Add ReCaptcha Activity

* ReCaptchas are implemented using a simple WebView with Javascript enable.

 * All HTTP responses inside the WebView are catched (using onPageFinished())
 ** When Google reCatcha cookies are detected, register cookies to the
    Downloader class and Return to MainActivity

app/src/main/AndroidManifest.xml

@@ -153,6 +153,9 @@
             android:label="@string/title_activity_channel"
             android:theme="@style/AppTheme.NoActionBar" />
 
+        <activity
+            android:name=".ReCaptchaActivity"
+            android:label="@string/reCaptchaActivity" />
     </application>
 
 </manifest>

app/src/main/java/org/schabi/newpipe/ReCaptchaActivity.java

@@ -0,0 +1,138 @@
+package org.schabi.newpipe;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.os.Build;
+import android.os.Bundle;
+import android.support.v4.app.NavUtils;
+import android.support.v7.app.ActionBar;
+import android.support.v7.app.AppCompatActivity;
+import android.view.MenuItem;
+import android.webkit.CookieManager;
+import android.webkit.ValueCallback;
+import android.webkit.WebSettings;
+import android.webkit.WebView;
+import android.webkit.WebViewClient;
+
+/**
+ * Created by beneth <bmauduit@beneth.fr> on 06.12.16.
+ *
+ * Copyright (C) Christian Schabesberger 2015 <chris.schabesberger@mailbox.org>
+ * ReCaptchaActivity.java is part of NewPipe.
+ *
+ * NewPipe is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * NewPipe is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with NewPipe.  If not, see <http://www.gnu.org/licenses/>.
+ */
+public class ReCaptchaActivity extends AppCompatActivity {
+    public static final String TAG = ReCaptchaActivity.class.toString();
+    public static final String YT_URL = "https://www.youtube.com";
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_recaptcha);
+
+        ActionBar actionBar = getSupportActionBar();
+        actionBar.setDisplayHomeAsUpEnabled(true);
+        actionBar.setTitle(R.string.reCaptcha_title);
+        actionBar.setDisplayShowTitleEnabled(true);
+
+        WebView myWebView = (WebView) findViewById(R.id.reCaptchaWebView);
+
+        // Enable Javascript
+        WebSettings webSettings = myWebView.getSettings();
+        webSettings.setJavaScriptEnabled(true);
+
+        ReCaptchaWebViewClient webClient = new ReCaptchaWebViewClient(this);
+        myWebView.setWebViewClient(webClient);
+
+        // Cleaning cache, history and cookies from webView
+        myWebView.clearCache(true);
+        myWebView.clearHistory();
+        android.webkit.CookieManager cookieManager = CookieManager.getInstance();
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            cookieManager.removeAllCookies(new ValueCallback<Boolean>() {
+                @Override
+                public void onReceiveValue(Boolean aBoolean) {}
+            });
+        } else {
+            cookieManager.removeAllCookie();
+        }
+
+        myWebView.loadUrl(YT_URL);
+    }
+
+    private class ReCaptchaWebViewClient extends WebViewClient {
+        private Activity context;
+        private String mCookies;
+
+        ReCaptchaWebViewClient(Activity ctx) {
+            context = ctx;
+        }
+
+        @Override
+        public void onPageFinished(WebView view, String url) {
+            String cookies = CookieManager.getInstance().getCookie(url);
+
+            // find cookies : s_gl & goojf and Add cookies to Downloader
+            if (find_access_cookies(cookies)) {
+                // Give cookies to Downloader class
+                Downloader.setCookies(mCookies);
+
+                // Closing activity and return to parent.
+                Intent intent = new Intent(context, org.schabi.newpipe.MainActivity.class);
+                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+                NavUtils.navigateUpTo(context, intent);
+            }
+        }
+
+        private boolean find_access_cookies(String cookies) {
+            boolean ret = false;
+            String c_s_gl = "";
+            String c_goojf = "";
+
+            String[] parts = cookies.split("; ");
+            for (String part : parts) {
+                if (part.trim().startsWith("s_gl")) {
+                    c_s_gl = part.trim();
+                }
+                if (part.trim().startsWith("goojf")) {
+                    c_goojf = part.trim();
+                }
+            }
+            if (c_s_gl.length() > 0 && c_goojf.length() > 0) {
+                ret = true;
+                //mCookies = c_s_gl + "; " + c_goojf;
+                // Youtube seems to also need the other cookies:
+                mCookies = cookies;
+            }
+
+            return ret;
+        }
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        int id = item.getItemId();
+        switch (id) {
+            case android.R.id.home: {
+                Intent intent = new Intent(this, org.schabi.newpipe.MainActivity.class);
+                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+                NavUtils.navigateUpTo(this, intent);
+                return true;
+            }
+            default:
+                return false;
+        }
+    }
+}

app/src/main/res/layout/activity_recaptcha.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical" android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <WebView
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:id="@+id/reCaptchaWebView" />
+</LinearLayout>

app/src/main/res/values/strings.xml

@@ -269,6 +269,8 @@
         "when a user tries to pick up one of cards.\n\n"
     </string>
     <string name="action_settings">Settings</string>
+    <string name="reCaptchaActivity">reCaptcha</string>
+    <string name="reCaptcha_title">reCaptcha Challenge</string>
 
     <!-- End of GigaGet's Strings -->