Long live the TuioTouch input plugin!

This is an import of the tuio2qt plugin (https://github.com/rburchell/tuio2qt),
as of sha 9b1f163ac52ea440e83f16b3906f9b55e21b87be henceforth to be developed as
a part of Qt itself.

This plugin offers touch events via QPA interfaces, using data offered over the
TUIO protocol (http://www.tuio.org).

It is useful for accepting touch input on devices which otherwise don't have
touch input (such as desktops) for the purposes of development, as well as
accepting input from some hardware which offers up touch events specifically
over the TUIO protocol.

Known "shortcomings" at this time, as documented in the README:
 * Multiple TUIO sources sending data at the same time will conflict. This will
   not cause problems, strictly speaking, but it will not work well (repeated
   touchpoint release/press events for the same IDs)
 * TCP transport is not currently supported. I don't see a need for it at this
   time, but I have left the capability in terms of port acceptance open for it
   to be made available.

Change-Id: I7178f9db13c635268db8460fbe4d4ea6be654c05
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

1 files changed, 337 insertions, 0 deletions

diff --git a/src/plugins/generic/tuiotouch/qtuiohandler.cpp b/src/plugins/generic/tuiotouch/qtuiohandler.cpp
new file mode 100644
index 0000000000..cf588afebc
--- /dev/null
+++ b/src/plugins/generic/tuiotouch/qtuiohandler.cpp
@@ -0,0 +1,337 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Robin Burchell <robin.burchell@viroteck.net>
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtCore 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 <QLoggingCategory>
+#include <QRect>
+#include <QWindow>
+#include <QGuiApplication>
+
+#include <qpa/qwindowsysteminterface.h>
+
+#include "qtuiocursor_p.h"
+#include "qtuiohandler_p.h"
+#include "qoscbundle_p.h"
+
+QT_BEGIN_NAMESPACE
+
+Q_LOGGING_CATEGORY(lcTuioSource, "qt.qpa.tuio.source")
+Q_LOGGING_CATEGORY(lcTuioSet, "qt.qpa.tuio.set")
+
+QTuioHandler::QTuioHandler(const QString &specification)
+    : m_device(new QTouchDevice) // not leaked, QTouchDevice cleans up registered devices itself
+{
+    QStringList args = specification.split(':');
+    int portNumber = 3333;
+    int rotationAngle = 0;
+    bool invertx = false;
+    bool inverty = false;
+
+    for (int i = 0; i < args.count(); ++i) {
+        if (args.at(i).startsWith("udp=")) {
+            QString portString = args.at(i).section('=', 1, 1);
+            portNumber = portString.toInt();
+        } else if (args.at(i).startsWith("tcp=")) {
+            QString portString = args.at(i).section('=', 1, 1);
+            portNumber = portString.toInt();
+            qWarning() << "TCP is not yet supported. Falling back to UDP on " << portNumber;
+        } else if (args.at(i) == "invertx") {
+            invertx = true;
+        } else if (args.at(i) == "inverty") {
+            inverty = true;
+        } else if (args.at(i).startsWith("rotate=")) {
+            QString rotateArg = args.at(i).section('=', 1, 1);
+            int argValue = rotateArg.toInt();
+            switch (argValue) {
+            case 90:
+            case 180:
+            case 270:
+                rotationAngle = argValue;
+            default:
+                break;
+            }
+        }
+    }
+
+    if (rotationAngle)
+        m_transform = QTransform::fromTranslate(0.5, 0.5).rotate(rotationAngle).translate(-0.5, -0.5);
+
+    if (invertx)
+        m_transform *= QTransform::fromTranslate(0.5, 0.5).scale(-1.0, 1.0).translate(-0.5, -0.5);
+
+    if (inverty)
+        m_transform *= QTransform::fromTranslate(0.5, 0.5).scale(1.0, -1.0).translate(-0.5, -0.5);
+
+    m_device->setName("TUIO"); // TODO: multiple based on SOURCE?
+    m_device->setType(QTouchDevice::TouchScreen);
+    m_device->setCapabilities(QTouchDevice::Position |
+                              QTouchDevice::Area |
+                              QTouchDevice::Velocity |
+                              QTouchDevice::NormalizedPosition);
+    QWindowSystemInterface::registerTouchDevice(m_device);
+
+    if (!m_socket.bind(QHostAddress::Any, portNumber)) {
+        qWarning() << "Failed to bind TUIO socket: " << m_socket.errorString();
+        return;
+    }
+
+    connect(&m_socket, &QUdpSocket::readyRead, this, &QTuioHandler::processPackets);
+}
+
+QTuioHandler::~QTuioHandler()
+{
+}
+
+void QTuioHandler::processPackets()
+{
+    while (m_socket.hasPendingDatagrams()) {
+        QByteArray datagram;
+        datagram.resize(m_socket.pendingDatagramSize());
+        QHostAddress sender;
+        quint16 senderPort;
+
+        qint64 size = m_socket.readDatagram(datagram.data(), datagram.size(),
+                                             &sender, &senderPort);
+
+        if (size == -1)
+            continue;
+
+        if (size != datagram.size())
+            datagram.resize(size);
+
+        QOscBundle bundle(datagram);
+        if (!bundle.isValid())
+            continue;
+
+        // "A typical TUIO bundle will contain an initial ALIVE message,
+        // followed by an arbitrary number of SET messages that can fit into the
+        // actual bundle capacity and a concluding FSEQ message. A minimal TUIO
+        // bundle needs to contain at least the compulsory ALIVE and FSEQ
+        // messages. The FSEQ frame ID is incremented for each delivered bundle,
+        // while redundant bundles can be marked using the frame sequence ID
+        // -1."
+        QList<QOscMessage> messages = bundle.messages();
+
+        foreach (const QOscMessage &message, messages) {
+            if (message.addressPattern() != "/tuio/2Dcur") {
+                qWarning() << "Ignoring unknown address pattern " << message.addressPattern();
+                continue;
+            }
+
+            QList<QVariant> arguments = message.arguments();
+            if (arguments.count() == 0) {
+                qWarning() << "Ignoring TUIO message with no arguments";
+                continue;
+            }
+
+            QByteArray messageType = arguments.at(0).toByteArray();
+            if (messageType == "source") {
+                process2DCurSource(message);
+            } else if (messageType == "alive") {
+                process2DCurAlive(message);
+            } else if (messageType == "set") {
+                process2DCurSet(message);
+            } else if (messageType == "fseq") {
+                process2DCurFseq(message);
+            } else {
+                qWarning() << "Ignoring unknown TUIO message type: " << messageType;
+                continue;
+            }
+        }
+    }
+}
+
+void QTuioHandler::process2DCurSource(const QOscMessage &message)
+{
+    QList<QVariant> arguments = message.arguments();
+    if (arguments.count() != 2) {
+        qWarning() << "Ignoring malformed TUIO source message: " << arguments.count();
+        return;
+    }
+
+    if (QMetaType::Type(arguments.at(1).type()) != QMetaType::QByteArray) {
+        qWarning() << "Ignoring malformed TUIO source message (bad argument type)";
+        return;
+    }
+
+    qCDebug(lcTuioSource) << "Got TUIO source message from: " << arguments.at(1).toByteArray();
+}
+
+void QTuioHandler::process2DCurAlive(const QOscMessage &message)
+{
+    QList<QVariant> arguments = message.arguments();
+
+    // delta the notified cursors that are active, against the ones we already
+    // know of.
+    //
+    // TBD: right now we're assuming one 2Dcur alive message corresponds to a
+    // new data source from the input. is this correct, or do we need to store
+    // changes and only process the deltas on fseq?
+    QMap<int, QTuioCursor> oldActiveCursors = m_activeCursors;
+    QMap<int, QTuioCursor> newActiveCursors;
+
+    for (int i = 1; i < arguments.count(); ++i) {
+        if (QMetaType::Type(arguments.at(i).type()) != QMetaType::Int) {
+            qWarning() << "Ignoring malformed TUIO alive message (bad argument on position" << i << arguments << ")";
+            return;
+        }
+
+        int cursorId = arguments.at(i).toInt();
+        if (!oldActiveCursors.contains(cursorId)) {
+            // newly active
+            QTuioCursor cursor(cursorId);
+            cursor.setState(Qt::TouchPointPressed);
+            newActiveCursors.insert(cursorId, cursor);
+        } else {
+            // we already know about it, remove it so it isn't marked as released
+            QTuioCursor cursor = oldActiveCursors.value(cursorId);
+            cursor.setState(Qt::TouchPointStationary); // position change in SET will update if needed
+            newActiveCursors.insert(cursorId, cursor);
+            oldActiveCursors.remove(cursorId);
+        }
+    }
+
+    // anything left is dead now
+    QMap<int, QTuioCursor>::ConstIterator it = oldActiveCursors.constBegin();
+
+    // deadCursors should be cleared from the last FSEQ now
+    m_deadCursors.reserve(oldActiveCursors.size());
+
+    // TODO: there could be an issue of resource exhaustion here if FSEQ isn't
+    // sent in a timely fashion. we should probably track message counts and
+    // force-flush if we get too many built up.
+    while (it != oldActiveCursors.constEnd()) {
+        m_deadCursors.append(it.value());
+        ++it;
+    }
+
+    m_activeCursors = newActiveCursors;
+}
+
+void QTuioHandler::process2DCurSet(const QOscMessage &message)
+{
+    QList<QVariant> arguments = message.arguments();
+    if (arguments.count() < 7) {
+        qWarning() << "Ignoring malformed TUIO set message with too few arguments: " << arguments.count();
+        return;
+    }
+
+    if (QMetaType::Type(arguments.at(1).type()) != QMetaType::Int   ||
+        QMetaType::Type(arguments.at(2).type()) != QMetaType::Float ||
+        QMetaType::Type(arguments.at(3).type()) != QMetaType::Float ||
+        QMetaType::Type(arguments.at(4).type()) != QMetaType::Float ||
+        QMetaType::Type(arguments.at(5).type()) != QMetaType::Float ||
+        QMetaType::Type(arguments.at(6).type()) != QMetaType::Float
+       ) {
+        qWarning() << "Ignoring malformed TUIO set message with bad types: " << arguments;
+        return;
+    }
+
+    int cursorId = arguments.at(1).toInt();
+    float x = arguments.at(2).toFloat();
+    float y = arguments.at(3).toFloat();
+    float vx = arguments.at(4).toFloat();
+    float vy = arguments.at(5).toFloat();
+    float acceleration = arguments.at(6).toFloat();
+
+    QMap<int, QTuioCursor>::Iterator it = m_activeCursors.find(cursorId);
+    if (it == m_activeCursors.end()) {
+        qWarning() << "Ignoring malformed TUIO set for nonexistent cursor " << cursorId;
+        return;
+    }
+
+    qCDebug(lcTuioSet) << "Processing SET for " << cursorId << " x: " << x << y << vx << vy << acceleration;
+    QTuioCursor &cur = *it;
+    cur.setX(x);
+    cur.setY(y);
+    cur.setVX(vx);
+    cur.setVY(vy);
+    cur.setAcceleration(acceleration);
+}
+
+QWindowSystemInterface::TouchPoint QTuioHandler::cursorToTouchPoint(const QTuioCursor &tc, QWindow *win)
+{
+    QWindowSystemInterface::TouchPoint tp;
+    tp.id = tc.id();
+    tp.pressure = 1.0f;
+
+    tp.normalPosition = QPointF(tc.x(), tc.y());
+
+    if (!m_transform.isIdentity())
+        tp.normalPosition = m_transform.map(tp.normalPosition);
+
+    tp.state = tc.state();
+    tp.area = QRectF(0, 0, 1, 1);
+
+    // we map the touch to the size of the window. we do this, because frankly,
+    // trying to figure out which part of the screen to hit in order to press an
+    // element on the UI is pretty tricky when one is not using an overlay-style
+    // TUIO device.
+    //
+    // in the future, it might make sense to make this choice optional,
+    // dependent on the spec.
+    QPointF relPos = QPointF(win->size().width() * tp.normalPosition.x(), win->size().height() * tp.normalPosition.y());
+    QPointF delta = relPos - relPos.toPoint();
+    tp.area.moveCenter(win->mapToGlobal(relPos.toPoint()) + delta);
+    tp.velocity = QVector2D(win->size().width() * tc.vx(), win->size().height() * tc.vy());
+    return tp;
+}
+
+
+void QTuioHandler::process2DCurFseq(const QOscMessage &message)
+{
+    Q_UNUSED(message); // TODO: do we need to do anything with the frame id?
+
+    QWindow *win = QGuiApplication::focusWindow();
+    if (!win)
+        return;
+
+    QList<QWindowSystemInterface::TouchPoint> tpl;
+
+    foreach (const QTuioCursor &tc, m_activeCursors) {
+        QWindowSystemInterface::TouchPoint tp = cursorToTouchPoint(tc, win);
+        tpl.append(tp);
+    }
+
+    foreach (const QTuioCursor &tc, m_deadCursors) {
+        QWindowSystemInterface::TouchPoint tp = cursorToTouchPoint(tc, win);
+        tp.state = Qt::TouchPointReleased;
+        tpl.append(tp);
+    }
+    QWindowSystemInterface::handleTouchEvent(win, m_device, tpl);
+
+    m_deadCursors.clear();
+}
+
+QT_END_NAMESPACE
+