[widgets][assetwidget] Add button to allow closing the current editor

This button allows the user to stop editing the current asset without
having to open a new one.

Fixes #243

beat/editor/test/test_assetwidget.py

@@ -617,3 +617,25 @@ class TestAssetWidget:
             )
 
         assert editor.error_label.toolTip() != ""
+
+    def test_closing(
+        self, qtbot, test_prefix, beat_context, asset_type, asset_type_prefix_entry_map
+    ):
+        asset_widget = AssetWidget()
+        qtbot.addWidget(asset_widget)
+        asset_widget.set_context(beat_context)
+
+        asset_name = asset_type_prefix_entry_map[asset_type][0]
+
+        assert not asset_widget.close_button.isEnabled()
+
+        asset = Asset(test_prefix, asset_type, asset_name)
+        with qtbot.waitSignal(asset_widget.currentAssetChanged):
+            asset_widget.loadAsset(asset)
+
+        assert asset_widget.close_button.isEnabled()
+
+        qtbot.mouseClick(asset_widget.close_button, QtCore.Qt.LeftButton)
+
+        assert not asset_widget.close_button.isEnabled()
+        assert asset_widget.current_editor.asset_type == AssetType.UNKNOWN

beat/editor/widgets/assetwidget.py

@@ -160,8 +160,18 @@ class AssetWidget(QWidget):
         self.tab_widget.addTab(self.json_widget, self.tr("Raw JSON"))
 
         self.asset_name_label = QLabel(self.tr("Unknown"))
+        close_icon = self.style().standardIcon(QStyle.SP_TitleBarCloseButton)
+        self.close_button = QPushButton(close_icon, "")
+        self.close_button.setFixedSize(16, 16)
+        self.close_button.setToolTip(self.tr("Close asset editor"))
+
+        top_layout = QHBoxLayout()
+        top_layout.addWidget(self.asset_name_label)
+        top_layout.addStretch()
+        top_layout.addWidget(self.close_button)
+
         layout = QVBoxLayout(self)
-        layout.addWidget(self.asset_name_label)
+        layout.addLayout(top_layout)
         layout.addWidget(self.tab_widget)
 
         edit_menu = QMenu(self)
@@ -184,6 +194,7 @@ class AssetWidget(QWidget):
         self.watcher.fileChanged.connect(self.__reloadFromHarddrive)
         self.update_timer.timeout.connect(self.__enableSave)
         self.update_timer.timeout.connect(self.__updateJsonWidget)
+        self.close_button.clicked.connect(self.__closeEditor)
         self.save_button.clicked.connect(self.saveJson)
         self.edit_code_action.triggered.connect(self.__editCode)
         self.edit_documentation_action.triggered.connect(self.__editDocumentation)
@@ -206,7 +217,9 @@ class AssetWidget(QWidget):
 
         self.editors.setCurrentWidget(self.type_editor_map[asset_type])
         self.edit_code_action.setEnabled(asset_type.has_code())
-        self.edit_documentation_action.setEnabled(asset_type is not AssetType.UNKNOWN)
+        is_unknown = asset_type == AssetType.UNKNOWN
+        self.edit_documentation_action.setEnabled(not is_unknown)
+        self.close_button.setEnabled(not is_unknown)
 
     @property
     def prefix_root_path(self):
@@ -342,6 +355,14 @@ class AssetWidget(QWidget):
         path = self.current_asset.code_path
         click.launch(url=path)
 
+    @pyqtSlot()
+    def __closeEditor(self):
+        self.set_current_editor(AssetType.UNKNOWN)
+        self.asset_name_label.setText(self.tr("Unknown"))
+        self.json_widget.clear()
+        self.__clear_watcher()
+        self.current_asset = None
+
     def closeEvent(self, event):
         """Re-impl will check and ask to save if the editor is dirty"""
 
@@ -399,12 +420,10 @@ class AssetWidget(QWidget):
             )
             if answer == QMessageBox.No:
                 return
-            self.set_current_editor(AssetType.UNKNOWN)
-            self.asset_name_label.setText(self.tr("Unknown"))
-            self.json_widget.clear()
-            self.__clear_watcher()
-            self.current_asset.delete()
-            self.current_asset = None
+            current_asset = self.current_asset
+            self.__closeEditor()
+            current_asset.delete()
+
         else:
             # Check before deletion
             asset = Asset.from_path(self.prefix_root_path, file_path)