Implement chrome.downloads.onDeterminingFilename()

chrome/browser/extensions/api/downloads/downloads_api.h

Index: chrome/browser/extensions/api/downloads/downloads_api.h
diff --git a/chrome/browser/extensions/api/downloads/downloads_api.h b/chrome/browser/extensions/api/downloads/downloads_api.h
index dafd4d4e92d9d513790b678cfc5a4a7febd81491..dbaaac08c10074aa26accdd7a6c9c91549a404d0 100644
--- a/chrome/browser/extensions/api/downloads/downloads_api.h
+++ b/chrome/browser/extensions/api/downloads/downloads_api.h
@@ -128,19 +128,6 @@ class DownloadsEraseFunction : public SyncExtensionFunction {
   DISALLOW_COPY_AND_ASSIGN(DownloadsEraseFunction);
 };
 
-class DownloadsSetDestinationFunction : public AsyncExtensionFunction {
- public:
-  DECLARE_EXTENSION_FUNCTION_NAME("downloads.setDestination");
-  DownloadsSetDestinationFunction();
-  virtual bool RunImpl() OVERRIDE;
-
- protected:
-  virtual ~DownloadsSetDestinationFunction();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(DownloadsSetDestinationFunction);
-};
-
 class DownloadsAcceptDangerFunction : public AsyncExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION_NAME("downloads.acceptDanger");
@@ -212,13 +199,50 @@ class DownloadsGetFileIconFunction : public AsyncExtensionFunction {
 
 // Observes a single DownloadManager and many DownloadItems and dispatches
 // onCreated and onErased events.
-class ExtensionDownloadsEventRouter
-  : public AllDownloadItemNotifier::Observer {
+class ExtensionDownloadsEventRouter : public content::NotificationObserver,
+                                      public AllDownloadItemNotifier::Observer {
  public:
+  typedef base::Callback<void(const FilePath& changed_filename,
+                              bool overwrite)> FilenameChangedCallback;
+
+  static bool AddFilenameDeterminer(

[battre, 2013/01/11 14:29:37]

These functions need descriptions. What are FilenameDeterminers? What are the
parameters? What are the return values?

[benjhayden, 2013/01/11 21:21:27]

Done.

+      Profile* profile,
+      bool include_incognito,
+      const std::string& ext_id,
+      const std::string& determiner_id);
+
+  static bool RemoveFilenameDeterminer(
+      Profile* profile,
+      bool include_incognito,
+      const std::string& ext_id,
+      const std::string& determiner_id);
+
+  static bool DetermineFilename(
+      Profile* profile,
+      bool include_incognito,
+      const std::string& ext_id,
+      const std::string& determiner_id,
+      int download_id,
+      const FilePath& filename,
+      bool overwrite);
+
   explicit ExtensionDownloadsEventRouter(
       Profile* profile, content::DownloadManager* manager);
   virtual ~ExtensionDownloadsEventRouter();
 
+  // Called by ChromeDownloadManagerDelegate during the filename determination
+  // process, allows extensions to change the item's target filename. If no
+  // extension wants to change the target filename, then |no_change| will be
+  // called and the filename determination process will continue as normal. If
+  // an extension wants to change the target filename, then |change| will be
+  // called with the new filename and a flag indicating whether the new file
+  // should overwrite any old files of the same name.
+  void OnDownloadFilenameDetermined(
+      content::DownloadItem* item,
+      const FilePath& suggested_path,
+      const base::Closure& no_change,
+      const FilenameChangedCallback& change);
+
   // AllDownloadItemNotifier::Observer interface
   virtual void OnDownloadCreated(
       content::DownloadManager* manager,
@@ -238,10 +262,27 @@ class ExtensionDownloadsEventRouter
 
  private:
   void DispatchEvent(const char* event_name, base::Value* json_arg);
+  virtual void Observe(
+      int type,
+      const content::NotificationSource& source,
+      const content::NotificationDetails& details) OVERRIDE;
 
   Profile* profile_;
+  content::NotificationRegistrar registrar_;
   AllDownloadItemNotifier notifier_;
 
+  // Each key in this map is a determiner id as returned by
+  // GetFilenameDeterminerId. Each string in the set values is an extension id
+  // that is listening to the subEvent named
+  // "chrome.downloads.onDeterminingFilename/$DETERMINER_ID".  When
+  // onDeterminingFilename is dispatched for a DownloadItem, that item's EDERD
+  // UserData is given the set of strings of the form
+  // "$EXTENSION_ID-$DETERMINER_ID" so that it can know when all determiners
+  // have reported.
+  typedef std::set<std::string> ExtensionIdSet;

[vabr (Chromium), 2013/01/11 12:43:40]

According to
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Declaration_Order
the typedefs should be first in the private section.

[benjhayden, 2013/01/11 21:21:27]

Done.

+  typedef base::hash_map<std::string, ExtensionIdSet> DeterminerMap;

[vabr (Chromium), 2013/01/11 12:43:40]

The lint says: "Add #include for hash_map<>"

(I used to think that '? errors' in the Lint column means that linting was
broken, but apparently it shows something :).)

[benjhayden, 2013/01/11 21:21:27]

I added base/hash_tables.h, but got a compiler warning when I added <hash_map>

[vabr (Chromium), 2013/01/15 08:19:22]

That sounds right, base/hash_tables.h includes <hash_map> anyway, so the
template hash_map<> will be defined in one of this file's #includes and lint
will be happy.

Happy about hash_map, that is, as now it complains about missing an #include
declaring vector :).

+  DeterminerMap filename_determiners_;
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionDownloadsEventRouter);
 };