gojs
Version:
Interactive diagrams, charts, and graphs, such as trees, flowcharts, orgcharts, UML, BPMN, or business diagrams
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HTML
<html>
<head>
<meta charset="UTF-8">
<title>Zoom Pinch GoJS Sample</title>
<meta name="description" content="Customize the pinch-zooming action of GoJS." />
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- Copyright 1998-2020 by Northwoods Software Corporation. -->
<script src="../release/go.js"></script>
<script src="../assets/js/goSamples.js"></script> <!-- this is only for the GoJS Samples framework -->
<script id="code">
function init() {
if (window.goSamples) goSamples(); // init for these samples -- you don't need to call this
var $ = go.GraphObject.make; // for conciseness in defining templates
myDiagram = $(go.Diagram, "myDiagramDiv", // create a Diagram for the DIV HTML element
{
"undoManager.isEnabled": true // enable undo & redo
});
// define a simple Node template
myDiagram.nodeTemplate =
$(go.Node, "Auto", // the Shape will go around the TextBlock
$(go.Shape, "RoundedRectangle", { strokeWidth: 0 },
// Shape.fill is bound to Node.data.color
new go.Binding("fill", "color")),
$(go.TextBlock,
{ margin: 8 }, // some room around the text
// TextBlock.text is bound to Node.data.key
new go.Binding("text", "key"))
);
// Override normal pinch zoom to zoom the selected node instead of the Diagram.
var originalScale = 1;
var startDistance = 0; // how far apart the touches are at the start
var isPinching = false;
// Initiates pinch-zooming on multi-touch devices.
myDiagram.toolManager.standardPinchZoomStart = function() {
var diagram = this.diagram;
if (diagram === null) return;
var e = diagram.lastInput;
var first = e.getMultiTouchViewPoint(0, new go.Point());
var second = e.getMultiTouchViewPoint(1, new go.Point());
if (!first.isReal() || !second.isReal()) {
return;
}
// event.isMultiTouch
// call doCancel to stop the rest of typical toolManager.domousedown/domousemove behavior
this.doCancel();
var node = diagram.selection.first();
if (node === null) return;
originalScale = node.scale;
var x = second.x - first.x;
var y = second.y - first.y;
var dist = Math.sqrt((x * x) + (y * y));
startDistance = dist;
e.bubbles = false;
e.handled = true;
isPinching = true;
myDiagram.startTransaction('zoom node');
};
// Continues pinch-zooming (started by {@link #standardPinchZoomStart} on multi-touch devices.
myDiagram.toolManager.standardPinchZoomMove = function() {
var diagram = this.diagram;
if (diagram === null) return;
var e = diagram.lastInput;
var first = e.getMultiTouchViewPoint(0, new go.Point());
var second = e.getMultiTouchViewPoint(1, new go.Point());
if (!first.isReal() || !second.isReal()) {
return;
}
// event.isMultiTouch
// call doCancel to stop the rest of typical toolManager.domousedown/domousemove behavior
this.doCancel();
var x = second.x - first.x;
var y = second.y - first.y;
var dist = Math.sqrt((x * x) + (y * y));
var scale = dist / startDistance;
var oldskip = myDiagram.skipsUndoManager;
var node = diagram.selection.first();
if (node !== null) node.scale = originalScale * scale;
e.bubbles = false;
e.handled = true;
};
myDiagram.toolManager.doMouseUp = function() {
if (isPinching) {
myDiagram.commitTransaction('zoom node');
isPinching = false;
}
go.ToolManager.prototype.doMouseUp.call(this);
}
myDiagram.model = new go.GraphLinksModel(
[
{ key: "Alpha", color: "lightblue" },
{ key: "Beta", color: "orange" },
{ key: "Gamma", color: "lightgreen" },
{ key: "Delta", color: "pink" }
],
[
{ from: "Alpha", to: "Beta" },
{ from: "Alpha", to: "Gamma" },
{ from: "Beta", to: "Beta" },
{ from: "Gamma", to: "Delta" },
{ from: "Delta", to: "Alpha" }
]);
}
</script>
</head>
<body onload="init()">
<div id="sample">
<!-- The DIV for the Diagram needs an explicit size or else we won't see anything.
This also adds a border to help see the edges of the viewport. -->
<div id="myDiagramDiv" style="border: solid 1px black; width:400px; height:400px"></div>
<p>
This sample gives an example of customizing
<a>Tool.standardPinchZoomStart</a> and
<a>Tool.standardPinchZoomMove</a>.
Select a node and pinch zoom to see the action modify the scale of the Node instead
of the scale of the Diagram.
</p>
</div>
</body>
</html>