Element Tools

This is the seventh article of the intermediate section of the JointJS tutorial. Go back to link labels. Alternatively, you can return to index of all articles.

JointJS allows creating fully customizable user interaction tools for your elements. These tools show up on user interaction (e.g. mouseover) with an element view and allow the user to interact with the underlying element model. For example:

JointJS source code: element-tools-example.js

The process of getting element tools up and running on your element view is relatively straightforward:

We will explain every step in turn. We will also touch on creating custom buttons.

Element Tools

An element tool (type joint.dia.ToolView) is a view that renders a certain type of control elements on top of the element view it is attached to; for example the Boundary tool renders an outline around the bounding box of the element. The JointJS library comes with a collection of pre-made element tool definitions in the joint.elementTools namespace.

The pre-made element tools include:

To create a new element tool, we call its constructor:

var boundaryTool = new joint.elementTools.Boundary();

The element tool constructors also accept optional arguments that modify the appearance and function of the created tools:

var boundaryTool = new joint.elementTools.Boundary({
    padding: 20,
    rotate: true,
    useModelGeometry: true,
});

Add to Tools View

Element tools always need to come bundled in a tools view object (type joint.dia.ToolsView). This allows them to be shown/hidden as a group above an element. We create a new tools view and add our tools to it:

var boundaryTool = new joint.elementTools.Boundary();
var removeButton = new joint.elementTools.Remove();

var toolsView = new joint.dia.ToolsView({
    tools: [
        boundaryTool,
        removeButton
    ]
});

Remember, it is necessary to create a new set of tools for every new tools view object we create; tools are automatically reassigned to the last tools view that uses them.

Finally, we need to add our tools view to an element view. The joint.dia.ElementView class comes with a suite of tools-related methods:

We can thus show all of our tools in one place:

var elementView = element.findView(paper);
elementView.addTools(toolsView);

JointJS source code: element-tools-all.js

Remember, it is necessary to create a new tools view object for every element view; tools view objects are automatically reassigned to the last element view that uses them.

Interaction

You can easily toggle visibility of element tools using the 'element:mouseenter'/'element:mouseleave' Paper events:

paper.on('element:mouseenter', function(elementView) {
    elementView.showTools();
});

paper.on('element:mouseleave', function(elementView) {
    elementView.hideTools();
});

JointJS source code: element-tools-interaction.js

More complex interaction scenarios might require showing, hiding or removing all tools at once. You can find relevant functions in the Paper class:

Note that our example toggles visibility of element tools by using the showTools()/hideTools() functions. Element tools may also be toggled by addTools()/removeTools() functions, which are demonstrated in the link tools tutorial. For element tools, there is no practical difference between the two approaches.

Custom Buttons

It is possible to create custom buttons to complement the pre-made Remove button tool; JointJS exposes the joint.elementTools.Button class for you to extend. The markup of the new button can be sent as options.markup, while the behavior of the button on pointerdown interaction is determined by the callback function provided in options.action.

You can add the extended button to the joint.elementTools namespace and then just use that class in the code:

joint.elementTools.InfoButton = joint.elementTools.Button.extend({
    name: 'info-button',
    options: {
        markup: [{
            tagName: 'circle',
            selector: 'button',
            attributes: {
                'r': 7,
                'fill': '#001DFF',
                'cursor': 'pointer'
            }
        }, {
            tagName: 'path',
            selector: 'icon',
            attributes: {
                'd': 'M -2 4 2 4 M 0 3 0 0 M -2 -1 1 -1 M -1 -4 1 -4',
                'fill': 'none',
                'stroke': '#FFFFFF',
                'stroke-width': 2,
                'pointer-events': 'none'
            }
        }],
        x: '100%',
        y: '100%'
        offset: {
            x: 0,
            y: 0
        },
        rotate: true,
        action: function(evt) {
            alert('View id: ' + this.id + '\n' + 'Model id: ' + this.model.id);
        }
    }
});

var infoButton = new joint.elementTools.InfoButton();
var toolsView = new joint.dia.ToolsView({
    tools: [infoButton]
});

var elementView = element.findView(paper);
elementView.addTools(toolsView);

JointJS source code: element-tools-custom-button.js

A single-use custom button can also be created by direct reference to the Button class, without making an entry in the joint.elementTools namespace:

var infoButton = new joint.elementTools.Button({
    markup: [{
        tagName: 'circle',
        selector: 'button',
        attributes: {
            'r': 7,
            'fill': '#001DFF',
            'cursor': 'pointer'
        }
    }, {
        tagName: 'path',
        selector: 'icon',
        attributes: {
            'd': 'M -2 4 2 4 M 0 3 0 0 M -2 -1 1 -1 M -1 -4 1 -4',
            'fill': 'none',
            'stroke': '#FFFFFF',
            'stroke-width': 2,
            'pointer-events': 'none'
        }
    }],
    x: '100%',
    y: '100%',
    offset: {
        x: 0,
        y: 0
    },
    rotate: true,
    action: function(evt) {
        alert('View id: ' + this.id + '\n' + 'Model id: ' + this.model.id);
    }
});

var toolsView = new joint.dia.ToolsView({
    tools: [infoButton]
});

var elementView = element.findView(paper);
elementView.addTools(toolsView);

In the next section of the intermediate tutorial, we will learn about link tools.