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.
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.
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.
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.
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 Diagram.None.
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.
Copies properties from this object to the given object, which is of the same class.
This is called by #copy and should be overridden for each class that adds properties.
There are examples of such overrides in the samples.
Please read the Introduction page on Extensions for how to override methods and how to call this base method.
A 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.
When 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.
Creates 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.
@expose
@return {Layout}
Create a new LayoutNetwork of LayoutVertexes and LayoutEdges.
This may be overridden in Layout subclasses to create instances of subclasses of
LayoutNetwork.
Please read the Introduction page on Extensions for how to override methods and how to call this base method.
@expose
@return {LayoutNetwork} a new LayoutNetwork.
Position all of the nodes that do not have an assigned Part#location
in the manner of a simple rectangular array.
The default implementation ignores all Groups and Links;
many subclasses of Layout ignore all instances of Parts
that are not Nodes or Links.
This 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.
@param {Part} part the Part being laid out
@param {Rect=} rect an optional Rect that will be modified and returned
@return {Rect} a Rect in document coordinates
@since 2.0
Compute 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.
Create 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 Introduction page on Extensions for how to override methods and how to call this base method.
@expose
@param {Diagram|Group|Iterable.
When 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 Introduction page on Extensions for how to override methods and how to call this base method.
@expose
