# The &okular; Handbook

Albert Astals Cid

    &Albert.Astals.Cid.mail;

Pino Toscano

    pino@kde.org

&FDLNotice;
2022-02-19
22.04

&okular; is a &kde; universal document viewer based on &kpdf; code.

KDE okular pdf ps postscript tiff djvu dvi xps comicbook fictionbook markdown mobipocket annotation

## Introduction

&okular; is a &kde; universal document viewer based on the code of the &kpdf; application. Although being based on &kpdf; code, &okular; has some unique features such as overview mode, improved presentation support and annotation support.

&okular; supports a lot of different formats like &PDF;, &PostScript;, Tiff, DjVU, Images (png, jpg, &etc;) XPS, Fiction Books, Comic Book, Plucker, EPub, Fax and Markdown. For all supported formats and their features see &okular; Document Format Handlers.

&okular;s Main Window
&okular;s Main Window

## Basic Usage

### Opening Files

To open any supported file in &okular;, select File Open... , choose a supported file in the dialog and click Open. Your file should now be displayed in the main window.

The new document will be opened in a new tab if the Open new files in tabs option on the General configuration page is checked.

You can close the tab by clicking with &MMB; on it.

The previously closed document in a tab can be reopened using the &Ctrl;&Shift;T File Undo close tab menu item.

If you have already opened files in &okular; before, you can quickly access them by selecting them in the File Open Recent menu.

&okular; is the default &kde; application for &PDF; and &PostScript; files, launched when you click with the &LMB; on such a file type in the filemanager. If you want to open any file whose format is supported by &okular; use Open with...&okular; from context menu in the filemanager.

After having a file opened you probably want to read it and therefore navigate through it. Go to the next section to learn more about this.

### Navigating

This section describes how you can navigate through a document in &okular;.

There are multiple ways of scrolling the viewing area. One is to use the &Up; and &Down; arrow keys. You may also use the scrollbar, your mousewheel or the &PgUp; and &PgDn; keys.

You can also use vim-like navigation keys, namely H to move to the top of the previous page, L to move to the top of the next page, J to move one line down, and K to move one line up.

Another way is to hold the &LMB; down at any place on the document while dragging the mouse in the opposite direction of where you want to move. This procedure only works if the Browse tool is enabled, which you can select by choosing Tools Browse.

When viewing a document in the Presentation mode use &Up; and &Down; arrow keys to switch between pages or slides. The number and the position of the current slide will be shown in the overlay at the right upper corner of screen.

If you want to read a document with several pages use the automatic scrolling feature of &okular;. Start automatic scrolling with &Shift;&Down; or &Shift;&Up;. Then use these keys to increase and decrease the scrolling speed. You can start or stop automatic scrolling temporarily by pressing the &Shift; key; pressing any other key deactivates this feature.

Another way to navigate through a document with several pages is to use the mouse pointer. Drag the page up or down, continue to drag even while reaching the bottom or top of the screen and behold. Once you cross the border of a page, the mouse cursor appears on top or bottom of the screen again and you can just continue to drag.

The sidebar on the left side of the screen enables two more ways of navigating through a document:

- If you click on a page thumbnail the viewing area will be brought to that page.

- If the document has a table of contents, clicking on a table of contents item will bring the document to the page linked to that item.

- If the document has layers, you can control the layers shown by checking or unchecking the items in the Layers list.

- If the document has bookmarks, enable the Bookmarks view and click them to go to the associated page. If bookmarks are not only shown for the current document, you can quickly switch to bookmarks in all recently opened files.

- If the document has annotations, enable the Annotations view and click the annotations or select them with the &Up; and &Down; arrow keys and press &Enter; to go to the associated page.

Some documents have links. In this case you can click on them and the view will change to the page it links to. If the link is to a web page or some other document the default &kde; handler for that format will be invoked. For example, clicking on a link pointing to https://www.kde.org will open the web page in the default &kde;'s web browser.

The document internal links work only when Browse Tool is used.

Additionally, you may use the following functionality to quickly move to specific places in the document:

- You can go to the beginning of the document using &Ctrl;Home or using Go Beginning of the document .

- You can go to the end of the document using &Ctrl;End or using Go End of the document .

- You can go forward in the document using &Space; or &PgDn;. To go to the next page of the document use the Next Page Toolbar button or Go Next Page in the menubar.

- You can go back in the document using &Backspace; or &PgUp;. To go to the previous page of the document use Previous Page Toolbar button or Go Previous Page in the menubar.

- You can go back to the positions in the document where you came from in a chronological order. Consider ⪚ reading the phrase As shown in [15], …, and you want to know quickly lookup reference [15]. So you click on it, and &okular; will jump to the list of references. Using &Alt;&Shift;&Left; or Go Back in the menubar will bring you back to exactly the position where you came from.

- You can go forward in the document after the jumping back as described above using &Alt;&Shift;&Right; or Go Forward in the menubar.

- You can go to the next match when searching using F3 or &Enter; (when the focus is on Find text field) keys or Edit Find Next menu item or move back to the previous match using &Shift;F3 or &Shift;&Enter; (when the focus is on Find text field) keys or Edit Find Previous menu item.

### Presentation Mode

The Presentation mode represents another way to view documents in &okular;. It can be enabled in View Presentation. It shows the document on a page per page basis. The pages are shown with zoom to page, that means all the page is visible.

&PDF; documents can even specify that they are always opened in presentation mode.

When in presentation mode, you have an helper bar located on the top of the screen. Just move the mouse cursor to the top of the screen to make it appear.

&okular; in Presentation Mode
&okular; in Presentation Mode

To navigate between pages you may use the &LMB; (next page) and the &RMB; (previous page), the mouse wheel, the arrow icons or the line edit in the top bar, or the keys specified in the Navigating section.

Use Play/Pause button in the top bar to start playing presentation or pause it, correspondingly.

You can exit presentation mode at any time by pressing the &Esc; key or clicking the Quit icon in the top bar.

You can also draw on the current page with a pencil. Click on the Toggle Drawing Mode icon in the top bar to enable or disable the possibility to draw in the presentation mode. The drawings are cleared automatically when leaving the presentation mode. You can also click on the Erase Drawings icon to remove the drawings in the current page.

The presentation mode has support for more than one screen in a multi-monitor configuration. With more than one screen a new button will appear in the top bar, with the icon of a screen: this is a drop down box that allows you to move the presentation to any of the other available screens.

Presentation mode has some configuration options, you can find their description in the chapter Configuring &okular;.

### Inverse Search between &latex; Editors and &okular;

Inverse search is a very useful feature when you are writing a &latex; document yourself. If everything is set up properly, you can click into &okular;'s window with the left mouse button while pressing &Shift;. After that editor loads the &latex; source file and jumps to the proper paragraph.

Inverse search cannot work unless:

- The source file has been compiled successfully.

- &okular; knows which editor you would like to use.

- The Browse tool has to be enabled, which you can select by choosing Tools Browse .

With this feature of &okular;, a left mouse click while pressing &Shift; in the &DVI; or &PDF; document will result in editor opening the corresponding &latex; document and attempt to go to the corresponding line. Remember to tell &okular; to use proper editor, in &okular;'s menu item Settings Configure Okular... (on the page Editor).

For more details on editor configuration please refer to the corresponding section of this manual.

Configuring &okular;
Configuring editor in &okular;

Configuring editor in &okular;

## &okular; Advanced Features

### Embedded Files

If the current document has some files embedded in it, when you open it a bar will appear above the page view to notify you about the embedded files.

The embedded files bar
The embedded files bar

In this case, you can either click on the link in the text of the bar or choose File Embedded Files to open the embedded files dialog. The dialog allows you to view the embedded files and to extract them.

### Forms

If the current document has forms, when you open it a bar will appear above the page view where you can enable the forms.

The forms bar
The forms bar

In this case, you can either click on Show Forms in the bar or choose View Show Forms to enter data into the form fields.

### Signatures

If the current document has signatures a bar will appear above the page view after the document opening. It allows you to open the Signatures panel.

The signatures bar
The signatures bar

Using the Signatures panel you can inspect the document signature and its certificate.

The signatures panel
The signatures panel

This feature is available for &PDF; documents only. You need to install at least version 0.51 of Poppler to get most signature information, version 0.68 to get signature location/reason information, and version 0.73 to get signature certificate information.

#### Adding Digital Signatures

You can add digital signatures to documents using the corresponding action in the Tools menu.

To be able to sign a document you need to have a proper PKCS signing certificate available on your system. &okular; does not have the ability to create such certificates since they need to be issued by certificate authorities to be useful for validation, &etc;

We use the Poppler library to handle signing of &PDF; documents and Poppler is using the NSS library to handle certificates. At the point of writing, Poppler will try to use one of the following NSS certificate stores in order (the first that exists):

- The current Firefox user certificate store.

- The system-wide `/etc/pki/nssdb` certificate store.

- The current user `$HOME/.pki/nssdb`

If you want to use a custom certificate store you can do so by setting it in the &PDF; Backend Configuration section of the Configure Backends... dialog.

This feature is available for &PDF; documents only. You need to install at least version 21.01 of Poppler to be able to add digital signatures to a document.

### Annotations

&okular; allows you to review and annotate your documents.

&okular;'s Annotations
&okular;'s Annotations

&okular; has two different kind of annotations:

Text annotations like Yellow Highlighter and Black Underlining can be used with files containing text (⪚ &PDF;).

Graphic annotations like Pop-up Note, Inline Note, Freehand Line, Highlighter, Straight Line, Polygon, Stamp, Underline, Ellipse, and Typewriter.

Graphic annotations are not limited to &PDF; files; they can be used for any format that &okular; supports.

Using the Annotations menu, you can add a Pop up Note or any other kind of annotation to add or edit comments.

&okular; has the "document archiving" feature. This is an &okular;-specific format for carrying the document plus various metadata related to it (currently only annotations). You can save a "document archive" from the open document by choosing File Save As and selecting Okular document archive in the Filter selector. Documents saved this way will get `.okular` as their filename extension. To open an &okular; document archive, just open it with &okular; as it would be ⪚ a &PDF; document.

You can also save annotations directly into &PDF; files. You can use File Save to save it over the current file or File Save As... to save it to a new file.

Note that adding, editing, or removing annotations may not be possible with DRM-enabled files.

It is possible to undo or redo any annotation action by using the corresponding item from the Edit menu. It is also possible to undo the action by pressing &Ctrl;Z and to redo a previously undone action by pressing &Ctrl;&Shift;Z.

You can configure the default properties and appearance of each annotation tool. Please refer to the corresponding section in this documentation.

#### Adding annotations

To add annotations to the document, you can use Quick Annotations button on the main &okular; toolbar, or activate the annotation toolbar. This is done by either selecting Tools Annotations or pressing F6. Once the annotation toolbar is shown, just press one of its buttons or use keyboard shortcuts (keys from 1 to 9) to use that annotation.

The annotation toolbar helps you to make annotations with drawings, shapes, and text messages. You can use the annotation toolbar to mark up a document (⪚ add lines, ellipses, polygons, stamps, highlights, underlines &etc;). The table below describes exactly what the default set of annotation toolbar buttons does.

Button | Tool Name | Description
--- | --- | ---
| Highlighter | Highlights text in the document with a given background color. Click on the tool button, then click with the &LMB; and drag to highlight a text snippet. It is possible to define the Type (Highlight, Squiggle, Underline or Strike out), Color, and Opacity for the highlighter. Just right-click on the highlighted text and select the Properties menu item.
| Underline | Underlines text with a straight line. Click on the tool button, then click with the &LMB; and drag to underline a text snippet. It is possible to define the Type (Highlight, Squiggle, Underline or Strike out), Color, and Opacity for the underline. Just right-click on the underlined text and select the Properties menu item.
| Squiggle | Underlines text with a squiggly line. Click on the tool button, then click with the &LMB; and drag to squiggly underline a text snippet. It is possible to define the Type (Highlight, Squiggle, Underline or Strike out), Color, and Opacity for the underline. Just right-click on the underlined text and select the Properties menu item.
| Strike Out | Strikes out some text. Click on the tool button, then click with the &LMB; and drag to squiggly strike out a text snippet. It is possible to define the Type (Highlight, Squiggle, Underline or Strike out), Color, and Opacity for the underline. Just right-click on the underlined text and select the Properties menu item.
| Typewriter | Adds text on a transparent background. This is useful for filling out forms lacking integrated editable text fields. Click on the tool button, then click with the &LMB; where you wish to add the top-left corner of the text, then drag to place the bottom-right one. Type some text, then click on the OK to save it, Clear to clear the text and start over, or Cancel to cancel. It is possible to define the Font and Text color for the text. Just right-click on the typewriter text created and select the Properties menu item.
| Inline Note | Draws an inline note. The note will be shown inline as is. Click on the tool button, then click with the &LMB; where you wish to add the top-left corner of the note, then drag to place the bottom-right one. Enter the text of the note then click on the OK to save the note, Clear to clear the note's text, or Cancel to cancel note creation. It is possible to define the Color, Opacity, Font, Align, and Border width for the note. Just right-click on the note icon created and select the Properties menu item.
| Pop-up Note | Draws a multiline note. The note can be viewed by double clicking on the icon created in the document. Click on the tool button, then click on the place in the document where the pop-up note should be added. Enter the text of pop-up note then click on the Close this note button in the top right corner of the pop-up window. It is possible to define the Color, Opacity, and Icon for the note. Just right-click on the note icon created and select the Properties menu item.
| Freehand Line | Draws free-form lines. Click on the tool button, then click with the &LMB; and drag to draw the line. It is possible to define the Color, Opacity, and Width for the line. Just right-click on the line created and select the Properties menu item.
| Arrow (drop-down list) | Draws an arrow between two points. Click on the tool button, then click with the &LMB; to place the starting point of the arrow, then drag to place the ending point of the line and click once more. It is possible to define the Color, Opacity, Width, Line start, Line end, Leader line length, and Leader line extension length for the line. Just right-click on the line created and select the Properties menu item.
| Straight line (drop-down list) | Draws a line between two points. Click on the tool button, then click with the &LMB; to place the starting point of the line, then drag to place the ending point of the line and click once more. It is possible to define the Color, Opacity, Width, Line start, Line end, Leader line length, and Leader line extension length for the line. Just right-click on the line created and select the Properties menu item.
| Rectangle (drop-down list) | Draws a rectangle around the chosen area. Click on the tool button, then click with the &LMB; to place the top-left corner of the rectangle, then drag to place the bottom-right one. It is possible to define the Type (Rectangle or Ellipse), Color, Opacity, Shape fill (and its color), and Width for the border. Just right-click on the border created and select the Properties menu item.
| Ellipse (drop-down list) | Draws an ellipse or rectangle around a chosen area. Click on the tool button, then click with the &LMB; and hold to place the top-left corner of the circumscribed rectangle for the ellipse, then drag to place the bottom-right one. It is possible to define the Type (Rectangle or Ellipse), Color, Opacity, Shape fill (and its color), and Width for the border. Just right-click on the border created and select the Properties menu item.
| Polygon (drop-down list) | Draws a closed shape from three or more line segments. The corresponding note can be viewed by double clicking inside the polygon. Click on the tool button, then click with the &LMB; to place the first vertex of the polygon, then drag to place of the second vertex. Proceed until you have drawn the whole polygon and connected back up with the first vertex. Click twice to add a note to the polygon. Enter the text of the note then click on the OK to save the note, Clear to clear the note, or Cancel to cancel note entry. It is possible to define the Color, Opacity, Shape fill (and its color), and Width for the polygon. Just right-click on the polygon created and select the Properties menu item.
| Stamp | Inserts a pre-defined shape into the document. Click on the tool button to choose the stamp from the drop-down list then click with the &LMB; to place the stamp. A single click just places a square stamp (useful for icons). To add a rectangular stamp you can click with the &LMB; and hold to place the top-left point, then drag to place the bottom-right one. It is possible to define the Opacity and Stamp symbol for the stamp. Just right-click on the stamp icon created and select the Properties menu item. This feature is experimental. Custom stamps inserted in &PDF; documents are not visible in &PDF; readers other than &okular;.

These are the default annotations provided by &okular;. Using the Annotations page of the configuration dialog you can add your own annotations like custom stamps, text markup or a geometrical shape with inner color to highlight regions &etc;

It is possible to add &latex; code into the text of annotations. To do so, add `$$code$$` into the text of annotation, where code is any valid &latex; equation. Follow the instructions that will appear on the screen to render it using a &latex; distribution installed in your system.

It is possible to configure the selected tool using the annotation toolbar itself:

Button | Option Name | Description
--- | --- | ---
| Line width | Click on this button to choose the width from the drop-down list.
/ | Annotation color | Click on this button to choose the color of the text or border of your annotation. You can chose one of the predefined colors or click on the Custom Color... item to open the color selection dialog.
| Annotation fill color | Click on this button to choose the fill color of your annotation. You can chose one of the predefined colors or click on the Custom Color... item to open the color selection dialog.
| Annotation opacity | Click on this button to choose the opacity of your annotation from the drop-down list (100% creates opaque annotations).
| Annotation font | Click on this button to open the font selection dialog.
| Advanced settings for the current annotation tool | Click on this button to open the general configuration dialog for your annotation.

There are three additional utility buttons on the annotation toolbar:

Button | Description
--- | ---
| Add the current annotation to the Quick Annotations menu on the main toolbar. You can use the default shortcuts from &Alt;9 to &Alt;0 to select the quick annotation actions any time you like, even with the annotation toolbar hidden.
| When checked, keep the current annotation tool active after use.
| Hide the annotation toolbar.

By pressing &Shift; you can constrain the angle of line and polygon annotations to 15° steps, and the ratio of shape annotations (⪚ Rectangle, Ellipse) to 1:1. You can also get a toolbar button from Configure Toolbars....

The contents of the Quick Annotations menu can be configured using the Annotations page of &okular; configuration dialog. This page can be opened by clicking Quick Annotations button, then choosing Configure Annotations... from the pop-up menu.

Activating the annotation toolbar will automatically switch to Browse Mode.

You can stop annotating any time by pressing the button of the annotation you are using again, or by pressing the &Esc; key.

The newly created annotation will have the author you set in the Annotations page in &okular;s configuration dialog as its author. The Annotations page can also be used to configure the content of the annotations toolbar.

#### Removing annotations

To remove an annotation, first select the Browse tool (Tools Browse) then just click on it with the &RMB;, and select Delete or select an annotation using the &LMB; and press the ∇ key.

When removing the annotation, its window will be closed if it is open.

#### Editing annotations

To edit an annotation, first select the Browse tool (Tools Browse) then click on an annotation with the &RMB; and select Properties. A dialog will appear with the general annotation settings (like color and opacity, author, &etc;) and the settings specific to that annotation type.

Annotation Property Dialog
Annotation Property Dialog

To move an annotation, hold down the &Ctrl; key, move the mouse pointer on it and then start dragging with the &LMB;.

If you click with the &LMB; on an annotation, it gets selected. Resize handles appear on the selection rectangle. When the cursor is moved over one of the 8 resize handles on the corners or edges, the cursor shape changes to indicate the resize mode. Click anywhere else on the annotation to move it. Pressing &Esc; or clicking an area outside the annotation cancels a selection.

Resizing is only available for the Inline Note, Typewriter, Stamp and Ellipse annotation types.

Some options may be disabled depending on the document's permissions (this typically only affects some &PDF; documents).

### Bookmark Management

&okular; has a very flexible bookmark system. &okular; saves the position on the page in bookmark and allows you to define more than one bookmark per page.

To manage bookmarks in &okular; you can use Bookmarks view from Sidebar, Bookmarks menu or context menu of document view (click with &RMB; to open it).

#### Bookmarks view

To open Bookmarks view, click on the Bookmarks tab at the top of the Sidebar. If the Sidebar is not shown, click the Show Sidebar button on the toolbar or the menu item, or the F7 Settings Show Sidebar menu item to make it visible.

Bookmark view context menu
Bookmark view context menu

The Show for all documents checkbox can be unchecked to show only the bookmarks from the current document.

The filter bar at the top of Bookmarks view can be used to filter the content of bookmark list pane according to the text in the box.

The list pane permits to view the bookmark list in a tree-like fashion: each document in the list can be expanded or collapsed by clicking on the < or v icon next to it.

Right-click menu of document item can be used to open document, rename its item or remove it from the list. Remember that the removal of a document item leads to the removal of all bookmarks in the corresponding document.

Right-click menus of individual bookmark items allow you to go to the bookmark, rename or remove it.

The Right-click menu of items in the table of contents can be used to create bookmarks or go to the next or previous bookmark.

### Command Line Options

Though &okular; may most often be started from the &kde; program menu, or a desktop icon, it can also be opened at the command line prompt of a terminal window. There are a few useful options that are available when doing this.

#### Specify a File

By specifying the path and name of a particular file the user can have &okular; open that file immediately upon startup. This option might look something like the following:

    % okular /home/myhome/docs/mydoc.pdf

For &PDF; documents, the name can be given as document_name#named_destination where named_destination is a particular named destination embedded in the document.

#### Other Command Line Options

The following command line help options are available

``okular` `-p --page number``

  Open a page with a given number in the document. Also available through ``okular` `-p number``

``okular` `--presentation``

  Start the document in presentation mode.

``okular` `--print``

  Start with print dialog.

``okular` `--print-and-exit``

  Start with print dialog and exit after printing.

``okular` `--unique``

  Unique instance control.

``okular` `--noraise``

  Allows to prevent &okular; window raising after the start.

``okular` `--find string``

  Tries to find and highlight a given string in the document. Only works if just one document is given as an argument of the ``okular`` command.

``okular` `--editor-cmd string``

  Sets the external editor command. You cannot set the editor command in an already running &okular; instance. Please note that `--unique` is not supported when setting the editor command at the commandline.

### Fit window to page

The Fit window to page feature resizes the window so that it is exactly the same size as the page at the current zoom factor. If the page doesn't completely fit on the screen, the window is enlarged so that the largest possible part of the page is shown.

This feature can be accessed by using the keyboard shortcut &Ctrl;J.

## The Menubar

### The File Menu

&Ctrl;O File Open...

  Open a supported file or &okular; document archive. If there is already an opened file it will be closed. For more information, see the section about Opening Files.

File Open Recent

  Open a file which was used previously from a submenu. If a file is currently being displayed it will be closed. For more information, see the section about Opening Files.

File Import PostScript as &PDF;...

  Open a &PostScript; file and convert it to &PDF;.

&Ctrl;&Shift;T File Undo close tab

  Reopen the last closed document. This action is active only if you have closed some document in tab during the current session.

File Open Containing Folder

  Open folder that contains the current document in your favorite file manager. This action is especially useful for the case when you have downloaded a &PDF; file from the internet that opens itself in &okular;. The location of this file may not be clear or easy to find without this feature.

&Ctrl;S File Save

  Saves the document including all the changes (annotations, form contents, &etc;), provided the document backend supports saving those changes. If the backend does not support saving the changes, the user will be given the option to either discard or to save them together with the document in an &okular; document archive.

&Ctrl;&Shift;S File Save As...

  Saves the document under a new name including all the changes (annotations, form contents, &etc;), provided the document backend supports saving changes. If the backend does not support saving the changes, the user will be given the option to either discard or to save them together with the document in an &okular; document archive.

  Note that, due to the way this is implemented, even if there are no changes to the file, the new file need not to be an exact bit-for-bit copy of the original file (⪚ can have a different SHA-1 hash, &etc;).

F5 File Reload

  Reload the currently open file.

&Ctrl;P File Print...

  Print the currently displayed document. Please take into account that &okular; has some specific options for printing &PDF; which are available via pressing the Options >> button then choosing the &PDF; Options. Use these options to print your annotations or configure rasterization mode if you have problems with printing some symbols or need to change the scale mode.

  The scale mode options are only available when you check the Force rasterization option.

File Print Preview...

  Show a preview of how the currently displayed document would be printed with the default options.

&Alt;Return File Properties

  Display some basic information about the document, such as title, author, creation date, and details about the fonts used. The available information depends on the type of document.

  Please pay attention on the information about substituting font in the Fonts tab of the Properties dialog. Many problems with font rendering can be solved by installing of the substituted fonts.

File Embedded Files...

  Show the files embedded in the document, if the document has any. For more information, see the section about the Embedded Files.

File Export As

  This item contains the export formats the current document can be exported to. The first entry for all kind of documents is always Plain Text....

  The second entry is Document Archive, which allows you to save the document with your annotations into an &okular;-specific archive format. Thus it is easily possible to share the original document and your annotations with other &okular; users or work with them collaboratively.

File Share

  This item contains the services which can be used to share the current document with other people or send it to your devices. The entries in this sub-menu are controlled by the system. They depend on the current document format and the installed KPurpose plugins.

&Ctrl;Q File Quit

  Close &okular;.

### The Edit Menu

&Ctrl;Z Edit Undo

  Undo the last annotation editing command (creation and removal of annotations, editing arbitrary annotation properties, relocating annotations with &Ctrl;+drag, and editing the text contents of an annotation).

&Ctrl;&Shift;Z Edit Redo

  Redo the last undo step when editing annotations.

&Ctrl;C Edit Copy

  Copy the currently selected text in Text Selection mode to the clipboard.

&Ctrl;A Edit Select All

  Selects all the text (if the document provides it). This works only in Text Selection mode.

Edit Select All Text on Current Page

  Selects all the text (if the document provides it) of the current page.

&Ctrl;F Edit Find...

  Show the find bar on the bottom of the viewing area that allows you to search for a string in the document.

F3 Edit Find Next

  Try to find the previous searched string again in the document.

&Shift;F3 Edit Find Previous

  Goes to the previous occurrence of the search string in the document.

### The View Menu

&Ctrl;&Shift;P View Presentation

  Activates the Presentation Mode. For more information, see the section about Presentation Mode.

&Ctrl;&Shift;F View Full Screen Mode

  Enables the full screen mode. Note that full screen mode is different from presentation mode insofar as the only peculiarity of full screen mode is that it hides the window decorations, the menubar and the toolbar.

&Ctrl;+ View Zoom In

  Increase the magnification of the document view.

&Ctrl;- View Zoom Out

  Decrease the magnification of the document view.

View Zoom to 100%

  Zoom the document image to the actual size as prescribed by the document parameters.

View Fit Width

  Change the magnification of the document view to a value that makes the pages' width equal to the document view's width.

View Fit Page

  Change the magnification of the document view to a value that makes at least one whole page visible.

View Auto Fit

  Change the magnification of the document view to a value that, depending on the size relation between the page and the view area, automatically either makes the pages' width equal to the document view's width (like fit-width), the pages' height equal to the document view's height (like fit-height), or the whole page visible (like fit-page).

View View Mode

  This submenu makes you choose the view mode for the pages. The possible options are: Single Page (only one page per row), Facing Pages (two pages per row, in a book style), Facing Pages (Center First Page) and Overview (the number of columns is the one specified in the &okular; settings).

  Additionally, you can enable the Continuous mode. In continuous mode, all pages of the document are shown, and you can smoothly scroll through them. Otherwise, only one page (or one row of pages) is shown at a time.

View Orientation

  This submenu allows you to changes the orientation of the pages of the document.

  The rotation is applied to the orientation of every page.

  You can select Original Orientation to restore the orientation of the document, discarding all the rotations applied manually.

View Trim View

  This submenu allows you to remove the white border of pages when viewing pages (Trim Margins item) or trim viewport to selection (Trim To Selection item).

  The trim to selection mode allows you to draw a selection over the rendered page in order to define a visible bounding box to be applied to all pages in the document. Selecting a small trim bounding box enforces minimum dimensions size (20% as a percentage of total page size).

  The trim margins mode is persistent across &okular; restarts. The trim to selection mode is forgotten across &okular; restarts.

  When you switch &okular; from trim margins mode to trim to selection mode, the view jumps out of trim margins mode for the bounding box selection interaction.

  The trim mode can be deactivated by selecting the same menu item that activates it once again.

View Show/Hide Forms

  Show or hides the display of the form fields of the document.

  This menu item is active only if the current document has form fields.

### The Go Menu

Go Previous Page

  View the previous page of the document.

Go Next Page

  View the next page of the document.

&Ctrl;&Home; Go Beginning of the document

  Go to the beginning of the document.

&Ctrl;&End; Go End of the document

  Go to the end of the document.

&Alt;&Shift;&Left; Go Back

  Go back to the previous view of the document.

&Alt;&Shift;&Right; Go Forward

  Move forward to the next view of the document. This only works if you have already moved back before.

&Ctrl;G Go Go to Page...

  Open a dialog which allows you to go to any page of the document.

### The Bookmarks Menu

&Ctrl;B Bookmarks Add/Remove Bookmark

  Add or remove a bookmark for the current position.

Bookmarks Rename Bookmark

  Rename a bookmark for the current position.

Bookmarks Previous Bookmark

  Go to the previous bookmark, or do nothing if there are no bookmarks prior to the current one.

Bookmarks Next Bookmark

  Go to the next bookmark, or do nothing if there are no bookmarks after the current one.

Bookmarks No Bookmarks

  This is an always disabled action that appears in this menu only if the current document has no bookmarks. Otherwise a list of all bookmarks is displayed here. Clicking on these bookmarks allows you to go directly to the associated position.

### The Tools Menu

&Ctrl;1 Tools Browse

  The mouse will have its normal behavior, &LMB; for dragging the document and following links and &RMB; for adding bookmarks and fit to width.

&Ctrl;2 Tools Zoom

  The mouse will work as a zoom tool. Clicking &LMB; and dragging will zoom the view to the selected area, clicking &RMB; will bring the document back to the previous zoom.

&Ctrl;3 Tools Area Selection

  The mouse will work as a rectangular region selection tool. In that mode clicking &LMB; and dragging will draw a selection box and provide the option of copying the selected content to the clipboard, speaking the selected text, or transforming the selection region into an image and saving it to a file.

&Ctrl;4 Tools Text Selection

  The mouse will work as a text selection tool. In that mode clicking &LMB; and dragging will give the option of selecting the text of the document. Then, just click with the &RMB; to copy to the clipboard or speak the current selection.

&Ctrl;5 Tools Table Selection

  Draw a rectangle around the text for the table, then click with the &LMB; to divide the text block into rows and columns. A &LMB; click on an existing line removes it and merges the adjacent rows or columns. Finally, just click with the &RMB; to copy the table to the clipboard.

&Ctrl;6 Tools Magnifier

  Activates the magnifier mode for the mouse pointer. Press and hold the &LMB; to activate magnifier widget, move the pointer for panning through the document. The magnifier scales each pixel in the document into 10 pixels in the magnifier widget.

F6 Tools Annotations

  Open the annotation toolbar. The annotation toolbar allows you to add annotations on the document you are reading. For more information, please see the section about Annotations.

Tools Digitally Sign...

  Starts the digital signature creation workflow. Addition of digital signatures is only supported for PDF files at this point. For more information, please see the section about Adding Digital Signatures.

Tools Speak Whole Document
Tools Speak Current Page
Tools Stop Speaking
Tools Pause/Resume Speaking

  These items allow you to speak the whole document or just the current page and stop speaking using the system speech service. This service is provided by a &Qt; library which wraps speech-dispatcher on &Linux;, and native speech systems on other platforms. It is possible to choose the current voice via &okular; Accessibility configuration page.

  The Speak ... actions are enabled only if a speech service is available in the system.

### The Settings and Help Menu

Apart from the common &kde; Settings and Help menus described in the Menu chapter of the &kde; Fundamentals documentation &okular; has these application specific menu entries:

F7 Settings Show Sidebar

  Shows or hides the Sidebar.

Settings Show Page Bar

  Toggle the page bar at the bottom of document area on and off to save vertical place in &okular; window. Note that the page numbers will be shown on the default toolbar anyway.

Settings Configure Backends...

  Opens the Backend Configuration window.

## Configuring &okular; Backends

You can configure &okular; backends by choosing Settings Configure Backends... . Currently, configuration options are provided for EPub, &PostScript;, FictionBook, Txt, OpenDocument Text, and &PDF; backends only.

The backends configuration dialog
The backends configuration dialog

Using backend configuration pages for EPub, FictionBook, Mobipocket, Markdown, TXT, and OpenDocument Text you can define the font to render documents in the corresponding formats. The Choose... button in these pages opens standard &kde; font configuration window. Please refer to the &kde; Fundamentals documentation for the details.

The description of Markdown, &PostScript; and &PDF; backends configuration pages can be found below.

### Markdown backend configuration

You can configure &okular; Markdown rendering backend based on Discount by choosing Markdown from the list on the left part of the configuration dialog. An additional configurable option is as follows.

Enable SmartyPants formatting

  When checked this option allows &okular; to process SmartyPants formatting. Such formatting can be troublesome in the technical texts because of unwanted substitutions (⪚, it replaces `(C)` with a copyright symbol). This option is checked by default.

### &PostScript; backend configuration

You can configure &okular; &PostScript; rendering backend based on Ghostscript by choosing Ghostscript from the list on the left part of the configuration dialog. The only configurable option is as follows.

Use platform fonts

  This option determines whether Ghostscript should be allowed to use platform fonts, if unchecked only usage of fonts embedded in the document will be allowed. This option is checked by default.

### &PDF; backend configuration

You can configure &okular; &PDF; rendering backend based on Poppler by choosing &PDF; from the list on the left part of the configuration dialog. The only configurable option is as follows.

Enhance thin lines

  Drawing lines in &okular; is implemented in two steps: generation of the clipping path and filling this clipping path. When the line in the original document is less than one pixel this two step implementation could cause problems. For those lines, the clipping path is filled with the filling color that depends on the thickness of the line part inside the clipping area. If the part of the line inside the clipping area gets very small the contrast between the shape and the background color can become too low for the line to be recognizable. The grids of such lines then looks very unpretty.

  Thin line (red), its clipping path (dashed line) and pixel boundaries (black solid lines) | Thin line shown at a low contrast

  To enhance the look of the thin lines &okular; implements two options.

  The first option is Solid. With this option &okular; adjusts clipping path and line position so that clipping path and line are on the same pixel boundary, &ie; &okular; enlarges the thin lines to one pixel on the output device. This mode is similar to the Enhance thin lines in Adobe Reader. If this option is chosen, the thin lines are always enlarged.

  Thin line with Solid enhancement

  Thin line with Solid enhancement

  The second option is Shape. With this option the clipping path and line are adjusted to pixel boundary as well, but the line intensity is corrected according to its width.

  Thin line with Shape enhancement

  Thin line with Shape enhancement

  The thin lines are not enhanced by default (option No).

#### &PDF; Digital Signature Certificates

This section allows you to set a custom Certificate Database to use when adding Digital Signatures to &PDF; files.

It also lists the certificates available in the current Certificate Database (if any).

## Configuring &okular;

### General configuration

You can configure &okular; by choosing Settings Configure &okular;.... The configuration dialog is split into six sections. This chapter describes the available options in detail.

- General

- Accessibility

- Performance

- Presentation

- Annotations

- Editor

The configuration dialog
The configuration dialog

Depending on the currently installed backends, the Settings Configure Backends... menu item could be enabled. This particular configuration dialog holds the configurations of the backends that can actually be configured.

### General

Use smooth scrolling

  Whether to display animated transitions when scrolling using the mouse wheel and keyboard.

Show scrollbars

  Whether to show scrollbars for the document view.

Link the thumbnails with the page

  Whether the thumbnails view should always display the current page or not.

Show hints and info messages

  Whether to show some informative messages on startup, file load, &etc;

Notify about embedded files, forms, or signatures

  Whether to show informative panels about embedded files, forms or signatures &etc;

Display document title in titlebar if available

  Whether to show the current document title in the titlebar of &okular; window. If no metadata for title found in the document or this item is unchecked &okular; shows filename of the document.

When not displaying document title

  You can choose any of two options, Display file name only or Display full file path.

Use custom background color

  Enables choosing the document background color (the color around the displayed page). By default, the &Qt; toolkit color is used when this option is unchecked.

Open new files in tabs

  Whether to open new documents in tabs. The tabs are disabled by default.

  The default shortcuts to switch between tabs are &Ctrl;. (Next tab) and &Ctrl;, (Previous tab).

Switch to existing tab if file is already open

  Whether &okular; should switch to a tab if the file is already open instead of opening a new tab. This option is enabled by default. Can be toggled only if Open new files in tabs is enabled.

Obey DRM limitations

  Whether &okular; should obey DRM (Digital Rights Management) restrictions. DRM limitations are used to make it impossible to perform certain actions with &PDF; documents, such as copying content to the clipboard. Note that in some configurations of &okular;, this option is not available.

Reload document on file change

  Whether opened files should be automatically checked for changes and updated, if necessary.

Show backend selection dialog

  Whether &okular; should ask the user which backend to use in case of more than one backend able to open the current file. If unchecked, &okular; will use the backend with the highest priority.

Right to left reading direction

  Whether to use right to left reading direction by default for the opened files. Can be useful for some writing systems.

Open in continuous mode by default

  Whether to use the continuous mode by default. In continuous mode, all pages of the document are shown, and you can smoothly scroll through them. Otherwise, only one page (or one row of pages) is shown at a time.

When using Browse Tool, wrap cursor at screen edges

  Allows endless scrolling around the entire document with the Browse Tool. If enabled, the mouse cursor will wrap to the opposite end of the screen when it touches the borders while dragging the document. This feature is only supported on X11.

Overview columns

  This option represents the number of columns to use in the overview mode.

Page Up/Down overlap

  Here you can define the percentage of the current viewing area that should be visible after pressing &PgUp;/&PgDn; keys.

Default Zoom

  This option specifies the default zoom mode for files which were never opened before. For those files which were opened before, the previous zoom mode is applied.

### Accessibility

Draw border around links

  Whether to draw a border around links.

Change colors

  Enables the color changing options.

Color mode

  Defines the color changing mode.

  Invert Colors

    Inverts colors on the view, &ie; black objects will be shown white.

  Change Paper Color

    Changes the paper's color, &ie; the document's background.

    The color can be selected using the Paper color swatch below.

  Change Dark & Light Colors

    Changes the dark and light color to your preference, that means black will not be rendered as black but as the selected dark color and white will not be rendered as white but as the selected light color.

  Convert to Black & White

    Converts the document to black and white. You can set the threshold and the contrast. Setting the threshold to a higher value by moving it to the right will result in lighter grays used.

  Invert Lightness

    Inverts lightness of all colors. Light and dark colors will be swapped, but hue and saturation will not be affected. The Contrast in images will usually be worse than in Invert Luma (sRGB Linear).

  Invert Luma (sRGB Linear)

    Inverts luma of all colors. Light and dark will be swapped, but hue and saturation will not be affected. The Contrast in images is preserved better than in Invert Lightness, but graphics and colorful text markup usually look worse. Uses sRGB luma coefficients, but no gamma correction.

  Invert Luma (Symmetric)

    Inverts luma of all colors, using symmetric luma coefficients. Light and dark will be swapped, but hue and saturation will not be affected. Very similar to Invert Lightness, but the contrast is in some cases better.

  Shift Hue Positive

    Shifts hue of all colors by 120 degrees. Can mitigate some contrast problems in colorful graphics.

  Shift Hue Negative

    Shifts hue of all colors by 240 degrees. Can mitigate some contrast problems in colorful graphics.

  You can configure keyboard shortcuts and toolbar actions for the color modes using the corresponding menu items in the Settings menu of the &okular; main window.

Text-to-speech engine

  Allows you to choose the text-to-speech (TTS) engine to be used by &okular;. The default is speechd TTS.

Text-to-speech voice

  Allows you to choose a voice for the text-to-speech engine to be used by &okular;. You can use all languages and voices depending on the available synthesizers on your platform. On &Linux;, speech-dispatcher is used by default to determine available voices.

### Performance

Enable transparency effects

  Draw selections and other special graphics using transparency effects. Disable the option to draw them using outline or opaque fill styles and increase speed on selections.

Memory usage

  &okular; can achieve best performance by tuning the memory usage, based on your system and your tastes. The more memory you let it to use, the faster the program will behave. The Default profile is good for every system, but you can prevent &okular; from using more memory than necessary by selecting the Low profile, or let it get the most out of your system using Aggressive. Use Greedy profile to preload all pages without risk of system memory overfull (only 50% of total memory or free memory will be used).

Rendering options

  Using this group of options you can improve text and image rendering in &okular;. The result depends on the device to display the document. Enable Text Antialias and Enable Graphics Antialias items can be used to switch on and off spatial anti-aliasing of text and images in document, correspondingly. Enable Text Hinting item is meant to be a switcher for font hinting. Antialiasing and hinting change how the documents are displayed, you may want to tweak them to your preference.

### Presentation

Advance every

  Enables automatic advancing of pages given a time period.

Loop after last page

  When navigating on presentation mode and going past the last page the first page will appear.

Touch navigation

  Allows you to fine-tune touchscreen navigation with tapping in the presentation using the following three possible values:

  - Tap left/right side to go back/forward: Tapping on the left (right) half of the screen makes the presentation go to the previous (next) slide.

  - Tap anywhere to go forward (default): Tapping on the screen makes the presentation go to the next slide, no matter where the screen is being tapped.

  - Disabled: Screen tapping does not do anything.

Background color

  The color that will fill the part of the screen not covered by the page when on presentation mode.

Mouse cursor

  Whether the mouse should be always hidden, always shown or hidden after a small time of inactivity.

Show progress indicator

  Whether to show a progress circle that shows the current page and the total number of pages on the upper right corner of the presentation screen every time you change the page.

Show summary page

  Whether to show a summary page at the beginning of the presentation with the title, author and number of pages of the document.

Enable transitions

  Use this check box to enable or disable transition effects between pages.

Default transition

  The transition effect between page and page if the document does not specify one. Set this to Random Transition to make &okular; randomly choose one of the available effects.

Placement

  In this section you can select the Screen used to display the presentation.

  Current Screen is same screen of the &okular; window that starts the presentation mode.

  Default Screen is the screen marked as default in the xinerama configuration.

  Screen 0, Screen 1 &etc; are the available screens.

Drawing Tool Configuration

  Manage the colors of the pencil used when drawing on the pages during the presentation mode.

### Annotations

The Annotations page of the configuration dialog
The Annotations page of the configuration dialog

Annotation toolbar

  Allows switching between Full Annotation Toolbar (default toolbar in the top section of the &okular; window) and Quick Annotation Toolbar (sliding toolbar with your favorite tools at the right part of the document pane).

Author

  The author of the contents added on a document. Default is the name from the Password & User Account page of the &systemsettings; module Account Details.

Annotation tools

  This pane is used to configure your annotation toolbar.

  There are five buttons (Add, Edit, Remove, Move Up, Move Down) and a list box (which lists the contents of the current annotation toolbar) which are used to configure the toolbar.

  If you need to add some tool button on the toolbar click on the Add button. You can choose the Name, the Type and the Appearance of the created tool.

  Please remember that annotation tools in &okular; are highly configurable. For example, you can have two buttons of the same tool but with different color. Do not hesitate to experiment in choosing the button set that is exactly tailored to your workflow.

  Click on some item in the list box then click on the corresponding button at the right part of the page to edit, remove, move up or move down the item. The keyboard shortcut of the tool (keys from 1 to 9) depends on its position in the list of annotation toolbar.

Using Custom Stamps

  1. Create the icon you want to use for your own stamp and save it in any graphics format supported by &okular;

  2. Click the Add button, select type Stamp and enter a name for your stamp.

  3. Enter the full path to your custom icon into the dropdown box in the Stamp Symbol group

### Editor

Editor

  Choose the editor you want to launch when &okular; wants to open a source file. This is the case when the document has references to the various points (usually row and column number) of sources it was generated from. The &DVI; format supports natively the addition of the information about the sources the &latex; document was generated from. A similar system exists for &PDF; documents, called pdfsync, which stores these extra information in an external file named after the &PDF; file itself (for example `mydocument.pdfsync` for `mydocument.pdf`).

  &okular; ships with preconfigured settings for the following editors: &kate;, Kile, SciTE, &Emacs; client, LyX client, TeXstudio, and TeXiFy IDEA.

  To use inverse search in &kile;, you have to compile your &latex; file with the Modern configuration.

Command

  This is the command and its parameters to invoke the selected editor with the source file of the actual document.

  This field will be filled automatically if you use one of the preconfigured editors. Otherwise, please choose Custom Text Editor in Editor drop down box and refer to the documentation on your favorite editor to find the proper command.

  You can use the following placeholders:

  - %f - the file name

  - %l - the line of the file to be reached

  - %c - the column of the file to be reached

  If %f is not specified, then the document name is appended to the specified command.

## Credits and License

Program Copyright:

- &Albert.Astals.Cid; &Albert.Astals.Cid.mail; Current maintainer

- Pino Toscano pino@kde.org

- Enrico Ros eros.kde@email.it &kpdf; developer

Documentation Copyright:

- &Albert.Astals.Cid; &Albert.Astals.Cid.mail; Author

- Titus Laska titus.laska@gmx.de Some updates and additions

- Pino Toscano pino@kde.org

&underFDL; &underGPL;
&documentation.index;