Set the viewport position and zoom

[FedericoGarciaGarcia]

There are functions to pan and zoom to annotations, but it'd be useful to set any position and any zoom in the viewport (and to get those values, too).

For a project, I have multiple Annotorious images that need to be in sync in terms of their viewport, so I created these functions to set them to any position and zoom I want and to get the target values:

/**
 * @param {OpenSeadragon.Viewer} viewer
 * @returns
 */
function getViewport(viewer) {
  const viewport = {
    x: viewer.viewport.centerSpringX.target.value,
    y: viewer.viewport.centerSpringY.target.value,
    zoom: viewer.viewport.zoomSpring.target.value,
  }

  return viewport;
}

/**
 * @param {OpenSeadragon.Viewer} viewer
 * @param {{x: number, y: number, zoom: number}} newViewport
 */
function setViewport(viewer, newViewport) {
  viewer.viewport.centerSpringX.resetTo(newViewport.x);
  viewer.viewport.centerSpringY.resetTo(newViewport.y);
  viewer.viewport.zoomTo(newViewport.zoom, null, true);
}

It'd be nice to have something like this built-in (or if there is already a better way to do it, please tell me).

[rsimon]

Since you can get those values from the viewer directly, there's no need to proxy this through Annotorious?

[FedericoGarciaGarcia]

Oh that is correct, I should ask in the OSD repo instead. Thanks.