fix a minor cursor restore bug

libs/canvas.py

@@ -99,8 +99,6 @@ class Canvas(QWidget):
         """Update line with last point and current coordinates."""
         pos = self.transformPos(ev.pos())
 
-        self.restoreCursor()
-
         # Polygon drawing.
         if self.drawing():
             self.overrideCursor(CURSOR_DRAW)
@@ -184,6 +182,7 @@ class Canvas(QWidget):
                 self.hShape.highlightClear()
                 self.update()
             self.hVertex, self.hShape = None, None
+            self.overrideCursor(CURSOR_DEFAULT)
 
     def mousePressEvent(self, ev):
         pos = self.transformPos(ev.pos())
@@ -210,6 +209,9 @@ class Canvas(QWidget):
                 self.selectedShapeCopy = None
                 self.repaint()
         elif ev.button() == Qt.LeftButton and self.selectedShape:
+            if self.selectedVertex():
+                self.overrideCursor(CURSOR_POINT)
+            else:
                 self.overrideCursor(CURSOR_GRAB)
         elif ev.button() == Qt.LeftButton:
             pos = self.transformPos(ev.pos())
@@ -640,10 +642,18 @@ class Canvas(QWidget):
         self.visible[shape] = value
         self.repaint()
 
+    def currentCursor(self):
+        cursor = QApplication.overrideCursor()
+        if cursor is not None:
+            cursor = cursor.shape()
+        return cursor
+
     def overrideCursor(self, cursor):
-        self.restoreCursor()
         self._cursor = cursor
+        if self.currentCursor() is None:
             QApplication.setOverrideCursor(cursor)
+        else:
+            QApplication.changeOverrideCursor(cursor)
 
     def restoreCursor(self):
         QApplication.restoreOverrideCursor()