Clicking the left mouse button on a window changes the current focus if the window does not already have the input focus. On the drawing window the left mouse button is also used to draw the rubber zoom box by holding down the left mouse button. In the editor window double clicking brings up help for the item under the cursor. Help exists for function names, constants and global data values. Double clicking the left mouse button with the mouse on the drawing page inserts the current x,y coordinates into the text file at the current text cursor location. If the mouse was positioned at the beginning of a coordinate pair that coordinate pair is replaced with the new one. If the mouse cursor is in the text region then hitting the left mouse button will move the current text cursor to the mouse cursor location. The left mouse button is also used to select items in drop down menus.
The right mouse button is used for highlighting elements of a drawing. If the mouse cursor is on top of a displayed element on the drawing page and the right mouse button is hit then the corresponding element is highlighted and the text cursor jumps to the corresponding line in the text that generated that element. Conversely, if the mouse cursor is on the text window hitting the right mouse button will highlight any graphics elements generated by the line under the mouse cursor. This feature is very useful for finding the code associated with a particular element of a drawing or the reverse. For the pull down selection lists, the right mouse button opens a help window for those items for which help is available.
When the mouse cursor is on the drawing page the current coordinates are printed at the top. The units and origin used are those in effect at the end of the last program execution. The default units are cm with the origin in the bottom left corner of the page. Pressing the middle mouse button (or both the left and right mouse buttons together on two button mice) with the mouse pointer on the drawing page causes the current coordinate reference point to be reset so that the status line subsequently reports the distance from this point if the relative option has been selected from the misc menu.