From 51cf49fe312f92cccde3e861d357e4b459976c0d Mon Sep 17 00:00:00 2001
From: Joel Holdsworth <joel@airwebreathe.org.uk>
Date: Sat, 22 Nov 2014 16:25:19 +0000
Subject: [PATCH] MainWindow: Handle device selection failure

This fixes bug #455
---
 pv/mainwindow.cpp           | 18 ++++++++++++++++--
 pv/mainwindow.hpp           |  6 ++++++
 pv/sigsession.cpp           | 14 +++++++++++---
 pv/toolbars/samplingbar.cpp |  2 +-
 4 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/pv/mainwindow.cpp b/pv/mainwindow.cpp
index f9aa81df..cc0e0d25 100644
--- a/pv/mainwindow.cpp
+++ b/pv/mainwindow.cpp
@@ -110,6 +110,20 @@ void MainWindow::run_stop()
 	}
 }
 
+void MainWindow::select_device(shared_ptr<Device> device)
+{
+	try {
+		session_.set_device(device);
+	} catch(const QString &e) {
+		QMessageBox msg(this);
+		msg.setText(e);
+		msg.setInformativeText(tr("Failed to Select Device"));
+		msg.setStandardButtons(QMessageBox::Ok);
+		msg.setIcon(QMessageBox::Warning);
+		msg.exec();
+	}
+}
+
 void MainWindow::setup_ui()
 {
 	setObjectName(QString::fromUtf8("MainWindow"));
@@ -364,7 +378,7 @@ void MainWindow::restore_ui_settings()
 	device = device_manager_.find_device_from_info(dev_info);
 
 	if (device) {
-		session_.set_device(device);
+		select_device(device);
 		update_device_list();
 	}
 
@@ -497,7 +511,7 @@ void MainWindow::on_actionConnect_triggered()
 	// If the user selected a device, select it in the device list. Select the
 	// current device otherwise.
 	if (dlg.exec())
-		session_.set_device(dlg.get_selected_device());
+		select_device(dlg.get_selected_device());
 
 	update_device_list();
 }
diff --git a/pv/mainwindow.hpp b/pv/mainwindow.hpp
index c7859d0a..8a67c615 100644
--- a/pv/mainwindow.hpp
+++ b/pv/mainwindow.hpp
@@ -32,6 +32,10 @@ struct srd_decoder;
 
 class QVBoxLayout;
 
+namespace sigrok {
+class Device;
+}
+
 namespace pv {
 
 class DeviceManager;
@@ -60,6 +64,8 @@ public:
 
 	void run_stop();
 
+	void select_device(std::shared_ptr<sigrok::Device> device);
+
 private:
 	void setup_ui();
 
diff --git a/pv/sigsession.cpp b/pv/sigsession.cpp
index 87ba9afa..84c75896 100644
--- a/pv/sigsession.cpp
+++ b/pv/sigsession.cpp
@@ -137,22 +137,30 @@ void Session::set_device(shared_ptr<Device> device)
 	if (session_device)
 		session_ = session_device->parent();
 
-	device_ = device;
 	decode_traces_.clear();
 
 	if (device) {
 		if (!session_device)
 		{
 			session_ = device_manager_.context()->create_session();
-			device->open();
+
+			try {
+				device->open();
+			} catch(const sigrok::Error &e) {
+				throw QString(e.what());
+			}
+
 			session_->add_device(device);
 		}
+
+		device_ = device;
 		session_->add_datafeed_callback([=]
 			(shared_ptr<Device> device, shared_ptr<Packet> packet) {
 				data_feed_in(device, packet);
 			});
 		update_signals(device);
-	}
+	} else
+		device_ = nullptr;
 
 	device_selected();
 }
diff --git a/pv/toolbars/samplingbar.cpp b/pv/toolbars/samplingbar.cpp
index cddfa5f5..b5a2aee5 100644
--- a/pv/toolbars/samplingbar.cpp
+++ b/pv/toolbars/samplingbar.cpp
@@ -432,7 +432,7 @@ void SamplingBar::on_device_selected()
 	if (!device)
 		return;
 
-	session_.set_device(device);
+	main_window_.select_device(device);
 
 	update_device_config_widgets();
 }
-- 
2.30.2