[Sugar-devel] [PATCH] Bring back dragging of elements from the activities to the frame clipboard - SL #3819

[Manuel Quiñones]

TestCase:

- open an activity like Browse, Read, Log (not Write, is a special case)
- bring up the frame
- drag things to the left side panel of the frame (images, links, or selected text)

The elements should be added to the clipboard which is inside the
panel.  They should have the proper icon and they should popup a
palette to act on them.

Note: if the dragged object is a link from Browse, Sugar tries to copy
the html to the disk.  But the current implementation looks wrong.  I
have opened #4477 to track it: http://bugs.sugarlabs.org/ticket/4477

Note: this doesn't solve the inverse operation: drag from the
clipboard to the activity.  This will be done in another patch.

API fixes:

- gtk.SelectionData.type  ->  Gtk.SelectionData.get_data_type() [1]
- gtk.SelectionData.data  ->  Gtk.SelectionData.get_data() [2]
- gtk.SelectionData.target  ->  Gtk.SelectionData.get_target() [3]
- context.targets  ->  context.list_targets() [4]
- context.drop_finish(...)  ->  Gdk.drop_finish(context, ...) [5]
- context.drag_status(...)  ->  Gdk.drag_status(context, ...) [6]
- context.get_source_widget()  ->  Gdk.drag_get_source_widget(context) [7]

[1] https://developer.gnome.org/gtk3/3.5/gtk3-Selections.html#gtk-selection-data-get-data-type
[2] https://developer.gnome.org/gtk3/3.5/gtk3-Selections.html#gtk-selection-data-get-data
[3] https://developer.gnome.org/gtk3/3.5/gtk3-Selections.html#gtk-selection-data-get-target
[4] https://developer.gnome.org/gdk/stable/gdk-Drag-and-Drop.html#gdk-drag-context-list-targets
[5] https://developer.gnome.org/gdk/stable/gdk-Drag-and-Drop.html#gdk-drop-finish
[6] https://developer.gnome.org/gdk/stable/gdk-Drag-and-Drop.html#gdk-drag-status
[7] https://developer.gnome.org/gtk3/stable/gtk3-Drag-and-Drop.html#gtk-drag-get-source-widget

Cast the type of the Gtk.SelectionData from Gdk.Atom to str.  Our code
treats it as str in sugar3.mime and asks methods like startswith which
fails if it is not a str-like object.

The data for the type 'text/uri-list' comes with a character '\x00' at
the end now.  Remove it so our functions like
sugar3.mime.split_uri_list don't break.

Signed-off-by: Manuel Quiñones <manuq at laptop.org>
---
 src/jarabe/frame/clipboardtray.py | 46 +++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 16 deletions(-)

diff --git a/src/jarabe/frame/clipboardtray.py b/src/jarabe/frame/clipboardtray.py
index abc885e..5115d61 100644
--- a/src/jarabe/frame/clipboardtray.py
+++ b/src/jarabe/frame/clipboardtray.py
@@ -76,26 +76,39 @@ class ClipboardTray(tray.VTray):
         return False
 
     def _add_selection(self, object_id, selection):
-        if not selection.data:
+        if not selection.get_data():
             return
 
-        logging.debug('ClipboardTray: adding type %r', selection.type)
+        selection_data = selection.get_data()
+        selection_type = selection.get_data_type()
+
+        # The type comes as a Gdk.Atom but we need it as str to
+        # compare it.
+        assert isinstance(selection_type, Gdk.Atom)
+        selection_type = str(selection_type)
+
+        logging.debug('ClipboardTray: adding type %r', selection_type)
 
         cb_service = clipboard.get_instance()
-        if selection.type == 'text/uri-list':
-            uris = selection.data.split('\n')
+        if selection_type == 'text/uri-list':
+            # For 'text/uri-list' type, last character is '\x00'.  This
+            # wasn't the case in GTK2.
+            assert selection_data[-1] == '\x00'
+            selection_data = selection_data[:-1]
+
+            uris = selection_data.split('\n')
             if len(uris) > 1:
                 raise NotImplementedError('Multiple uris in text/uri-list' \
                                           ' still not supported.')
 
             cb_service.add_object_format(object_id,
-                                         selection.type,
+                                         selection_type,
                                          uris[0],
                                          on_disk=True)
         else:
             cb_service.add_object_format(object_id,
-                                         selection.type,
-                                         selection.data,
+                                         selection_type,
+                                         selection_data,
                                          on_disk=False)
 
     def _object_added_cb(self, cb_service, cb_object):
@@ -132,9 +145,9 @@ class ClipboardTray(tray.VTray):
         logging.debug('ClipboardTray._drag_motion_cb')
 
         if self._internal_drag(context):
-            context.drag_status(Gdk.DragAction.MOVE, time)
+            Gdk.drag_status(context, Gdk.DragAction.MOVE, time)
         else:
-            context.drag_status(Gdk.DragAction.COPY, time)
+            Gdk.drag_status(context, Gdk.DragAction.COPY, time)
             self.props.drag_active = True
 
         return True
@@ -148,15 +161,16 @@ class ClipboardTray(tray.VTray):
         if self._internal_drag(context):
             # TODO: We should move the object within the clipboard here
             if not self._context_map.has_context(context):
-                context.drop_finish(False, Gtk.get_current_event_time())
+                Gdk.drop_finish(context, False, Gtk.get_current_event_time())
             return False
 
         cb_service = clipboard.get_instance()
         object_id = cb_service.add_object(name="")
 
-        self._context_map.add_context(context, object_id, len(context.targets))
+        context_targets = context.list_targets()
+        self._context_map.add_context(context, object_id, len(context_targets))
 
-        for target in context.targets:
+        for target in context_targets:
             if str(target) not in ('TIMESTAMP', 'TARGETS', 'MULTIPLE'):
                 widget.drag_get_data(context, target, time)
 
@@ -167,13 +181,13 @@ class ClipboardTray(tray.VTray):
     def drag_data_received_cb(self, widget, context, x, y, selection,
                               targetType, time):
         logging.debug('ClipboardTray: got data for target %r',
-            selection.target)
+            selection.get_target())
 
         object_id = self._context_map.get_object_id(context)
         try:
             if selection is None:
                 logging.warn('ClipboardTray: empty selection for target %s',
-                    selection.target)
+                    selection.get_target())
             else:
                 self._add_selection(object_id, selection)
 
@@ -181,10 +195,10 @@ class ClipboardTray(tray.VTray):
             # If it's the last target to be processed, finish
             # the dnd transaction
             if not self._context_map.has_context(context):
-                context.drop_finish(True, Gtk.get_current_event_time())
+                Gdk.drop_finish(context, True, Gtk.get_current_event_time())
 
     def _internal_drag(self, context):
-        source_widget = context.get_source_widget()
+        source_widget = Gtk.drag_get_source_widget(context)
         if source_widget is None:
             return False
         view_ancestor = source_widget.get_ancestor(Gtk.Viewport)
-- 
1.8.1.4