mxGeometry

Extends mxRectangle to represent the geometry of a cell.

For vertices, the geometry consists of the x- and y-location, and the width and height.  For edges, the geometry consists of the optional terminal- and control points.  The terminal points are only required if an edge is unconnected, and are stored in the sourcePoint and targetPoint variables, respectively.

Example

If an edge is unconnected, that is, it has no source or target terminal, then a geometry with terminal points for a new edge can be defined as follows.

geometry.setTerminalPoint(new mxPoint(x1, y1), true);
geometry.points = [new mxPoint(x2, y2)];
geometry.setTerminalPoint(new mxPoint(x3, y3), false);

Control points are used regardless of the connected state of an edge and may be ignored or interpreted differently depending on the edge’s mxEdgeStyle.

To disable automatic reset of control points after a cell has been moved or resized, the the <mxGraph.resizeEdgesOnMove> and mxGraph.resetEdgesOnResize may be used.

Edge Labels

Using the x- and y-coordinates of a cell’s geometry, it is possible to position the label on edges on a specific location on the actual edge shape as it appears on the screen.  The x-coordinate of an edge’s geometry is used to describe the distance from the center of the edge from -1 to 1 with 0 being the center of the edge and the default value.  The y-coordinate of an edge’s geometry is used to describe the absolute, orthogonal distance in pixels from that point.  In addition, the mxGeometry.offset is used as an absolute offset vector from the resulting point.

This coordinate system is applied if relative is true, otherwise the offset defines the absolute vector from the edge’s center point to the label and the values for <x> and <y> are ignored.

The width and height parameter for edge geometries can be used to set the label width and height (eg. for word wrapping).

Ports

The term “port” refers to a relatively positioned, connectable child cell, which is used to specify the connection between the parent and another cell in the graph.  Ports are typically modeled as vertices with relative geometries.

Offsets

The offset field is interpreted in 3 different ways, depending on the cell and the geometry.  For edges, the offset defines the absolute offset for the edge label.  For relative geometries, the offset defines the absolute offset for the origin (top, left corner) of the vertex, otherwise the offset defines the absolute offset for the label inside the vertex or group.