create-gojs-kit
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A CLI for downloading GoJS samples, extensions, and docs
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Interactive Drawing of Polygons or Polylines | GoJS Diagramming Library
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GoJS
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window.addEventListener("DOMContentLoaded", function () {
// topnav
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if (topButton && topnavList) {
topButton.addEventListener("click", function (e) {
topnavList
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// if the clicked element isn't the list, close the list
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<div class="flex flex-col prose">
<div class="w-full max-w-screen-xl mx-auto">
<!-- * * * * * * * * * * * * * -->
<!-- Start of GoJS sample code -->
<script src="https://cdn.jsdelivr.net/npm/gojs@3.1.0"></script>
<div id="allSampleContent" class="p-4 w-full">
<div id="sample">
<div id="myDiagramDiv" style="border: solid 1px black; width: 100%; height: 350px"></div>
<div id="buttons">
<button id="select">Select</button>
<button id="drawPolygon">Draw Polygon</button>
<button id="drawPolyline">Draw Polyline</button>
<button id="finishDrawing">Finish Drawing</button>
<button id="cancelDrawing">Cancel Drawing</button>
<button id="undo">Undo Last Point</button>
<br />
<label><input type="checkbox" id="allowResizing" checked="checked" />Allow Resizing</label>
<label><input type="checkbox" id="allowReshaping" checked="checked" />Allow Reshaping</label>
<label><input type="checkbox" id="allowResegmenting" checked="checked" />Allow Resegmenting</label>
<label><input type="checkbox" id="allowRotating" checked="checked" />Allow Rotating</label>
</div>
<p>
This sample demonstrates the PolygonDrawingTool, a custom <a>Tool</a> added to the Diagram's mouseDownTools. It is defined in its own file, as
<a href="../extensions/PolygonDrawingTool.js">PolygonDrawingTool.js</a>. It also demonstrates the GeometryReshapingTool, another custom tool, defined in
<a href="../extensions/GeometryReshapingTool.js">GeometryReshapingTool.js</a>.
</p>
<p>
These extensions serve as examples of features that can be added to GoJS by writing new classes. With the PolygonDrawingTool, a new mode is supported that
allows the user to draw custom shapes. With the GeometryReshapingTool, users can change the geometry (i.e. the "shape") of a <a>Shape</a>s in a selected
<a>Node</a>.
</p>
<p>
Click a "Draw" button and then click in the diagram to place a new point in a polygon or polyline shape. Right-click, double-click, or Enter to finish.
Press <b>Escape</b> to cancel, or <b>Z</b> to remove the last point. Click the "Select" button to switch back to the normal selection behavior, so that you
can select, resize, and rotate the shapes. The checkboxes control whether you can resize, reshape, and/or rotate selected shapes.
</p>
<div>
<button id="save">Save</button>
<button id="load">Load</button>
</div>
<textarea id="mySavedDiagram" style="width: 100%; height: 300px">
{ "position": "0 0",
"model": { "class": "go.GraphLinksModel",
"nodeDataArray": [ {"loc":"183 148", "geo":"F M0 145 L75 2 L131 87 L195 0 L249 143z", "key":-1} ],
"linkDataArray": [ ]
} }
</textarea>
</div>
<script src="../extensions/PolygonDrawingTool.js"></script>
<script src="../extensions/GeometryReshapingTool.js"></script>
<script id="code">
function init() {
myDiagram = new go.Diagram('myDiagramDiv');
myDiagram.toolManager.mouseDownTools.insertAt(3, new GeometryReshapingTool({ isResegmenting: true }));
myDiagram.nodeTemplate =
new go.Node({
selectionObjectName: 'SHAPE',
// custom selection adornment: a blue rectangle
selectionAdornmentTemplate:
new go.Adornment('Auto')
.add(
new go.Shape({ stroke: 'dodgerblue', fill: null }),
new go.Placeholder({ margin: -1 })
),
resizable: true,
resizeObjectName: 'SHAPE',
rotatable: true,
rotationSpot: go.Spot.Center,
reshapable: true // GeometryReshapingTool assumes nonexistent Part.reshapeObjectName would be "SHAPE"
})
.bindTwoWay('location', 'loc', go.Point.parse, go.Point.stringify)
.bindTwoWay('angle')
.add(
new go.Shape({ name: 'SHAPE', fill: 'lightgray', strokeWidth: 1 })
.bindTwoWay('desiredSize', 'size', go.Size.parse, go.Size.stringify)
.bindTwoWay('geometryString', 'geo')
.bind('fill')
.bind('stroke')
.bind('strokeWidth')
);
// create polygon drawing tool for myDiagram, defined in PolygonDrawingTool.js
// install as first mouse-down-tool
myDiagram.toolManager.mouseDownTools.insertAt(0, new PolygonDrawingTool({
// provide the default JavaScript object for a new polygon in the model
archetypePartData: { fill: 'yellow', stroke: 'blue', strokeWidth: 3 },
isPolygon: true,
isEnabled: false
}));
document.getElementById('select').onclick = () => mode(false);
document.getElementById('drawPolygon').onclick = () => mode(true, true);
document.getElementById('drawPolyline').onclick = () => mode(true, false);
document.getElementById('finishDrawing').onclick = () => finish(true);
document.getElementById('cancelDrawing').onclick = () => finish(false);
document.getElementById('undo').onclick = undo;
document.getElementById('allowResizing').onclick = () => {
myDiagram.commit(d => d.allowResize = !d.allowResize);
updateAllAdornments();
};
document.getElementById('allowReshaping').onclick = () => {
myDiagram.commit(d => d.allowReshape = !d.allowReshape);
updateAllAdornments();
};
document.getElementById('allowResegmenting').onclick = () => {
toggleResegmenting();
};
document.getElementById('allowRotating').onclick = () => {
myDiagram.commit(d => d.allowRotate = !d.allowRotate);
updateAllAdornments();
};
document.getElementById('save').onclick = save;
document.getElementById('load').onclick = load;
load(); // load a simple diagram from the textarea
}
function mode(draw, polygon) {
// assume PolygonDrawingTool is the first tool in the mouse-down-tools list
var tool = myDiagram.toolManager.mouseDownTools.elt(0);
tool.isEnabled = draw;
tool.isPolygon = polygon;
tool.archetypePartData.fill = polygon ? 'yellow' : null;
tool.temporaryShape.fill = polygon ? 'yellow' : null;
if (draw) myDiagram.currentTool = tool;
}
// this command ends the PolygonDrawingTool
function finish(commit) {
var tool = myDiagram.currentTool;
if (commit && tool instanceof PolygonDrawingTool) {
var lastInput = myDiagram.lastInput;
if (lastInput.event instanceof window.MouseEvent) tool.removeLastPoint(); // remove point from last mouse-down
tool.finishShape();
} else {
tool.doCancel();
}
}
// this command removes the last clicked point from the temporary Shape
function undo() {
var tool = myDiagram.currentTool;
if (tool instanceof PolygonDrawingTool) {
var lastInput = myDiagram.lastInput;
if (lastInput.event instanceof window.MouseEvent) tool.removeLastPoint(); // remove point from last mouse-down
tool.undo();
}
}
function updateAllAdornments() {
// called after checkboxes change Diagram.allow...
myDiagram.selection.each(p => p.updateAdornments());
}
function toggleResegmenting() {
var tool = myDiagram.toolManager.findTool('GeometryReshaping');
tool.isResegmenting = !tool.isResegmenting;
updateAllAdornments();
}
// save a model to and load a model from Json text, displayed below the Diagram
function save() {
var str = '{ "position": "' + go.Point.stringify(myDiagram.position) + '",\n "model": ' + myDiagram.model.toJson() + ' }';
document.getElementById('mySavedDiagram').value = str;
}
function load() {
var str = document.getElementById('mySavedDiagram').value;
try {
var json = JSON.parse(str);
myDiagram.initialPosition = go.Point.parse(json.position || '0 0');
myDiagram.model = go.Model.fromJson(json.model);
myDiagram.model.undoManager.isEnabled = true;
} catch (ex) {
alert(ex);
}
}
window.addEventListener('DOMContentLoaded', init);
</script>
</div>
<!-- * * * * * * * * * * * * * -->
<!-- End of GoJS sample code -->
</div>
<div id="allTagDescriptions" class="p-4 w-full max-w-screen-xl mx-auto">
<hr/>
<h3 class="text-xl">GoJS Features in this sample</h3>
<!-- blacklist tags that do not correspond to a specific GoJS feature -->
<h4>Tools</h4>
<p>
<a href="../api/symbols/Tool.html" target="api">Tool</a>s handle all input events, such as mouse and keyboard interactions, in a Diagram.
There are many kinds of predefined Tool classes that implement all of the common operations that users do.
</p>
<p>
For flexibility and simplicity, all input events are canonicalized as <a href="../api/symbols/InputEvent.html" target="api">InputEvent</a>s and
redirected by the diagram to go to the <a href="../api/symbols/Diagram.html#currentTool" target="api">Diagram.currentTool</a>.
By default the Diagram.currentTool is an instance of <a href="../api/symbols/ToolManager.html" target="api">ToolManager</a> held as the <a href="../api/symbols/Diagram.html#toolManager" target="api">Diagram.toolManager</a>.
The ToolManager implements support for all mode-less tools.
The ToolManager is responsible for finding another tool that is ready to run and then making it the new current tool.
This causes the new tool to process all of the input events (mouse, keyboard, and touch) until the tool decides that it is finished,
at which time the diagram's current tool reverts back to the <a href="../api/symbols/Diagram.html#defaultTool" target="api">Diagram.defaultTool</a>, which is normally the ToolManager, again.
</p>
<p>
More information can be found in the <a href="../intro/tools.html">GoJS Intro</a>.
</p>
<p>
<a href="../samples/index.html#tools">Related samples</a>
</p>
<hr>
<!-- blacklist tags that do not correspond to a specific GoJS feature -->
<h4>GoJS Extensions</h4>
<p>
<b>GoJS</b> can be extended in a variety of ways.
The most common way to change the standard behavior is to set properties on the <a href="../api/symbols/GraphObject.html" target="api">GraphObject</a>, <a href="../api/symbols/Diagram.html" target="api">Diagram</a>, <a href="../api/symbols/CommandHandler.html" target="api">CommandHandler</a>, <a href="../api/symbols/Tool.html" target="api">Tool</a>, or <a href="../api/symbols/Layout.html" target="api">Layout</a>.
But when the desired property does not exist, you might need to override methods of CommandHandler, Tool, Layout, Link, or Node.
Methods that you can override are documented in the API reference.
Various features of GoJS can be overriden, either by replacing a method on an instance (a feature of JavaScript) or by defining a subclass.
You should not modify the prototypes of any of the <b>GoJS</b> classes.
</p>
<p>
In addition to our samples, <b>GoJS</b> provides an <strong><a href="../samples/#extensions">extensions gallery</a></strong>,
showcasing the creation of custom tools and layouts.
Those classes and samples are written in TypeScript, available at <code>../extensionsJSM/</code>,
as ECMAScript/JavaScript modules -- these use the <code>../release/go-module.js</code> library.
We recommend that you copy the files that you need into your project, so that you can adjust how they refer to the GoJS library
that you choose and so that you can include them into your own building and packaging procedures.
</p>
<p>
More information can be found in the <a href="../intro/extensions.html">GoJS Intro</a>.
</p>
<p>
<a href="../samples/index.html#extensions">Related samples</a>
</p>
<hr>
<!-- blacklist tags that do not correspond to a specific GoJS feature -->
<h4>Geometry Path Strings</h4>
<p>
The <b>GoJS</b> <a href="../api/symbols/Geometry.html" target="api">Geometry</a> class controls the "shape" of a <a href="../api/symbols/Shape.html" target="api">Shape</a>,
whereas the <a href="../api/symbols/Shape.html#fill" target="api">Shape.fill</a> and <a href="../api/symbols/Shape.html#stroke" target="api">Shape.stroke</a> and other shape properties control the colors and appearance of the shape.
For common shape figures, there are predefined geometries that can be used by setting <a href="../api/symbols/Shape.html#figure" target="api">Shape.figure</a>.
However one can also define custom geometries.
</p>
<p>
One can construct any Geometry by allocating and initializing a <a href="../api/symbols/Geometry.html" target="api">Geometry</a> of at least one <a href="../api/symbols/PathFigure.html" target="api">PathFigure</a> holding some <a href="../api/symbols/PathSegment.html" target="api">PathSegment</a>s.
But you may find that using the string representation of a Geometry is easier to write and save in a database.
Use the static method <a href="../api/symbols/Geometry.html#parse" target="api">Geometry.parse</a> or the <a href="../api/symbols/Shape.html#geometryString" target="api">Shape.geometryString</a> property to transform a geometry path string into a <a href="../api/symbols/Geometry.html" target="api">Geometry</a> object.
</p>
<p>
More information can be found in the <a href="../intro/geometry.html">GoJS Intro</a>.
</p>
<p>
<a href="../samples/index.html#geometries">Related samples</a>
</p>
<hr>
</div>
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