Refactor ModuleAdd. Add history::State::clear()

include/history.hpp

@@ -10,6 +10,7 @@
 namespace rack {
 
 
+struct ModuleWidget;
 struct CableWidget;
 
 
@@ -56,19 +57,15 @@ struct ModuleAction : Action {
 struct ModuleAdd : ModuleAction {
 	Model *model;
 	math::Vec pos;
+	json_t *moduleJ;
+	~ModuleAdd();
+	void setModule(ModuleWidget *mw);
 	void undo() override;
 	void redo() override;
 };
 
 
-struct ModuleRemove : ModuleAction {
-	Model *model;
-	math::Vec pos;
-	json_t *moduleJ;
-	~ModuleRemove();
-	void undo() override;
-	void redo() override;
-};
+struct ModuleRemove : InverseAction<ModuleAdd> {};
 
 
 struct ModuleMove : ModuleAction {
@@ -116,6 +113,7 @@ struct State {
 	int actionIndex = 0;
 
 	~State();
+	void clear();
 	void push(Action *action);
 	void undo();
 	void redo();

src/app/ModuleBrowser.cpp

@@ -88,9 +88,7 @@ struct ModuleBox : OpaqueWidget {
 
 			// Push ModuleAdd history action
 			history::ModuleAdd *h = new history::ModuleAdd;
-			h->model = moduleWidget->model;
-			h->moduleId = moduleWidget->module->id;
-			h->pos = moduleWidget->box.pos;
+			h->setModule(moduleWidget);
 			app()->history->push(h);
 		}
 		OpaqueWidget::onButton(e);

src/app/ModuleWidget.cpp

@@ -553,10 +553,7 @@ void ModuleWidget::removeAction() {
 
 	// Push ModuleRemove history action
 	history::ModuleRemove *moduleRemove = new history::ModuleRemove;
-	moduleRemove->model = model;
-	moduleRemove->moduleId = module->id;
-	moduleRemove->pos = box.pos;
-	moduleRemove->moduleJ = toJson();
+	moduleRemove->setModule(this);
 	complexAction->push(moduleRemove);
 
 	app()->history->push(complexAction);
@@ -568,8 +565,8 @@ void ModuleWidget::removeAction() {
 void ModuleWidget::bypassAction() {
 	// Push ModuleBypass history action
 	history::ModuleBypass *h = new history::ModuleBypass;
-	h->bypass = !module->bypass;
 	h->moduleId = module->id;
+	h->bypass = !module->bypass;
 	app()->history->push(h);
 	h->redo();
 }
@@ -586,9 +583,7 @@ void ModuleWidget::cloneAction() {
 
 	// Push ModuleAdd history action
 	history::ModuleAdd *h = new history::ModuleAdd;
-	h->model = clonedModuleWidget->model;
-	h->moduleId = clonedModuleWidget->module->id;
-	h->pos = clonedModuleWidget->box.pos;
+	h->setModule(clonedModuleWidget);
 	app()->history->push(h);
 }
 

src/history.cpp

@@ -32,81 +32,74 @@ void ComplexAction::push(Action *action) {
 }
 
 
-void ModuleAdd::undo() {
-	ModuleWidget *moduleWidget = app()->scene->rackWidget->getModule(moduleId);
-	assert(moduleWidget);
-	app()->scene->rackWidget->removeModule(moduleWidget);
-	delete moduleWidget;
+ModuleAdd::~ModuleAdd() {
+	json_decref(moduleJ);
 }
 
-void ModuleAdd::redo() {
-	ModuleWidget *moduleWidget = model->createModuleWidget();
-	assert(moduleWidget);
-	assert(moduleWidget->module);
-	moduleWidget->module->id = moduleId;
-	moduleWidget->box.pos = pos;
-	app()->scene->rackWidget->addModule(moduleWidget);
+void ModuleAdd::setModule(ModuleWidget *mw) {
+	model = mw->model;
+	assert(mw->module);
+	moduleId = mw->module->id;
+	pos = mw->box.pos;
+	// ModuleAdd doesn't *really* need the state to be serialized, although ModuleRemove certainly does.
+	// However, creating a module may give it a nondeterministic initial state for whatever reason, so serialize anyway.
+	moduleJ = mw->toJson();
 }
 
-
-ModuleRemove::~ModuleRemove() {
-	json_decref(moduleJ);
-}
-
-void ModuleRemove::undo() {
-	ModuleWidget *moduleWidget = model->createModuleWidget();
-	assert(moduleWidget);
-	assert(moduleWidget->module);
-	moduleWidget->module->id = moduleId;
-	moduleWidget->box.pos = pos;
-	moduleWidget->fromJson(moduleJ);
-	app()->scene->rackWidget->addModule(moduleWidget);
+void ModuleAdd::undo() {
+	ModuleWidget *mw = app()->scene->rackWidget->getModule(moduleId);
+	assert(mw);
+	app()->scene->rackWidget->removeModule(mw);
+	delete mw;
 }
 
-void ModuleRemove::redo() {
-	ModuleWidget *moduleWidget = app()->scene->rackWidget->getModule(moduleId);
-	assert(moduleWidget);
-	app()->scene->rackWidget->removeModule(moduleWidget);
-	delete moduleWidget;
+void ModuleAdd::redo() {
+	ModuleWidget *mw = model->createModuleWidget();
+	assert(mw);
+	assert(mw->module);
+	mw->module->id = moduleId;
+	mw->box.pos = pos;
+	mw->fromJson(moduleJ);
+	app()->scene->rackWidget->addModule(mw);
 }
 
 
 void ModuleMove::undo() {
-	ModuleWidget *moduleWidget = app()->scene->rackWidget->getModule(moduleId);
-	assert(moduleWidget);
-	moduleWidget->box.pos = oldPos;
+	ModuleWidget *mw = app()->scene->rackWidget->getModule(moduleId);
+	assert(mw);
+	mw->box.pos = oldPos;
 }
 
 void ModuleMove::redo() {
-	ModuleWidget *moduleWidget = app()->scene->rackWidget->getModule(moduleId);
-	assert(moduleWidget);
-	moduleWidget->box.pos = newPos;
+	ModuleWidget *mw = app()->scene->rackWidget->getModule(moduleId);
+	assert(mw);
+	mw->box.pos = newPos;
 }
 
 
 void ModuleBypass::undo() {
-	ModuleWidget *moduleWidget = app()->scene->rackWidget->getModule(moduleId);
-	assert(moduleWidget);
-	moduleWidget->module->bypass = !bypass;
+	ModuleWidget *mw = app()->scene->rackWidget->getModule(moduleId);
+	assert(mw);
+	mw->module->bypass = !bypass;
 }
 
 void ModuleBypass::redo() {
-	ModuleWidget *moduleWidget = app()->scene->rackWidget->getModule(moduleId);
-	assert(moduleWidget);
-	moduleWidget->module->bypass = bypass;
+	ModuleWidget *mw = app()->scene->rackWidget->getModule(moduleId);
+	assert(mw);
+	mw->module->bypass = bypass;
 }
 
 
 void ParamChange::undo() {
-	ModuleWidget *moduleWidget = app()->scene->rackWidget->getModule(moduleId);
-	assert(moduleWidget);
-	moduleWidget->module->params[paramId].value = oldValue;
+	ModuleWidget *mw = app()->scene->rackWidget->getModule(moduleId);
+	assert(mw);
+	mw->module->params[paramId].value = oldValue;
 }
 
 void ParamChange::redo() {
-	ModuleWidget *moduleWidget = app()->scene->rackWidget->getModule(moduleId);
-	assert(moduleWidget);
-	moduleWidget->module->params[paramId].value = newValue;
+	ModuleWidget *mw = app()->scene->rackWidget->getModule(moduleId);
+	assert(mw);
+	mw->module->params[paramId].value = newValue;
 }
 
 
@@ -152,9 +145,15 @@ void CableAdd::redo() {
 
 
 State::~State() {
+	clear();
+}
+
+void State::clear() {
 	for (Action *action : actions) {
 		delete action;
 	}
+	actions.clear();
+	actionIndex = 0;
 }
 
 void State::push(Action *action) {