {@link OpenSeadragon.Viewer#canvas} element.

@event canvas-key
@memberof OpenSeadragon.Viewer
@type {object}
@property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised this event.
@property {Object} originalEvent - The original DOM event.
@property {Boolean} preventDefaultAction - Set to true to prevent default keyboard behaviour. Default: false.
@property {Boolean} preventVerticalPan - Set to true to prevent keyboard vertical panning. Default: false.
@property {Boolean} preventHorizontalPan - Set to true to prevent keyboard horizontal panning. Default: false.
@property {?Object} userData - Arbitrary subscriber-defined object.