Chrome (version 10 and above) uses WebUI settings by default for all platforms. Access it via the wrench menu (“Preferences” on Mac and Linux; “Options” on Windows and ChromeOS), or by typing chrome://settings into the address bar.
One advantage of chrome://settings over platform-native dialogs is that it is shared by all platforms; therefore, it is easier to add new options UI and to keep all platforms in sync.
Note that at the time of this writing, DOMUI is being renamed to WebUI. The two terms will be used interchangeably herein.
Strings live in chrome/app/generated_resources.grd
. There are several rules governing the format of strings:
<if expr="pp_ifdef('use_titlecase')">
blocks. Do this even if your string is a single word because it may not be a single word in another locale.generated_resources.grd
and use product name placeholders; if they differ more substantially, use chromium_strings.grd
and google_chrome_strings.grd
.The C++ WebUI handler classes for chrome://settings live in chrome/browser/ui/webui/options/
. These objects both handle messages from and dispatch messages to the page. Each handler is a logical grouping of related functionality. Hence ContentSettingsHandler
is both the delegate and controller of the content settings subpage.
A handler sends a message to the page via dom_ui_->CallJavascriptFunction()
and registers for messages from the page via dom_ui_->RegisterMessageCallback()
.
The HTML, CSS, and JS resources live in chrome/browser/resources/options
. They are compiled into one resource at compile time by grit, via <link>
, <src>
and <include>
tags in options.html
. There is no need to add new files to any .gyp
file.
Some things that are good to know:
decorate()
. * Javascript calls into C++ via chrome.send
. * Some automatic preference handling is provided in preferences.js
and pref_ui.js
. * Strings defined in a WebUI handler are available via localStrings.getString()
and friends.Suppose you want to add a pref controlled by a checkbox.
Ask one of the UI leads where your option belongs. First point of contact should be Alex Ainslie .
Add the string to chrome/app/generated_resources.grd
near related strings. No trailing punctuation; sentence case.
For simple prefs, the UI is kept in sync with the value automagically (see CoreOptionsHandler
). Find the handler most closely relevant to your pref. The only action we need take here is to make the page aware of the new string. Locate the method in the handler called GetLocalizedStrings
and look at its body for examples of SetString
usage. The first parameter is the javascript name for the string.
An example of the form a checkbox should take in html:
<label class="checkbox"> <input id="clear-cookies-on-exit" pref="profile.clear_site_data_on_exit" type="checkbox"> <span i18n-content="clearCookiesOnExit"></span> </label>
Of note:
checkbox
class allows us to style all checkboxes the same via CSSchrome/common/pref_names.cc
and allows the prefs framework to automatically keep it in sync with the value in C++i18n-content
value matches the string we defined in the WebUI handler. The textContent
of the span
will automatically be set to the associated text.In this example, no additional JS or CSS are needed.