Window managers usually allow two methods of changing the FOCUS WINDOW ( the window into which input typed at the keyboard goes ). Either the focus follows the mouse pointer - FOLLOW FOCUS; or the focus goes into a window after the pointer is moved into it and a button is clicked - CLICK TO FOCUS. Once the focus is inside a particular window it is under the control of the program which owns the window.
Motif programs have two possible internal focus models which are analagous to the window manager focus models. IMPLICIT focus means that keyboard input goes to whichever item in the window is under the mouse pointer. EXPLICIT means that at any particular time one of the items in the window gets all keyboard input. The item which gets the keyboard input is changed by what is typed at the keyboard, by clicking the left mouse button or by the program itself. The internal focus model of Motplot is set to EXPLICIT.
The WIDGET ( item ) which currently has the keyboard focus is shown by the LOCATION CURSOR. This is usually a thin rectangle drawn around the item ( white in the standard motplot colour scheme ). Text areas show that they have the foucs by displaying their flashing cursor ( which is invisible when they have not got the focus ).
To move the keyboard focus among the items in any particular window use TAB and SHIFT-TAB. Some items are in groups. For example all the buttons at the bottom of the Spectrum Reading Dialog are a single group. Move the focus among the items in a group by using the UP, DOWN, LEFT and RIGHT arrows on the keypad. This focus NAVIGATION is easier to learn by practising than by description. More written details may be found in the Motif Users' Guide and the Motif Style Guide.When text areas have the keyboard focus any keys typed at the keyboard appear in the text area. ( Remeber though that some text areas only accept numerical input ). Other items, PUSH BUTTONS for example, may be operated by the keyboard when they have the focus. To operate most items use the SPACE BAR.
One of the buttons in any dialog will usually show an extra shadow around itself. For example when the Spectrum Reading Window first appears it is the Read button which has this DEFAULT BUTTON SHADOW. Pressing the RETURN key when the keyboard focus is on any of the items in the window will have the same effect as operating the button which has the default shadow.