function ViewportScroller(viewport, plugin, window) {
  this.viewport_ = viewport;
  this.plugin_ = plugin;
  this.window_ = window;
  this.mousemoveCallback_ = null;
  this.timerId_ = null;
  this.scrollVelocity_ = null;
  this.lastFrameTime_ = 0;
}
/**
 * Creates a new ViewportScroller.
 * A ViewportScroller scrolls the page in response to drag selection with the
 * mouse.
 *
 * @param {Object} viewport The viewport info of the page.
 * @param {Object} plugin The PDF plugin element.
 * @param {Object} window The window containing the viewer.
 * @constructor
 */
Creates a new ViewportScroller.
A ViewportScroller scrolls the page in response to drag selection with the
mouse.

@param {Object} viewport The viewport info of the page.
@param {Object} plugin The PDF plugin element.
@param {Object} window The window containing the viewer.
@constructor
Creates a new ViewportScroller . A ViewportScroller scrolls the page in response to drag selection with the mouse . @param { Object } viewport The viewport info of the page . @param { Object } plugin The PDF plugin element . @param { Object } window The window containing the viewer . @constructor
function ViewportScroller(viewport, plugin, window) {
  this.viewport_ = viewport;
  this.plugin_ = plugin;
  this.window_ = window;
  this.mousemoveCallback_ = null;
  this.timerId_ = null;
  this.scrollVelocity_ = null;
  this.lastFrameTime_ = 0;
}
function ViewportScroller ( viewport , plugin , window ) { this . viewport_ = viewport ; this . plugin_ = plugin ; this . window_ = window ; this . mousemoveCallback_ = null ; this . timerId_ = null ; this . scrollVelocity_ = null ; this . lastFrameTime_ = 0 ; }
Creates a new ViewportScroller.
Creates a new ViewportScroller .