<!--
Copyright (c) 2006-2013, JGraph Ltd
Drop example for mxGraph. This example demonstrates handling
native drag and drop of images (requires modern browser).
-->
<html>
<head>
<title>Drop example for mxGraph</title>
<!-- Sets the basepath for the library if not in same directory -->
<script type="text/javascript">
mxBasePath = '../src';
</script>
<!-- Loads and initializes the library -->
<script type="text/javascript" src="../src/js/mxClient.js"></script>
<!-- Example code -->
<script type="text/javascript">
// Program starts here. Creates a sample graph in the
// DOM node with the specified ID. This function is invoked
// from the onLoad event handler of the document (see below).
function main(container)
{
// Checks if the browser is supported
var fileSupport = window.File != null && window.FileReader != null && window.FileList != null;
if (!fileSupport || !mxClient.isBrowserSupported())
{
// Displays an error message if the browser is not supported.
mxUtils.error('Browser is not supported!', 200, false);
}
else
{
// Disables the built-in context menu
mxEvent.disableContextMenu(container);
// Creates the graph inside the given container
var graph = new mxGraph(container);
// Enables rubberband selection
new mxRubberband(graph);
mxEvent.addListener(container, 'dragover', function(evt)
{
if (graph.isEnabled())
{
evt.stopPropagation();
evt.preventDefault();
}
});
mxEvent.addListener(container, 'drop', function(evt)
{
if (graph.isEnabled())
{
evt.stopPropagation();
evt.preventDefault();
// Gets drop location point for vertex
var pt = mxUtils.convertPoint(graph.container, mxEvent.getClientX(evt), mxEvent.getClientY(evt));
var tr = graph.view.translate;
var scale = graph.view.scale;
var x = pt.x / scale - tr.x;
var y = pt.y / scale - tr.y;
// Converts local images to data urls
var filesArray = event.dataTransfer.files;
for (var i = 0; i < filesArray.length; i++)
{
handleDrop(graph, filesArray[i], x + i * 10, y + i * 10);
}
}
});
}
};
// Handles each file as a separate insert for simplicity.
// Use barrier to handle multiple files as a single insert.
function handleDrop(graph, file, x, y)
{
if (file.type.substring(0, 5) == 'image')
{
var reader = new FileReader();
reader.onload = function(e)
{
// Gets size of image for vertex
var data = e.target.result;
// SVG needs special handling to add viewbox if missing and
// find initial size from SVG attributes (only for IE11)
if (file.type.substring(0, 9) == 'image/svg')
{
var comma = data.indexOf(',');
var svgText = atob(data.substring(comma + 1));
var root = mxUtils.parseXml(svgText);
// Parses SVG to find width and height
if (root != null)
{
var svgs = root.getElementsByTagName('svg');
if (svgs.length > 0)
{
var svgRoot = svgs[0];
var w = parseFloat(svgRoot.getAttribute('width'));
var h = parseFloat(svgRoot.getAttribute('height'));
// Check if viewBox attribute already exists
var vb = svgRoot.getAttribute('viewBox');
if (vb == null || vb.length == 0)
{
svgRoot.setAttribute('viewBox', '0 0 ' + w + ' ' + h);
}
// Uses width and height from viewbox for
// missing width and height attributes
else if (isNaN(w) || isNaN(h))
{
var tokens = vb.split(' ');
if (tokens.length > 3)
{
w = parseFloat(tokens[2]);
h = parseFloat(tokens[3]);
}
}
w = Math.max(1, Math.round(w));
h = Math.max(1, Math.round(h));
data = 'data:image/svg+xml,' + btoa(mxUtils.getXml(svgs[0], '\n'));
graph.insertVertex(null, null, '', x, y, w, h, 'shape=image;image=' + data + ';');
}
}
}
else
{
var img = new Image();
img.onload = function()
{
var w = Math.max(1, img.width);
var h = Math.max(1, img.height);
// Converts format of data url to cell style value for use in vertex
var semi = data.indexOf(';');
if (semi > 0)
{
data = data.substring(0, semi) + data.substring(data.indexOf(',', semi + 1));
}
graph.insertVertex(null, null, '', x, y, w, h, 'shape=image;image=' + data + ';');
};
img.src = data;
}
};
reader.readAsDataURL(file);
}
};
</script>
</head>
<!-- Page passes the container for the graph to the program -->
<body onload="main(document.getElementById('graphContainer'))">
Drag & drop your images below:<br>
<!-- Creates a container for the graph with a grid wallpaper -->
<div id="graphContainer"
style="position:relative;overflow:hidden;width:621px;height:441px;background:url('editors/images/grid.gif');cursor:default;">
</div>
</body>
</html>