.TH HINTVIEW 1 "15 October 2025" "Version 3.0.0"
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.\"=====================================================================
.SH NAME
hintview \- displaying HINT files
.SH SYNOPSIS
.B hintview
.RI [ options ]
.RI [ file ]
.\"=====================================================================
.SH DESCRIPTION
.B Hintview
displays a binary
.B HINT
file, usually with the
.BR .hnt
extension.
.PP
The binary
.B HINT
file format is designed for on-screen reading of documents.
Using hintview to display a
.B HINT
file, its content will dynamically
adapt to the available display area. For complete information on the
.B HINT
file format and programs to view
.B HINT
files, see
.BR  https://hint.userweb.mwn.de .
.\"=====================================================================
.SH OPTIONS
This version of
.B hintview
understands the following command line options:
.TP
.B -a
Start in autoreload mode. If in autoreload mode, the viewer will check 
the modification time of the displayed
.B HINT
file each time the cursor enters the window.
If the modification time has changed, the file is reloaded.
The viewer attempts to position the new file at about the same position
as the old file. This attempt might fail if large scale changes have
been made to the file. 
.sp
See also the 
.B Ctrl-A
and the
.B Ctrl-R
key.
.TP
.B -h
Open the document on the "home" page. The home page is a location
specified by the document author as a good starting point for reading
the document.
.sp
See also the 
.B Ctrl-H 
key.
.TP
.B --help
Print help message and exit.
.TP
.B -d
Start the viewer in "dark" mode. In this mode the viewer will display
the document using a dark background and light foreground color to reduce
eye strain in a surrounding with dim lighting.
.sp
See also the 
.B Ctrl-D
key.
.TP
.B --version
Print version information and exit.
.TP
.B -z
Zoom to 100%. The
.B HINT
viewer can display a document using a given
zoom factor to make characters appear larger or smaller to either
improve readability or increase the amount of text that can be displayed
in a given window. This option resets the zoom factor so that a 10pt
font will appear on screen at the same size as it would appear in a 
printed book.
.sp
See also the 
.B Ctrl-Z
key.
.\"=====================================================================
.SH KEYSTROKES
.B Hintview
recognizes the following keystrokes when typed in its window.
.TP
.B Ctrl-A
Toggle autoreload mode. See also the
.B -a
option and the
.B Ctrl-R
key.
.TP
.B Ctrl-O
Open the
.B File
dialog. 
.TP
.B Ctrl-D
Toggle between dark and light mode. See also the
.B -d
option.
.TP
.B Ctrl-T
Show a clickable table of content.
.TP
.B Ctrl-Q
Quit. Terminate the program.
.TP
.B Ctrl-R
Reload the content. The file is reloaded and the viewer
attempts to position the new file at about the same position
as the old file. This attempt might fail if large scale changes have
been made to the file. See also the
.B Ctrl-A
key and the
.B -a
option.
.TP
.B Ctrl-F
Open the
.B Find
dialog.
.TP
.B Ctrl-G
Find the next occurrence.
.TP
.B Ctrl-Z
Zoom to 100%. See also the
.B -z
option.
.TP
.BR Home , \ Ctrl-H
Move to the "home" page. The home page is a location specified by the 
document author as a good starting point for reading the document.
.TP
.B Page-Down
Move to the next page.
.TP
.B Page-Up
Move to the previous page.
.TP
.B NUM +
Increase the gamma correction by 0.1
.TP
.B NUM -
Decrease the gamma correction by 0.1
.\"=====================================================================
.SH MOUSE ACTIONS
The following actions are executed using the 
.BR left\ mouse\ button .
.TP
.B Click
If the mouse is positioned on a link, move to the link target. Links are
displayed in blue color.
.TP
.B Drag
Dragging from the top-left to the bottom-right increases the zoom factor.
Dragging in the opposite direction decreases the zoom factor. See also the
.B Ctrl-Z
key and the
.B -z
option.
.TP
.B Scroll wheel (EXPERIMENTAL)
Using the scroll wheel is a fast way of paging forward and backward.
.\"=====================================================================
.SH NOTES
This is a program to render 
.B HINT
files using GTK-3. Other programs to display 
.B HINT
files are available on the 
.B HINT
project home page at 
.B https://hint.userweb.mwn.de/
where you find viewers for the Windows and Android operating systems.
.sp
Currently the best way to produce
.B HINT
files is the use of 
.BR hitex ,
or
.BR hilatex ,
versions of \*(TX that produce 
.B HINT
files as output. The 
.B HINT
file format is described in 
.IR "HINT: The file format"
which is available as a book or in electronic form from the 
.B HINT
project home page. The 
.B HINT
file format is independent of \*(TX and allows the implementation
of generators for all kind of word-processors. The 
.B hintview
program however uses parts of Donald E. Knuth's implementation
of \*(TX, notably its line breaking routine, to produce good
quality rendering of documents.
.\"=====================================================================
.SH AVAILABILITY
.B hintview
is tested on the Linux platform but
should compile on a large variety of machine architectures
and operating systems.
hitex and hilatex are part of the \*(TX Live distribution.
.PP
.\"=====================================================================
.SH "SEE ALSO"
.BR hitex (1),
.BR histretch (1),
.BR hishrink (1).
.\"=====================================================================
.SH AUTHORS
Martin Ruckert
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