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CIGAL Reference Manual, Chapter 1 (Topics): keyboard

Keyboard -- CIGAL-defined special keys on the terminal keyboard

CIGAL uses many of the special function keys available on the keyboard. The most useful keys are assigned their standard meaning:

  1. RETURN - generally used to tell the program to go ahead and execute the written command, either at the end of a command line or after pointing to a selected menu item
  2. Ctrl-C - generally interrupts whatever the program is currently doing and returns to wait for the next CIGAL command. However, interrupts can be trapped during execution of a CIGAL macro command (see MACROS(1)), in which case the macro may not be terminated (see CTRAP(4), FLAGS(4)).
  3. Ctrl-A - show the progress of the current active process
  4. Ctrl-B - clear the type-ahead buffer
  5. Ctrl-D - change the value of the DEBUG variable
  6. Ctrl-E - stop the current command using the ERROR flag. Unlike Ctrl-C, which can do other things in addition to stopping the current command (like aborting macro programs and redrawing menus), the Ctrl-E key only cancels a single active command by acting as though that command encountered an error.

The ESC key and the function keys F1 through F10 have no internally defined significance. The meaning of these keys is assigned via the function menu (see MENUS(1) and MENU(2)). The idea here is to let you use these handy keys to let you execute frequently used commands with a single keystroke.

The meanings of some of the other special keys depend on what you are doing at the time. For example, In normal command mode:

When you are entering commands in response to the prompt in the it easier to enter and edit commands. These keys are:

      PageUP       Go back to a previously entered command; you can step
                     back through the last 24 commands (see [[jvs:cigal:manual:chapter2:journal|JOURNAL(2)]])
      PageDown     Go forward to a previously entered command (un-PageUp)
      LeftArrow    Move left along the command line, without erasing
      RightArrow   Move right along the command line
      Home         Move to the beginning of the command line
      End          Move to the end of the command line
      Delete       Delete the charecter at the current cursor position
      Insert       Toggle between overwrite and insertion modes; in
                     overwrite, newly typed characters replace existing
                     ones, in insertion, new characters are slid in among
                     the old
      Control-U    Erase the current command line

With practice, these command editing keys are very helpful for those of us who can't type.

Using menus:

When you have a menu displayed on the screen the 4 arrow keys can be used to move around the menu and the ENTER key is used to execute the selected item (see MENUS(1)). However, if you start to type a command while in the menu mode then the arrows revert to their command editing meaning (see above) for as long as there is text on the line. If you erase the command line then you can again use the arrow keys to move around the menus.

Moving the graphics cursor:

The arrow keys can also be used to move the cursor for those commands that expect you to point to some place on the screen. Pressing one of the arrow keys should cause the cursor to move in the corresponding direction (see CURSOR(4)). In this mode, however, the number of pixels that the cursor moves each time you press an arrow key is variable depending on the current “jumpsize”. Jumpsize can be 1, 8, or 64 pixels, and you switch from one jumpsize to another each time you press the Insert key; cycling through the 3 step sizes: 1, 8, and 64. The purpose of jumpsize is to let you move quickly across the image in big steps, and still let you switch to small steps in order to point to any individual pixel accurately.

Using the SKETCH command:

When you are using the SKETCH command the following keys have additional special meanings:

       Delete     Erase the last vector
       Insert     Redraw the last vector
       End        Erase the last list of vectors
       Home       Redraw the last list of vectors

See SKETCH(2) for more information on this mode.

See Also:
CIGAL Home, CIGAL Manual, Topics List, Manual Help

jvs/cigal/manual/chapter1/keyboard.txt · Last modified: 2022/11/18 16:08 (external edit)