browse: add drag-and-drop for external applications

Allow dragging from the browse widget into external applications.

Related-to: git-cola#335

Signed-off-by: David Aguilar <davvid@gmail.com>

cola/models/browse.py

@@ -50,6 +50,7 @@ def text(cls, column):
 
 class GitRepoModel(QtGui.QStandardItemModel):
     """Provides an interface into a git repository for browsing purposes."""
+
     def __init__(self, parent):
         QtGui.QStandardItemModel.__init__(self, parent)
         self._interesting_paths = self._get_paths()
@@ -67,6 +68,11 @@ def __init__(self, parent):
         self._direntries = {'': self.invisibleRootItem()}
         self._initialize()
 
+    def mimeData(self, indexes):
+        paths = qtutils.paths_from_indexes(self, indexes,
+                                           item_type=GitRepoNameItem.TYPE)
+        return qtutils.mimedata_from_paths(paths)
+
     def _create_column(self, col, path):
         """Creates a StandardItem for use in a treeview cell."""
         # GitRepoNameItem is the only one that returns a custom type(),
@@ -413,8 +419,8 @@ class GitRepoItem(QtGui.QStandardItem):
     """
     def __init__(self, column, path):
         QtGui.QStandardItem.__init__(self)
-        self.setEditable(False)
         self.setDragEnabled(False)
+        self.setEditable(False)
         entry = GitRepoEntryManager.entry(path)
         if column == Columns.STATUS:
             QtCore.QObject.connect(entry, SIGNAL(column), self.set_status)
@@ -437,6 +443,7 @@ class GitRepoNameItem(GitRepoItem):
     def __init__(self, path):
         GitRepoItem.__init__(self, Columns.NAME, path)
         self.path = path
+        self.setDragEnabled(True)
 
     def type(self):
         """

cola/qtutils.py

@@ -62,18 +62,42 @@ def create_listwidget_item(text, filename):
 
 class TreeWidgetItem(QtGui.QTreeWidgetItem):
 
-    def __init__(self, text, filename, exists):
+    TYPE = QtGui.QStandardItem.UserType + 101
+
+    def __init__(self, path, icon, exists):
         QtGui.QTreeWidgetItem.__init__(self)
+        self.path = path
         self.exists = exists
-        self.setIcon(0, cached_icon_from_path(filename))
-        self.setText(0, text)
+        self.setIcon(0, cached_icon_from_path(icon))
+        self.setText(0, path)
+
+    def type(self):
+        return self.TYPE
 
 
 def create_treewidget_item(text, filename, exists=True):
     """Creates a QTreeWidgetItem with text and the icon at filename."""
     return TreeWidgetItem(text, filename, exists)
 
 
+def paths_from_indexes(model, indexes,
+                       item_type=TreeWidgetItem.TYPE,
+                       item_filter=None):
+    """Return paths from a list of QStandardItemModel indexes"""
+    items = [model.itemFromIndex(i) for i in indexes]
+    return paths_from_items(items, item_type=item_type, item_filter=item_filter)
+
+
+def paths_from_items(items,
+                     item_type=TreeWidgetItem.TYPE,
+                     item_filter=None):
+    """Return a list of paths from a list of items"""
+    if item_filter is None:
+        item_filter = lambda x: True
+    return [i.path for i in items
+            if i.type() == item_type and item_filter(i)]
+
+
 @memoize
 def cached_icon_from_path(filename):
     return QtGui.QIcon(filename)
@@ -689,6 +713,13 @@ def create_toolbutton(text=None, layout=None, tooltip=None, icon=None):
     return button
 
 
+def mimedata_from_paths(paths):
+    """Return mimedata with a list of absolute path URLs"""
+    urls = [QtCore.QUrl(core.abspath(path)) for path in paths]
+    mimedata = QtCore.QMimeData()
+    mimedata.setUrls(urls)
+    return mimedata
+
 # Syntax highlighting
 
 def TERMINAL(pattern):

cola/widgets/browse.py

@@ -87,6 +87,7 @@ class RepoTreeView(standard.TreeView):
     def __init__(self, parent):
         standard.TreeView.__init__(self, parent)
 
+        self.setDragEnabled(True)
         self.setRootIsDecorated(True)
         self.setSortingEnabled(False)
         self.setSelectionMode(QtGui.QAbstractItemView.ExtendedSelection)
@@ -246,11 +247,13 @@ def item_from_index(self, model_index):
         index = model_index.sibling(model_index.row(), 0)
         return self.model().itemFromIndex(index)
 
+    def paths_from_indexes(self, indexes):
+        return qtutils.paths_from_indexes(self.model(), indexes,
+                                          item_type=GitRepoNameItem.TYPE)
+
     def selected_paths(self):
         """Return the selected paths."""
-        items = map(self.model().itemFromIndex, self.selectedIndexes())
-        return [i.path for i in items
-                    if i.type() == GitRepoNameItem.TYPE]
+        return self.paths_from_indexes(self.selectedIndexes())
 
     def selected_staged_paths(self, selection=None):
         """Return selected staged paths."""

cola/widgets/status.py

@@ -891,10 +891,7 @@ def copy_path(self):
         filename = selection.selection_model().filename()
         qtutils.copy_path(filename)
 
-    def mimeData(self, indexes):
-        """Add a list of selected files to the mime data"""
-        urls = [QtCore.QUrl(core.abspath(path))
-                for path in selection.union(self.selection())]
-        mimedata = QtCore.QMimeData()
-        mimedata.setUrls(urls)
-        return mimedata
+    def mimeData(self, items):
+        """Return a list of absolute-path URLs"""
+        paths = qtutils.paths_from_items(items, item_filter=lambda x: x.exists)
+        return qtutils.mimedata_from_paths(paths)

share/doc/git-cola/relnotes.rst

@@ -4,7 +4,8 @@ Usability, bells and whistles
 -----------------------------
 * Updated Brazillian Portuguese translation.
 
-* The status widget now allows drag and drop into external applications.
+* The status and browse widgets now allow drag-and-drop into
+  external applications.
 
   https://github.com/git-cola/git-cola/issue/335