make deletion hotkey configurable (fixes #10)

sloth/annotations/model.py

@@ -530,14 +530,6 @@ class AnnotationTreeView(QTreeView):
         QTreeView.setModel(self, model)
         self.resizeColumns()
 
-    def keyPressEvent(self, event):
-        ## handle deletions of items
-        if event.key() == Qt.Key_Delete:
-            self.model().itemFromIndex(self.currentindex()).delete()
-
-        ## it is important to use the keyPressEvent of QAbstractItemView, not QTreeView
-        QAbstractItemView.keyPressEvent(self, event)
-
     def rowsInserted(self, index, start, end):
         QTreeView.rowsInserted(self, index, start, end)
         self.resizeColumns()

sloth/conf/default_config.py

@@ -61,11 +61,12 @@ LABELS = (
 # third entry -- if present -- is expected to be a string describing the 
 # action.
 HOTKEYS = (
-    ('PgDown',    lambda lt: lt.gotoNext(),                 'Next image/frame'),
-    ('PgUp',      lambda lt: lt.gotoPrevious(),             'Previous image/frame'),
-    ('Tab',       lambda lt: lt.selectNextAnnotation(),     'Select next annotation'),
-    ('Shift+Tab', lambda lt: lt.selectPreviousAnnotation(), 'Select previous annotation'),
-    ('ESC',       lambda lt: lt.exitInsertMode(),           'Exit insert mode'),
+    ('PgDown',    lambda lt: lt.gotoNext(),                  'Next image/frame'),
+    ('PgUp',      lambda lt: lt.gotoPrevious(),              'Previous image/frame'),
+    ('Tab',       lambda lt: lt.selectNextAnnotation(),      'Select next annotation'),
+    ('Shift+Tab', lambda lt: lt.selectPreviousAnnotation(),  'Select previous annotation'),
+    ('Del',       lambda lt: lt.deleteSelectedAnnotations(), 'Delete selected annotations'),
+    ('ESC',       lambda lt: lt.exitInsertMode(),            'Exit insert mode'),
 )
 
 # CONTAINERS

sloth/core/labeltool.py

@@ -347,6 +347,11 @@ class LabelTool(QObject):
         if self._mainwindow is not None:
             return self._mainwindow.scene.selectNextItem(reverse=True)
 
+    def deleteSelectedAnnotations(self):
+        if self._mainwindow is not None:
+            for item in self._mainwindow.scene.selectedItems():
+                item.modelItem().delete()
+
     def exitInsertMode(self):
         if self._mainwindow is not None:
             return self._mainwindow.buttonarea.exitInsertMode()