Accessibility Features of &brandFullName; 的易用性

&brandShortName; includes many features to make the browser and web content accessible to all users, including those who have low vision, no vision, or limited ability to use a keyboard or mouse. 內建許多可讓使用者更容易存取瀏覽器與網路內容的特性，包含那些擁有低視覺、沒有視覺，或是只能以有限的能力使用鍵盤或滑鼠的使用者。

Using a Keyboard 使用鍵盤

Keyboard Shortcuts 鍵盤快捷鍵

A list of common keyboard shortcuts is available in 通用的鍵盤快捷鍵列表在 <a href="shortcuts.xhtml">&brandShortName; Keyboard Shortcuts 鍵盤快捷鍵</a>.。 Online, you can find 您也可以線上尋找 <a target="_blank" href="http://www.mozilla.org/support/firefox/keyboard">a comparison chart of keyboard shortcuts 鍵盤快捷鍵的比較圖表 </a> implemented in 應用在 &brandShortName;, Microsoft Internet Explorer, and Opera.

Allow Text To Be Selected With The Keyboard 允許使用鍵盤選取文字

<a href="prefs.xhtml#accessibility">Allow text to be selected with the keyboard 允許使用鍵盤選取文字</a> allows you to move through web content as if you were inside a read-only editor. 提供您像在唯讀的編輯器中搬移網路內容的體驗。 You can use the keyboard to select web content and copy it to the clipboard. 您可以使用鍵盤選取網頁內容並將他複製到剪貼簿中。 您可以啟用這項功能經由選擇 You can enable this feature by selecting &pref.menuPath;, opening the 開啟 General 一般 tab in the 頁面於Advanced 進階 panel,設定面板，並且選取啟用 and checking the Allow text to be selected with the keyboard 允許使用鍵盤選取文字 &pref.singular;.

You can press 您也可以在任何時間以鍵盤上的 F7 at any time to turn this feature on or off. 來啟用或關閉此功能。 當你按下 When you press F7, &brandShortName; will ask if you really want to turn on this feature. 再次詢問您是否要啟用此項功能。 您可以關閉這個提示經由選取 You can disable this prompt by selecting Don't show this dialog again. 不要再顯示此提示。

Begin Finding When You Begin Typing

<a href="prefs.xhtml#accessibility">Begin finding when you begin typing</a> allows you to quickly navigate to text or hyperlinks in a web page. This feature has two modes. Press / and start typing to search all text on the current page, or press ' before your string to search hyperlinks only. &brandShortName; will highlight matching text or hyperlinks as you type.

The following keyboard shortcuts control this feature:

• Type more characters to narrow your search. &brandShortName; will highlight the next matching hyperlink or text or alert you that nothing matched.
• Press &accelKey;+G or F3 to find the next occurrence of your current search string.
• Press &accelKey;+&shiftKey;+G or &shiftKey;+F3 to find the previous occurrence of your current search string.
• Press Backspace to undo the last character you typed. &brandShortName; will back up to the previously highlighted text.
• Press Esc to cancel a search. You can also cancel a search by changing focus, scrolling the page with the mouse or keyboard, or simply waiting for the timeout.

You can change the default behavior of this feature by selecting &pref.menuPath;, opening the General tab of the Advanced panel, and checking the Begin finding when you begin typing &pref.singular;. If this option is checked, you can start typing at any time to auto-start an inline search. By default auto-started searches look for all text on the page. You can still explicitly press ' or / to start finding in one mode or the other.

You can use this feature to get to buttons, text boxes and other form controls. Search for the text immediately before the form control you want and press Tab. Pressing Tab automatically exits the search and sets focus to the next form field or button after the highlighted text.

Using a Mouse

Common Mouse Shortcuts

A list of common mouse shortcuts is available in <a href="mouse_shortcuts.xhtml">&brandShortName; Mouse Shortcuts</a>.

Fonts and Colors

Overriding Page Fonts

Some web sites may display text in fonts that are difficult to read, and other sites may rely on the browser's default fonts. You can set your default fonts by going to &pref.menuPath;, selecting the Content panel, and selecting a default font and size in the Fonts & Colors section.

You can specify default fonts for different styles, including serif, sans-serif, and monospace by clicking the Advanced button. However, many web pages specify their own fonts, so your choices will have no effect on such pages. To override the fonts defined by such pages, uncheck the Allow pages to choose their own fonts, instead of my selections above &pref.singular;.

Note that some web pages may display incorrectly depending on your choice of a default font.

Setting a Minimum Font Size

Some web sites may display text which is too small to read comfortably. To make such pages easier to read, you can set a minimum font size. On web pages that try to display text smaller than this size, &brandShortName; will enlarge the text to your chosen size.

To set a minimum font size, go to &pref.menuPath;, select the Content panel, and click the Advanced button in the Fonts & Colors section. You can specify a minimum font size from the dropdown menu.

Note that some web pages may display incorrectly depending on your choice of a minimum font size.

Resizing Page Text

You can temporarily change the size of text on any web page in the View > Text Size menu. The new size will remain in effect until you close your browser window or tab, even if you navigate to a different web site.

The following keyboard shortcuts control text size:

• Press &accelKey;++ to increase the text size. This zooms the text to 120% of its original size, then 150%, 200%, 300%, 450%, 675%, 1013%, and 1519%.
• Press &accelKey;+- to decrease the text size. This zooms the text to 90% of its original size, then 50%, 33%, 22%, 15%, 10%, 7%, 4%, 3%, 2%, and 1%.
• Press &accelKey;+0 to reset the text size to the web page's default size.

Note that some web pages may display incorrectly if you increase or decrease the text size.

Overriding Page Colors

Some web sites may display text and background colors that are difficult to read, and other sites may rely on the browser's default colors. You can set your default colors by going to &pref.menuPath;, selecting the Content panel, and clicking the Colors button in the Fonts & Colors section. You can set default text and background colors, as well as default colors for visited and unvisited hyperlinks. You can also specify whether hyperlinks should be underlined.

However, many web pages set their own colors, so your choices will have no effect. To override the colors defined by web pages, uncheck the Allow pages to choose their own colors, instead of my selections above &pref.singular;.

Controlling Web Content

Blocking Popup Windows

See <a href="popup.xhtml">Controlling Popups</a> for information on blocking popup windows.

Turning Off Java Applets

Some web pages provide a rich interactive experience with Java™ applets. However, some users that rely on keyboard navigation may experience problems with some Java applets that automatically set focus and do not provide a way to break out of the applet and navigate to the rest of the web page. If this is a problem for you, you can disable Java by going to &pref.menuPath;, selecting the Content and unchecking the Enable Java &pref.singular;.

Restricting JavaScript Behavior

You can turn off JavaScript entirely by going to &pref.menuPath;, selecting the Content panel, and unchecking Enable JavaScript. Some web pages rely on JavaScript and may not work properly if JavaScript is disabled.

If you do not wish to disable JavaScript entirely, there are also a number of advanced JavaScript settings to restrict the behavior of scripts. Immediately after the Enable JavaScript checkbox, click the Advanced button to open the Advanced JavaScript Settings window. You can control whether scripts are allowed to move or resize existing windows, raise or lower windows, disable or replace context menus, hide the status bar, or change status bar text.

Compatibility With Assistive Technologies

The latest information about compatibility with third-party assistive technologies is online at <a target="_blank" href="http://www.mozilla.org/access/compatibility">Access Mozilla: Compatibility with assistive technologies</a>.

Finding Help Online

You may also post accessibility questions to the <a target="_blank" href="http://forums.mozillazine.org/viewforum.php?f=38">&brandShortName; Support forum</a>.