Event Handler for Mouse and Window Events

This function, located in the file ui_can_MWEvent.c, does the following:

SWITCH (event type)
  ButtonPress:
    get event data;
    SWITCH (mouse button):
      left button:
        remember current first position for selection of area;
        draw selection rectangle;
      middle button:
        remember current position as source unit, if there is
        a unit;
  ButtonRelease:
    get event data;
    SWITCH (mouse button):
      left button:
        delete selection rectangle;
        remember second position for area and normalize both
        coordinates;
        select or unselect area;
      middle button:
        IF info panel created THEN
          show this unit as target and remembered 
          unit as source;
      right button:
        IF empty position THEN
           unselect all (in this subnet)
        ELSE
           unselect this single unit
  EnterNotify (mouse is moved into a graphic window):
    set this window as actual and show new status;
  MouseMoves (mouse is moved):
    show new status, if new grid position reached;
  MouseDragg (mouse is moved with at least one button down):
    if the left button is pressed, delete old selection box, 
    draw a new one.
save position of the event in the global variables
ui_pixPosOld and ui_gridPosOld;

The actions to these events are defined in this function. The results affect the info panel and the status panel.