[duxhelp] Problems with the "go to page" and "go to next and previous page"

  • From: Dave Durber <dadurber@xxxxxxxxxxxxx>
  • To: duxhelp@xxxxxxxxxxxxx
  • Date: Thu, 22 Jul 2004 12:25:54 -0400

I have two questions as follows:

When you press <CTRL+G> to go to a specific page, the program will
often come up with a message telling you that you cannot go to that
location.  However, when you press the <ENTER> key, you will
invariably find yourself at the location you requested regardless of
the previous message.

I think that DBT comes up with that message because it cannot
calculate accurately enough, for example, where the top-of-the page is
on certain pages.

A good idea might be to use the same or similar system that
WordPerfect used, that is:

[spg], which stood for "soft page break".  This code indicated when a
page was filled up and a new page began.  You would see this code when
paragraphs, list and outline items spread across page boundaries from
one page to another.

[hpg], which stood for "hard page break".  This code was used when you
wanted to end the current page and start a new page.

Now, if DBT used such a system, then the go to page function could
search for the [spg] or [hpg] codes, calculate the number of codes to
reach that location and place you at the top of that page that you

This brings me onto another function, that is the <CTRL+PGDN> "go to
next page" and the <CTRL+PGUP> "go to previous page commands, which at
present do not work as they really should.

Although these keystrokes do move the cursor to the next and previous
page, in my experience they do not move the cursor to the top of the
page by default, which should be the case.

Example:  If you have a braille file on-screen that contains 50 pages
of text and the cursor is on "page15 line5 column1, you press
<CTRL+PGDN> to go to top of page 16, the status line should say
"page16 line1 column1", logically, this is where the cursor should be
located but, in my experience when you read the status line it
actually reads "page16 line5 column1", which is the same line and
column positions as the previous page.  This might vary depending on
format codes and styles that might be in effect at that location in
the file which might force DBT to place the cursor as near to
"column1" on "page16 line5" as possible.

Likewise, if you want to move the cursor from its current location
which is "page 16 line5 column1" an move it to the top of page 15 You
should have to press <CTRL+PGUP> once to move the cursor to the top of
"page 16 line1 column1", which is the top of the current page and then
press the <CTRL+PGUP> again to move the cursor to the top of the
previous page which is "page15 line1 column1".

From my experience this is not the case.  If the cursor is on "page16
line1 column1" and you press <CTRL+PGUP> the cursor moves to the
previous page with the same line and column location, that is "line5
column1", depending on the format or style codes that might be in
effect at that location in the file which might force DBT to place the
cursor as near to "column1" "page15 line5" as possible.

Like the "go to" command if DBT used codes such as [spg] and [hpg] to
indicate hard and soft page breaks, Dbt could search for these codes
to accurately place the cursor at the top of the next and previous
page when the <CTRL+PGDN> and <CTRL+PGUP> key combinations are used. 


Dave Durber

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