2 * Copyright © 2020-2022 Soren Stoutner <soren@stoutner.com>.
4 * This file is part of Privacy Browser Android <https://www.stoutner.com/privacy-browser-android>.
6 * Privacy Browser Android is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * Privacy Browser Android is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with Privacy Browser Android. If not, see <http://www.gnu.org/licenses/>.
20 package com.stoutner.privacybrowser.asynctasks;
22 import android.app.Activity;
23 import android.content.Context;
24 import android.net.Uri;
25 import android.os.AsyncTask;
26 import android.webkit.CookieManager;
27 import android.webkit.MimeTypeMap;
29 import androidx.fragment.app.DialogFragment;
30 import androidx.fragment.app.FragmentManager;
32 import com.stoutner.privacybrowser.R;
33 import com.stoutner.privacybrowser.activities.MainWebViewActivity;
34 import com.stoutner.privacybrowser.dataclasses.PendingDialog;
35 import com.stoutner.privacybrowser.dialogs.SaveDialog;
36 import com.stoutner.privacybrowser.helpers.ProxyHelper;
38 import java.lang.ref.WeakReference;
39 import java.net.HttpURLConnection;
40 import java.net.Proxy;
42 import java.text.NumberFormat;
44 public class PrepareSaveDialog extends AsyncTask<String, Void, String[]> {
45 // Define weak references.
46 private final WeakReference<Activity> activityWeakReference;
47 private final WeakReference<Context> contextWeakReference;
48 private final WeakReference<FragmentManager> fragmentManagerWeakReference;
50 // Define the class variables.
51 private final String userAgent;
52 private final boolean cookiesEnabled;
53 private String urlString;
55 // The public constructor.
56 public PrepareSaveDialog(Activity activity, Context context, FragmentManager fragmentManager, String userAgent, boolean cookiesEnabled) {
57 // Populate the weak references.
58 activityWeakReference = new WeakReference<>(activity);
59 contextWeakReference = new WeakReference<>(context);
60 fragmentManagerWeakReference = new WeakReference<>(fragmentManager);
62 // Store the class variables.
63 this.userAgent = userAgent;
64 this.cookiesEnabled = cookiesEnabled;
68 protected String[] doInBackground(String... urlToSave) {
69 // Get a handle for the activity and context.
70 Activity activity = activityWeakReference.get();
71 Context context = contextWeakReference.get();
73 // Abort if the activity is gone.
74 if (activity == null || activity.isFinishing()) {
75 // Return a null string array.
79 // Get the URL string.
80 urlString = urlToSave[0];
82 // Define the strings.
83 String formattedFileSize;
84 String fileNameString;
86 // Populate the file size and name strings.
87 if (urlString.startsWith("data:")) { // The URL contains the entire data of an image.
88 // Remove `data:` from the beginning of the URL.
89 String urlWithoutData = urlString.substring(5);
91 // Get the URL MIME type, which ends with a `;`.
92 String urlMimeType = urlWithoutData.substring(0, urlWithoutData.indexOf(";"));
94 // Get the Base64 data, which begins after a `,`.
95 String base64DataString = urlWithoutData.substring(urlWithoutData.indexOf(",") + 1);
97 // Calculate the file size of the data URL. Each Base64 character represents 6 bits.
98 formattedFileSize = NumberFormat.getInstance().format(base64DataString.length() * 3L / 4) + " " + context.getString(R.string.bytes);
100 // Set the file name according to the MIME type.
101 fileNameString = context.getString(R.string.file) + "." + MimeTypeMap.getSingleton().getExtensionFromMimeType(urlMimeType);
102 } else { // The URL refers to the location of the data.
103 // Initialize the formatted file size string.
104 formattedFileSize = context.getString(R.string.unknown_size);
106 // Because everything relating to requesting data from a webserver can throw errors, the entire section must catch exceptions.
108 // Convert the URL string to a URL.
109 URL url = new URL(urlString);
111 // Instantiate the proxy helper.
112 ProxyHelper proxyHelper = new ProxyHelper();
114 // Get the current proxy.
115 Proxy proxy = proxyHelper.getCurrentProxy(context);
117 // Open a connection to the URL. No data is actually sent at this point.
118 HttpURLConnection httpUrlConnection = (HttpURLConnection) url.openConnection(proxy);
120 // Add the user agent to the header property.
121 httpUrlConnection.setRequestProperty("User-Agent", userAgent);
123 // Add the cookies if they are enabled.
124 if (cookiesEnabled) {
125 // Get the cookies for the current domain.
126 String cookiesString = CookieManager.getInstance().getCookie(url.toString());
128 // only add the cookies if they are not null.
129 if (cookiesString != null) {
130 // Add the cookies to the header property.
131 httpUrlConnection.setRequestProperty("Cookie", cookiesString);
135 // The actual network request is in a `try` bracket so that `disconnect()` is run in the `finally` section even if an error is encountered in the main block.
137 // Get the status code. This initiates a network connection.
138 int responseCode = httpUrlConnection.getResponseCode();
140 // Check the response code.
141 if (responseCode >= 400) { // The response code is an error message.
142 // Set the formatted file size to indicate a bad URL.
143 formattedFileSize = context.getString(R.string.invalid_url);
145 // Set the file name according to the URL.
146 fileNameString = getFileNameFromUrl(context, urlString, null);
147 } else { // The response code is not an error message.
149 String contentLengthString = httpUrlConnection.getHeaderField("Content-Length");
150 String contentDispositionString = httpUrlConnection.getHeaderField("Content-Disposition");
151 String contentTypeString = httpUrlConnection.getContentType();
153 // Remove anything after the MIME type in the content type string.
154 if (contentTypeString.contains(";")) {
155 // Remove everything beginning with the `;`.
156 contentTypeString = contentTypeString.substring(0, contentTypeString.indexOf(";"));
159 // Only process the content length string if it isn't null.
160 if (contentLengthString != null) {
161 // Convert the content length string to a long.
162 long fileSize = Long.parseLong(contentLengthString);
164 // Format the file size.
165 formattedFileSize = NumberFormat.getInstance().format(fileSize) + " " + context.getString(R.string.bytes);
168 // Get the file name string from the content disposition.
169 fileNameString = getFileNameFromHeaders(context, contentDispositionString, contentTypeString, urlString);
172 // Disconnect the HTTP URL connection.
173 httpUrlConnection.disconnect();
175 } catch (Exception exception) {
176 // Set the formatted file size to indicate a bad URL.
177 formattedFileSize = context.getString(R.string.invalid_url);
179 // Set the file name according to the URL.
180 fileNameString = getFileNameFromUrl(context, urlString, null);
184 // Return the formatted file size and name as a string array.
185 return new String[] {formattedFileSize, fileNameString};
188 // `onPostExecute()` operates on the UI thread.
190 protected void onPostExecute(String[] fileStringArray) {
191 // Get a handle for the activity and the fragment manager.
192 Activity activity = activityWeakReference.get();
193 FragmentManager fragmentManager = fragmentManagerWeakReference.get();
195 // Abort if the activity is gone.
196 if (activity == null || activity.isFinishing()) {
201 // Instantiate the save dialog.
202 DialogFragment saveDialogFragment = SaveDialog.saveUrl(urlString, fileStringArray[0], fileStringArray[1], userAgent, cookiesEnabled);
204 // Try to show the dialog. Sometimes the window is not active.
206 // Show the save dialog. It must be named `save_dialog` so that the file picker can update the file name.
207 saveDialogFragment.show(fragmentManager, activity.getString(R.string.save_dialog));
208 } catch (Exception exception) {
209 // Add the dialog to the pending dialog array list. It will be displayed in `onStart()`.
210 MainWebViewActivity.pendingDialogsArrayList.add(new PendingDialog(saveDialogFragment, activity.getString(R.string.save_dialog)));
214 // Content dispositions can contain other text besides the file name, and they can be in any order.
215 // Elements are separated by semicolons. Sometimes the file names are contained in quotes.
216 public static String getFileNameFromHeaders(Context context, String contentDispositionString, String contentTypeString, String urlString) {
217 // Define a file name string.
218 String fileNameString;
220 // Only process the content disposition string if it isn't null.
221 if (contentDispositionString != null) { // The content disposition is not null.
222 // Check to see if the content disposition contains a file name.
223 if (contentDispositionString.contains("filename=")) { // The content disposition contains a filename.
224 // Get the part of the content disposition after `filename=`.
225 fileNameString = contentDispositionString.substring(contentDispositionString.indexOf("filename=") + 9);
227 // Remove any `;` and anything after it. This removes any entries after the filename.
228 if (fileNameString.contains(";")) {
229 // Remove the first `;` and everything after it.
230 fileNameString = fileNameString.substring(0, fileNameString.indexOf(";") - 1);
233 // Remove any `"` at the beginning of the string.
234 if (fileNameString.startsWith("\"")) {
235 // Remove the first character.
236 fileNameString = fileNameString.substring(1);
239 // Remove any `"` at the end of the string.
240 if (fileNameString.endsWith("\"")) {
241 // Remove the last character.
242 fileNameString = fileNameString.substring(0, fileNameString.length() - 1);
244 } else { // The headers contain no useful information.
245 // Get the file name string from the URL.
246 fileNameString = getFileNameFromUrl(context, urlString, contentTypeString);
248 } else { // The content disposition is null.
249 // Get the file name string from the URL.
250 fileNameString = getFileNameFromUrl(context, urlString, contentTypeString);
253 // Return the file name string.
254 return fileNameString;
257 private static String getFileNameFromUrl(Context context, String urlString, String contentTypeString) {
258 // Convert the URL string to a URI.
259 Uri uri = Uri.parse(urlString);
261 // Get the last path segment.
262 String lastPathSegment = uri.getLastPathSegment();
264 // Use a default file name if the last path segment is null.
265 if (lastPathSegment == null) {
266 lastPathSegment = context.getString(R.string.file);
268 if (MimeTypeMap.getSingleton().hasMimeType(contentTypeString)) { // The content type contains a MIME type.
269 // Add the file extension that matches the MIME type.
270 lastPathSegment = lastPathSegment + "." + MimeTypeMap.getSingleton().getExtensionFromMimeType(contentTypeString);
274 // Return the last path segment as the file name.
275 return lastPathSegment;