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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
// Suppress for literal UA comment below. detekt doesn't support lower-level annotations
@file:Suppress("MaxLineLength")
package org.mozilla.focus.browser
import android.content.Context
import android.content.pm.PackageManager
import android.os.Build
import androidx.annotation.VisibleForTesting
import android.text.TextUtils
import android.webkit.WebSettings
/** A collection of user agent functionality. */
object UserAgent {
/**
* Build the browser specific portion of the UA String, based on the webview's existing UA String.
*/
@VisibleForTesting
internal fun getUABrowserString(existingUAString: String, focusToken: String): String {
// Use the default WebView agent string here for everything after the platform, but insert
// Focus in front of Chrome.
// E.g. a default webview UA string might be:
// Mozilla/5.0 (Linux; Android 7.1.1; Pixel XL Build/NOF26V; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/56.0.2924.87 Safari/537.36
// And we reuse everything from AppleWebKit onwards, except for adding Focus.
var start = existingUAString.indexOf("AppleWebKit")
if (start == -1) {
// I don't know if any devices don't include AppleWebKit, but given the diversity of Android
// devices we should have a fallback: we search for the end of the platform String, and
// treat the next token as the start:
start = existingUAString.indexOf(")") + 2
// If this was located at the very end, then there's nothing we can do, so let's just
// return focus:
if (start >= existingUAString.length) {
return focusToken
}
}
val tokens = existingUAString.substring(start).split(" ".toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray()
for (i in tokens.indices) {
if (tokens[i].startsWith("Chrome")) {
tokens[i] = focusToken + " " + tokens[i]
return TextUtils.join(" ", tokens)
}
}
// If we didn't find the chrome and safari tokens, we just append the focus token at the end:
return TextUtils.join(" ", tokens) + " " + focusToken
}
@JvmStatic
fun buildUserAgentString(context: Context, settings: WebSettings, appName: String): String {
val uaBuilder = StringBuilder()
uaBuilder.append("Mozilla/5.0")
// WebView by default includes "; wv" as part of the platform string, but we're a full browser
// so we shouldn't include that.
// Most webview based browsers (and chrome), include the device name AND build ID, e.g.
// "Pixel XL Build/NOF26V", that seems unnecessary (and not great from a privacy perspective),
// so we skip that too.
// To get a Desktop UA, we do what Focus does and
// 1) Don't use Firefox in the UA to avoid getting Gecko pages
// 2) Remove Android so we don't get mobile pages
uaBuilder.append(" (Linux; Android ").append(Build.VERSION.RELEASE).append(") ")
val existingWebViewUA = settings.userAgentString
val appVersion: String? // unknown if Android framework returns null but not worth crashing over.
try {
appVersion = context.packageManager.getPackageInfo(context.packageName, 0).versionName
} catch (e: PackageManager.NameNotFoundException) {
// This should be impossible - we should always be able to get information about ourselves:
throw IllegalStateException("Unable find package details for Focus", e)
}
val focusToken = appName + "/" + appVersion
uaBuilder.append(getUABrowserString(existingWebViewUA, focusToken))
return uaBuilder.toString()
}
}