FGQCanvas: Multi-window support (for RPi4)

To support EGLFS on the RPi4 dual outputs, enable multiple windows
within a single process.

utils/fgqcanvas/WindowData.cpp

@@ -0,0 +1,86 @@
+#include "WindowData.h"
+
+#include <QScreen>
+#include <QGuiApplication>
+#include <QDebug>
+
+#include "jsonutils.h"
+
+WindowData::WindowData(QObject *parent) : QObject(parent)
+{
+
+}
+
+QJsonObject WindowData::saveState() const
+{
+    QJsonObject json;
+    json["rect"] = rectToJsonArray(m_windowRect);
+    if (!m_screenName.isEmpty()) {
+        json["screen"] = m_screenName;
+    }
+    if (!m_title.isEmpty()) {
+        json["title"] = m_title;
+    }
+    // support frameless option here?
+    json["state"] = static_cast<int>(m_state);
+    return json;
+}
+
+bool WindowData::restoreState(QJsonObject state)
+{
+    m_windowRect = jsonArrayToRect(state.value("rect").toArray());
+    emit windowRectChanged(m_windowRect);
+
+    if (state.contains("screen")) {
+        m_screenName = state.value("screen").toString();
+    } else {
+        m_screenName.clear();
+    }
+
+    if (state.contains("title")) {
+        m_title = state.value("title").toString();
+    }
+
+    if (state.contains("state")) {
+        m_state = static_cast<Qt::WindowState>(state.value("state").toInt());
+    }
+
+    return true;
+}
+
+QRect WindowData::windowRect() const
+{
+    return m_windowRect;
+}
+
+QScreen *WindowData::screen() const
+{
+    if (m_screenName.isEmpty())
+        return nullptr;
+
+    QStringList screenNames;
+    Q_FOREACH(auto s, qApp->screens()) {
+        if (s->name() == m_screenName) {
+            return s;
+        }
+        screenNames.append(s->name());
+    }
+
+    qWarning() << "couldn't find a screen with name:" << m_screenName;
+    qWarning() << "Available screens:" << screenNames.join(", ");
+    return nullptr;
+}
+
+void WindowData::setWindowState(Qt::WindowState ws)
+{
+    m_state = ws;
+}
+
+void WindowData::setWindowRect(QRect windowRect)
+{
+    if (m_windowRect == windowRect)
+        return;
+
+    m_windowRect = windowRect;
+    emit windowRectChanged(m_windowRect);
+}

utils/fgqcanvas/WindowData.h

@@ -0,0 +1,46 @@
+#ifndef WINDOWDATA_H
+#define WINDOWDATA_H
+
+#include <QObject>
+#include <QJsonObject>
+#include <QRect>
+
+class QScreen;
+
+class WindowData : public QObject
+{
+    Q_OBJECT
+
+    Q_PROPERTY(QRect windowRect READ windowRect WRITE setWindowRect NOTIFY windowRectChanged)
+public:
+    explicit WindowData(QObject *parent = nullptr);
+
+    QJsonObject saveState() const;
+    bool restoreState(QJsonObject state);
+
+    QRect windowRect() const;
+    QScreen* screen() const;
+
+    Qt::WindowState windowState() const
+    { return m_state; }
+
+    void setWindowState(Qt::WindowState ws);
+
+    QString title() const
+    { return m_title; }
+signals:
+
+    void windowRectChanged(QRect windowRect);
+
+public slots:
+
+    void setWindowRect(QRect windowRect);
+
+private:
+    QRect m_windowRect;
+    Qt::WindowState m_state = Qt::WindowNoState;
+    QString m_screenName;
+    QString m_title;
+};
+
+#endif // WINDOWDATA_H

utils/fgqcanvas/applicationcontroller.cpp

@@ -36,9 +36,12 @@
 #include <QTimer>
 #include <QGuiApplication>
 #include <QSettings>
+#include <QQuickView>
+#include <QQmlContext>
 
 #include "jsonutils.h"
 #include "canvasconnection.h"
+#include "WindowData.h"
 
 ApplicationController::ApplicationController(QObject *parent)
     : QObject(parent)
@@ -72,18 +75,6 @@ ApplicationController::~ApplicationController()
     delete m_netAccess;
 }
 
-void ApplicationController::setWindow(QWindow *window)
-{
-    m_window = window;
-}
-
-void ApplicationController::restoreWindowState()
-{
-    if (!m_window)
-        return;
-    m_window->setWindowState(m_windowState);
-}
-
 void ApplicationController::loadFromFile(QString path)
 {
     if (!QFile::exists(path)) {
@@ -104,6 +95,42 @@ void ApplicationController::setDaemonMode()
     m_daemonMode = true;
 }
 
+void ApplicationController::createWindows()
+{
+    if (m_windowList.empty()) {
+        defineDefaultWindow();
+    }
+
+    for (int index = 0; index < m_windowList.size(); ++index) {
+        auto wd = m_windowList.at(index);
+        QQuickView* qqv = new QQuickView;
+        qqv->rootContext()->setContextProperty("_application", this);
+        qqv->rootContext()->setContextProperty("_windowNumber", index);
+        qqv->setResizeMode(QQuickView::SizeRootObjectToView);
+        qqv->setSource(QUrl{"qrc:///qml/Window.qml"});
+        qqv->setTitle(wd->title());
+
+        if (m_daemonMode) {
+            qqv->setScreen(wd->screen());
+            qqv->setGeometry(wd->windowRect());
+            qqv->setWindowState(wd->windowState());
+        } else {
+            // interactive mode, restore window size etc
+
+        }
+
+        qqv->show();
+    }
+}
+
+void ApplicationController::defineDefaultWindow()
+{
+    auto w = new WindowData(this);
+    w->setWindowRect(QRect{0, 0, 1024, 768});
+    m_windowList.append(w);
+    emit windowListChanged();
+}
+
 void ApplicationController::save(QString configName)
 {
     QDir d(QStandardPaths::writableLocation(QStandardPaths::AppDataLocation));
@@ -364,6 +391,11 @@ QQmlListProperty<CanvasConnection> ApplicationController::activeCanvases()
     return QQmlListProperty<CanvasConnection>(this, m_activeCanvases);
 }
 
+QQmlListProperty<WindowData> ApplicationController::windowList()
+{
+    return QQmlListProperty<WindowData>(this, m_windowList);
+}
+
 QNetworkAccessManager *ApplicationController::netAccess() const
 {
     return m_netAccess;
@@ -371,6 +403,9 @@ QNetworkAccessManager *ApplicationController::netAccess() const
 
 bool ApplicationController::showUI() const
 {
+    if (m_daemonMode)
+        return false;
+
     if (m_blockUIIdle)
         return true;
 
@@ -490,10 +525,12 @@ QByteArray ApplicationController::saveState(QString name) const
     }
 
     json["canvases"] = canvases;
-    if (m_window) {
+
-        json["window-rect"] = rectToJsonArray(m_window->geometry());
+    QJsonArray windows;
-        json["window-state"] = static_cast<int>(m_window->windowState());
+    Q_FOREACH (auto w, m_windowList) {
+        windows.append(w->saveState());
     }
+    json["windows"] = windows;
 
     // background color?
 
@@ -509,18 +546,29 @@ void ApplicationController::restoreState(QByteArray bytes)
     QJsonDocument jsonDoc = QJsonDocument::fromJson(bytes);
     QJsonObject json = jsonDoc.object();
 
-    if (m_window) {
+    // clear windows
-        QRect r = jsonArrayToRect(json.value("window-rect").toArray());
+    Q_FOREACH(auto w, m_windowList) {
-        if (r.isValid()) {
+        w->deleteLater();
-            m_window->setGeometry(r);
+    }
+    m_windowList.clear();
+
+    for (auto w : json.value("windows").toArray()) {
+        auto wd = new WindowData(this);
+        m_windowList.append(wd);
+        wd->restoreState(w.toObject());
     }
 
-        // we have to cache the state becuase it seems to be ignored
+    if (m_windowList.isEmpty()) {
-        // before show is called();
+        // check for previous single-window data
-        m_windowState = static_cast<Qt::WindowState>(json.value("window-state").toInt());
+        auto w = new WindowData(this);
-        m_window->setWindowState(m_windowState);
+        if (json.contains("window-rect")) {
+            w->setWindowRect(jsonArrayToRect(json.value("window-rect").toArray()));
+        }
+        if (json.contains("window-state")) {
+            w->setWindowState(static_cast<Qt::WindowState>(json.value("window-state").toInt()));
+        }
+        m_windowList.append(w);
     }
-    // background color
 
     for (auto c : json.value("canvases").toArray()) {
         auto cc = new CanvasConnection(this);
@@ -533,6 +581,7 @@ void ApplicationController::restoreState(QByteArray bytes)
         cc->reconnect();
     }
 
+    emit windowListChanged();
     emit activeCanvasesChanged();
 }
 

utils/fgqcanvas/applicationcontroller.h

@@ -27,6 +27,7 @@
 class CanvasConnection;
 class QWindow;
 class QTimer;
+class WindowData;
 
 class ApplicationController : public QObject
 {
@@ -42,6 +43,7 @@ class ApplicationController : public QObject
 
 
     Q_PROPERTY(QQmlListProperty<CanvasConnection> activeCanvases READ activeCanvases NOTIFY activeCanvasesChanged)
+    Q_PROPERTY(QQmlListProperty<WindowData> windowList READ windowList NOTIFY windowListChanged)
 
     Q_ENUMS(Status)
 
@@ -54,15 +56,12 @@ class ApplicationController : public QObject
     Q_PROPERTY(bool showGettingStarted READ showGettingStarted WRITE setShowGettingStarted NOTIFY showGettingStartedChanged)
 public:
     explicit ApplicationController(QObject *parent = nullptr);
-    ~ApplicationController();
+    ~ApplicationController() override;
-
-    void setWindow(QWindow* window);
-
-    void restoreWindowState();
 
     void loadFromFile(QString path);
 
     void setDaemonMode();
+    void createWindows();
 
     Q_INVOKABLE void query();
     Q_INVOKABLE void cancelQuery();
@@ -86,6 +85,7 @@ public:
     QVariantList canvases() const;
 
     QQmlListProperty<CanvasConnection> activeCanvases();
+    QQmlListProperty<WindowData> windowList();
 
     QNetworkAccessManager* netAccess() const;
 
@@ -129,6 +129,7 @@ signals:
     void portChanged(unsigned int port);
 
     void activeCanvasesChanged();
+    void windowListChanged();
 
     void canvasListChanged();
     void statusChanged(Status status);
@@ -179,6 +180,8 @@ private:
 
     QByteArray createSnapshot(QString name) const;
 
+    void defineDefaultWindow();
+
     QString m_host;
     unsigned int m_port;
     QVariantList m_canvases;
@@ -189,8 +192,7 @@ private:
     QNetworkReply* m_query = nullptr;
     QVariantList m_snapshots;
 
-    QWindow* m_window = nullptr;
+    QList<WindowData*> m_windowList;
-    Qt::WindowState m_windowState = Qt::WindowNoState;
 
     bool m_daemonMode = false;
     bool m_showUI = true;

utils/fgqcanvas/canvasconnection.cpp

@@ -77,6 +77,7 @@ QJsonObject CanvasConnection::saveState() const
     json["url"] = m_webSocketUrl.toString();
     json["path"] = QString::fromUtf8(m_rootPropertyPath);
     json["rect"] = rectToJsonArray(m_destRect.toRect());
+    json["window"] = m_windowIndex;
     return json;
 }
 
@@ -86,6 +87,10 @@ bool CanvasConnection::restoreState(QJsonObject state)
     m_rootPropertyPath = state.value("path").toString().toUtf8();
     m_destRect = jsonArrayToRect(state.value("rect").toArray());
 
+    if (state.contains("window")) {
+        m_windowIndex = state.value("window").toInt();
+    }
+
     emit geometryChanged();
     emit rootPathChanged();
     emit webSocketUrlChanged();
@@ -167,6 +172,14 @@ QSizeF CanvasConnection::size() const
     return m_destRect.size();
 }
 
+void CanvasConnection::setWindowIndex(int index)
+{
+    if (m_windowIndex != index) {
+        m_windowIndex = index;
+        emit geometryChanged();
+    }
+}
+
 LocalProp *CanvasConnection::propertyRoot() const
 {
     return m_localPropertyRoot.get();

utils/fgqcanvas/canvasconnection.h

@@ -46,6 +46,8 @@ class CanvasConnection : public QObject
     Q_PROPERTY(QPointF origin READ origin WRITE setOrigin NOTIFY geometryChanged)
     Q_PROPERTY(QSizeF size READ size WRITE setSize NOTIFY geometryChanged)
 
+    Q_PROPERTY(int windowIndex READ windowIndex WRITE setWindowIndex NOTIFY geometryChanged)
+
     Q_PROPERTY(QUrl webSocketUrl READ webSocketUrl NOTIFY webSocketUrlChanged)
     Q_PROPERTY(QString rootPath READ rootPath NOTIFY rootPathChanged)
 public:
@@ -84,6 +86,13 @@ public:
 
     QSizeF size() const;
 
+    int windowIndex() const
+    {
+        return m_windowIndex;
+    }
+
+    void setWindowIndex(int index);
+
     LocalProp* propertyRoot() const;
 
     QUrl webSocketUrl() const
@@ -132,6 +141,7 @@ private:
     QUrl m_webSocketUrl;
     QByteArray m_rootPropertyPath;
     QRectF m_destRect;
+    int m_windowIndex = 0;
 
     QWebSocket m_webSocket;
     QNetworkAccessManager* m_netAccess = nullptr;

utils/fgqcanvas/canvaspainteddisplay.cpp

@@ -108,7 +108,6 @@ void CanvasPaintedDisplay::onConnectionStatusChanged()
 
 void CanvasPaintedDisplay::buildElements()
 {
-    qDebug() << Q_FUNC_INFO;
     m_rootElement = new FGCanvasGroup(nullptr, m_connection->propertyRoot());
     // this is important to elements can discover their connection
     // by walking their parent chain

utils/fgqcanvas/configs/example_config.json

@@ -0,0 +1,32 @@
+{
+    "canvases": [
+        {
+            "path": "/canvas/by-index/texture[4]",
+            "rect": [
+                300,
+                253,
+                852,
+                745
+            ],
+            "url": "ws://localhost:8080/PropertyTreeMirror/canvas/by-index/texture[4]"
+        },
+        {
+            "path": "/canvas/by-index/texture[7]",
+            "rect": [
+                1171,
+                259,
+                747,
+                711
+            ],
+            "url": "ws://localhost:8080/PropertyTreeMirror/canvas/by-index/texture[7]"
+        }
+    ],
+    "configName": "738_captain",
+    "window-rect": [
+        1001,
+        2188,
+        1920,
+        1052
+    ],
+    "window-state": 2
+}

utils/fgqcanvas/configs/multi_window_config.json

@@ -0,0 +1,38 @@
+{
+    "canvases": [
+        {
+            "path": "/canvas/by-index/texture[4]",
+            "rect": [
+                300,
+                253,
+                852,
+                745
+            ],
+            "url": "ws://localhost:8080/PropertyTreeMirror/canvas/by-index/texture[4]"
+        },
+        {
+            "path": "/canvas/by-index/texture[7]",
+            "rect": [
+                1171,
+                259,
+                747,
+                711
+            ],
+            "window":1,
+            "url": "ws://localhost:8080/PropertyTreeMirror/canvas/by-index/texture[7]"
+        }
+    ],
+    "configName": "738_captain",
+    "windows": [
+        {
+            "title": "First Window",
+            "rect":[100, 100, 500, 300]
+        },
+
+        {
+            "title": "Another Window",
+            "rect":[150, 400, 500, 300],
+            "screen":"Colour LCD"
+        }
+    ]
+}

utils/fgqcanvas/fgcanvas.pro

@@ -6,6 +6,7 @@ TARGET = fgqcanvas
 TEMPLATE = app
 
 SOURCES += main.cpp\
+    WindowData.cpp \
     fgcanvasgroup.cpp \
     fgcanvaselement.cpp \
     fgcanvaspaintcontext.cpp \
@@ -25,6 +26,7 @@ SOURCES += main.cpp\
 
 
 HEADERS +=  \
+    WindowData.h \
     fgcanvasgroup.h \
     fgcanvaselement.h \
     fgcanvaspaintcontext.h \
@@ -48,7 +50,8 @@ RESOURCES += \
 
 OTHER_FILES += \
     qml/* \
-    doc/*
+    doc/* \
+    config/*
 
 #Q_XCODE_DEVELOPMENT_TEAM.name = DEVELOPMENT_TEAM
 #Q_XCODE_DEVELOPMENT_TEAM.value = "James Turner"

utils/fgqcanvas/fgqcanvas_resources.qrc

@@ -1,6 +1,6 @@
 <RCC>
     <qresource prefix="/">
-        <file>qml/mainMenu.qml</file>
+        <file>qml/Window.qml</file>
         <file>qml/Button.qml</file>
         <file>qml/InputLine.qml</file>
         <file alias="images/checkerboard">qml/checkerboard.png</file>

utils/fgqcanvas/main.cpp

@@ -27,6 +27,7 @@
 #include "canvasdisplay.h"
 #include "canvasconnection.h"
 #include "canvaspainteddisplay.h"
+#include "WindowData.h"
 
 int main(int argc, char *argv[])
 {
@@ -38,12 +39,6 @@ int main(int argc, char *argv[])
 
     QCommandLineParser parser;
     parser.addPositionalArgument("config", QCoreApplication::translate("main", "JSON configuration to load"));
-    QCommandLineOption framelessOption(QStringList() << "frameless",
-                                   QCoreApplication::translate("main", "Use a frameless window"));
-    QCommandLineOption screenOption(QStringList() << "screen",
-                                   QCoreApplication::translate("main", "Run full-screen on <scren>"), "screen");
-    parser.addOption(framelessOption);
-    parser.addOption(screenOption);
     parser.process(a);
 
     ApplicationController appController;
@@ -52,48 +47,10 @@ int main(int argc, char *argv[])
     qmlRegisterType<CanvasDisplay>("FlightGear", 1, 0, "CanvasDisplay");
     qmlRegisterType<CanvasPaintedDisplay>("FlightGear", 1, 0, "PaintedCanvasDisplay");
 
+    qmlRegisterUncreatableType<WindowData>("FlightGear", 1, 0, "WindowData", "Don't create me");
     qmlRegisterUncreatableType<CanvasConnection>("FlightGear", 1, 0, "CanvasConnection", "Don't create me");
     qmlRegisterUncreatableType<ApplicationController>("FlightGear", 1, 0, "Application", "Can't create");
 
-    QQuickView quickView;
-    appController.setWindow(&quickView);
-    if (parser.isSet(framelessOption)) {
-        quickView.setFlag(Qt::FramelessWindowHint, true);
-    }
-
-    bool restoreWindowState = true;
-    if (parser.isSet(screenOption)) {
-        QString screenName = parser.value(screenOption);
-        QStringList allScreenNames;
-
-        QScreen* found = nullptr;
-        Q_FOREACH(QScreen* s, a.screens()) {
-            allScreenNames << s->name();
-            if (s->name() == screenName) {
-                found = s;
-                break;
-            }
-        }
-
-        if (!found) {
-            qFatal("Unable to find screen: %s: screens are: %s", screenName.toLatin1().data(),
-                   allScreenNames.join(",").toLatin1().data());
-        }
-
-        quickView.setScreen(found);
-        quickView.setGeometry(found->geometry());
-        quickView.setFlag(Qt::FramelessWindowHint, true);
-        restoreWindowState = false;
-
-        qInfo() << "Requested to run on screen:" << screenName << "with geometry" << found->geometry();
-    } else {
-        // windows mode, default geeometry
-        quickView.setWidth(1024);
-        quickView.setHeight(768);
-    }
-
-    quickView.rootContext()->setContextProperty("_application", &appController);
-
     const QStringList args = parser.positionalArguments();
 
     if (!args.empty()) {
@@ -101,15 +58,8 @@ int main(int argc, char *argv[])
         appController.loadFromFile(args.front());
     }
 
-    quickView.setResizeMode(QQuickView::SizeRootObjectToView);
+    appController.createWindows();
-    quickView.setSource(QUrl("qrc:///qml/mainMenu.qml"));
-    quickView.show();
-
-    if (restoreWindowState) {
-        appController.restoreWindowState();
-    }
 
     int result = a.exec();
-
     return result;
 }

utils/fgqcanvas/qml/Window.qml

@@ -1,13 +1,15 @@
 import QtQuick 2.0
-import FlightGear 1.0 as FG
+import QtQuick.Window 2.4 as QQ2W
 
 Rectangle {
     width: 1024
     height: 768
     color: "black"
 
-    property double __uiOpacity: _application.showUI ? 1.0 : 0.0
+    // only show the UI on the main window
+    property double __uiOpacity: (isMainWindow && _application.showUI) ? 1.0 : 0.0
     property bool __uiVisible: true
+    readonly property bool isMainWindow: (_windowNumber === 0)
 
     Behavior on __uiOpacity {
         SequentialAnimation {
@@ -27,9 +29,25 @@ Rectangle {
 
     Repeater {
         model: _application.activeCanvases
-        delegate: CanvasFrame {
+
-            id: display
+        // we use a loader to only create canvases on the correct window
-            canvas: modelData
+        // by driving the 'active' property
+        delegate: Loader {
+            id: canvasLoader
+            sourceComponent: canvasFrame
+            active: modelData.windowIndex === _windowNumber
+
+            Binding {
+                target: canvasLoader.item
+                property: "canvas"
+                value: model.modelData
+            }
+        }
+    }
+
+    Component {
+        id: canvasFrame
+        CanvasFrame {
             showUi: __uiVisible
         }
     }
@@ -58,6 +76,7 @@ Rectangle {
     }
 
     GetStarted {
+        visible: isMainWindow
         anchors.centerIn: parent
     }