feat: hide preview controls on empty click

tests/test_image_canvas.py

@@ -91,6 +91,20 @@ class TestImageCanvasControls(unittest.TestCase):
         self.assertTrue(self._controls_visible(canvas))
         self.assertEqual(canvas._drag_tag, "print")
 
+    def test_clicking_empty_canvas_hides_controls_without_changing_transform(self):
+        from PySide6.QtCore import QPointF
+
+        canvas = self._canvas()
+        before = self._state_tuple(canvas)
+
+        canvas._on_press(QPointF(-20.0, -20.0))
+
+        self.assertFalse(canvas._controls_visible)
+        self.assertFalse(self._controls_visible(canvas))
+        self.assertTrue(canvas._print_item.isVisible())
+        self.assertIsNone(canvas._drag_tag)
+        self.assertEqual(self._state_tuple(canvas), before)
+
     def test_loading_print_restores_controls_visible_by_default(self):
         canvas = self._canvas()
         canvas._hide_controls()