From b6ed9b2e7c8b8444ca51cfe7dc8c62ef588f56dd Mon Sep 17 00:00:00 2001
From: Jussi Kuokkanen <jussi.kuokkanen@protonmail.com>
Date: Thu, 31 Aug 2023 20:38:22 +0300
Subject: [PATCH] return optional from model traverse callback

Allows callers to stop traversing model when they are done processing
---
 src/tuxclocker-qt/Utils.cpp                    | 11 ++++++-----
 src/tuxclocker-qt/Utils.hpp                    |  2 +-
 src/tuxclocker-qt/data/DeviceModelDelegate.cpp | 15 ++++++++-------
 3 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/src/tuxclocker-qt/Utils.cpp b/src/tuxclocker-qt/Utils.cpp
index 7ec5f5b..fa54e6e 100644
--- a/src/tuxclocker-qt/Utils.cpp
+++ b/src/tuxclocker-qt/Utils.cpp
@@ -20,16 +20,17 @@ QVariant fromAssignmentArgument(TuxClocker::Device::AssignmentArgument arg) {
 	return QVariant{};
 }
 
-using ModelTraverseCallback =
-    std::function<QModelIndex(QAbstractItemModel *, const QModelIndex &, int)>;
-
 void traverseModel(
     const ModelTraverseCallback &cb, QAbstractItemModel *model, const QModelIndex &parent) {
 	for (int i = 0; i < model->rowCount(parent); i++) {
+		auto nextOpt = cb(model, parent, i);
+		if (!nextOpt.has_value())
+			// Returning nothing is used as indication we should stop traversing
+			return;
+
 		// We get the next index we should traverse, and the funtion does
 		// its thing with the model and index
-		auto nextIndex = cb(model, parent, i);
-
+		auto nextIndex = nextOpt.value();
 		if (model->hasChildren(nextIndex)) {
 			traverseModel(cb, model, nextIndex);
 		}
diff --git a/src/tuxclocker-qt/Utils.hpp b/src/tuxclocker-qt/Utils.hpp
index 789f66b..fb31ffc 100644
--- a/src/tuxclocker-qt/Utils.hpp
+++ b/src/tuxclocker-qt/Utils.hpp
@@ -5,7 +5,7 @@
 namespace Utils {
 
 using ModelTraverseCallback =
-    std::function<QModelIndex(QAbstractItemModel *, const QModelIndex &, int)>;
+    std::function<std::optional<QModelIndex>(QAbstractItemModel *, const QModelIndex &, int)>;
 
 void traverseModel(
     const ModelTraverseCallback &, QAbstractItemModel *, const QModelIndex &parent = QModelIndex());
diff --git a/src/tuxclocker-qt/data/DeviceModelDelegate.cpp b/src/tuxclocker-qt/data/DeviceModelDelegate.cpp
index 60e4bd5..9189607 100644
--- a/src/tuxclocker-qt/data/DeviceModelDelegate.cpp
+++ b/src/tuxclocker-qt/data/DeviceModelDelegate.cpp
@@ -162,28 +162,29 @@ void DeviceModelDelegate::setAssignableData(
 }
 
 bool DeviceModelDelegate::subtreeHasAssignableDefaults(
-    QAbstractItemModel *model, const QModelIndex &item) {
+    QAbstractItemModel *model, const QModelIndex &index) {
 	QSettings settings{"tuxclocker"};
 	settings.beginGroup("assignableDefaults");
 	bool hasDefaults = false;
 
-	auto cb = [&settings, &hasDefaults](
-		      QAbstractItemModel *model, const QModelIndex &index, int row) {
+	auto cb = [&settings, &hasDefaults](QAbstractItemModel *model, const QModelIndex &index,
+		      int row) -> std::optional<const QModelIndex> {
 		auto ifaceIndex = model->index(row, DeviceModel::InterfaceColumn, index);
 		auto assProxyV = ifaceIndex.data(DeviceModel::AssignableProxyRole);
 
-		qDebug() << model->index(row, DeviceModel::NameColumn, index).data();
+		auto name = model->index(row, DeviceModel::NameColumn, index).data();
 		if (assProxyV.isValid()) {
 			auto nodePath = qvariant_cast<AssignableProxy *>(assProxyV)->dbusPath();
 			if (settings.contains(nodePath.replace('/', '-'))) {
-				// TODO: break out of the function here
+				// This stops traversing model
 				hasDefaults = true;
+				return std::nullopt;
 			}
 		}
-
 		return model->index(row, DeviceModel::NameColumn, index);
 	};
-	Utils::traverseModel(cb, model);
+	auto nameIndex = model->index(index.row(), DeviceModel::NameColumn, index.parent());
+	Utils::traverseModel(cb, model, nameIndex);
 
 	return hasDefaults;
 }