evdevtouch: Add hotplug support

Follow the exact same structure as evdevmouse and keyboard.

We must do monitoring via device discovery just like we do for keyboards and mice.
Otherwise the usage of touchscreens that connect via USB or can be turned on/off
independently from the board becomes troublesome.

Change-Id: I2de3b519e8d617b0612e5df486e481bbc09b9c8c
Reviewed-by: Andy Nichols <andy.nichols@theqtcompany.com>

1 files changed, 122 insertions, 0 deletions

diff --git a/src/platformsupport/input/evdevtouch/qevdevtouchmanager.cpp b/src/platformsupport/input/evdevtouch/qevdevtouchmanager.cpp
new file mode 100644
index 0000000000..98fc83700c
--- /dev/null
+++ b/src/platformsupport/input/evdevtouch/qevdevtouchmanager.cpp
@@ -0,0 +1,122 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the plugins module of the Qt Toolkit.
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+** $QT_BEGIN_LICENSE:LGPL21$
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+** accordance with the commercial license agreement provided with the
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+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
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+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qevdevtouchmanager_p.h"
+#include "qevdevtouchhandler_p.h"
+
+#include <QStringList>
+#include <QGuiApplication>
+#include <QLoggingCategory>
+#include <QtPlatformSupport/private/qdevicediscovery_p.h>
+#include <private/qguiapplication_p.h>
+#include <private/qinputdevicemanager_p_p.h>
+
+QT_BEGIN_NAMESPACE
+
+Q_DECLARE_LOGGING_CATEGORY(qLcEvdevTouch)
+
+QEvdevTouchManager::QEvdevTouchManager(const QString &key, const QString &specification, QObject *parent)
+    : QObject(parent)
+{
+    Q_UNUSED(key);
+
+    if (qEnvironmentVariableIsSet("QT_QPA_EVDEV_DEBUG"))
+        const_cast<QLoggingCategory &>(qLcEvdevTouch()).setEnabled(QtDebugMsg, true);
+
+    QString spec = QString::fromLocal8Bit(qgetenv("QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS"));
+
+    if (spec.isEmpty())
+        spec = specification;
+
+    QStringList args = spec.split(QLatin1Char(':'));
+    QStringList devices;
+
+    foreach (const QString &arg, args) {
+        if (arg.startsWith(QLatin1String("/dev/"))) {
+            devices.append(arg);
+            args.removeAll(arg);
+        }
+    }
+
+    // build new specification without /dev/ elements
+    m_spec = args.join(QLatin1Char(':'));
+
+    foreach (const QString &device, devices)
+        addDevice(device);
+
+    // when no devices specified, use device discovery to scan and monitor
+    if (devices.isEmpty()) {
+        qCDebug(qLcEvdevTouch) << "evdevtouch: Using device discovery";
+        m_deviceDiscovery = QDeviceDiscovery::create(QDeviceDiscovery::Device_Touchpad | QDeviceDiscovery::Device_Touchscreen, this);
+        if (m_deviceDiscovery) {
+            QStringList devices = m_deviceDiscovery->scanConnectedDevices();
+            foreach (const QString &device, devices)
+                addDevice(device);
+            connect(m_deviceDiscovery, SIGNAL(deviceDetected(QString)), this, SLOT(addDevice(QString)));
+            connect(m_deviceDiscovery, SIGNAL(deviceRemoved(QString)), this, SLOT(removeDevice(QString)));
+        }
+    }
+}
+
+QEvdevTouchManager::~QEvdevTouchManager()
+{
+    qDeleteAll(m_activeDevices);
+}
+
+void QEvdevTouchManager::addDevice(const QString &deviceNode)
+{
+    qCDebug(qLcEvdevTouch) << "Adding device at" << deviceNode;
+    QEvdevTouchScreenHandlerThread *handler;
+    handler = new QEvdevTouchScreenHandlerThread(deviceNode, m_spec);
+    if (handler) {
+        m_activeDevices.insert(deviceNode, handler);
+        QInputDeviceManagerPrivate::get(QGuiApplicationPrivate::inputDeviceManager())->setDeviceCount(
+            QInputDeviceManager::DeviceTypeTouch, m_activeDevices.count());
+    } else {
+        qWarning("evdevtouch: Failed to open touch device %s", qPrintable(deviceNode));
+    }
+}
+
+void QEvdevTouchManager::removeDevice(const QString &deviceNode)
+{
+    if (m_activeDevices.contains(deviceNode)) {
+        qCDebug(qLcEvdevTouch) << "Removing device at" << deviceNode;
+        QEvdevTouchScreenHandlerThread *handler = m_activeDevices.value(deviceNode);
+        m_activeDevices.remove(deviceNode);
+        QInputDeviceManagerPrivate::get(QGuiApplicationPrivate::inputDeviceManager())->setDeviceCount(
+            QInputDeviceManager::DeviceTypeTouch, m_activeDevices.count());
+        delete handler;
+    }
+}
+
+QT_END_NAMESPACE