GraphPaper is a library for creating 2D interactive workspaces in web application. It isn't an out-of-the-box solution, a lot of implementation details are pushed to consumers. GraphPaper serves as a foundation for handling user interactions and transformation of objects, but markup and styling of those objects are left to the caller whenever possible.
GraphPaper was an offshoot of ScratchGraph, and is one of its core dependencies.
GraphPaper is very much a work-in-progress, expect major, breaking, changes to the public API. That said, releases are semantically versioned, with major releases are tagged appropriately, so things should not unexpectedly break if consumed appropiately.
- Adding, removing, and querying entities on a sheet
- Entity methods
- Entity events
- Multi-Entity Selection & Transformation
- Connectors (TBD)
- Clusters (TBD)
Sheets are workspaces. Entities are things that live and can be manipulated within Sheets.
Everything GraphPaper deals with is encapsulated on a Sheet. A sheet is a surface where GraphPaper entities can be added and actions on those entities can be performed.
To create a Sheet, we'll first need a DOM element with some basic styling:
<!DOCTYPE html>
<html>
<head>
<title>GraphPaper Demo</title>
<script src="../dist/graphpaper.js" type="text/javascript"></script>
<style type="text/css">
* { margin:0; padding:0; font-family:LatoRegular; font-size:14px; font-weight:normal; box-sizing:border-box; }
html, body { width:100%; height:100%; }
body { background:#fff; }
#sheet {
border:0px solid #f00;
width:1000px;
height:1000px;
overflow:hidden;
position:relative;
transform-origin:0 0;
}
</style>
</head>
<body>
<div id="sheet"></div>
</body>
</html>Now we can create the GraphPaper.Sheet object:
const sheet = new GraphPaper.Sheet(
document.getElementById('sheet'), // DOM element of the Sheet
window // parent window
);The sheet will be created with the default, 12x12, dotted grid (note that this is one instance where GraphPaper does take control of some styling, as the grid requires dynamic generation of an SVG image).
The sheet will be created and rendered. Now we can add entities to the sheet.
Entities are things which live on the sheet. GraphPaper can handle interactions with entities, taking responsibility for transformations, computing and rendering connectors between entities, selecting and transforming a set of entities, etc.
Let's create a simple entity that we can translate on the sheet. We'll update the page to add a <div> for the entity, another <div> that'll serve as a handle (the thing you click on and drag to move the entity) for translation, and some styles for both.
<!DOCTYPE html>
<html>
<head>
<title>GraphPaper Demo</title>
<script src="../dist/graphpaper.js" type="text/javascript"></script>
<style type="text/css">
* { margin:0; padding:0; font-family:LatoRegular; font-size:14px; font-weight:normal; box-sizing:border-box; }
html, body { width:100%; height:100%; }
body { background:#fff; }
#sheet {
border:0px solid #f00;
width:1000px;
height:1000px;
overflow:hidden;
position:relative;
transform-origin:0 0;
}
#entity1 {
display:flex;
align-items:center;
justify-content:center;
position:absolute;
width:52px;
height:52px;
background:#fff;
border:1px solid #0094ff;
border-radius:4px;
}
#translateHandle {
cursor:move;
display:block;
width:12px;
height:12px;
background:#0094ff;
border-radius:12px;
}
</style>
</head>
<body>
<div id="sheet">
<div id="entity1">
<div id="translateHandle"></div>
</div>
</div>
</body>
</html>Now let's create the GraphPaper.Entity object (note that units for size and positioning are CSS pixels)
:
const entity = new GraphPaper.Entity(
'gp-entity-001', // id
0, // x
0, // y
44, // width
44, // height
sheet, // parent GraphPaper.Sheet
document.getElementById('entity1'), // DOM element for the entity
[document.getElementById('translateHandle')], // DOM elements for the object's translation handles
[] // DOM elements for the object's resize handles
);... and add this entity to our sheet:
sheet.addEntity(entity);The translate handle won't do anything yet. There's one final step, we need to tell the sheet that it should listen for and handle transformations, this is done via:
sheet.initTransformationHandlers();Now you can drag the entity around the canvas by dragging translateHandle, either via a mouse or touch interaction. The entity will automatically snap to the grid on the sheet.