[widgets][toolchaineditor] Improve empty block menu handling

If any of the menu shall be empty, set an disabled action stating that
nothing valid is found. This is better than the currently empty menu.

Part of #239

beat/editor/test/test_toolchaineditor.py

@@ -166,3 +166,16 @@ class TestToolchainEditor:
         editor.load_json(reference_json)
 
         assert editor.dump_json() == reference_json
+
+    def test_empty_block_list(self, qtbot):
+        editor = ToolchainEditor()
+
+        actions = editor.toolchain.analyzer_edit_menu.actions()
+        assert len(actions) == 1
+        assert actions[0].text() == "No valid analyzers found"
+        actions = editor.toolchain.block_edit_menu.actions()
+        assert len(actions) == 1
+        assert actions[0].text() == "No valid blocks found"
+        actions = editor.toolchain.dataset_edit_menu.actions()
+        assert len(actions) == 1
+        assert actions[0].text() == "No valid datasets found"

beat/editor/widgets/toolchaineditor.py

@@ -763,6 +763,9 @@ class BlockType(Enum):
             raise KeyError("{} is not a valid block type".format(name))
 
 
+BLOCKTYPE_PROPERTY = "__block_type__"
+
+
 class Block(QGraphicsObject):
     """Block item"""
 
@@ -1446,16 +1449,19 @@ class ToolchainWidget(QWidget):
         self.dataset_button.setToolTip("Dataset")
         self.dataset_button.setIcon(QIcon(":/resources/dataset"))
         self.dataset_edit_menu = QMenu(self)
+        self.dataset_edit_menu.setProperty(BLOCKTYPE_PROPERTY, BlockType.DATASETS)
 
         self.block_button = QPushButton()
         self.block_button.setToolTip("Block")
         self.block_button.setIcon(QIcon(":/resources/block"))
         self.block_edit_menu = QMenu(self)
+        self.block_edit_menu.setProperty(BLOCKTYPE_PROPERTY, BlockType.BLOCKS)
 
         self.analyzer_button = QPushButton()
         self.analyzer_button.setToolTip("Analyzer")
         self.analyzer_button.setIcon(QIcon(":/resources/analyzer"))
         self.analyzer_edit_menu = QMenu(self)
+        self.analyzer_edit_menu.setProperty(BLOCKTYPE_PROPERTY, BlockType.ANALYZERS)
 
         self.toolbar.addWidget(self.dataset_button)
         self.toolbar.addWidget(self.block_button)
@@ -1468,6 +1474,27 @@ class ToolchainWidget(QWidget):
         layout.addWidget(self.toolbar)
         layout.addWidget(self.view)
 
+        for menu in [
+            self.dataset_edit_menu,
+            self.block_edit_menu,
+            self.analyzer_edit_menu,
+        ]:
+            self.__setup_menu(menu, [])
+
+    def __setup_menu(self, menu, item_list):
+        menu.clear()
+        block_type = menu.property(BLOCKTYPE_PROPERTY)
+        if item_list:
+            for item in item_list:
+                menu.addAction(
+                    item, partial(self.button_item_selected, block_type, item)
+                )
+        else:
+            action = menu.addAction(
+                self.tr("No valid {} found".format(block_type.name.lower()))
+            )
+            action.setEnabled(False)
+
     def add_loop_block(self):
         loops, ok = LoopDialog.getLoops(
             self,
@@ -1601,7 +1628,7 @@ class ToolchainWidget(QWidget):
         inputs = []
         outputs = []
 
-        if block_type == BlockType.DATASETS.name:
+        if block_type == BlockType.DATASETS:
             inputs = None
             name_split = name.split("/")
             database_name = name_split[0] + "/" + name_split[1]
@@ -1624,7 +1651,7 @@ class ToolchainWidget(QWidget):
                                     outputs.append(key)
 
         else:
-            if block_type == BlockType.ANALYZERS.name:
+            if block_type == BlockType.ANALYZERS:
                 outputs = None
             asset = Asset(self.prefix_path, AssetType.ALGORITHM, name)
             declaration = asset.declaration
@@ -1671,29 +1698,12 @@ class ToolchainWidget(QWidget):
     ):
         self.prefix_path = prefix_path
 
-        for dataset_name in dataset_list:
-            self.dataset_edit_menu.addAction(
-                self.tr(dataset_name),
-                partial(
-                    self.button_item_selected, BlockType.DATASETS.name, dataset_name
-                ),
-            )
-
-        for algorithm_name in algorithm_list:
-            self.block_edit_menu.addAction(
-                self.tr(algorithm_name),
-                partial(
-                    self.button_item_selected, BlockType.BLOCKS.name, algorithm_name
-                ),
-            )
-
-        for analyzer_name in analyzer_list:
-            self.analyzer_edit_menu.addAction(
-                self.tr(analyzer_name),
-                partial(
-                    self.button_item_selected, BlockType.ANALYZERS.name, analyzer_name
-                ),
-            )
+        for menu, item_list in [
+            (self.dataset_edit_menu, dataset_list),
+            (self.block_edit_menu, algorithm_list),
+            (self.analyzer_edit_menu, analyzer_list),
+        ]:
+            self.__setup_menu(menu, item_list)
 
         self.dataset_button.setMenu(self.dataset_edit_menu)
         self.block_button.setMenu(self.block_edit_menu)