'\" t
.\"     Title: katarakt
.\"    Author: [see the "AUTHOR" section]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 03/20/2021
.\"    Manual: Katarakt Manual
.\"    Source: Katarakt
.\"  Language: English
.\"
.TH "KATARAKT" "1" "03/20/2021" "Katarakt" "Katarakt Manual"
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.nh
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.\" * MAIN CONTENT STARTS HERE *
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.SH "NAME"
katarakt \- a simple PDF viewer with three layouts
.SH "SYNOPSIS"
.sp
\fBkatarakt\fR ([\fIOPTIONS\fR] \fIFILE\fR|(\-u \fIURL\fR))*
.SH "DESCRIPTION"
.sp
It\(cqs a PDF viewer\&. It views PDFs\&.
.sp
There are currently three layouts\&. The \fIsingle layout\fR is very simple and only supports scrolling on a per page basis\&. As the name suggests the current page is displayed in the center and zoomed to fit the window\&. It is active by default\&.
.sp
The \fIgrid layout\fR is much more advanced and offers continuous (smooth, per pixel) scrolling, zooming and adjusting the column count\&. Pages keep their correct relative size and are shown in a grid\&.
.sp
The \fIpresenter layout\fR is for giving a presentation\&. It opens a second window, to be viewed on the projector, and shows the current and next slide in the main window\&.
.sp
For every file passed on the command line a separate process is spawned\&.
.SH "OPTIONS"
.PP
\fB\-u\fR, \fB\-\-url\fR
.RS 4
Instead of opening a local document, download it from the given URL\&.
.RE
.PP
\fB\-p\fR, \fB\-\-page\fR \fINUM\fR
.RS 4
Start on page
\fINUM\fR\&.
.RE
.PP
\fB\-f\fR, \fB\-\-fullscreen\fR
.RS 4
Start in fullscreen mode\&.
.RE
.PP
\fB\-q\fR, \fB\-\-quit\fR \fItrue\fR|\fIfalse\fR
.RS 4
If true, quit on initialization failure\&. If false, show the window even if an error occured\&. Overrides the config option
\fBquit_on_init_fail\fR\&.
.RE
.PP
\fB\-s\fR, \fB\-\-single\-instance\fR \fItrue\fR|\fIfalse\fR
.RS 4
If true, prevents opening the same document twice and focuses the existing instance\&. Overrides the config option
\fBsingle_instance_per_file\fR\&.
.RE
.PP
\fB\-\-write\-default\-config\fR \fIFILE\fR
.RS 4
Write the built\-in default configuration to
\fIFILE\fR
and exit\&. Hint: on unix systems, you can use
\fI\-\-write\-defaults /dev/stdout\fR
to print the defaults\&.
.RE
.PP
\fB\-v\fR, \fB\-\-version\fR
.RS 4
Print version information and exit\&.
.RE
.PP
\fB\-h\fR, \fB\-\-help\fR
.RS 4
Print help and exit\&.
.RE
.SH "CONFIGURATION"
.sp
Variables and key bindings can be changed by modifying the katarakt\&.ini file\&. By default it is read from \fI$XDG_CONFIG_HOME\fR\&.
.sp
Variables must be listed under the section "[Settings]", keys under section "[Keys]"\&. Settings that are not present in the config file use the built\-in default\&. For a list of all variables with a short explanation see below\&.
.SH "KEY BINDINGS"
.PP
\fBq\fR
.RS 4
Quit
\fBkatarakt\fR\&.
.RE
.PP
\fB1\fR
.RS 4
Switch to
\fIsingle layout\fR\&. Views a single page at a time, scaled to fit the screen\&.
.RE
.PP
\fB2\fR
.RS 4
Switch to
\fIgrid layout\fR\&. Views pages in a continuous fashion, scaled to fit the window width\&. Supports zooming and multiple columns\&.
.RE
.PP
\fB3\fR
.RS 4
Switch to
\fIpresenter layout\fR\&. Views the current page and a smaller preview of the next page\&. Also, opens a second window that shows only the current page for displaying on a projector\&.
.RE
.PP
\fBUp\fR, \fBDown\fR, \fBLeft\fR, \fBRight\fR, \fBk\fR, \fBj\fR, \fBh\fR, \fBl\fR
.RS 4
Move around (up/down/left/right)\&.
.RE
.PP
\fB^u\fR, \fB^d\fR
.RS 4
Scroll up/down half the screen\&.
.RE
.PP
\fBBackSpace\fR, \fBSpace\fR, \fB^b\fR, \fB^f\fR
.RS 4
Scroll up/down the screen\&. By default scrolls 90% to create an overlapping region\&.
.RE
.PP
\fBPgUp\fR, \fBPgDown\fR
.RS 4
Scroll up/down one page\&. Kind of swaps the pages in place\&.
.RE
.PP
\fBHome\fR, \fBEnd\fR, \fBg\fR, \fBG\fR
.RS 4
Go to the first/last page\&.
.RE
.PP
\fB^g\fR
.RS 4
Show
\fIgoto page\fR
bar\&.
.RE
.PP
\fB/\fR
.RS 4
Show the search bar\&. Hitting
\fBEsc\fR
will hide the results, searching for an empty string will clear them\&. If the search term contains an uppercase letter the search is case sensitive ("smartcase")\&. If you search for the same term twice the next hit starting from the current view is selected\&.
.RE
.PP
\fB?\fR
.RS 4
Show the search bar\&. This next search will be backwards\&.
.RE
.PP
\fBn\fR, \fBN\fR
.RS 4
Focus next/previous search hit\&. This does not take the current view into account\&. For finding the next hit around the current view search for the same term again\&.
.RE
.PP
\fB^n\fR, \fB^N\fR
.RS 4
Focus next/previous search hit that is currently not visible\&.
.RE
.PP
\fB^o\fR, \fB^i\fR, \fBAlt\-Left\fR, \fBAlt\-Right\fR
.RS 4
Move backward/forward through the jump list\&. Entries are added automatically when jumping\&.
.RE
.PP
\fBm\fR
.RS 4
Manually add the current page to the jump list\&.
.RE
.PP
\fB\-\fR, \fB+\fR, \fB=\fR
.RS 4
Adjust zoom level (\fIgrid layout\fR
only)\&.
.RE
.PP
\fBz\fR
.RS 4
Reset zoom level to default, i\&.e\&. fit width (\fIgrid layout\fR
only)\&.
.RE
.PP
\fB[\fR, \fB]\fR
.RS 4
Adjust column count (\fIgrid layout\fR
only)\&.
.RE
.PP
\fB{\fR, \fB}\fR
.RS 4
Adjust the column the first page will be displayed in\&. Useful for reading in a book layout with a cover page (\fIgrid layout\fR
only)\&.
.RE
.PP
\fB,\fR, \fB\&.\fR
.RS 4
Rotate pages left/right\&.
.RE
.PP
\fBt\fR
.RS 4
Toggle the page number display in the bottom right corner\&.
.RE
.PP
\fBi\fR
.RS 4
Toggle between normal and inverted color rendering\&.
.RE
.PP
\fB^c\fR
.RS 4
Copy the current selection to the global clipboard\&.
.RE
.PP
\fBv\fR
.RS 4
Swap the mouse buttons for selection and panning\&. The the left mouse button\(cqs current operation is indicated by the mouse cursor\&.
.RE
.PP
\fBf\fR
.RS 4
Toggle fullscreen\&.
.RE
.PP
\fBr\fR
.RS 4
Reload the document\&. This can also be achieved by sending SIGUSR1 to the process\&.
\fBkatarakt\fR
reloads automatically if the opened file has changed\&.
.RE
.PP
\fBo\fR
.RS 4
Open a different document; shows a file dialog\&.
.RE
.PP
\fBs\fR
.RS 4
Show a file dialog to save the current document\&.
.RE
.PP
\fBF9\fR
.RS 4
Toggle the table of contents\&.
.RE
.PP
\fBx\fR
.RS 4
Toggle freezing the slide currently displayed in the projector window\&. When frozen, scrolling only affects the main window\&.
.RE
.SH "VARIABLES"
.PP
\fIstring\fR \fBdefault_layout\fR
.RS 4
single: The layout on startup\&. Possible values:
\fIsingle\fR,
\fIgrid\fR,
\fIpresenter\fR\&.
.RE
.PP
\fIstring\fR \fBbackground_color\fR
.RS 4
0xDF202020: Background color in ARGB Format\&. Alpha only works when using a compositor\&.
.RE
.PP
\fIstring\fR \fBbackground_color_fullscreen\fR
.RS 4
0xFF000000: Fullscreen background color in ARGB Format\&.
.RE
.PP
\fIstring\fR \fBunrendered_page_color\fR
.RS 4
0x40FFFFFF: Color that gets drawn instead of a page that hasn\(cqt been rendered yet\&. If colors are inverted, this gets inverted as well\&.
.RE
.PP
\fIint\fR \fBclick_link_button\fR
.RS 4
1: The mouse button used for clicking links\&. Buttons 1\-5 are supported\&.
.RE
.PP
\fIint\fR \fBdrag_view_button\fR
.RS 4
2: The mouse button used for scrolling the view\&. Double\-clicking this button centers the view around the location of the click\&. This is especially useful when using many columns to get an overview\&. Resets the column count to 1\&.
.RE
.PP
\fIint\fR \fBselect_text_button\fR
.RS 4
1: The mouse button used for text selection\&. Double\- and triple\-clicking are supported to select with word/line granularity\&.
.RE
.PP
\fIint\fR \fBhide_mouse_timeout\fR
.RS 4
2000: The delay in milliseconds after which the mouse cursor is hidden\&. Set to 0 to disable\&.
.RE
.PP
\fIint\fR \fBsmooth_scroll_delta\fR
.RS 4
30: Pixel offset when moving around\&.
.RE
.PP
\fIfloat\fR \fBscreen_scroll_factor\fR
.RS 4
0\&.9: Factor for scrolling the screen\&. Should be <= 1 to create an overlapping region\&.
.RE
.PP
\fIfloat\fR \fBjump_padding\fR
.RS 4
0\&.2: Distance from the border of the screen to keep for jump targets, e\&.g\&. search hits\&. Moves the view so that search hits are centered more\&.
.RE
.PP
\fIint\fR \fBrect_margin\fR
.RS 4
2: Number of pixels search rects are expanded by\&.
.RE
.PP
\fIint\fR \fBuseless_gap\fR
.RS 4
2: Gap between two pages in
\fIgrid layout\fR
in pixels\&.
.RE
.PP
\fIint\fR \fBmin_zoom\fR
.RS 4
\-14: Smallest zoom value\&.
.RE
.PP
\fIint\fR \fBmax_zoom\fR
.RS 4
30: Biggest zoom value\&.
.RE
.PP
\fIfloat\fR \fBzoom_factor\fR
.RS 4
0\&.05: Influences the number of steps between min and max\&.
.RE
.PP
\fIint\fR \fBmin_page_width\fR
.RS 4
50: Pages can not be smaller than this\&.
.RE
.PP
\fIbool\fR \fBquit_on_init_fail\fR
.RS 4
false: If true, quit katarakt if the document fails to open\&.
.RE
.PP
\fIbool\fR \fBsingle_instance_per_file\fR
.RS 4
false: If set and katarakt is called with a file that is already shown in another katarakt instance, then the other katarakt window is activated instead\&.
.RE
.PP
\fIstring\fR \fBstylesheet\fR
.RS 4
See
http://doc\&.qt\&.io/qt\-4\&.8/stylesheet\&.html\&. It can be overridden via Qt\(cqs
\fB\-stylesheet\fR
command line option\&. The following example changes the
\fIgoto page\fR
bar:

.sp
.if n \{\
.RS 4
.\}
.nf
stylesheet="
GotoLine {
        margin: 0px;
        padding: 4px;
        border\-top\-right\-radius: 6px;
        border\-top: 1px solid black;
        border\-right: 1px solid black;
}"
.fi
.if n \{\
.RE
.\}
.RE
.PP
\fIstring\fR \fBpage_overlay_text\fR
.RS 4
Page %1/%2: The text in the bottom right corner\&.
.RE
.PP
\fIstring\fR \fBicon_theme\fR
.RS 4
The name of your icon theme\&. Fill in if auto detection fails\&.
.RE
.PP
\fIint\fR \fBprefetch_count\fR
.RS 4
4: Number of pages exceeding the currently visible ones to render, back\- and forwards respectively\&.
.RE
.PP
\fIfloat\fR \fBinverted_color_contrast\fR
.RS 4
0\&.5: the contrast when using inverted colors to avoid too much brightness\&.
.RE
.PP
\fIfloat\fR \fBinverted_color_brightening\fR
.RS 4
0\&.15: amount of brightening when using inverted colors to shift black to gray\&.
.RE
.PP
\fIint\fR \fBmouse_wheel_factor\fR
.RS 4
120: QT delta for turning the mouse wheel 1 click\&. Shouldn\(cqt need to be touched\&.
.RE
.PP
\fIbool\fR \fBthumbnail_filter\fR
.RS 4
true: Enables the higher quality downsampling filter for thumbnails\&.
.RE
.PP
\fIint\fR \fBthumbnail_size\fR
.RS 4
32: One dimension of square thumbnails saved at run\-time for every page that was once rendered\&.
.RE
.SH "COMMUNITY"
.sp
Feel free to join the IRC channel \fI#katarakt\fR on freenode\&.
.SH "AUTHOR"
.sp
\fBkatarakt\fR is written by Philipp Erhardt\&.
.SH "RESOURCES"
.sp
GitLab: https://gitlab\&.cs\&.fau\&.de/Qui_Sum/katarakt