Accessing web page and browser information
Vaadin 7 includes a new Page class offering access to various
client-side information and events concerning the web page and browser
window in which the Vaadin UI resides. The Page instance corresponding
to a given UI is accessed via the getPage()
method of the UI or using
a static method Page.getCurrent()
.
You can access the browser window size and add size change listeners:
Page page = someUI.getPage();
page.addBrowserWindowResizeListener(new BrowserWindowResizeListener() {
public void browserWindowResized(BrowserWindowResizeEvent event) {
Notification.show("Window width=" + event.getWidth() + ", height=" + event.getHeight());
}
});
You can access the optional fragment part of the location URI and add fragment change listeners:
page.setUriFragment(page.getUriFragment() + "foo");
page.addUriFragmentChangedListener(new UriFragmentChangedListener() {
public void uriFragmentChanged(UriFragmentChangedEvent event) {
Notification.show("Fragment=" + event.getUriFragment());
}
});
You can access client browser details:
Notification.show("IP" + browser.getAddress() +
"User-Agent:" + browser.getBrowserApplication() +
"Linux: " + browser.isLinux());
Note: If you are using a reverse proxy, you must get the value
X-Forwarded-For
from request headers. You cannot get a browser name,
but you can check which browser are using.