Allow the layout to be empty

Author: lufte

src/test.py

@@ -40,7 +40,7 @@ class SplitExceptionTestCase(unittest.TestCase):
     def setUp(self):
         self.app = QApplication([])
         self.ws = [Widget(i) for i in range(2)]
-        self.layout = get_empty_tiling_layout(2)
+        self.layout = QTilingLayout(max_span=2)
         self.layout.addWidget(self.ws[0], 0, 0, 2, 1)
         self.layout.addWidget(self.ws[1], 0, 1, 2, 1)
 
@@ -145,8 +145,7 @@ def test(self):
 
     def _perform_operation(self, max_span, positions, widget, operation):
         self.trace.append((positions[widget], operation))
-        layout = QTilingLayout(self.widgets[0], max_span=max_span)
-        layout.removeWidget(self.widgets[0])
+        layout = QTilingLayout(max_span=max_span)
         for i in range(len(positions)):
             layout._add_widget(self.widgets[i], *positions[i], False)
         try:
@@ -171,13 +170,6 @@ def _perform_operation(self, max_span, positions, widget, operation):
                                 random.choice(new_operations))
 
 
-def get_empty_tiling_layout(max_span):
-    mock_widget = QWidget()
-    layout = QTilingLayout(mock_widget, max_span=max_span)
-    layout.removeWidget(mock_widget)
-    return layout
-
-
 class TransposedMethodsTestCase(unittest.TestCase):
 
     #  ┌───┬──────────┐
@@ -192,7 +184,7 @@ class TransposedMethodsTestCase(unittest.TestCase):
     def setUp(self):
         self.app = QApplication([])
         self.widgets = [Widget(i) for i in range(5)]
-        self.layout = get_empty_tiling_layout(4)
+        self.layout = QTilingLayout(max_span=4)
         self.layout.addWidget(self.widgets[0], 0, 0, 2, 1)
         self.layout.addWidget(self.widgets[1], 0, 1, 1, 3)
         self.layout.addWidget(self.widgets[2], 1, 1, 1, 1)
@@ -278,7 +270,7 @@ class StateTestCase(unittest.TestCase):
     def setUp(self):
         self.app = QApplication([])
         self.widgets = [Widget(i) for i in range(5)]
-        self.layout = get_empty_tiling_layout(4)
+        self.layout = QTilingLayout(max_span=4)
         self.layout.addWidget(self.widgets[0], 0, 0, 2, 1)
         self.layout.addWidget(self.widgets[1], 0, 1, 1, 3)
         self.layout.addWidget(self.widgets[2], 1, 1, 1, 1)
@@ -317,7 +309,7 @@ class SplitsTestCase(unittest.TestCase):
     def setUp(self):
         self.app = QApplication([])
         self.ws = [Widget(i) for i in range(2)]
-        self.layout = get_empty_tiling_layout(2)
+        self.layout = QTilingLayout(max_span=2)
         self.layout.addWidget(self.ws[0], 0, 0, 2, 2)
 
     def test_hsplit_after(self):
@@ -368,7 +360,7 @@ class RemoveTestCase(unittest.TestCase):
     def setUp(self):
         self.app = QApplication([])
         self.widgets = [Widget(i) for i in range(5)]
-        self.layout = get_empty_tiling_layout(4)
+        self.layout = QTilingLayout(max_span=4)
         self.layout.addWidget(self.widgets[0], 0, 0, 2, 1)
         self.layout.addWidget(self.widgets[1], 0, 1, 1, 3)
         self.layout.addWidget(self.widgets[2], 1, 1, 1, 1)
@@ -415,11 +407,6 @@ def test_vertical_remove(self):
             (2, 3, 2, 1)
         )
 
-    def test_remove_last_widget(self):
-        with self.assertRaises(SplitLimitException):
-            for widget in self.widgets:
-                self.layout.remove_widget(widget)
-
 
 class IndependentBlockTestCase(unittest.TestCase):
 
@@ -438,7 +425,7 @@ class IndependentBlockTestCase(unittest.TestCase):
     #  └───────────┴───────┴───┘
     def setUp(self):
         self.app = QApplication([])
-        self.layout = get_empty_tiling_layout(6)
+        self.layout = QTilingLayout(max_span=6)
         self.ws = [Widget(i) for i in range(11)]
         self.layout.addWidget(self.ws[0], 0, 0, 4, 1)
         self.layout.addWidget(self.ws[1], 0, 1, 2, 2)
@@ -491,7 +478,7 @@ def setUp(self):
     #  │░░░│   1   │
     #  └───┴───────┘
     def test_right_space(self):
-        layout = get_empty_tiling_layout(3)
+        layout = QTilingLayout(max_span=3)
         widgets = [Widget(0), Widget(1)]
         layout.addWidget(widgets[0], 0, 0, 1, 1)
         layout.addWidget(widgets[1], 2, 1, 1, 2)
@@ -509,7 +496,7 @@ def test_right_space(self):
     #  │   1   │░░░│
     #  └───────┴───┘
     def test_left_space(self):
-        layout = get_empty_tiling_layout(3)
+        layout = QTilingLayout(max_span=3)
         widgets = [Widget(0), Widget(1)]
         layout.addWidget(widgets[0], 0, 2, 1, 1)
         layout.addWidget(widgets[1], 2, 0, 1, 2)
@@ -527,7 +514,7 @@ def test_left_space(self):
     #  │   2   │░░░│
     #  └───────┴───┘
     def test_not_enough_space(self):
-        layout = get_empty_tiling_layout(3)
+        layout = QTilingLayout(max_span=3)
         widgets = [Widget(0), Widget(1), Widget(2)]
         layout.addWidget(widgets[0], 0, 2, 1, 1)
         layout.addWidget(widgets[1], 1, 2, 1, 1)
@@ -548,7 +535,7 @@ def test_not_enough_space(self):
     #  │░░░░░░░░░░░│
     #  └───────────┘
     def test_move_supporters(self):
-        layout = get_empty_tiling_layout(3)
+        layout = QTilingLayout(max_span=3)
         widgets = [Widget(0), Widget(1), Widget(2)]
         layout.addWidget(widgets[0], 0, 0, 1, 1)
         layout.addWidget(widgets[1], 1, 0, 1, 1)
@@ -577,7 +564,7 @@ class SupportersTestCase(unittest.TestCase):
     #  └───────────────────┘
     def setUp(self):
         self.app = QApplication([])
-        self.layout = get_empty_tiling_layout(5)
+        self.layout = QTilingLayout(max_span=5)
         self.ws = [Widget(i) for i in range(7)]
         self.layout.addWidget(self.ws[0], 0, 0, 1, 5)
         self.layout.addWidget(self.ws[1], 1, 0, 3, 3)
@@ -618,7 +605,7 @@ def setUp(self):
     #  │░░░░░░░░░░░│
     #  └───────────┘
     def test_top_block(self):
-        layout = get_empty_tiling_layout(3)
+        layout = QTilingLayout(max_span=3)
         widgets = [Widget(0), Widget(1), Widget(2)]
         layout.addWidget(widgets[0], 0, 0, 1, 1)
         layout.addWidget(widgets[1], 1, 0, 1, 1)
@@ -639,7 +626,7 @@ def test_top_block(self):
     #  │░░░░░░░░░░░│
     #  └───────────┘
     def test_left_block(self):
-        layout = get_empty_tiling_layout(3)
+        layout = QTilingLayout(max_span=3)
         widgets = [Widget(0), Widget(1), Widget(2)]
         layout.addWidget(widgets[0], 0, 0, 1, 3)
         layout.addWidget(widgets[1], 1, 0, 1, 1)
@@ -660,7 +647,7 @@ def test_left_block(self):
     #  │░░░░░░░░░░░│
     #  └───────────┘
     def test_right_block(self):
-        layout = get_empty_tiling_layout(3)
+        layout = QTilingLayout(max_span=3)
         widgets = [Widget(0), Widget(1), Widget(2)]
         layout.addWidget(widgets[0], 0, 0, 2, 1)
         layout.addWidget(widgets[1], 0, 1, 1, 2)
@@ -681,7 +668,7 @@ def test_right_block(self):
     #  │ 3 │ 4 │   │
     #  └───┴───┴───┘
     def test_no_suitable_block(self):
-        layout = get_empty_tiling_layout(3)
+        layout = QTilingLayout(max_span=3)
         widgets = [Widget(0), Widget(1), Widget(2), Widget(3), Widget(4)]
         layout.addWidget(widgets[0], 0, 0, 2, 1)
         layout.addWidget(widgets[1], 0, 1, 1, 2)
@@ -703,7 +690,7 @@ class BlockTestCase(unittest.TestCase):
     #  └───┴───────┘
     def setUp(self):
         self.app = QApplication([])
-        self.layout = get_empty_tiling_layout(3)
+        self.layout = QTilingLayout(max_span=3)
         self.ws = [Widget(i) for i in range(2)]
         self.layout.addWidget(self.ws[0], 1, 3, 1, 1)
         self.layout.addWidget(self.ws[1], 2, 1, 1, 2)
@@ -755,7 +742,7 @@ class RecBlockTestCase(unittest.TestCase):
     #  └───────────────┴───────────────┘
     def setUp(self):
         self.app = QApplication([])
-        self.layout = get_empty_tiling_layout(8)
+        self.layout = QTilingLayout(max_span=8)
         self.ws = [Widget(i) for i in range(6)]
         self.layout.addWidget(self.ws[0], 0, 0, 3, 2)
         self.layout.addWidget(self.ws[1], 0, 2, 2, 6)
@@ -897,7 +884,7 @@ class CriticalBlockTestCase(unittest.TestCase):
     #  └───────┴───────┴───────┴───────┴───────┴───────┘
     def setUp(self):
         self.app = QApplication([])
-        self.layout = get_empty_tiling_layout(12)
+        self.layout = QTilingLayout(max_span=12)
         self.ws = [Widget(i) for i in range(29)]
         self.layout.addWidget(self.ws[0], 0, 0, 2, 2)
         self.layout.addWidget(self.ws[1], 0, 2, 3, 2)
@@ -1001,7 +988,7 @@ class EmptyBlockTestCase(unittest.TestCase):
     #  └───────────────────────┘
     def setUp(self):
         self.app = QApplication([])
-        self.layout = get_empty_tiling_layout(6)
+        self.layout = QTilingLayout(max_span=6)
         self.ws = [Widget(i) for i in range(8)]
         self.layout.addWidget(self.ws[0], 0, 0, 1, 5)
         self.layout.addWidget(self.ws[1], 1, 0, 4, 1)
@@ -1059,7 +1046,7 @@ class NeighbourTestCase(unittest.TestCase):
     #  └───────────────────────────────────┘
     def setUp(self):
         self.app = QApplication([])
-        self.layout = get_empty_tiling_layout(9)
+        self.layout = QTilingLayout(max_span=9)
         self.ws = [Widget(i) for i in range(19)]
         self.layout.addWidget(self.ws[0], 0, 0, 1, 2)
         self.layout.addWidget(self.ws[1], 0, 2, 1, 3)

src/tilinglayout.py

@@ -51,10 +51,11 @@ def __init__(self, state, widget, operation):
 
 class QTilingLayout(QGridLayout):
 
-    def __init__(self, widget, *args, max_span=12, **kwargs):
+    def __init__(self, *args, initial_widget=None, max_span=12, **kwargs):
         super().__init__(*args, **kwargs)
         self.max_span = max_span
-        self.addWidget(widget, 0, 0, self.max_span, self.max_span)
+        if initial_widget:
+            self.addWidget(initial_widget, 0, 0, self.max_span, self.max_span)
 
     def _is_point_inside_grid(self, row, col):
         """Determines if the point is inside the layout."""
@@ -131,26 +132,26 @@ def _restore_state(self, prev_state):
     def remove_widget(self, widget):
         """Removes a widget from the layout and fills the remaining space"""
         if self.count() == 1:
-            raise SplitLimitException
-
-        original_state = self._get_state()
-        try:
-            widget_pos = self._get_item_position(widget, False)
-            transpose = widget_pos[3] < widget_pos[2]
-            ib = self._get_independent_block(widget, transpose)
             self.removeWidget(widget)
-            widget.hide()
-            widgets = list(ib.get_widgets())
-            self._rearrange_widgets(widgets, ib)
-            # Rearrange widgets in the opposite direction as the resizing
-            # results in some widgets sharing the space better with their
-            # neighbours
-            whole_block = CriticalBlock(self, not transpose, 0, 0,
-                                        self.max_span, self.max_span)
-            self._rearrange_widgets(list(whole_block.get_widgets()),
-                                    whole_block)
-        except Exception as e:
-            raise SplitException(original_state, widget, 'remove') from e
+        else:
+            original_state = self._get_state()
+            try:
+                widget_pos = self._get_item_position(widget, False)
+                transpose = widget_pos[3] < widget_pos[2]
+                ib = self._get_independent_block(widget, transpose)
+                self.removeWidget(widget)
+                widget.hide()
+                widgets = list(ib.get_widgets())
+                self._rearrange_widgets(widgets, ib)
+                # Rearrange widgets in the opposite direction as the resizing
+                # results in some widgets sharing the space better with their
+                # neighbours
+                whole_block = CriticalBlock(self, not transpose, 0, 0,
+                                            self.max_span, self.max_span)
+                self._rearrange_widgets(list(whole_block.get_widgets()),
+                                        whole_block)
+            except Exception as e:
+                raise SplitException(original_state, widget, 'remove') from e
 
     def hsplit(self, old_widget, new_widget, put_before=False):
         """Splits the specified widget horizontally.