2 * Copyright 2020-2024 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.coroutines
22 import android.app.Activity
23 import android.content.Context
24 import android.net.Uri
25 import android.provider.OpenableColumns
26 import android.util.Base64
27 import android.webkit.CookieManager
29 import androidx.viewpager2.widget.ViewPager2
31 import com.google.android.material.snackbar.Snackbar
33 import com.stoutner.privacybrowser.R
34 import com.stoutner.privacybrowser.helpers.ProxyHelper
36 import kotlinx.coroutines.CoroutineScope
37 import kotlinx.coroutines.Dispatchers
38 import kotlinx.coroutines.launch
39 import kotlinx.coroutines.withContext
41 import java.io.BufferedInputStream
42 import java.io.InputStream
43 import java.net.HttpURLConnection
45 import java.text.NumberFormat
48 class SaveUrlCoroutine {
49 fun save(context: Context, activity: Activity, urlString: String, fileUri: Uri, userAgent: String, cookiesEnabled: Boolean) {
50 // Create a canceled boolean.
53 // Use a coroutine to save the URL.
54 CoroutineScope(Dispatchers.Main).launch {
55 // Get a cursor from the content resolver.
56 val contentResolverCursor = activity.contentResolver.query(fileUri, null, null, null)!!
58 // Move to the first row.
59 contentResolverCursor.moveToFirst()
61 // Get the file name from the cursor.
62 val fileNameString = contentResolverCursor.getString(contentResolverCursor.getColumnIndexOrThrow(OpenableColumns.DISPLAY_NAME))
65 contentResolverCursor.close()
67 // Get a handle for the no swipe view pager.
68 val webViewViewPager2 = activity.findViewById<ViewPager2>(R.id.webview_viewpager2)
70 // Create a saving file snackbar.
71 val savingFileSnackbar = Snackbar.make(webViewViewPager2, activity.getString(R.string.saving_file, 0, fileNameString), Snackbar.LENGTH_INDEFINITE)
72 .setAction(R.string.cancel) { canceled = true }
74 // Display the saving file snackbar.
75 savingFileSnackbar.show()
77 // Download the URL on the IO thread.
78 withContext(Dispatchers.IO) {
80 // Open an output stream.
81 val outputStream = activity.contentResolver.openOutputStream(fileUri)!!
84 if (urlString.startsWith("data:")) { // The URL contains the entire data of an image.
85 // Get the Base64 data, which begins after a `,`.
86 val base64DataString = urlString.substring(urlString.indexOf(",") + 1)
88 // Decode the Base64 string to a byte array.
89 val base64DecodedDataByteArray = Base64.decode(base64DataString, Base64.DEFAULT)
91 // Write the Base64 byte array to the output stream.
92 outputStream.write(base64DecodedDataByteArray)
93 } else { // The URL points to the data location on the internet.
94 // Get the URL from the calling activity.
95 val url = URL(urlString)
97 // Instantiate the proxy helper.
98 val proxyHelper = ProxyHelper()
100 // Get the current proxy.
101 val proxy = proxyHelper.getCurrentProxy(context)
103 // Open a connection to the URL. No data is actually sent at this point.
104 val httpUrlConnection = url.openConnection(proxy) as HttpURLConnection
106 // Add the user agent to the header property.
107 httpUrlConnection.setRequestProperty("User-Agent", userAgent)
109 // Add the cookies if they are enabled.
110 if (cookiesEnabled) {
111 // Get the cookies for the current domain.
112 val cookiesString = CookieManager.getInstance().getCookie(url.toString())
114 // Only add the cookies if they are not null.
115 if (cookiesString != null) {
116 // Add the cookies to the header property.
117 httpUrlConnection.setRequestProperty("Cookie", cookiesString)
121 // Create the file size value.
124 // Create the formatted file size variable.
125 var formattedFileSize = ""
127 // 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.
129 // Get the content length header, which causes the connection to the server to be made.
130 val contentLengthString = httpUrlConnection.getHeaderField("Content-Length")
132 // Check to see if the content length is populated.
133 if (contentLengthString != null) { // The content length is populated.
134 // Convert the content length to an long.
135 fileSize = contentLengthString.toLong()
137 // Format the file size for display.
138 formattedFileSize = NumberFormat.getInstance().format(fileSize)
139 } else { // The content length is null.
140 // Set the file size to be `-1`.
144 // Get the response body stream.
145 val inputStream: InputStream = BufferedInputStream(httpUrlConnection.inputStream)
147 // Initialize the conversion buffer byte array.
148 // This is set to a 50,000 bytes so that frequent updating of the snackbar doesn't freeze the interface on download, although `inputStream.read` currently uses 8,000 as an upper limit.
149 // <https://redmine.stoutner.com/issues/709>
150 val conversionBufferByteArray = ByteArray(50_000)
152 // Initialize the longs.
153 var downloadedBytesCounterLong: Long = 0
154 var lastSnackbarUpdateLong: Long = 0
156 // Define the buffer length variable.
157 var bufferLength: Int
159 // Attempt to read data from the input stream and store it in the output stream. Also store the amount of data read in the buffer length variable.
160 while ((inputStream.read(conversionBufferByteArray).also { bufferLength = it } > 0) && !canceled) { // Proceed while the amount of data stored in the buffer in > 0.
161 // Write the contents of the conversion buffer to the file output stream.
162 outputStream.write(conversionBufferByteArray, 0, bufferLength)
164 // Update the downloaded bytes counter.
165 downloadedBytesCounterLong += bufferLength
167 // Format the number of bytes downloaded.
168 val formattedNumberOfBytesDownloadedString = NumberFormat.getInstance().format(downloadedBytesCounterLong)
170 // Get the current time.
171 val currentTimeLong = Date().time
173 // Update the snackbar if more than 100 milliseconds have passed since the last update.
174 // Updating the snackbar is so resource intensive that it will throttle the download if it is done too frequently.
175 if (currentTimeLong - lastSnackbarUpdateLong > 100) {
176 // Store the update time.
177 lastSnackbarUpdateLong = currentTimeLong
180 withContext(Dispatchers.Main) {
181 // Check to see if the file size is known.
182 if (fileSize == -1L) { // The size of the download file is not known.
183 // Update the snackbar.
184 savingFileSnackbar.setText(activity.getString(R.string.saving_file_progress, formattedNumberOfBytesDownloadedString, fileNameString))
185 } else { // The size of the download file is known.
186 // Calculate the download percentage.
187 val downloadPercentage = downloadedBytesCounterLong * 100 / fileSize
189 // Update the snackbar.
190 savingFileSnackbar.setText(activity.getString(R.string.saving_file_percentage_progress, downloadPercentage, formattedNumberOfBytesDownloadedString, formattedFileSize,
198 // Close the input stream.
201 // Disconnect the HTTP URL connection.
202 httpUrlConnection.disconnect()
206 // Close the output stream.
210 withContext(Dispatchers.Main) {
211 // Dismiss the saving file snackbar.
212 savingFileSnackbar.dismiss()
214 // Display a final disposition snackbar.
216 // Display the download cancelled snackbar.
217 Snackbar.make(webViewViewPager2, activity.getString(R.string.download_cancelled), Snackbar.LENGTH_SHORT).show()
219 // Display the file saved snackbar.
220 Snackbar.make(webViewViewPager2, activity.getString(R.string.saved, fileNameString), Snackbar.LENGTH_LONG).show()
222 } catch (exception: Exception) {
224 withContext(Dispatchers.Main) {
225 // Dismiss the saving file snackbar.
226 savingFileSnackbar.dismiss()
228 // Display the file saving error.
229 Snackbar.make(webViewViewPager2, activity.getString(R.string.error_saving_file, fileNameString, exception), Snackbar.LENGTH_INDEFINITE).show()