Sketcher ConstrainLock

Description
Constraint Lock applies and  constraints to selected vertices (points) in the sketch. If a single vertex is selected, the horizontal and vertical distance constraints will refer to the sketch origin point. If two or more points are selected, horizontal and vertical distance constraints will be added for each pair of points. There is no automatic prompt to edit the constraints' values, they must be edited manually.

Usage

 * 1) Select one or more vertices (points) in the sketch.
 * 2) Press the  button.
 * 3) To edit the constraints values, double-click on a constraint value in the 3D view, or double-click on the constraint or right-click and select Edit value in the Constraint list in the Tasks tab.

Note: the constraint tool can also be started with no prior selection, but it will then only work on a single vertex, and reference the constraints to the sketch origin point. By default the command will be in continue mode to create new constraints; press the right mouse button or once to quit the command.

Scripting
The Lock constraint is a GUI command which creates a  Horizontal distance and a  Vertical distance constraint, it is not a constraint of its own. See the Scripting Sketcher constraints in Python page for details and examples on how to create these constraints from Python scripts.