test_stickygraphicsview: Add tests for fractional scene rects

Author: ales-erjavec

Orange/widgets/utils/tests/test_stickygraphicsview.py

@@ -1,18 +1,23 @@
 from PyQt5.QtCore import Qt, QRectF, QPoint, QPointF
 from PyQt5.QtGui import QBrush, QWheelEvent
-from PyQt5.QtWidgets import QGraphicsScene, QWidget, QApplication
+from PyQt5.QtWidgets import QGraphicsScene, QWidget, QApplication, QStyle
 
 from Orange.widgets.tests.base import GuiTest
 
 from Orange.widgets.utils.stickygraphicsview import StickyGraphicsView
 
 
 class TestStickyGraphicsView(GuiTest):
-    def test(self):
+    def create_view(self):
         view = StickyGraphicsView()
         scene = QGraphicsScene(view)
-        scene.setBackgroundBrush(QBrush(Qt.lightGray, Qt.CrossPattern))
         view.setScene(scene)
+        return view
+
+    def test(self):
+        view = self.create_view()
+        scene = view.scene()
+        scene.setBackgroundBrush(QBrush(Qt.lightGray, Qt.CrossPattern))
         scene.addRect(
             QRectF(0, 0, 300, 20), Qt.red, QBrush(Qt.red, Qt.BDiagPattern))
         scene.addRect(QRectF(0, 25, 300, 100))
@@ -48,6 +53,66 @@ def test(self):
 
         qWheelScroll(header.viewport(), angleDelta=QPoint(0, -720 * 8))
 
+    @staticmethod
+    def _ensure_laid_out(view: QWidget) -> None:
+        """Ensure view has had pending resize events flushed."""
+        # when a widget is not visible it does not get resizeEvents dispatched
+        # immediately, only before it is actually shown or its rendering is
+        # requested.
+        view.grab()
+
+    def _test_visibility(self, view: StickyGraphicsView) -> None:
+        header = view.headerView()
+        footer = view.footerView()
+        vsbar = view.verticalScrollBar()
+        vsbar.triggerAction(vsbar.SliderToMinimum)
+        self._ensure_laid_out(view)
+
+        self.assertFalse(header.isVisibleTo(view))
+        self.assertTrue(footer.isVisibleTo(view))
+
+        vsbar.triggerAction(vsbar.SliderSingleStepAdd)
+        self._ensure_laid_out(view)
+
+        self.assertTrue(header.isVisibleTo(view))
+        self.assertTrue(footer.isVisibleTo(view))
+
+        vsbar.triggerAction(vsbar.SliderToMaximum)
+        self._ensure_laid_out(view)
+
+        self.assertTrue(header.isVisibleTo(view))
+        self.assertFalse(footer.isVisibleTo(view))
+
+        vsbar.triggerAction(vsbar.SliderSingleStepSub)
+        self._ensure_laid_out(view)
+        if not view.style().styleHint(QStyle.SH_ScrollBar_Transient, None, vsbar):
+            # cannot reliably test due to QTBUG-65074
+            self.assertTrue(header.isVisibleTo(view))
+            self.assertTrue(footer.isVisibleTo(view))
+
+    def test_fractional_1(self):
+        view = self.create_view()
+        view.resize(300, 100)
+        scenerect = QRectF(-0.1, -0.1, 300.2, 300.2)
+        headerrect = QRectF(-0.1, -0.1, 300.2, 20.2)
+        footerrect = QRectF(-0.1, 279.9, 300.2, 20.2)
+        view.setSceneRect(scenerect)
+        view.setHeaderSceneRect(headerrect)
+        view.setFooterSceneRect(footerrect)
+        self._test_visibility(view)
+
+    def test_fractional_2(self):
+        view = self.create_view()
+        view.resize(300, 100)
+        view.grab()
+        scenerect = QRectF(0.1, 0.1, 300, 299.8)
+        headerrect = QRectF(0.1, 0.1, 300, 20)
+        footerrect = QRectF(0.1, 299.9 - 20, 300, 20)
+        view.setSceneRect(scenerect)
+        view.setHeaderSceneRect(headerrect)
+        view.setFooterSceneRect(footerrect)
+        self._test_visibility(view)
+
 
 def qWheelScroll(
         widget: QWidget, buttons=Qt.NoButton, modifiers=Qt.NoModifier,