The ncurses "scroll" bug.

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Greg Field

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Oct 25, 2015, 11:45:21 PM10/25/15
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Ncurses scroll bug.

Open/ed uses the package "ncurses".
Ncurses has a small problem in that "click" and "scroll" functionality can not be used at the same time.
By "click", we mean using a mouse button for single and double clicking.
By "scroll", we mean using the mouse wheel or the top surface on Apple Magic Mouse.

Open/ed has a workaround in place for this. No additional configuration should be needed by you as
Opened is built with static libraries and can match the workaround to the issue in the library used.

The temporary workaround is that Open/ed flips between two states, 1) for clicking, and 2) for scrolling.

However, be aware of the side effects :

  • When you scroll down, there will be no delay. 
  • When you scroll up, there will be a short delay.
    Scroll up just one line, wait for the cursor to move up one line, then you can scroll up (or down) as rapidly as you like. 
  • When you press a keyboard key, or do a mouse click (other then scroll), then Open/ed comes out of scroll mode.
    The action to do this may not be a double or triple click. Any type of click, while in scroll mode, is treated as a single click.
    If you need to do a double click, straight after scrolling, do a single click (or keyboard key), then the double click. 

If you would like to understand "state change" workaround better,

  1. (Minimum Open/ed version for this feature is 14.10.25). 
  2. Create a file "$HOME/.curwin.conf". (Note the dot for hidden file).
  3. Add a single line containing " mint beep on".
  4. Then restart Open/ed.
  5. You will get a beep each time Open/ed does a mouse scroll state change.
  6. Delete the file when you are done to stop the beep.
  7. Alternately you can comment the line out with a leading '#' character. 
  8. Warning ! The ".curwin.conf" file is a developers tool. 
    It should not be relied on to have stable syntax. 

We believe this issue is fixed in ncurses 6.0 and when this is available for OSX, we will incorporate the fix to Open/ed. 
The fix should make scrolling and any other keyboard or mouse action, seamless.


The ncurses web page.

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