Layers in EJ2 JavaScript Diagram control
18 Apr 202318 minutes to read
Layer is used to organize related shapes on a diagram control. A layer is a named category of shapes. By assigning shapes to different layers, you can selectively view, remove, and lock different categories of shapes.
In diagram, Layers provide a way to change the properties of all shapes that have been assigned to that layer. The following properties can be set.
- Visible
- Lock
- Objects
- AddInfo
Visible
The layer’s visible property is used to control the visibility of the elements assigned to the layer.
ej.diagrams.Diagram.Inject(ej.diagrams.Diagram, ej.diagrams.ConnectorModel,ej.diagrams.NodeModel,ej.diagrams.LayerModel);
// A node is created and stored in nodes array.
var nodes = [{
id: 'node1',
width: 100,
height: 100,
offsetX: 100,
offsetY: 100,
annotations: [{
content: 'Default Shape'
}]
},
{
id: 'node2',
width: 100,
height: 100,
offsetX: 300,
offsetY: 100,
shape: {
type: 'Path',
data: 'M540.3643,137.9336L546.7973,159.7016L570.3633,159.7296L550.7723,171.9366L558.9053,194.9966L540.3643,' +
'179.4996L521.8223,194.9966L529.9553,171.9366L510.3633,159.7296L533.9313,159.7016L540.3643,137.9336z'
},
annotations: [{
content: 'Path Element'
}]
}
];
var connectors = [{
id: 'connector1',
type: 'Straight',
sourcePoint: {
x: 100,
y: 300
},
targetPoint: {
x: 200,
y: 400
},
}];
// initialize diagram component
var diagram = new ej.diagrams.Diagram({
width: '100%',
height: '600px',
connectors: connectors,
nodes: nodes,
layers: [{
id: 'layer1',
visible: true,
objects: ['node1']
}
]
},'#element');Lock
The layer’s lock property is used to prevent or allow changes to the elements dimension and position.
ej.diagrams.Diagram.Inject(ej.diagrams.Diagram, ej.diagrams.ConnectorModel,ej.diagrams.NodeModel,ej.diagrams.LayerModel);
// A node is created and stored in nodes array.
var nodes = [
{
id: 'node1',
width: 100,
height: 100,
offsetX: 100,
offsetY: 100,
annotations: [{
content: 'Default Shape'
}]
},
{
id: 'node2',
width: 100,
height: 100,
offsetX: 300,
offsetY: 100,
shape: {
type: 'Path',
data: 'M540.3643,137.9336L546.7973,159.7016L570.3633,159.7296L550.7723,171.9366L558.9053,194.9966L540.3643,' +
'179.4996L521.8223,194.9966L529.9553,171.9366L510.3633,159.7296L533.9313,159.7016L540.3643,137.9336z'
},
annotations: [{
content: 'Path Element'
}]
}
];
var connectors = [{
id: 'connector1',
type: 'Straight',
sourcePoint: {
x: 100,
y: 300
},
targetPoint: {
x: 200,
y: 400
},
}];
// initialize diagram component
var diagram = new ej.diagrams.Diagram({
width: '100%',
height: '600px',
connectors: connectors,
nodes: nodes,
layers: [
{
id: 'layer1',
visible: true,
objects: ['node1'],
lock: true
},
{
id: 'layer2',
visible: true,
objects: ['node2'],
lock: false
}
]
},'#element');Objects
The layer’s objects property defines the diagram elements to the layer.
ej.diagrams.Diagram.Inject(ej.diagrams.Diagram, ej.diagrams.ConnectorModel,ej.diagrams.NodeModel,ej.diagrams.LayerModel);
// A node is created and stored in nodes array.
var nodes = [{
id: 'node1',
width: 100,
height: 100,
offsetX: 100,
offsetY: 100,
annotations: [{
content: 'Default Shape'
}]
},
{
id: 'node2',
width: 100,
height: 100,
offsetX: 300,
offsetY: 100,
shape: {
type: 'Path',
data: 'M540.3643,137.9336L546.7973,159.7016L570.3633,159.7296L550.7723,171.9366L558.9053,194.9966L540.3643,' +
'179.4996L521.8223,194.9966L529.9553,171.9366L510.3633,159.7296L533.9313,159.7016L540.3643,137.9336z'
},
annotations: [{
content: 'Path Element'
}]
}
];
var connectors = [{
id: 'connector1',
type: 'Straight',
sourcePoint: {
x: 100,
y: 300
},
targetPoint: {
x: 200,
y: 400
},
}];
// initialize diagram component
var diagram = new ej.diagrams.Diagram({
width: '100%',
height: '600px',
connectors: connectors,
nodes: nodes,
layers: [
{
id: 'layer1',
visible: true,
objects: ['node1', 'node2']
},
{
id: 'layer2',
visible: true,
objects: ['node2']
}
]
},'#element');AddInfo
The addInfo property of layers allow you to maintain additional information to the layers.
The following code illustrates how to add additional information to the layers.
ej.diagrams.Diagram.Inject(ej.diagrams.Diagram, ej.diagrams.ConnectorModel,ej.diagrams.NodeModel,ej.diagrams.LayerModel);
// A node is created and stored in nodes array.
var nodes = [{
id: 'node1',
width: 100,
height: 100,
offsetX: 100,
offsetY: 100,
annotations: [{
content: 'Default Shape'
}]
},
{
id: 'node2',
width: 100,
height: 100,
offsetX: 300,
offsetY: 100,
shape: {
type: 'Path',
data: 'M540.3643,137.9336L546.7973,159.7016L570.3633,159.7296L550.7723,171.9366L558.9053,194.9966L540.3643,' +
'179.4996L521.8223,194.9966L529.9553,171.9366L510.3633,159.7296L533.9313,159.7016L540.3643,137.9336z'
},
annotations: [{
content: 'Path Element'
}]
}
];
var connectors = [{
id: 'connector1',
type: 'Straight',
sourcePoint: {
x: 100,
y: 300
},
targetPoint: {
x: 200,
y: 400
},
}];
var addInfo = { Description: 'Layer1' };
// initialize Diagram component
var diagram = new ej.diagrams.Diagram({
width: '100%',
height: '600px',
connectors: connectors,
nodes: nodes,
layers: [{
id: 'layer1',
visible: true,
objects: ['node1', 'node2'],
addInfo: addInfo
},
{
id: 'layer2',
visible: true,
objects: ['node2']
}
]
});Add layer at runtime
Layers can be added at runtime by using the addLayer public method.
The layer’s ID property defines the ID of the layer, and its further used to find the layer at runtime and do any customization.
The following code illustrates how to add a layer.
var diagramElement = document.getElementById('element');
var diagram = diagramElement.ej2_instances[0];
// add the layers to the existing diagram layer collection
diagram.addLayer(
{
id: 'newlayer',
objects: [],
visible: true,
lock: false,
zIndex: -1
},
[{
type: 'Straight',
sourcePoint: {
x: 100,
y: 300
},
targetPoint: {
x: 200,
y: 400
}
}]);Remove layer at runtime
Layers can be removed at runtime by using the removeLayer public method.
The following code illustrates how to remove a layer.
var diagramElement = document.getElementById('element');
var diagram = diagramElement.ej2_instances[0];
// remove the diagram layers
diagram.removeLayer([diagram.model.layers[i]]);moveObjects
Objects of the layers can be moved by using the moveObjects public method.
The following code illustrates how to move objects from one layer to another layer from the diagram.
var diagramElement = document.getElementById('element');
var diagram = diagramElement.ej2_instances[0];
// move the objects of diagram layers
diagram.moveObjects(['connector1'], 'layer2');bringLayerForward
Layers can be moved forward at runtime by using the bringLayerForward public method.
The following code illustrates how to bring forward to layer.
var diagramElement = document.getElementById('element');
var diagram = diagramElement.ej2_instances[0];
// move the layer forward
diagram.bringLayerForward('layer1');sendLayerBackward
Layers can be moved backward at runtime by using the sendLayerBackward public method.
The following code illustrates how to send backward to layer.
var diagramElement = document.getElementById('element');
var diagram = diagramElement.ej2_instances[0];
// move the layer backward
diagram.sendLayerBackward('layer1');cloneLayer
Layers can be cloned with its object by using the cloneLayer public method.
The following code illustrates how to bring forward to layer.
var diagramElement = document.getElementById('element');
var diagram = diagramElement.ej2_instances[0];
// clone a layer with its object
diagram.cloneLayer('layer2');getActiveLayer
To get the active layers back in diagram, use the getActiveLayer public method.
The following code illustrates how to bring forward to layer.
var diagramElement = document.getElementById('element');
var diagram: Object[] = diagramElement.ej2_instances[0];
// gets the active layer back
diagram.getActiveLayer();setActiveLayer
Set the active layer by using the setActiveLayer public method.
The following code illustrates how to bring forward to layer.
var diagramElement = document.getElementById('element');
var diagram: Object[] = diagramElement.ej2_instances[0];
// set the active layer
//@param layerName defines the name of the layer which is to be active layer
diagram.setActiveLayer('layer2');