Use the Cog browser to access Digi Embedded Yocto WPE WebKit functionality.
To control the browser from the command line, run Cog in the background:
~# cog &
The browser runs the digi-webkit-examples web application by default. From this web application, you can test the hardware acceleration capabilites of WebKit.
You can also open a different webpage by specifying its URL when executing Cog, such as:
~# cog www.digi.com &
Cog displays the web page in fullscreen mode with no toolbars or navigation buttons. To navigate to a new URL or go to the previous page, use the cogctl CLI application. This application communicates with the Cog process via D-Bus and allows you to execute the following commands:
~# cogctl help Available commands: appid Display application ID being remotely controlled objpath Display the D-Bus object path being used help Obtain help about commands open Open an URL previous Navigate backward in the page view history next Navigate forward in the page view history ping Check whether Cog is running quit Exit the application reload Reload the current page
For example, to go back to the previous page:
~# cogctl previous
Configure the Cog browser
Cog configuration options allow you to modify the browser’s features and performance. To view all available parameters, run:
~# cog --help-all Usage: cog [OPTION?] [URL] [...] WebKitSettings options can be used to configure features exposed to the loaded Web content. BOOL values are either 'true', '1', 'false', or '0'. Omitting the value implies '1'. INTEGER values can be decimal, octal (prefix '0'), or hexadecimal (prefix '0x'). UNSIGNED values behave like INTEGER, but negative values are not accepted. FLOAT values may optionally use decimal separators and scientific notation. STRING values may need quoting when passed from the shell. --allow-file-access-from-file-urls=BOOL Whether file access is allowed from file URLs. --allow-modal-dialogs=BOOL Whether it is possible to create modal dialogs --allow-top-navigation-to-data-urls=BOOL Whether or not top frame navigation is allowed to data URLs --allow-universal-access-from-file-urls=BOOL Whether or not universal access is allowed from the context of file scheme URLs --auto-load-images=BOOL Load images automatically. --cursive-font-family=STRING The font family used as the default for content using cursive font. --default-charset=STRING The default text charset used when interpreting content with unspecified charset. --default-font-family=STRING The font family to use as the default for content that does not specify a font. --default-font-size=UNSIGNED The default font size used to display text. [...] Application Options: --version Print version and exit --print-appid Print application ID and exit --scale=FACTOR Zoom/Scaling factor applied to Web content (default: 1.0, no scaling) --device-scale=FACTOR Output device scaling factor (default: 1.0, no scaling, 96 DPI) --doc-viewer Document viewer mode: optimizes for local loading of Web content. This reduces memory usage at the cost of reducing caching of resources loaded from the network. -d, --dir-handler=SCHEME:PATH Add a URI scheme handler for a directory --webprocess-failure=ACTION Action on WebProcess failures: error-page (default), exit, exit-ok, restart. -C, --config=PATH Path to a configuration file -b, --bg-color=BG_COLOR Background color, as a CSS name or in #RRGGBBAA hex syntax (default: white) --web-extensions-dir=PATH Load Web Extensions from given directory.
WebKit uses caches to improve load times. In some cases, prolonged use of these caches can reduce the total memory available in the system, causing the browser (and the system) to slow down. The following Cog parameters can help solve memory issues associated with caching:
-
--enable-page-cache=false
disables the page cache, which stores the state of pages you’ve visited. -
--doc-viewer
disables the resource cache, which stores resources that might be shared among different subpages in the same website (such as images and stylesheets).
While these parameters reduce the amount of memory taken up by caches, in some cases they do so at the cost of increased load times. These options are recommended when an embedded device’s total RAM is 1 GiB or smaller. Otherwise, slowdowns can occur after browsing several pages in succession. |