From 74d0c6be6d1ee6a482d49856f6661ee557a679f9 Mon Sep 17 00:00:00 2001
From: Tomeu Vizoso <tomeu@tomeuvizoso.net>
Date: Wed, 15 Oct 2008 18:56:53 +0000
Subject: Add a "Download link" option to the link palette

---
diff --git a/downloadmanager.py b/downloadmanager.py
index 4b6e84f..8d5fae9 100644
--- a/downloadmanager.py
+++ b/downloadmanager.py
@@ -23,6 +23,7 @@ import urlparse
 
 import gtk
 import hulahop
+import xpcom
 from xpcom.nsError import *
 from xpcom import components
 from xpcom.components import interfaces
@@ -43,7 +44,8 @@ if dbus.version >= (0, 82, 3):
 else:
     DBUS_PYTHON_TIMEOUT_UNITS_PER_SECOND = 1000
 
-NS_BINDING_ABORTED = 0x804b0002     # From nsNetError.h
+NS_BINDING_ABORTED = 0x804b0002             # From nsNetError.h
+NS_ERROR_SAVE_LINK_AS_TIMEOUT = 0x805d0020  # From nsURILoader.h
 
 DS_DBUS_SERVICE = 'org.laptop.sugar.DataStore'
 DS_DBUS_INTERFACE = 'org.laptop.sugar.DataStore'
@@ -285,3 +287,89 @@ components.registrar.registerFactory('{23c51569-e9a1-4a92-adeb-3723db82ef7c}',
                                      'Sugar Download',
                                      '@mozilla.org/transfer;1',
                                      Factory(Download))
+
+def save_link(url, text, owner_document):
+    # Inspired on Firefox' browser/base/content/nsContextMenu.js:saveLink()
+
+    cls = components.classes["@mozilla.org/network/io-service;1"]
+    io_service = cls.getService(interfaces.nsIIOService)
+    uri = io_service.newURI(url, None, None)
+    channel = io_service.newChannelFromURI(uri)
+
+    auth_prompt_callback = xpcom.server.WrapObject(
+            _AuthPromptCallback(owner_document.defaultView),
+            interfaces.nsIInterfaceRequestor)
+    channel.notificationCallbacks = auth_prompt_callback
+
+    channel.loadFlags = channel.loadFlags | \
+        interfaces.nsIRequest.LOAD_BYPASS_CACHE | \
+        interfaces.nsIChannel.LOAD_CALL_CONTENT_SNIFFERS
+
+    if _implements_interface(channel, interfaces.nsIHttpChannel):
+        channel.referrer = io_service.newURI(owner_document.documentURI, None,
+                                             None)
+
+    # kick off the channel with our proxy object as the listener
+    listener = xpcom.server.WrapObject(
+            _SaveLinkProgressListener(owner_document),
+            interfaces.nsIStreamListener)
+    channel.asyncOpen(listener, None)
+
+def _implements_interface(obj, interface):
+    try:
+        obj.QueryInterface(interface)
+        return True
+    except xpcom.Exception, e:
+        if e.errno == NS_NOINTERFACE:
+            return False
+        else:
+            raise
+
+class _AuthPromptCallback(object):
+    _com_interfaces_ = interfaces.nsIInterfaceRequestor
+
+    def __init__(self, dom_window):
+        self._dom_window = dom_window
+
+    def getInterface(self, uuid):
+        if uuid in [interfaces.nsIAuthPrompt, interfaces.nsIAuthPrompt2]:
+            cls = components.classes["@mozilla.org/embedcomp/window-watcher;1"]
+            window_watcher = cls.getService(interfaces.nsIPromptFactory)
+            return window_watcher.getPrompt(self._dom_window, uuid)
+        return None
+
+class _SaveLinkProgressListener(object):
+    _com_interfaces_ = interfaces.nsIStreamListener
+
+    """ an object to proxy the data through to
+    nsIExternalHelperAppService.doContent, which will wait for the appropriate
+    MIME-type headers and then prompt the user with a file picker
+    """
+
+    def __init__(self, owner_document):
+        self._owner_document = owner_document
+        self._external_listener = None
+
+    def onStartRequest(self, request, context):
+        if request.status != NS_OK:
+            logging.error("Error downloading link")
+            return
+
+        cls = components.classes[
+                "@mozilla.org/uriloader/external-helper-app-service;1"]
+        external_helper = cls.getService(interfaces.nsIExternalHelperAppService)
+
+        channel = request.QueryInterface(interfaces.nsIChannel)
+
+        self._external_listener = \
+            external_helper.doContent(channel.contentType, request, 
+                                      self._owner_document.defaultView, True)
+        self._external_listener.onStartRequest(request, context)
+
+    def onStopRequest(self, request, context, statusCode):
+        self._external_listener.onStopRequest(request, context, statusCode)
+
+    def onDataAvailable(self, request, context, inputStream, offset, count):
+        self._external_listener.onDataAvailable(request, context, inputStream,
+                                                offset, count);
+
diff --git a/palettes.py b/palettes.py
index bae47a5..feb6ddb 100644
--- a/palettes.py
+++ b/palettes.py
@@ -30,6 +30,8 @@ from sugar.graphics.icon import Icon
 from sugar import profile
 from sugar.activity import activity
 
+import downloadmanager
+
 class ContentInvoker(Invoker):
     _com_interfaces_ = interfaces.nsIDOMEventListener
 
@@ -59,7 +61,8 @@ class ContentInvoker(Invoker):
             else:
                 title = None
 
-            self.palette = LinkPalette(self._browser, title, target.href)
+            self.palette = LinkPalette(self._browser, title, target.href,
+                                       target.ownerDocument)
             self.notify_right_click()
         elif target.tagName.lower() == 'img':
             if target.title:
@@ -75,11 +78,13 @@ class ContentInvoker(Invoker):
             self.notify_right_click()
 
 class LinkPalette(Palette):
-    def __init__(self, browser, title, url):
+    def __init__(self, browser, title, url, owner_document):
         Palette.__init__(self)
 
-        self._url = url
         self._browser = browser
+        self._title = title
+        self._url = url
+        self._owner_document = owner_document
 
         if title is not None:
             self.props.primary_text = title
@@ -100,6 +105,11 @@ class LinkPalette(Palette):
         self.menu.append(menu_item)
         menu_item.show()
 
+        menu_item = MenuItem(_('Download link'))
+        menu_item.connect('activate', self.__download_activate_cb)
+        self.menu.append(menu_item)
+        menu_item.show()
+
     def __follow_activate_cb(self, menu_item):
         self._browser.load_uri(self._url)
         self._browser.grab_focus()
@@ -130,6 +140,9 @@ class LinkPalette(Palette):
     def __clipboard_clear_func_cb(self, clipboard, data):
         pass
 
+    def __download_activate_cb(self, menu_item):
+        downloadmanager.save_link(self._url, self._title, self._owner_document)
+
 class ImagePalette(Palette):
     def __init__(self, title, url):
         Palette.__init__(self)
--
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