Correct row position calculation.

cocoa/tests_backend/widgets/table.py

@@ -74,17 +74,17 @@ def row_position(self, row):
         # Pick a point half way across horizontally, and half way down the row,
         # taking into account the size of the rows and the header
         row_height = self.native_table.rowHeight
-        return self.native.convertPoint(
+        return self.native_table.convertPoint(
             NSPoint(
                 self.width / 2,
-                row * row_height + self.header_height + row_height / 2,
+                (row * row_height) + (row_height / 2),
             ),
             toView=None,
         )
 
     async def select_row(self, row, add=False):
         point = self.row_position(row)
-        # Selection maintains an inner mouse event loop, so we can't
+        # Table maintains an inner mouse event loop, so we can't
         # use the "wait for another event" approach for the mouse events.
         # Use a short delay instead.
         await self.mouse_event(
@@ -102,14 +102,30 @@ async def select_row(self, row, add=False):
 
     async def activate_row(self, row):
         point = self.row_position(row)
-        # Selection maintains an inner mouse event loop, so we can't
+        # Table maintains an inner mouse event loop, so we can't
         # use the "wait for another event" approach for the mouse events.
         # Use a short delay instead.
-        await self.mouse_event(NSEventType.LeftMouseDown, point, delay=0.1)
-        await self.mouse_event(NSEventType.LeftMouseUp, point, delay=0.1)
+        await self.mouse_event(
+            NSEventType.LeftMouseDown,
+            point,
+            delay=0.1,
+        )
+        await self.mouse_event(
+            NSEventType.LeftMouseUp,
+            point,
+            delay=0.1,
+        )
 
         # Second click, with a click count.
         await self.mouse_event(
-            NSEventType.LeftMouseDown, point, delay=0.1, clickCount=2
+            NSEventType.LeftMouseDown,
+            point,
+            delay=0.1,
+            clickCount=2,
+        )
+        await self.mouse_event(
+            NSEventType.LeftMouseUp,
+            point,
+            delay=0.1,
+            clickCount=2,
         )
-        await self.mouse_event(NSEventType.LeftMouseUp, point, delay=0.1, clickCount=2)

testbed/tests/widgets/test_table.py

@@ -106,9 +106,8 @@ async def multiselect_probe(main_window, multiselect_widget):
 async def test_scroll(widget, probe):
     """The table can be scrolled"""
 
-    # Store the initial position; it might be <0 for implementation reasons.
-    initial_position = probe.scroll_position
-    assert initial_position <= 0
+    # Due to the interaction of scrolling with the header row, the scroll might be <0.
+    assert probe.scroll_position <= 0
 
     # Scroll to the bottom of the table
     widget.scroll_to_bottom()
@@ -133,7 +132,9 @@ async def test_scroll(widget, probe):
     widget.scroll_to_top()
     await probe.wait_for_scroll_completion()
     await probe.redraw("Table scrolled to bottom")
-    assert probe.scroll_position == initial_position
+
+    # Due to the interaction of scrolling with the header row, the scroll might be <0.
+    assert probe.scroll_position <= 0
 
 
 async def test_select(widget, probe, source, on_select_handler):