Abstract model of the detail

A detail should be a black box for the user.

To specify a nominal size and graphic of the detail, use its parameters. It is necessary to specify these parameters, and not all parameters should be available for the user, but they should be known for graphic recognition. There are the public parameters, which the user can see, and the protected parameters, which define graphic, but the user cannot see them. These parameters can have values, defined by GOST, or the user can set their values.

When editing the detail with grips, you should define their number and the parameters they specify; define grips to specify the insertion point and the detail's orientation.

The view of the insertion dialog (or its data form) is also added to the user interface of the detail. Its view and behaviour is the black box of the detail, the form and the dialog should be convenient for the user to specify the nominal size and the parameters of the detail.

The geometric dependences are set by the detail's planes, which are a vector and a point together. The number and the position of these planes should be defined to set the dependences. The planes can be changed if they specify the detail's position according to the dependence with another detail, and unchanged (if another detail is linked to this plane); they do not change the insertion point of the detail according to the dependences.

The planes are defined according to the local coordinate system. The insertion point is its origin (pntOrigin). The direction vector (vecDirection) and vector in the drawing's plane (vecPlane), orthogonal to it, are X and Y axes.

The mathematically highlighted plane will be in the b/2 horizontal and in the h vertical distance from the insertion point. The Vector of the plane will be collinear to the vecDirection direction vector. It is enough to specify the new position of the detail if the plane is changed according to the dependence.

When changing a detail's parameters (when there are parametric dependences or when specifying the values of the parameter in the dialog), it is necessary to define new values for the parameters, select new values from the table, change the planes etc.

To define discrete values of the parameters, select them from the table. The table is organized in such a way that one row corresponds with one nominal size and the columns of the table contain the detail's parameters. The parameters can have String, Integer and Real types. The parameters have a comment, which is used in the insertion dialog. Columns and rows have unique identifiers, saved during the import and export processes of the table to provide the correspondence of the nominal sizes and already existing details in the drawing (selected rows and parameters in the table when editing the object).