[widgets][assetwidget] Use a debounce timer to update

This avoids reloading the json_widget content immediately on
each keyboard input or mouse event (i.e. combobox mouse wheel
update)

beat/editor/test/test_assetwidget.py

@@ -89,13 +89,13 @@ class TestAssetWidget:
     def test_dirty(self, qtbot, monkeypatch, test_prefix, asset_type_prefix_entry_map):
         asset_widget = AssetWidget()
         qtbot.addWidget(asset_widget)
+        asset_widget.set_prefix_root(test_prefix)
+
         description = "dummy description"
 
         # Question about saving editor content after modification before a new json is loaded
         monkeypatch.setattr(QMessageBox, "question", lambda *args: QMessageBox.No)
 
-        asset_widget.set_prefix_root(test_prefix)
-
         for (
             asset_type,
             (asset_name, editor_type),
@@ -106,7 +106,7 @@ class TestAssetWidget:
                 )
                 assert not asset_widget.current_editor.is_dirty()
 
-                with qtbot.waitSignal(asset_widget.current_editor.dataChanged):
+                with qtbot.waitSignal(asset_widget.json_widget.textChanged):
                     qtbot.keyClicks(
                         asset_widget.current_editor.description_lineedit, description
                     )
@@ -120,10 +120,10 @@ class TestAssetWidget:
     def test_save(self, qtbot, monkeypatch, test_prefix, asset_type_prefix_entry_map):
         asset_widget = AssetWidget()
         qtbot.addWidget(asset_widget)
-        description = "dummy description"
-
         asset_widget.set_prefix_root(test_prefix)
 
+        description = "dummy description"
+
         for (
             asset_type,
             (asset_name, editor_type),
@@ -132,7 +132,7 @@ class TestAssetWidget:
                 asset_path = self.get_asset_path(test_prefix, asset_type, asset_name)
                 asset_widget.load_json(asset_path)
 
-                with qtbot.waitSignal(asset_widget.current_editor.dataChanged):
+                with qtbot.waitSignal(asset_widget.json_widget.textChanged):
                     qtbot.keyClicks(
                         asset_widget.current_editor.description_lineedit, description
                     )

beat/editor/widgets/assetwidget.py

@@ -27,6 +27,7 @@ import simplejson as json
 
 from PyQt5.QtCore import pyqtSlot
 from PyQt5.QtCore import QFileSystemWatcher
+from PyQt5.QtCore import QTimer
 
 from PyQt5.QtWidgets import QPushButton
 from PyQt5.QtWidgets import QTabWidget
@@ -118,6 +119,9 @@ class AssetWidget(QWidget):
 
         self.current_json = None
         self.watcher = QFileSystemWatcher()
+        self.update_timer = QTimer()
+        self.update_timer.setSingleShot(True)
+        self.update_timer.setInterval(200)
 
         self.json_widget = QTextEdit()
         self.json_widget.setReadOnly(True)
@@ -147,6 +151,8 @@ class AssetWidget(QWidget):
         layout.addLayout(button_layout)
 
         self.watcher.fileChanged.connect(self.__reload_from_harddrive)
+        self.update_timer.timeout.connect(self.__enable_save)
+        self.update_timer.timeout.connect(self.__update_json_widget)
         self.save_button.clicked.connect(self.save_json)
 
     @property
@@ -170,7 +176,7 @@ class AssetWidget(QWidget):
         """Update the content of this widget"""
 
         try:
-            self.current_editor.dataChanged.disconnect(self)
+            self.current_editor.dataChanged.disconnect(self.update_timer)
         except TypeError:
             # Nothing was connected yet
             pass
@@ -181,8 +187,7 @@ class AssetWidget(QWidget):
             asset_type = self.__asset_type_for_path(self.current_json)
             editor = self.editors_type[asset_type]
             editor.load_json(json.loads(json_data))
-            editor.dataChanged.connect(self.__enable_save)
-            editor.dataChanged.connect(self.__update_json_widget)
+            editor.dataChanged.connect(self.update_timer.start)
             self.editors.setCurrentWidget(editor)
 
         self.save_button.setEnabled(False)