OVERVIEW

Seadragon Ajax ("Seajax") v2 is a Javascript library for using deep zoom content (DZI and DZC files, as supported by
Silverlight) in web pages, and for easily creating beautiful zooming interfaces. It introduces the Seadragon2.Image
element and the accompanying <sdimg> tag, which mimics the <img> tag but references a deep zoom image or a particular
element from a deep zoom collection. Seajax smoothly blends different resolution levels, and works in virtually every
major browser. It automatically prioritizes network requests for image tiles that cover more area or are closer to the
center of the screen. Seajax also provides a Viewer, which allows for fluid mouse-controlled panning and zooming of HTML
or SVG content. Furthermore, the Viewer can be used to manipulate the coordinate space of a canvas element, or to
control multiple kinds of content simultaneously (such as a canvas element with an HTML overlay).

This repository also contains code for creating a control that mimics the PivotViewer found in Silverlight, where a user
can filter and sort a deep zoom collection. Collection data can come from a CXML file or be added dynamically on the
client. For more info on setting up a page using this PivotViewer implementation, see v2/app/pivot/quickstart.html.
Unlike the library portion, which aims to support every major browser, PivotViewer requires a browser with the <canvas>
element, meaning IE8 and earlier are unsupported.

As a historical note, most of this code was written in 2010 and was targeted at mouse interaction, so updates may be
needed for newer browsers and touch interaction.


BUILDING

To build all outputs, run Build/Scripts/seajax_v2.py using Python 2. The build script is currently set up to call
ajaxmin for its minification step, but that could easily be swapped for another minifier if you prefer. After building,
the bin/v2 directory will contain various files containing different subsets of the Seajax functionality. The most
complete feature set (and therefore the biggest js file) is the "pivot" file. The "zoom" file has just the features
needed for creating a pan&zoom container; the "image" file has features for loading and displaying DZC and DZI content,
and the "zoomimage" file contains both. "utils" and "ajax" are more minimal builds containing various helper functions.
You should only ever need one of these js files (no need to include both "utils" and "pivot" on your page, because the
"pivot" build contains everything from "utils", for example). No external libraries are needed.


USING

Pivot:
See the instructions in v2/app/pivot/quickstart.html

Image:
Add an <sdimg> element in your markup, or create it in code with one of the following:
    var img = new Seadragon2.Image();
    var img = document.createElement("sdimg");
Set its src property like you would with a normal <img>, but point it at deep zoom data:
    img.src = "someimage.dzi";
    img.src = "somecollection.dzc#5"; // note the hash indicates which item from the collection

Viewer:
Make any element pan&zoom the content that it contains by creating a Viewer:
    var viewer = new Seadragon2.Viewer(document.getElementById("myViewerDiv"), {
        viewportOptions: {
            maxZoom: 10,
            minZoom: 0.4,
            visibilityRatio: 0.5
        }
    });
See the code comments in v2/src/zoomcontainer/Viewer.js for descriptions of all available viewportOptions, and to
reference other methods that can be called on the Viewer object once it's constructed.