[Android] Prompt with infobar on filename conflict

chrome/android/java/src/org/chromium/chrome/browser/download/ChromeDownloadDelegate.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.download;
 
 import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Environment;
 import android.text.TextUtils;
 import android.util.Log;
 import android.webkit.MimeTypeMap;
 import android.webkit.URLUtil;
 import android.widget.Toast;
 
 import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.Tab;
 import org.chromium.chrome.browser.infobar.ConfirmInfoBar;
+import org.chromium.chrome.browser.infobar.DownloadOverwriteInfoBar;
 import org.chromium.chrome.browser.infobar.InfoBar;
 import org.chromium.chrome.browser.infobar.InfoBarListeners;
 import org.chromium.chrome.browser.tabmodel.TabModelSelector;
 import org.chromium.content.browser.ContentViewDownloadDelegate;
 import org.chromium.content.browser.DownloadInfo;
 import org.chromium.content_public.browser.WebContents;
 
 import java.io.File;
 import java.util.List;
 
@@ skipping 264 matching lines @@
     @Override
     public void onDangerousDownload(String filename, int downloadId) {
         DownloadInfo downloadInfo = new DownloadInfo.Builder()
                 .setFileName(filename)
                 .setDescription(filename)
                 .setHasDownloadId(true)
                 .setDownloadId(downloadId).build();
         confirmDangerousDownload(downloadInfo);
     }
 
+    private boolean launchInfoBarIfFileExists(final DownloadInfo info) {
+        String fileName = info.getFileName();
+        File dir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
+        if (!dir.mkdir() && !dir.isDirectory()) return false;
+        String dirName = dir.getName();
+        final File file = new File(dir, info.getFileName());
+        String fullDirPath = file.getParent();
+        if (!file.exists()) return false;
+        if (TextUtils.isEmpty(fileName) || TextUtils.isEmpty(dirName)
+                || TextUtils.isEmpty(fullDirPath)) {
+            return false;
+        }
+
+        InfoBar infoBar = new DownloadOverwriteInfoBar(0, new DownloadOverwriteInfoBar.Callback() {
+            @Override
+            public void onCloseButtonClicked(DownloadOverwriteInfoBar infoBar) {
+                infoBar.dismissJavaOnlyInfoBar();
+            }
+
+            @Override
+            public void onAction(DownloadOverwriteInfoBar infoBar, int action) {
+                if (action == InfoBar.ACTION_TYPE_OVERWRITE) {
+                    // Android DownloadManager does not have an overwriting option.
+                    // We remove the file here instead.
+                    file.delete();
+                }
+                if (action == InfoBar.ACTION_TYPE_OVERWRITE
+                        || action == InfoBar.ACTION_TYPE_CREATE_NEW_FILE) {
+                    enqueueDownloadManagerRequestInternal(info);
+                }
+                infoBar.dismissJavaOnlyInfoBar();
+            }
+        }, fileName, dirName, fullDirPath);
+        infoBar.setExpireOnNavigation(false);
+        mTab.getInfoBarContainer().addInfoBar(infoBar);
+        return true;
+    }
+
     /**
      * Sends the download request to Android download manager.
      *
      * @param info Download information about the download.
      */
     protected void enqueueDownloadManagerRequest(final DownloadInfo info) {
+        if (!launchInfoBarIfFileExists(info)) {
+            enqueueDownloadManagerRequestInternal(info);
+        }
+    }
+
+    private void enqueueDownloadManagerRequestInternal(final DownloadInfo info) {
         DownloadManagerService.getDownloadManagerService(
                 mContext.getApplicationContext()).enqueueDownloadManagerRequest(info, true);
         closeBlankTab();
     }
 
     /**
      * Check the external storage and notify user on error.
      *
      * @param fileName Name of the download file.
      */
@@ skipping 164 matching lines @@
 
     protected Context getContext() {
         return mContext;
     }
 
     private static native String nativeGetDownloadWarningText(String filename);
     private static native boolean nativeIsDownloadDangerous(String filename);
     private static native void nativeDangerousDownloadValidated(
             Object tab, int downloadId, boolean accept);
 }