This is an extension and not part of the main GoJS library. Note that the API for this class may change at any time. If you intend to use an extension in production, you should copy the code to your own source directory. See the Extensions intro page for more information.
Optionalinit: Partial<SpiralLayout>Gets or sets the top-left point for where the graph should be positioned when laid out. The default value for this property is the Point(0, 0). Setting this property to a new value invalidates this layout. This property is likely to be set by many Layouts that belong to a Group when the layout is performed.
Gets or sets a function that determines the initial size and position in document coordinates of a LayoutVertex corresponding to a Node. This function is called by getLayoutBounds. The default value for this property is null, in which case the GraphObject.actualBounds of the Node is used. Setting this property to a new value invalidates this layout.
The non-null value must be a function that takes 3 arguments. The first argument will be the Part whose bounds the Layout should use. The second argument will be this Layout. The third argument will be a Rect that must be modified and returned The return value must be in document coordinates. You may find it convenient to call GraphObject.getDocumentBounds to get the bounds in document coordinates of an object within the node.
since2.0
Gets or sets whether the spiral should go clockwise or counter-clockwise.
The default value is true.
ReadonlydiagramGets the Diagram that owns this layout, if it is the value of Diagram.layout.
If this property and group are non-null, the Group should be in this Diagram.
see
ReadonlygroupGets the Group that uses this layout, if it is the value of a group's Group.layout.
If this property is set to a Group, the diagram is automatically set to be the Group's Diagram.
see
Gets or sets whether this layout is performed on an initial layout. The default value is true. Setting this property to false causes isValidLayout to be set to true so that the diagram does not perform this layout.
If you set both isInitial and isOngoing to false, there will be no automatic layout invalidation, because invalidateLayout will not set isValidLayout to false. To get your nodes to appear, you will need to explicitly set or data-bind their Part.location or GraphObject.position to real Point values, because automatic layout will not assign any positions.
Another way of controlling when layouts are invalidated is by setting Part.isLayoutPositioned or Part.layoutConditions.
Gets or sets whether this layout can be invalidated by invalidateLayout. Set this to false to prevent actions such as adding or removing Parts from invalidating this layout. The default value is true. Setting this property does not invalidate this layout.
If you set both isInitial and isOngoing to false, there will be no automatic layout invalidation, because invalidateLayout will not set isValidLayout to false. To get your nodes to appear, you will need to explicitly set or data-bind their Part.location or GraphObject.position to real Point values, because automatic layout will not assign any positions.
Another way of controlling when layouts are invalidated is by setting Part.isLayoutPositioned or Part.layoutConditions.
Gets or sets whether this layout be performed in real-time, before the end of a transaction. All layouts that are invalidated will be performed at the end of a transaction. The default value is null. A null value is treated as true for a Diagram.layout but false for a Group.layout. Setting this property does not invalidate this layout.
Gets or sets whether this layout routes Links. The default value is true. When false, this layout will not explicitly set the Link.points, and the default routing of each individual Link will take place after the Nodes are moved by commitLayout. Setting this property does not invalidate this layout.
Some layouts ignore links, in which case this property is ignored.
Gets or sets whether this layout needs to be performed again (if false). Instead of setting this property directly, it is normal to set it to false by calling invalidateLayout, since that also requests performing a layout in the near future.
Gets or sets whether this layout depends on the Diagram.viewportBounds's size. If set to true, the layout will invalidate when the Diagram's viewport changes size. This only applies to diagram layouts, not to group layouts, and only when Diagram.autoScale is set to AutoScale.None.
The default value is false. Setting this property to true will invalidate this layout.
It is possible that a viewport-sized layout will trigger the Diagram to require scrollbars, which modifies the Diagram.viewportBounds, which will in turn trigger another layout. This is uncommon, but possible with GridLayout if the results require a vertical scrollbar, and that vertical scrollbar shrinks the viewport width enough that a grid column can no longer fit. When designing custom layouts, one should be careful that this behavior does not result in an infinite loop.
Gets or sets the LayoutNetwork used by this Layout, if any. The default value is null. Setting this property does not invalidate this layout. Not all kinds of layout make use of a LayoutNetwork. Call createNetwork or makeNetwork to create a network.
Gets or sets the radius distance.
The default value is NaN.
Gets or sets the spacing between nodes.
The default value is 100.
OverridecloneCopies properties to a cloned Layout.
ProtectedcollectA convenient way of converting the Diagram|Group|Iterable argument to doLayout to an actual collection of eligible Parts. The resulting Set will not include any Nodes or Links for which Part.canLayout is false. If the argument includes a Group for which Group.layout is null, the resulting Set will include the member parts of that group rather than that group itself. You will not need to call collectParts if you call makeNetwork, because that method does effectively the same thing when building the LayoutNetwork.
Typical usage:
public doLayout(coll) {
// COLL might be a Diagram or a Group or some Iterable<Part>
const it = this.collectParts(coll).iterator;
while (it.next()) {
const node = it.value;
if (node instanceof go.Node) {
. . . position the node . . .
}
}
}
Protected VirtualcommitWhen using a LayoutNetwork, commit changes to the diagram by setting Node positions and by routing the Links. This is called by updateParts within a transaction.
You should not call this method -- it is a "protected virtual" method. This may be overridden by subclasses of Layout. By default this method is implemented as follows:
protected commitLayout() {
if (this.network === null) return;
const vit = this.network.vertexes.iterator;
while (vit.next()) {
const vert = vit.value;
vert.commit();
}
if (this.isRouting) {
const eit = this.network.edges.iterator;
while (eit.next()) {
const edge = eit.value;
edge.commit();
}
}
}
Please read the Learn page on Extensions for how to override methods and how to call this base method.
VirtualcopyCreates a copy of this Layout and returns it. When a Group is copied that has a Group.layout, the Layout must also be copied. This calls cloneProtected on a newly constructed Layout.
VirtualcreateCreate a new LayoutNetwork of LayoutVertexes and LayoutEdges. This may be overridden in Layout subclasses to create instances of subclasses of LayoutNetwork. Please read the Learn page on Extensions for how to override methods and how to call this base method.
a new LayoutNetwork.
OverridedoThis method actually positions all of the Nodes, assuming that the ordering of the nodes is given by a single link from one node to the next. This respects the spacing property to affect the layout.
VirtualgetThis method is called by layouts to determine the size and initial position of the nodes that it is laying out. Normally this just returns the part's GraphObject.actualBounds. However, if boundsComputation has been set to a function, that function will be called in order to return the bounds of the given Part in document coordinates that the layout should pretend it has.
a Rect in document coordinates
since2.0
Protected VirtualinitialCompute the desired value of arrangementOrigin if this Layout is being performed for a Group.
This is typically called near the beginning of the implementation of doLayout:
this.arrangementOrigin = this.initialOrigin(this.arrangementOrigin);
if the layout wants to respect the pre-layout location of the Group when deciding where to position its member nodes.
If isOngoing is true and if an initial layout has not yet been performed, set the isValidLayout property to false, and ask to perform another layout in the near future. If isInitial is true, this layout is invalidated only when the Diagram.model is replaced, not under the normal circumstances such as when parts are added or removed or due to other calls to Layout._invalidateLayout.
If you set both isInitial and isOngoing to false, there will be no automatic layout invalidation, because this method will not set isValidLayout to false. However you can still set isValidLayout explicitly.
This is typically called when a layout property value has changed, or when a Part is added or removed or changes visibility, if Part.layoutConditions includes the pertinent flags.
VirtualmakeCreate and initialize a LayoutNetwork with the given nodes and links. This should be called by doLayout when this layout uses a network. This method calls createNetwork to allocate the network. This may be overridden in Layout subclasses to customize the initialization. Please read the Learn page on Extensions for how to override methods and how to call this base method.
normally the value of a call to createNetwork initialized by vertexes and edges corresponding to the coll argument.
VirtualupdateWhen using a LayoutNetwork, update the "physical" node positionings and link routings. This should be called by doLayout when this layout uses a network. This calls commitLayout to actually set Node positions and route Links. This performs the changes within a transaction. Please read the Learn page on Extensions for how to override methods and how to call this base method.
A custom go.Layout that lays out a chain of nodes in a spiral.
This layout assumes the graph is a chain of go.Nodes, spacing controls the spacing between nodes.
If you want to experiment with this extension, try the Spiral Layout sample.