Added DeviceManager

This class now manages the application device list, scanning for
devices, and releasing them when they are no longer needed.

This fixes bug #108.

CMakeLists.txt

@@ -100,6 +100,7 @@ configure_file (
 
 set(pulseview_SOURCES
 	main.cpp
+	pv/devicemanager.cpp
 	pv/mainwindow.cpp
 	pv/sigsession.cpp
 	pv/data/analog.cpp

main.cpp

@@ -34,6 +34,7 @@
 #include "signalhandler.h"
 #endif
 
+#include "pv/devicemanager.h"
 #include "pv/mainwindow.h"
 
 #include "config.h"
@@ -128,20 +129,12 @@ int main(int argc, char *argv[])
 		srd_decoder_load_all();
 #endif
 
-		// Initialize all libsigrok drivers
-		sr_dev_driver **const drivers = sr_driver_list();
-		for (sr_dev_driver **driver = drivers; *driver; driver++) {
-			if (sr_driver_init(sr_ctx, *driver) != SR_OK) {
-				qDebug("Failed to initialize driver %s",
-					(*driver)->name);
-				ret = 1;
-				break;
-			}
-		}
+		try {
+			// Create the device manager, initialise the drivers
+			pv::DeviceManager device_manager(sr_ctx);
 
-		if (ret == 0) {
 			// Initialise the main window
-			pv::MainWindow w(open_file);
+			pv::MainWindow w(device_manager, open_file);
 			w.show();
 
 #ifdef ENABLE_SIGNALS
@@ -162,6 +155,9 @@ int main(int argc, char *argv[])
 
 			// Run the application
 			ret = a.exec();
+
+		} catch(std::exception e) {
+			qDebug() << e.what();
 		}
 
 #ifdef ENABLE_SIGROKDECODE

pv/devicemanager.cpp

@@ -0,0 +1,135 @@
+/*
+ * This file is part of the PulseView project.
+ *
+ * Copyright (C) 2013 Joel Holdsworth <joel@airwebreathe.org.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#include "devicemanager.h"
+
+#include <cassert>
+#include <cstring>
+#include <stdexcept>
+#include <string>
+
+#include <libsigrok/libsigrok.h>
+
+using namespace std;
+
+namespace pv {
+
+DeviceManager::DeviceManager(struct sr_context *sr_ctx) :
+	_sr_ctx(sr_ctx)
+{
+	init_drivers();
+	scan_all_drivers();
+}
+
+DeviceManager::~DeviceManager()
+{
+	release_devices();
+}
+
+const std::list<sr_dev_inst*>& DeviceManager::devices() const
+{
+	return _devices;
+}
+
+list<sr_dev_inst*> DeviceManager::driver_scan(
+	struct sr_dev_driver *const driver, GSList *const drvopts)
+{
+	list<sr_dev_inst*> driver_devices;
+
+	assert(driver);
+
+	// Remove any device instances from this driver from the device
+	// list. They will not be valid after the scan.
+	list<sr_dev_inst*>::iterator i = _devices.begin();
+	while (i != _devices.end()) {
+		if ((*i)->driver == driver)
+			i = _devices.erase(i);
+		else
+			i++;
+	}
+
+	// Clear all the old device instances from this driver
+	sr_dev_clear(driver);
+
+	// Do the scan
+	GSList *const devices = sr_driver_scan(driver, drvopts);
+	for (GSList *l = devices; l; l = l->next)
+		driver_devices.push_back((sr_dev_inst*)l->data);
+	g_slist_free(devices);
+	driver_devices.sort(compare_devices);
+
+	// Add the scanned devices to the main list
+	_devices.insert(_devices.end(), driver_devices.begin(),
+		driver_devices.end());
+	_devices.sort(compare_devices);
+
+	return driver_devices;
+}
+
+void DeviceManager::init_drivers()
+{
+	// Initialise all libsigrok drivers
+	sr_dev_driver **const drivers = sr_driver_list();
+	for (sr_dev_driver **driver = drivers; *driver; driver++) {
+		if (sr_driver_init(_sr_ctx, *driver) != SR_OK) {
+			throw runtime_error(
+				string("Failed to initialize driver ") +
+				string((*driver)->name));
+		}
+	}
+}
+
+void DeviceManager::release_devices()
+{
+	sr_dev_driver **const drivers = sr_driver_list();
+	for (sr_dev_driver **driver = drivers; *driver; driver++)
+		sr_dev_clear(*driver);
+}
+
+void DeviceManager::scan_all_drivers()
+{
+	// Scan all drivers for all devices.
+	struct sr_dev_driver **const drivers = sr_driver_list();
+	for (struct sr_dev_driver **driver = drivers; *driver; driver++)
+		driver_scan(*driver);
+}
+
+bool DeviceManager::compare_devices(const sr_dev_inst *const a,
+	const sr_dev_inst *const b)
+{
+	assert(a);
+	assert(b);
+
+	const int vendor_cmp = strcasecmp(a->vendor, b->vendor);
+	if(vendor_cmp < 0)
+		return true;
+	else if(vendor_cmp > 0)
+		return false;
+
+	const int model_cmp = strcasecmp(a->model, b->model);
+	if(model_cmp < 0)
+		return true;
+	else if(model_cmp > 0)
+		return false;
+
+	return strcasecmp(a->version, b->version) < 0;
+}
+
+} // namespace pv

pv/devicemanager.h

@@ -0,0 +1,64 @@
+/*
+ * This file is part of the PulseView project.
+ *
+ * Copyright (C) 2013 Joel Holdsworth <joel@airwebreathe.org.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#ifndef PULSEVIEW_PV_DEVICEMANAGER_H
+#define PULSEVIEW_PV_DEVICEMANAGER_H
+
+#include <glib.h>
+
+#include <list>
+
+struct sr_context;
+struct sr_dev_driver;
+struct sr_dev_inst;
+
+namespace pv {
+
+class DeviceManager
+{
+public:
+	DeviceManager(struct sr_context *sr_ctx);
+
+	~DeviceManager();
+
+	const std::list<sr_dev_inst*>& devices() const;
+
+	std::list<sr_dev_inst*> driver_scan(
+		struct sr_dev_driver *const driver,
+		GSList *const drvopts = NULL);
+
+private:
+	void init_drivers();
+
+	static void release_devices();
+
+	void scan_all_drivers();
+
+	static bool compare_devices(const sr_dev_inst *const a,
+		const sr_dev_inst *const b);
+
+private:
+	struct sr_context *const _sr_ctx;
+	std::list<sr_dev_inst*> _devices;
+};
+
+} // namespace pv
+
+#endif // PULSEVIEW_PV_DEVICEMANAGER_H

pv/dialogs/connect.cpp

@@ -18,8 +18,12 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
+#include <boost/foreach.hpp>
+
 #include "connect.h"
 
+#include "pv/devicemanager.h"
+
 extern "C" {
 /* __STDC_FORMAT_MACROS is required for PRIu64 and friends (in C++). */
 #define __STDC_FORMAT_MACROS
@@ -27,13 +31,16 @@ extern "C" {
 #include <libsigrok/libsigrok.h>
 }
 
+using namespace std;
+
 extern sr_context *sr_ctx;
 
 namespace pv {
 namespace dialogs {
 
-Connect::Connect(QWidget *parent) :
+Connect::Connect(QWidget *parent, pv::DeviceManager &device_manager) :
 	QDialog(parent),
+	_device_manager(device_manager),
 	_layout(this),
 	_form(this),
 	_form_layout(&_form),
@@ -148,11 +155,12 @@ void Connect::scan_pressed()
 		drvopts = g_slist_append(drvopts, src);
 	}
 
-	GSList *const devices = sr_driver_scan(driver, drvopts);
+	const list<sr_dev_inst*> devices = _device_manager.driver_scan(
+		driver, drvopts);
 
-	for (GSList *l = devices; l; l = l->next) {
+	g_slist_free_full(drvopts, (GDestroyNotify)free_drvopts);
 
-		sr_dev_inst *const sdi = (sr_dev_inst*)l->data;
+	BOOST_FOREACH(sr_dev_inst *const sdi, devices) {
 
 		QString text;
 		if (sdi->vendor && sdi->vendor[0])
@@ -172,9 +180,6 @@ void Connect::scan_pressed()
 		_device_list.addItem(item);
 	}
 
-	g_slist_free(devices);
-	g_slist_free_full(drvopts, (GDestroyNotify)free_drvopts);
-
 	_device_list.setCurrentRow(0);
 	_button_box.button(QDialogButtonBox::Ok)->setDisabled(false);
 }

pv/dialogs/connect.h

@@ -34,6 +34,9 @@ struct sr_config;
 struct sr_dev_inst;
 
 namespace pv {
+
+class DeviceManager;
+
 namespace dialogs {
 
 class Connect : public QDialog
@@ -41,7 +44,7 @@ class Connect : public QDialog
 	Q_OBJECT
 
 public:
-	Connect(QWidget *parent);
+	Connect(QWidget *parent, pv::DeviceManager &device_manager);
 
 	struct sr_dev_inst* get_selected_device() const;
 
@@ -61,6 +64,8 @@ private:
 	static void free_drvopts(sr_config *src);
 
 private:
+	pv::DeviceManager &_device_manager;
+
 	QVBoxLayout _layout;
 
 	QWidget _form;

pv/mainwindow.cpp

@@ -23,6 +23,7 @@
 #endif
 
 #include <boost/bind.hpp>
+#include <boost/foreach.hpp>
 
 #include <QAction>
 #include <QApplication>
@@ -36,6 +37,8 @@
 #include <QWidget>
 
 #include "mainwindow.h"
+
+#include "devicemanager.h"
 #include "dialogs/about.h"
 #include "dialogs/connect.h"
 #include "toolbars/samplingbar.h"
@@ -49,12 +52,15 @@
 #include <glib.h>
 #include <libsigrok/libsigrok.h>
 
+using namespace std;
 
 namespace pv {
 
-MainWindow::MainWindow(const char *open_file_name,
+MainWindow::MainWindow(DeviceManager &device_manager,
+	const char *open_file_name,
 	QWidget *parent) :
-	QMainWindow(parent)
+	QMainWindow(parent),
+	_device_manager(device_manager)
 {
 	setup_ui();
 	if (open_file_name) {
@@ -189,12 +195,7 @@ void MainWindow::setup_ui()
 	_sampling_bar = new toolbars::SamplingBar(this);
 
 	// Populate the device list and select the initially selected device
-	scan_devices();
-	if(!_devices.empty()) {
-		struct sr_dev_inst *const initial_sdi = _devices.front();
-		_sampling_bar->set_selected_device(initial_sdi);
-		_session.set_device(initial_sdi);
-	}
+	update_device_list();
 
 	connect(_sampling_bar, SIGNAL(device_selected()), this,
 		SLOT(device_selected()));
@@ -212,23 +213,6 @@ void MainWindow::setup_ui()
 
 }
 
-void MainWindow::scan_devices()
-{
-	_devices.clear();
-
-	/* Scan all drivers for all devices. */
-	struct sr_dev_driver **const drivers = sr_driver_list();
-	for (struct sr_dev_driver **driver = drivers; *driver; driver++) {
-		GSList *const devices = sr_driver_scan(*driver, NULL);
-		for (GSList *l = devices; l; l = l->next)
-			_devices.push_back((sr_dev_inst*)l->data);
-		g_slist_free(devices);
-	}
-
-	assert(_sampling_bar);
-	_sampling_bar->set_device_list(_devices);
-}
-
 void MainWindow::session_error(
 	const QString text, const QString info_text)
 {
@@ -237,6 +221,30 @@ void MainWindow::session_error(
 		Q_ARG(QString, info_text));
 }
 
+void MainWindow::update_device_list(struct sr_dev_inst *selected_device)
+{
+	assert(_sampling_bar);
+
+	const list<sr_dev_inst*> &devices = _device_manager.devices();
+	_sampling_bar->set_device_list(devices);
+
+	if (!selected_device && !devices.empty()) {
+		// Fall back to the first device in the list.
+		selected_device = devices.front();
+
+		// Try and find the demo device and select that by default
+		BOOST_FOREACH (struct sr_dev_inst *sdi, devices)
+			if (strcmp(sdi->driver->name, "demo") == 0) {
+				selected_device = sdi;
+			}
+	}
+
+	if (selected_device) {
+		_sampling_bar->set_selected_device(selected_device);
+		_session.set_device(selected_device);
+	}
+}
+
 void MainWindow::load_file(QString file_name)
 {
 	const QString errorMessage(
@@ -269,20 +277,12 @@ void MainWindow::on_actionOpen_triggered()
 
 void MainWindow::on_actionConnect_triggered()
 {
-	dialogs::Connect dlg(this);
+	dialogs::Connect dlg(this, _device_manager);
 	if (!dlg.exec())
 		return;
 
 	struct sr_dev_inst *const sdi = dlg.get_selected_device();
-	if (sdi) {
-		assert(_sampling_bar);
-
-		_devices.push_back(sdi);
-		_sampling_bar->set_device_list(_devices);
-		_sampling_bar->set_selected_device(sdi);
-
-		_session.set_device(sdi);
-	}
+	update_device_list(sdi);
 }
 
 void MainWindow::on_actionQuit_triggered()

pv/mainwindow.h

@@ -37,6 +37,8 @@ class QWidget;
 
 namespace pv {
 
+class DeviceManager;
+
 namespace toolbars {
 class SamplingBar;
 }
@@ -50,15 +52,24 @@ class MainWindow : public QMainWindow
 	Q_OBJECT
 
 public:
-	explicit MainWindow(const char *open_file_name = NULL,
+	explicit MainWindow(DeviceManager &device_manager,
+		const char *open_file_name = NULL,
 		QWidget *parent = 0);
 
 private:
 	void setup_ui();
-	void scan_devices();
 
 	void session_error(const QString text, const QString info_text);
 
+	/**
+	 * Updates the device list in the sampling bar, and updates the
+	 * selection.
+	 * @param selected_device The device to select, or NULL if the
+	 * first device in the device list should be selected.
+	 */
+	void update_device_list(
+		struct sr_dev_inst *selected_device = NULL);
+
 private slots:
 	void load_file(QString file_name);
 
@@ -86,9 +97,9 @@ private slots:
 	void capture_state_changed(int state);
 
 private:
+	DeviceManager &_device_manager;
 
 	SigSession _session;
-	std::list<sr_dev_inst*> _devices;
 
 	pv::view::View *_view;