undoable removeComponent action

src/command.py

@@ -19,6 +19,7 @@ class Command(QtCore.QObject):
     def __init__(self):
         QtCore.QObject.__init__(self)
         self.core = Core()
+        Core.mode = 'commandline'
         self.dataDir = self.core.dataDir
         self.canceled = False
 

src/component.py

@@ -59,9 +59,8 @@ class ComponentMetaclass(type(QtCore.QObject)):
         '''Intercepts the command() method to check for global args'''
         def commandWrapper(self, arg):
             if arg.startswith('preset='):
-                from presetmanager import getPresetDir
                 _, preset = arg.split('=', 1)
-                path = os.path.join(getPresetDir(self), preset)
+                path = os.path.join(self.core.getPresetDir(self), preset)
                 if not os.path.exists(path):
                     print('Couldn\'t locate preset "%s"' % preset)
                     quit(1)

src/core.py

@@ -64,31 +64,39 @@ class Core:
         for i, component in enumerate(self.selectedComponents):
             component.compPos = i
 
-    def insertComponent(self, compPos, moduleIndex, loader):
+    def insertComponent(self, compPos, component, loader):
         '''
             Creates a new component using these args:
-            (compPos, moduleIndex in self.modules, MWindow/Command/Core obj)
+            (compPos, component obj or moduleIndex, MWindow/Command/Core obj)
         '''
         if compPos < 0 or compPos > len(self.selectedComponents):
             compPos = len(self.selectedComponents)
         if len(self.selectedComponents) > 50:
             return None
-        log.debug('Inserting Component from module #%s' % moduleIndex)
+        if type(component) is int:
-        component = self.modules[moduleIndex].Component(
+            # create component using module index in self.modules
-            moduleIndex, compPos, self
+            moduleIndex = int(component)
+            log.debug('Creating new component from module #%s' % moduleIndex)
+            component = self.modules[moduleIndex].Component(
+                moduleIndex, compPos, self
+            )
+            # init component's widget for loading/saving presets
+            component.widget(loader)
+        else:
+            moduleIndex = -1
+            log.debug(
+                'Inserting previously-created %s component' % component.name)
+
+        component._error.connect(
+            loader.videoThreadError
         )
         self.selectedComponents.insert(
             compPos,
             component
         )
         self.componentListChanged()
-        self.selectedComponents[compPos]._error.connect(
+        if moduleIndex > -1:
-            loader.videoThreadError
+            self.updateComponent(compPos)
-        )
-
-        # init component's widget for loading/saving presets
-        self.selectedComponents[compPos].widget(loader)
-        self.updateComponent(compPos)
 
         if hasattr(loader, 'insertComponent'):
             loader.insertComponent(compPos)
@@ -156,6 +164,10 @@ class Core:
                 break
         return saveValueStore
 
+    def getPresetDir(self, comp):
+        '''Get the preset subdir for a particular version of a component'''
+        return os.path.join(Core.presetDir, str(comp), str(comp.version))
+
     def openProject(self, loader, filepath):
         ''' loader is the object calling this method which must have
         its own showMessage(**kwargs) method for displaying errors.

src/gui/actions.py

@@ -0,0 +1,37 @@
+'''
+    QCommand classes for every undoable user action performed in the MainWindow
+'''
+from PyQt5.QtWidgets import QUndoCommand
+
+
+class RemoveComponent(QUndoCommand):
+    def __init__(self, parent, selectedRows):
+        super().__init__('Remove component')
+        self.parent = parent
+        componentList = self.parent.window.listWidget_componentList
+        self.selectedRows = [
+            componentList.row(selected) for selected in selectedRows
+        ]
+        self.components = [
+            parent.core.selectedComponents[i] for i in self.selectedRows
+        ]
+
+    def redo(self):
+        stackedWidget = self.parent.window.stackedWidget
+        componentList = self.parent.window.listWidget_componentList
+        for index in self.selectedRows:
+            stackedWidget.removeWidget(self.parent.pages[index])
+            componentList.takeItem(index)
+            self.parent.core.removeComponent(index)
+            self.parent.pages.pop(index)
+            self.parent.changeComponentWidget()
+        self.parent.drawPreview()
+
+    def undo(self):
+        componentList = self.parent.window.listWidget_componentList
+        for index, comp in zip(self.selectedRows, self.components):
+            self.parent.core.insertComponent(
+                index, comp, self.parent
+            )
+        self.parent.drawPreview()
+

src/gui/mainwindow.py

@@ -16,9 +16,10 @@ import time
 import logging
 
 from core import Core
-import preview_thread
+import gui.preview_thread as preview_thread
-from preview_win import PreviewWindow
+from gui.preview_win import PreviewWindow
-from presetmanager import PresetManager
+from gui.presetmanager import PresetManager
+from gui.actions import *
 from toolkit import disableWhenEncoding, disableWhenOpeningProject, checkOutput
 
 
@@ -43,9 +44,12 @@ class MainWindow(QtWidgets.QMainWindow):
         QtWidgets.QMainWindow.__init__(self)
         self.window = window
         self.core = Core()
+        Core.mode = 'GUI'
         log.debug(
             'Main thread id: {}'.format(int(QtCore.QThread.currentThreadId())))
 
+        self.undoStack = QtWidgets.QUndoStack(self)
+
         # widgets of component settings
         self.pages = []
         self.lastAutosave = time.time()
@@ -62,7 +66,7 @@ class MainWindow(QtWidgets.QMainWindow):
 
         self.presetManager = PresetManager(
             uic.loadUi(
-                os.path.join(Core.wd, 'presetmanager.ui')), self)
+                os.path.join(Core.wd, 'gui', 'presetmanager.ui')), self)
 
         # Create the preview window and its thread, queues, and timers
         log.debug('Creating preview window')
@@ -298,6 +302,9 @@ class MainWindow(QtWidgets.QMainWindow):
         QtWidgets.QShortcut("Ctrl+A", self.window, self.openSaveProjectDialog)
         QtWidgets.QShortcut("Ctrl+O", self.window, self.openOpenProjectDialog)
         QtWidgets.QShortcut("Ctrl+N", self.window, self.createNewProject)
+        QtWidgets.QShortcut("Ctrl+Z", self.window, self.undoStack.undo)
+        QtWidgets.QShortcut("Ctrl+Y", self.window, self.undoStack.redo)
+        QtWidgets.QShortcut("Ctrl+Shift+Z", self.window, self.undoStack.redo)
 
         # Hotkeys for component list
         for inskey in ("Ctrl+T", QtCore.Qt.Key_Insert):
@@ -685,15 +692,10 @@ class MainWindow(QtWidgets.QMainWindow):
 
     def removeComponent(self):
         componentList = self.window.listWidget_componentList
-
+        selected = componentList.selectedItems()
-        for selected in componentList.selectedItems():
+        if selected:
-            index = componentList.row(selected)
+            action = RemoveComponent(self, selected)
-            self.window.stackedWidget.removeWidget(self.pages[index])
+            self.undoStack.push(action)
-            componentList.takeItem(index)
-            self.core.removeComponent(index)
-            self.pages.pop(index)
-            self.changeComponentWidget()
-        self.drawPreview()
 
     @disableWhenEncoding
     def moveComponent(self, change):

src/gui/presetmanager.py

@@ -302,7 +302,7 @@ class PresetManager(QtWidgets.QDialog):
                     self.findPresets()
                     self.drawPresetList()
                     for i, comp in enumerate(self.core.selectedComponents):
-                        if getPresetDir(comp) == path \
+                        if self.core.getPresetDir(comp) == path \
                                 and comp.currentPreset == oldName:
                             self.core.openPreset(newPath, i, newName)
                             self.parent.updateComponentTitle(i, False)
@@ -351,8 +351,3 @@ class PresetManager(QtWidgets.QDialog):
 
     def clearPresetListSelection(self):
         self.window.listWidget_presets.setCurrentRow(-1)
-
-
-def getPresetDir(comp):
-    '''Get the preset subdir for a particular version of a component'''
-    return os.path.join(Core.presetDir, str(comp), str(comp.version))

src/main.py

@@ -35,11 +35,11 @@ def main():
         log.debug("Finished creating command object")
 
     elif mode == 'GUI':
-        from mainwindow import MainWindow
+        from gui.mainwindow import MainWindow
         import atexit
         import signal
 
-        window = uic.loadUi(os.path.join(wd, "mainwindow.ui"))
+        window = uic.loadUi(os.path.join(wd, "gui", "mainwindow.ui"))
         # window.adjustSize()
         desc = QtWidgets.QDesktopWidget()
         dpi = desc.physicalDpiX()