Add libinput support

Supports relative pointer, axis, keyboard and touch events.

libinput support is only available in combination with libudev.
libxkbcommon is required to perform key mapping. For now the
default keymap is used always (selected when building xkbcommon).

[ChangeLog][QtGui] Added a plugin to get mouse, keyboard and touch events
via libinput.

Change-Id: I469d8992c0cd3e79225cefaeb931697baf86a92b
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

1 files changed, 165 insertions, 0 deletions

diff --git a/src/platformsupport/input/libinput/qlibinputtouch.cpp b/src/platformsupport/input/libinput/qlibinputtouch.cpp
new file mode 100644
index 0000000000..ed453a6a9a
--- /dev/null
+++ b/src/platformsupport/input/libinput/qlibinputtouch.cpp
@@ -0,0 +1,165 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the plugins module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia. For licensing terms and
+** conditions see http://qt.digia.com/licensing. For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** 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
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights. These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qlibinputtouch_p.h"
+#include <libinput.h>
+#include <QtGui/QGuiApplication>
+#include <QtGui/QScreen>
+
+QT_BEGIN_NAMESPACE
+
+QWindowSystemInterface::TouchPoint *QLibInputTouch::DeviceState::point(int32_t slot)
+{
+    const int id = qMax(0, slot);
+
+    for (int i = 0; i < m_points.count(); ++i)
+        if (m_points.at(i).id == id)
+            return &m_points[i];
+
+    return Q_NULLPTR;
+}
+
+QLibInputTouch::DeviceState *QLibInputTouch::deviceState(libinput_event_touch *e)
+{
+    libinput_device *dev = libinput_event_get_device(libinput_event_touch_get_base_event(e));
+    return &m_devState[dev];
+}
+
+static inline QPointF getPos(libinput_event_touch *e)
+{
+    const QSize screenSize = QGuiApplication::primaryScreen()->geometry().size();
+    const double x = libinput_event_touch_get_x_transformed(e, screenSize.width());
+    const double y = libinput_event_touch_get_y_transformed(e, screenSize.height());
+    return QPointF(x, y);
+}
+
+void QLibInputTouch::registerDevice(libinput_device *dev)
+{
+    QTouchDevice *&td = m_devState[dev].m_touchDevice;
+    td = new QTouchDevice;
+    td->setName(QString::fromUtf8(libinput_device_get_name(dev)));
+    td->setType(QTouchDevice::TouchScreen);
+    td->setCapabilities(QTouchDevice::Position | QTouchDevice::Area);
+    QWindowSystemInterface::registerTouchDevice(td);
+}
+
+void QLibInputTouch::unregisterDevice(libinput_device *dev)
+{
+    Q_UNUSED(dev);
+    // There is no way to remove a QTouchDevice.
+}
+
+void QLibInputTouch::processTouchDown(libinput_event_touch *e)
+{
+    int slot = libinput_event_touch_get_slot(e);
+    DeviceState *state = deviceState(e);
+    QWindowSystemInterface::TouchPoint *tp = state->point(slot);
+    if (tp) {
+        qWarning("Incorrect touch state");
+    } else {
+        QWindowSystemInterface::TouchPoint newTp;
+        newTp.id = qMax(0, slot);
+        newTp.state = Qt::TouchPointPressed;
+        newTp.area = QRect(0, 0, 8, 8);
+        newTp.area.moveCenter(getPos(e));
+        state->m_points.append(newTp);
+    }
+}
+
+void QLibInputTouch::processTouchMotion(libinput_event_touch *e)
+{
+    int slot = libinput_event_touch_get_slot(e);
+    DeviceState *state = deviceState(e);
+    QWindowSystemInterface::TouchPoint *tp = state->point(slot);
+    if (tp) {
+        const QPointF p = getPos(e);
+        if (tp->area.center() != p) {
+            tp->area.moveCenter(p);
+            // 'down' may be followed by 'motion' within the same "frame".
+            // Handle this by compressing and keeping the Pressed state until the 'frame'.
+            if (tp->state != Qt::TouchPointPressed)
+                tp->state = Qt::TouchPointMoved;
+        } else {
+            tp->state = Qt::TouchPointStationary;
+        }
+    } else {
+        qWarning("Inconsistent touch state (got 'motion' without 'down')");
+    }
+}
+
+void QLibInputTouch::processTouchUp(libinput_event_touch *e)
+{
+    int slot = libinput_event_touch_get_slot(e);
+    DeviceState *state = deviceState(e);
+    QWindowSystemInterface::TouchPoint *tp = state->point(slot);
+    if (tp) {
+        tp->state = Qt::TouchPointReleased;
+        // There may not be a Frame event after the last Up. Work this around.
+        Qt::TouchPointStates s = 0;
+        for (int i = 0; i < state->m_points.count(); ++i)
+            s |= state->m_points.at(i).state;
+        if (s == Qt::TouchPointReleased)
+            processTouchFrame(e);
+    } else {
+        qWarning("Inconsistent touch state (got 'up' without 'down')");
+    }
+}
+
+void QLibInputTouch::processTouchCancel(libinput_event_touch *e)
+{
+    DeviceState *state = deviceState(e);
+    if (state->m_touchDevice)
+        QWindowSystemInterface::handleTouchCancelEvent(Q_NULLPTR, state->m_touchDevice, QGuiApplication::keyboardModifiers());
+    else
+        qWarning("TouchCancel without registered device");
+}
+
+void QLibInputTouch::processTouchFrame(libinput_event_touch *e)
+{
+    DeviceState *state = deviceState(e);
+    if (state->m_touchDevice && !state->m_points.isEmpty()) {
+        QWindowSystemInterface::handleTouchEvent(Q_NULLPTR, state->m_touchDevice, state->m_points,
+                                                 QGuiApplication::keyboardModifiers());
+        for (int i = 0; i < state->m_points.count(); ++i) {
+            QWindowSystemInterface::TouchPoint &tp(state->m_points[i]);
+            if (tp.state == Qt::TouchPointReleased)
+                state->m_points.removeAt(i--);
+            else if (tp.state == Qt::TouchPointPressed)
+                tp.state = Qt::TouchPointStationary;
+        }
+    } else {
+        qWarning("TouchFrame without registered device");
+    }
+}
+
+QT_END_NAMESPACE