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diff --git a/documentation/content/en/books/accessibility/lowvision/_index.adoc b/documentation/content/en/books/accessibility/lowvision/_index.adoc new file mode 100644 index 0000000000..7424045052 --- /dev/null +++ b/documentation/content/en/books/accessibility/lowvision/_index.adoc @@ -0,0 +1,464 @@ +--- +title: Chapter 4. Low Vision +part: Part II. Vision +prev: books/accessibility/colors +next: books/accessibility/blindness +description: Assistive technologies for low vision +tags: ["Accessibility", "Low Vision", "Magnify", "Desktop"] +showBookMenu: true +weight: 7 +params: + path: "/books/accessibility/lowvision/" +--- + +[[lowvision]] += Low Vision +:doctype: book +:toc: macro +:toclevels: 1 +:icons: font +:sectnums: +:sectnumlevels: 6 +:sectnumoffset: 4 +:partnums: +:source-highlighter: rouge +:experimental: +:images-path: books/accessibility/lowvision/ + +ifdef::env-beastie[] +ifdef::backend-html5[] +:imagesdir: ../../../../images/{images-path} +endif::[] +ifndef::book[] +include::shared/authors.adoc[] +include::shared/mirrors.adoc[] +include::shared/releases.adoc[] +include::shared/attributes/attributes-{{% lang %}}.adoc[] +include::shared/{{% lang %}}/teams.adoc[] +include::shared/{{% lang %}}/mailing-lists.adoc[] +include::shared/{{% lang %}}/urls.adoc[] +toc::[] +endif::[] +ifdef::backend-pdf,backend-epub3[] +include::../../../../../shared/asciidoctor.adoc[] +endif::[] +endif::[] + +ifndef::env-beastie[] +toc::[] +include::../../../../../shared/asciidoctor.adoc[] +endif::[] + +[[lowvisin-intro]] +== Introduction + +This chapter outlines accessibility features available in graphical desktop environments designed for users with low vision, such as virtual magnifiers, easy-to-read fonts, and screen scaling. + +[[hidpi]] +== Desktop Size + +Graphical environments allow users to adjust the desktop display size, a feature commonly known as screen scaling or HiDPI scaling. +The goal is to enlarge desktop elements such as icons, text, and windows to improve visibility and accessibility. + +[[kde-hidpi]] +=== KDE Plasma + +Open the `_Display Configuration_` module: + +[source,shell] +.... +% kcmshell6 kcm_kscreen +.... + +Select the scaling via the `_Global Scale_` bar. +The change will take effect after a KDE Plasma restart. + +[[xfce-hidpi]] +=== XFCE + +To set a custom scaling factor, for example 4, run the following command: + +[source,shell] +.... +% xfconf-query -c xsettings -p /Gdk/WindowScalingFactor -s 4 +.... + +Alternatively, HiDPI scaling can be enabled with a fixed 2x factor using the graphical interface. +This option is available in the `_Appearance_` dialog, under the `_Settings_` tab as `_Window Scaling_`. +To open the `_Appearance_` dialog, execute: + +[source,shell] +.... +% xfce4-appearance-settings +.... + +[[lowvision-font]] +== Font + +The package:x11-fonts/atkinson-hyperlegible[] provides the _atkinson-hyperlegible_ font. +It is designed for good readability, the letter shapes aim to increase character recognition. +To install, execute: + +[source,shell] +.... +# pkg install atkinson-hyperlegible +.... + +The remainder of this section describes how to set up fonts in various graphical environments using _atkinson-hyperlegible_ as an example. + +[[kde-fonts]] +=== KDE Plasma + +KDE allows selecting a font and its size via the `_Fonts_` module. +Run: + +[source,shell] +.... +% kcmshell6 kcm_fonts +.... + +Click on the Adjust `_All Fonts..._` button to select the font and its size for all graphical elements. +Alternatively, you can choose the font and size for individual elements using the forms below. + +At the bottom of the window, you can also select options such as `_Anti-Aliasing_`, `_Sub-pixel Rendering_`, `_Hinting_`, and `_Force Font DPI_`. +Each option has an icon on the right to open a help dialog. + +[[xfce-fonts]] +=== XFCE + +XFCE allows you to select the font and size for window titles and content text, as well as the font size for icon labels. + +[source,shell] +.... +% xfconf-query -c xfwm4 -p /general/title_font -s "Atkinson Hyperlegible 15" <1> +% xfconf-query -c xsettings -p /Gtk/FontName -s "Atkinson Hyperlegible 15" <2> +% xfconf-query -c xsettings -p /Gtk/MonospaceFontName -s "Atkinson Hyperlegible 15" <3> +% xfconf-query -c xfce4-desktop -p /desktop-icons/use-custom-font-size -s true <4> +% xfconf-query -c xfce4-desktop -p /desktop-icons/font-size -s 15.0 <5> +.... + +<.> Set the window title font to _Atkinson Hyperlegible_, size 15. +<.> Set the window content font to _Atkinson Hyperlegible_, size 15. +<.> Set the monospace font within windows to _Atkinson Hyperlegible_, size 15. +<.> Enable custom font sizing for icons. +<.> Set the icon font size to 15.0. + +Alternatively, you can configure the same settings using the graphical XFCE configuration dialogs. + +To select the font for window titles, open the `_Window Manager_` dialog: + +[source,shell] +.... +% xfwm4-settings +.... + +To choose the font used inside windows, open the `_Appearance_` dialog and go to the `_Fonts_` tab: + +[source,shell] +.... +% xfce4-appearance-settings +.... + +[TIP] +==== +In the Fonts tab, you can also adjust options such as `_anti-aliasing_`, `_Hinting_`, `_Sub-pixel order_`, and `_Custom DPI_`. +For more details, see the https://docs.xfce.org/xfce/xfce4-settings/appearance#fonts[XFCE documentation]. +==== + +To set the font size for icons, open the `_Desktop_` dialog and go to the `_Desktop Icons_` tab where you can adjust the icon font size: + +[source,shell] +.... +% xfdesktop-settings +.... + +[[magnify]] +== Magnify + +This section describes various utilities that magnify portions of the screen, acting as virtual magnifying lenses. +Some tools continuously enlarge the area beneath the mouse cursor, while others do not. +Certain utilities automatically move the magnified window to follow the cursor, whereas others keep it fixed in place. + +.Screen magnifier utilities. +[options="header", cols="1,1,1,1"] +|=== +| Name | Auto Update | Auto Move Lens | Package + +| lupe +| Yes +| No +| package:x11/lupe[] + +| kmag +| Yes +| No +| package:accessibility/kmag[] + +| xlupe +| Yes +| No +| package:x11/xlupe[] + +| xmag +| No +| No +| package:x11/xmag[] + +| xzoom +| No +| No +| package:x11/xzoom[] + +|=== + +The rest of this section details the steps to install, configure, and launch the utilities. + +[[lupe]] +=== lupe + +The man:lupe[1] utility is a screen magnifier for the X Window System that updates the magnified area in real time. +To install it, run: + +[source,shell] +.... +# pkg install lupe +.... + +By default, lupe magnifies the screen content beneath the mouse pointer within a circular area (25×25 pixels) displayed at the center of the screen. +To start lupe, run: + +[source,shell] +.... +% lupe +.... + +To exit lupe, press the `q` key. + +[TIP] +==== +Start lupe with the `-noshape` option to display the magnified area in a separate, movable window. +Without this option, the magnifier is locked to the center of the screen. +==== + +[[kmag]] +=== kmag + +The man:kmag[1] utility provides a screen magnifier that displays a zoomed view of the area under the mouse cursor in a dedicated window. +The magnifier window includes a menu with various options and settings for customization. + +To install kmag, run: + +[source,shell] +.... +# pkg install kmag +.... + +To launch kmag, execute: + +[source,shell] +.... +% kmag +.... + +[[xlupe]] +=== xlupe + +The package:x11/xlupe[] utility is a screen magnifier for the X Window System that updates the magnified view in real time. +To install it, run: + +[source,shell] +.... +# pkg install xlupe +.... + +To launch xlupe, execute: + +[source,shell] +.... +% xlupe +.... + +The utility does not include a manual page, but it starts in a graphical window with buttons that allow you to configure its options interactively. + +[[xmag]] +=== xmag + +The man:xmag[1] utility is a basic screen magnifier for the X Window System. +Unlike other magnifiers, it does not update the magnified area in real time. + +To install it, run: + +To install, execute: + +[source,shell] +.... +# pkg install xmag +.... + +To launch xmag, execute: + +[source,shell] +.... +% mag +.... + +[NOTE] +==== +xmag does not display a magnified area immediately upon launch. +Click anywhere on the screen with the left mouse button to select a region, and xmag will open a window showing a magnified view of that area. +The application window includes a few buttons offering limited functionality. +==== + +[[xzoom]] +=== xzoom + +The man:xzoom[1] utility is a screen magnifier for the X Window System that updates the magnified view in real time. +To install it, run: + +[source,shell] +.... +# pkg install xzoom +.... + +To launch xzoom, execute: + +[source,shell] +.... +% xzoom +.... + +[NOTE] +==== +Unlike other magnifiers, xzoom does not automatically follow the mouse cursor or magnify the area beneath it in its own window. +Interaction is keyboard-driven, refer to man:xzoom[1] for available commands and usage details. +==== + +[[lowvision-mouse]] +== Mouse + +[[mouse-apparance]] +=== Apparance + +Some desktop environments allow you to change the size, color, and other graphical properties of the mouse cursor. + +[[kde-mouse]] +==== KDE Plasma + +KDE Plasma provides the `_Cursors_` module to select the mouse cursor theme and size. +To launch it, run: + +[source,shell] +.... +% kcmshell6 kcm_cursortheme +.... + +Select an installed cursor theme in the window. +There is a `_Size_` drop-down menu in the top left corner to choose the mouse cursor size, +available sizes depend on the selected theme. + +Click the `_Get New..._` icon in the top right corner to install a new theme. +You can install new themes from the new window. +As a suggestion, search for `_Large Mouse Cursors_`, a black and white high contrast theme. + +[[xfce-mouse]] +==== XFCE + +XFCE allows you to set the size and color of the mouse pointer via `_Mouse and Touchpad_` dialog. +To run the dialog start: + +[source,shell] +.... +% xfce4-mouse-settings +.... + +Then click on the `_Theme_` tab to select a size and a style. + +[NOTE] +==== +Some themes, included the _Default_, do not support cursor size customization. +==== + +Alternatively, you can achieve the same result via the `xfconf-query` command. +The following example set the current theme cursur to size 50: + +[source,shell] +.... +% xfconf-query -c xsettings -n -p /Gtk/CursorThemeSize -s 50 +.... + +[[find-mouse-cursor]] +=== Find Cursor + +Some desktop environments provide a visul feedback of the mouse pointer's current position. + +[[kde-find-mouse-cursor]] +==== KDE Plasma + +KDE Plasma draws two circular lines moving around the mouse cursor. +Open the `Desktop Effects` module: + +[source,shell] +.... +% kcmshell6 kcm_kwin_effects +.... + +Enable the `_Track Mouse_` checkbox. +Draw circular lines by pressing `Meta` + `Ctrl` keys. +You can change the shortcut via the `_Configure_` button related to `_Track Mouse_`. + +[TIP] +==== +On keyboards where the `Meta` key is not present, it is usually replaced by the `Super` key. +Refer to https://en.wikipedia.org/wiki/Meta_key and https://en.wikipedia.org/wiki/Super_key_(keyboard_button) for more information. +==== + + +[[xfce-find-mouse-cursor]] +==== XFCE + +Xfce draws large red circles around the mouse pointer. +Type: + +[source,shell] +.... +% xfce4-find-cursor +.... + +The above command draws circles for a few seconds. + +**Keyboard Shortcut** + +XFCE allows to add a keyboard shortcut. +Circles are drawn for as long as the shortcut keys are pressed. +To use the shortcut before enable the feature then choose the key combination to bind to `xfce4-find-cursor`. + +Example to enable and bind `Ctrl` + `Super` + `k`: +[source,shell] +.... +xfconf-query -c accessibility -p /FindCursor -s true +xfconf-query -c xfce4-keyboard-shortcuts -n -t 'string' -p '/commands/custom/<Ctrl><Super>k' -s xfce4-find-cursor +.... + +**Keyboard Shortcut via Dialogs** + +Alternatively, you can achieve the same result via the XFCE configuration dialogs. +First step, open the XFCE `_Accessibility_` dialog: + +[source,shell] +.... +% xfce4-accessibility-settings +.... + +Click on `_Mouse_` tab and enable the `_Show location of pointer on keypress_` checkbox. + +Second step, open the XFCE `_Keyboard_` dialog: + +[source,shell] +.... +% xfce4-keyboard-settings +.... + +Click on `_Application Shortcuts_` tab. +Click on `_+ Add_` button, it opens the `_Shortcut Command_` dialog. +Write _xfce4-find-cursor_ in the form, then click on the `_OK_` button. +Choose a key combination to bind to `xfce4-find-cursor` in the new dialog. |