Create label_qlist_widget.py

DataAnnotation/labelme/labelme/widgets/label_qlist_widget.py

+from qtpy import QtWidgets
+
+
+class LabelQListWidget(QtWidgets.QListWidget):
+
+    def __init__(self, *args, **kwargs):
+        super(LabelQListWidget, self).__init__(*args, **kwargs)
+        self.canvas = None
+        self.itemsToShapes = []
+        self.setSelectionMode(QtWidgets.QAbstractItemView.ExtendedSelection)
+
+    def get_shape_from_item(self, item):
+        for index, (item_, shape) in enumerate(self.itemsToShapes):
+            if item_ is item:
+                return shape
+
+    def get_item_from_shape(self, shape):
+        for index, (item, shape_) in enumerate(self.itemsToShapes):
+            if shape_ is shape:
+                return item
+
+    def clear(self):
+        super(LabelQListWidget, self).clear()
+        self.itemsToShapes = []
+
+    def setParent(self, parent):
+        self.parent = parent
+
+    def dropEvent(self, event):
+        shapes = self.shapes
+        super(LabelQListWidget, self).dropEvent(event)
+        if self.shapes == shapes:
+            return
+        if self.canvas is None:
+            raise RuntimeError('self.canvas must be set beforehand.')
+        self.parent.setDirty()
+        self.canvas.loadShapes(self.shapes)
+
+    @property
+    def shapes(self):
+        shapes = []
+        for i in range(self.count()):
+            item = self.item(i)
+            shape = self.get_shape_from_item(item)
+            shapes.append(shape)
+        return shapes