diff --git a/LVGLCore.cpp b/LVGLCore.cpp
index 9843d7f..3df7de0 100644
--- a/LVGLCore.cpp
+++ b/LVGLCore.cpp
@@ -15,7 +15,7 @@ QLVGL lvgl(nullptr);
 
 #include "LVGLObject.h"
 
-static void lvgl_core_flush_cb(lv_disp_drv_t *disp, const lv_area_t *area, lv_color_t *color_p)
+void lvgl_core_flush_cb(lv_disp_drv_t *disp, const lv_area_t *area, lv_color_t *color_p)
 {
 	QLVGL *self = reinterpret_cast<QLVGL*>(disp->user_data);
 	self->dispFlush(disp, area, color_p);
@@ -133,9 +133,9 @@ void QLVGL::init(int width, int height)
 	//lv_log_register_print_cb(lvgl_print_cb);
 }
 
-bool QLVGL::changeResolution(lv_coord_t width, lv_coord_t height)
+bool QLVGL::changeResolution(QSize size)
 {
-	const uint32_t n = static_cast<uint32_t>(width * height);
+	const uint32_t n = static_cast<uint32_t>(size.width() * size.height());
 	if (n != m_disp_buf.size) {
 		m_disp_framebuffer.resize(n);
 		m_buf1.resize(n);
@@ -143,8 +143,8 @@ bool QLVGL::changeResolution(lv_coord_t width, lv_coord_t height)
 		lv_disp_buf_init(&m_disp_buf, m_buf1.data(), m_buf2.data(), n);
 	}
 
-	m_disp_drv.hor_res = static_cast<lv_coord_t>(width);
-	m_disp_drv.ver_res = static_cast<lv_coord_t>(height);
+	m_disp_drv.hor_res = static_cast<lv_coord_t>(size.width());
+	m_disp_drv.ver_res = static_cast<lv_coord_t>(size.height());
 	lv_disp_drv_update(lv_disp_get_default(), &m_disp_drv);
 
 	return false;
@@ -170,7 +170,7 @@ QPixmap QLVGL::grab(const QRect &region) const
 	QImage img(region.width(), region.height(), QImage::Format_ARGB32);
 	for (auto y = 0; y < region.height(); ++y)
 		memcpy(img.scanLine(y + region.y()),
-				 &m_disp_framebuffer[y * stride + region.x()],
+				 &m_disp_framebuffer[static_cast<size_t>(y * stride + region.x())],
 				static_cast<size_t>(stride) * 4
 				);
 	return QPixmap::fromImage(img);
diff --git a/LVGLCore.h b/LVGLCore.h
index ae45a60..09c9215 100644
--- a/LVGLCore.h
+++ b/LVGLCore.h
@@ -25,7 +25,7 @@ public:
 
 	void init(int width, int height);
 
-	bool changeResolution(lv_coord_t width, lv_coord_t height);
+	bool changeResolution(QSize size);
 
 	QPixmap framebuffer() const;
 	QPixmap grab(const QRect &region) const;
@@ -117,9 +117,9 @@ private:
 	lv_style_t m_screen_style;
 	const LVGLFontData *m_defaultFont;
 
-	QVector<lv_color_t> m_disp_framebuffer;
-	QVector<lv_color_t> m_buf1;
-	QVector<lv_color_t> m_buf2;
+	std::vector<lv_color_t> m_disp_framebuffer;
+	std::vector<lv_color_t> m_buf1;
+	std::vector<lv_color_t> m_buf2;
 	lv_disp_buf_t m_disp_buf;
 	lv_disp_drv_t m_disp_drv;
 
diff --git a/LVGLNewDialog.cpp b/LVGLNewDialog.cpp
index b7d5483..e75cc1a 100644
--- a/LVGLNewDialog.cpp
+++ b/LVGLNewDialog.cpp
@@ -43,14 +43,14 @@ QString LVGLNewDialog::selectedName() const
 	return m_ui->edit_name->text();
 }
 
-QPair<lv_coord_t, lv_coord_t> LVGLNewDialog::selectedResolution() const
+QSize LVGLNewDialog::selectedResolution() const
 {
-	lv_coord_t w = static_cast<lv_coord_t>(m_ui->spin_width->value());
-	lv_coord_t h = static_cast<lv_coord_t>(m_ui->spin_height->value());
+	int w = m_ui->spin_width->value();
+	int h = m_ui->spin_height->value();
 
 	if (m_ui->radio_portrait->isChecked())
 		qSwap(w, h);
-	return qMakePair<lv_coord_t,lv_coord_t>(w, h);
+	return QSize(w, h);
 }
 
 void LVGLNewDialog::accept()
diff --git a/LVGLNewDialog.h b/LVGLNewDialog.h
index 6ad6f60..f9fa15e 100644
--- a/LVGLNewDialog.h
+++ b/LVGLNewDialog.h
@@ -18,7 +18,7 @@ public:
 	virtual ~LVGLNewDialog() override;
 
 	QString selectedName() const;
-	QPair<lv_coord_t,lv_coord_t> selectedResolution() const;
+	QSize selectedResolution() const;
 
 public slots:
 	virtual void accept() override;
diff --git a/LVGLProject.cpp b/LVGLProject.cpp
index b2ba85c..372afcb 100644
--- a/LVGLProject.cpp
+++ b/LVGLProject.cpp
@@ -15,11 +15,13 @@
 
 LVGLProject::LVGLProject()
 	: m_name("App")
+	, m_resolution(LV_HOR_RES_MAX, LV_VER_RES_MAX)
 {
 }
 
-LVGLProject::LVGLProject(const QString &name)
+LVGLProject::LVGLProject(const QString &name, QSize resolution)
 	: m_name(name)
+	, m_resolution(resolution)
 {
 }
 
@@ -28,6 +30,11 @@ QString LVGLProject::name() const
 	return m_name;
 }
 
+QSize LVGLProject::resolution() const
+{
+	return m_resolution;
+}
+
 LVGLProject *LVGLProject::load(const QString &fileName)
 {
 	QFile file(fileName);
@@ -42,6 +49,14 @@ LVGLProject *LVGLProject::load(const QString &fileName)
 	if (!lvglObj.contains("widgets"))
 		return nullptr;
 
+	QSize resolution;
+	if (lvglObj.contains("resolution")) {
+		QJsonObject res = lvglObj["resolution"].toObject();
+		resolution = QSize(res["width"].toInt(), res["height"].toInt());
+	} else {
+		resolution = QSize(LV_HOR_RES_MAX, LV_VER_RES_MAX);
+	}
+
 	QJsonArray imageArr = doc["images"].toArray();
 	for (int i = 0; i < imageArr.size(); ++i) {
 		LVGLImageData *img = new LVGLImageData(imageArr[i].toObject());
@@ -62,7 +77,7 @@ LVGLProject *LVGLProject::load(const QString &fileName)
 		LVGLObject::parse(object, nullptr);
 	}
 
-	return new LVGLProject(lvglObj["name"].toString());
+	return new LVGLProject(lvglObj["name"].toString(), resolution);
 }
 
 bool LVGLProject::save(const QString &fileName) const
@@ -90,8 +105,12 @@ bool LVGLProject::save(const QString &fileName) const
 	for (const LVGLFontData *f:lvgl.customFonts())
 		fontArr.append(f->toJson());
 
+	QJsonObject resolution({{"width", m_resolution.width()},
+									{"height", m_resolution.height()}
+								  });
 	QJsonObject screen({{"widgets", widgetArr},
-							  {"name", m_name}
+							  {"name", m_name},
+							  {"resolution", resolution}
 							 });
 	if (lvgl.screenColorChanged())
 		screen.insert("screen color", QVariant(lvgl.screenColor()).toString());
diff --git a/LVGLProject.h b/LVGLProject.h
index c3a404b..a1e90b2 100644
--- a/LVGLProject.h
+++ b/LVGLProject.h
@@ -2,14 +2,16 @@
 #define LVGLPROJECT_H
 
 #include <QString>
+#include <QSize>
 
 class LVGLProject
 {
 public:
 	LVGLProject();
-	LVGLProject(const QString &name);
+	LVGLProject(const QString &name, QSize resolution);
 
 	QString name() const;
+	QSize resolution() const;
 
 	static LVGLProject *load(const QString &fileName);
 	bool save(const QString &fileName) const;
@@ -17,6 +19,7 @@ public:
 
 private:
 	QString m_name;
+	QSize m_resolution;
 
 };
 
diff --git a/LVGLSimulator.cpp b/LVGLSimulator.cpp
index c7090a9..3db853f 100644
--- a/LVGLSimulator.cpp
+++ b/LVGLSimulator.cpp
@@ -146,9 +146,9 @@ void LVGLSimulator::setMouseEnable(bool enable)
 	m_mouseEnabled = enable;
 }
 
-void LVGLSimulator::changeResolution(lv_coord_t width, lv_coord_t height)
+void LVGLSimulator::changeResolution(QSize size)
 {
-	m_scene->setSceneRect(0, 0, width, height);
+	m_scene->setSceneRect(0, 0, size.width(), size.height());
 }
 
 void LVGLSimulator::mousePressEvent(QMouseEvent *event)
diff --git a/LVGLSimulator.h b/LVGLSimulator.h
index 7a32321..0ac9ee7 100644
--- a/LVGLSimulator.h
+++ b/LVGLSimulator.h
@@ -50,7 +50,7 @@ public slots:
 	void setZoomLevel(int level);
 	void clear();
 	void setMouseEnable(bool enable);
-	void changeResolution(lv_coord_t width, lv_coord_t height);
+	void changeResolution(QSize size);
 
 signals:
 	void objectSelected(LVGLObject *obj);
diff --git a/MainWindow.cpp b/MainWindow.cpp
index f4d6485..f592b8f 100644
--- a/MainWindow.cpp
+++ b/MainWindow.cpp
@@ -168,7 +168,7 @@ void MainWindow::loadRecent()
 {
 	QAction *action = qobject_cast<QAction*>(QObject::sender());
 	if (action == nullptr) return;
-	loadUI(action->data().toString());
+	loadProject(action->data().toString());
 }
 
 void MainWindow::openNewProject()
@@ -176,14 +176,14 @@ void MainWindow::openNewProject()
 	LVGLNewDialog dialog(this);
 	if (dialog.exec() == QDialog::Accepted) {
 		delete m_project;
-		m_project = new LVGLProject(dialog.selectedName());
+		m_project = new LVGLProject(dialog.selectedName(), dialog.selectedResolution());
 		m_ui->simulation->clear();
 		setEnableBuilder(true);
 		setWindowTitle("LVGL Builder - [" + m_project->name() + "]");
 		const auto res = dialog.selectedResolution();
-		lvgl.changeResolution(res.first, res.second);
-		m_ui->simulation->changeResolution(res.first, res.second);
-	} else {
+		lvgl.changeResolution(res);
+		m_ui->simulation->changeResolution(res);
+	} else if (m_project == nullptr) {
 		setEnableBuilder(false);
 		setWindowTitle("LVGL Builder");
 	}
@@ -265,7 +265,7 @@ void MainWindow::adjustForCurrentFile(const QString &fileName)
 	updateRecentActionList();
 }
 
-void MainWindow::loadUI(const QString &fileName)
+void MainWindow::loadProject(const QString &fileName)
 {
 	delete m_project;
 	m_ui->simulation->clear();
@@ -277,6 +277,8 @@ void MainWindow::loadUI(const QString &fileName)
 	} else {
 		adjustForCurrentFile(fileName);
 		setWindowTitle("LVGL Builder - [" + m_project->name() + "]");
+		lvgl.changeResolution(m_project->resolution());
+		m_ui->simulation->changeResolution(m_project->resolution());
 		setEnableBuilder(true);
 	}
 	updateImages();
@@ -299,7 +301,7 @@ void MainWindow::on_action_load_triggered()
 	QString fileName = QFileDialog::getOpenFileName(this, "Load lvgl", "", "LVGL (*.lvgl)");
 	if (fileName.isEmpty())
 		return;
-	loadUI(fileName);
+	loadProject(fileName);
 }
 
 void MainWindow::on_action_save_triggered()
diff --git a/MainWindow.h b/MainWindow.h
index fdf4be6..58dec80 100644
--- a/MainWindow.h
+++ b/MainWindow.h
@@ -58,7 +58,7 @@ private:
 
 	void updateRecentActionList();
 	void adjustForCurrentFile(const QString &fileName);
-	void loadUI(const QString &fileName);
+	void loadProject(const QString &fileName);
 	void setEnableBuilder(bool enable);
 
 	Ui::MainWindow *m_ui;