Migrate mac installer to delegate-driven model

chrome/installer/mac/app/Downloader.m

 // Copyright 2016 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.
 
-#import <Foundation/Foundation.h>
+#import "Downloader.h"
 
-#import "DownloadDelegate.h"
-#import "Downloader.h"
+#include <assert.h>
+
 #import "NetworkCommunication.h"
 #import "OmahaXMLParser.h"
 
 @implementation Downloader
 
+@synthesize delegate = delegate_;
+
 // TODO: make this overrideable with commandline argument? or enviro variable
 + (NSString*)getDownloadsFilePath {
   NSArray* downloadPaths = NSSearchPathForDirectoriesInDomains(
       NSDownloadsDirectory, NSUserDomainMask, YES);
   NSString* filePathToDownloads = [downloadPaths objectAtIndex:0];
   NSArray* filenameComposition = @[ filePathToDownloads, @"GoogleChrome.dmg" ];
   NSString* completeFilePath =
       [NSString pathWithComponents:filenameComposition];
   return completeFilePath;
 }
@@ skipping 28 matching lines @@
   NSMutableArray* completeURLs =
       [self appendFilename:parser.chromeImageFilename toURLs:incompleteURLs];
 
   NSURL* chromeURL = [completeURLs firstObject];
   return chromeURL;
 }
 
 // Downloads contents of chromeURL to downloads folders and delegates the work
 // to the DownloadDelegate class.
 - (BOOL)writeChromeImageToDownloadsDirectory:(NSURL*)chromeURL {
-  DownloadDelegate* delegate = [[DownloadDelegate alloc] init];
   NetworkCommunication* downloadTask =
-      [[NetworkCommunication alloc] initWithDelegate:delegate];
+      [[NetworkCommunication alloc] initWithDelegate:self];
 
   // TODO: What if file already exists?
   [downloadTask createRequestWithUrlAsString:[chromeURL absoluteString]
                                   andXMLBody:nil];
   [downloadTask sendDownloadRequest];
 
   NSFileManager* manager = [[NSFileManager alloc] init];
   return [manager fileExistsAtPath:[Downloader getDownloadsFilePath]];
 }
 
 // Pieces together the getting the URL portion and downloading the contents of
 // URL portion.
 - (BOOL)downloadChromeImageToDownloadsDirectory:(NSData*)omahaResponseXML {
   NSURL* chromeURL = [self getChromeImageURLFromOmahaResponse:omahaResponseXML];
   BOOL writeWasSuccessful =
       [self writeChromeImageToDownloadsDirectory:chromeURL];
   return writeWasSuccessful;
 }
 
+// Skeleton of delegate method to provide download progress updates.
+// TODO: Make use of (totalBytesWritten/totalBytesExpectedToWrite)*100
+// to generate download progress percentage.
+- (void)URLSession:(NSURLSession*)session
+                 downloadTask:(NSURLSessionDownloadTask*)downloadTask
+                 didWriteData:(int64_t)bytesWritten
+            totalBytesWritten:(int64_t)totalBytesWritten
+    totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite {
+}
+
+// Delegate method to move downloaded disk image to user's Download directory.
+- (void)URLSession:(NSURLSession*)session
+                 downloadTask:(NSURLSessionDownloadTask*)downloadTask
+    didFinishDownloadingToURL:(NSURL*)location {
+  assert([location isFileURL]);
+  NSFileManager* manager = [[NSFileManager alloc] init];
+  NSURL* downloadsDirectory =
+      [[NSURL alloc] initFileURLWithPath:[Downloader getDownloadsFilePath]];
+  if ([manager fileExistsAtPath:location.path]) {
+    [manager moveItemAtURL:location toURL:downloadsDirectory error:nil];
+  } else {
+    // TODO: Error Handling
+  }
+}
+
+- (void)URLSession:(NSURLSession*)session
+                    task:(NSURLSessionTask*)task
+    didCompleteWithError:(NSError*)error {
+  // TODO: Error Handling
+
+  [delegate_ onDownloadSuccess];
+}
+
 @end