Setting the Attach Ratio

Each Attach option features an additional Ratio parameter that defines the effective change of the corresponding edge in relation to the edge of the template in which the child is used.

If this parameter is set to 1/1, the border of the edge follows the template edge exactly. With a value of 1/2, for example, the edge only follows with half the speed, which means that if the template edge is moved by 10 pixels, the attached edge is only moved 5 pixels.

To keep a child unchanged in size but horizontally centered in the template, set the values for left and right to 1/2.
To keep a child unchanged in size but vertically centered in the template, set the values for top and bottom to 1/2.