To extend a line (input of distance)

 To the user it is necessary to specify linear object on a map. The choice of object must be done in area of that piece of the metrics (the first or last) which is necessary for prolonging. After a choice of object a dialogue «To extend a line» will appear.  

Parameters an angle and a direction of dialogue already correspond to an extended piece, it is necessary for user to enter only distance and to press button "To map". At desire it is possible to bring corrective amendments into any element of dialogue, but in this case the created point of an extended line will not be in a range (stvor) with the chosen piece of the metrics.