Add Qt dialog state controller

Allow standard control of drill-down dialogs (with back / forward
navigation)

src/GUI/CMakeLists.txt

@@ -186,6 +186,8 @@ if (HAVE_QT)
                         FGQQWindowManager.hxx
                         PathUrlHelper.cxx
                         PathUrlHelper.hxx
+                        DialogStateController.cxx
+                        DialogStateController.hxx
                         )
 
     set_property(TARGET fgqmlui PROPERTY AUTOMOC ON)

src/GUI/DialogStateController.cxx

@@ -0,0 +1,65 @@
+// Copyright (C) 2020  James Turner  <james@flightgear.org>
+//
+// 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 Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+#include "config.h"
+
+#include "DialogStateController.hxx"
+
+#include <QDebug>
+
+void DialogStateController::add(QString key, QJSValue cb)
+{
+    bool wasEmpty = m_changes.isEmpty();
+    if (!cb.isCallable()) {
+        qWarning() << "tried to insert non-callable into state key:" << key;
+        return;
+    }
+
+    m_changes.insert(key, cb);
+
+    if (wasEmpty) {
+        emit canApplyChanged(true);
+    }
+}
+
+void DialogStateController::apply()
+{
+    auto it = m_changes.begin();
+    for (; it != m_changes.end(); ++it) {
+        QJSValueList args;
+        args.append(QJSValue(it.key()));
+        it.value().call(args);
+    }
+}
+
+void DialogStateController::cancel()
+{
+    m_changes.clear();
+    emit canApplyChanged(false);
+}
+
+void DialogStateController::restoreDefaults()
+{
+}
+
+void DialogStateController::setCanRestoreDefaults(bool canRestoreDefaults)
+{
+    if (m_canRestoreDefaults == canRestoreDefaults)
+        return;
+
+    m_canRestoreDefaults = canRestoreDefaults;
+    emit canRestoreDefaultsChanged(m_canRestoreDefaults);
+}

src/GUI/DialogStateController.hxx

@@ -0,0 +1,66 @@
+// Copyright (C) 2020  James Turner  <james@flightgear.org>
+//
+// 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 Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+#ifndef DialogStateController_h
+#define DialogStateController_h
+
+#include <QJSValue>
+#include <QMap>
+#include <QObject>
+
+class DialogStateController : public QObject
+{
+    Q_OBJECT
+
+    Q_PROPERTY(bool canRestoreDefaults READ canRestoreDefaults WRITE setCanRestoreDefaults NOTIFY canRestoreDefaultsChanged)
+    Q_PROPERTY(bool canApply READ canApply NOTIFY canApplyChanged)
+public:
+    Q_INVOKABLE void add(QString key, QJSValue cb);
+
+    bool canApply() const
+    {
+        return m_canApply;
+    }
+
+    bool canRestoreDefaults() const
+    {
+        return m_canRestoreDefaults;
+    }
+
+public slots:
+
+    void apply();
+
+    void cancel();
+
+    void restoreDefaults();
+
+    void setCanRestoreDefaults(bool canRestoreDefaults);
+
+signals:
+    void canApplyChanged(bool canApply);
+
+    void canRestoreDefaultsChanged(bool canRestoreDefaults);
+
+private:
+    // list of tracked changes
+    QMap<QString, QJSValue> m_changes;
+
+    bool m_canApply = false;
+    bool m_canRestoreDefaults = false;
+};
+
+#endif /* DialogStateController_h */

src/GUI/QQuickDrawable.cxx

@@ -39,14 +39,13 @@
 #include <osgViewer/GraphicsWindow>
 #include <osgViewer/Viewer>
 
-//#include <GUI/DialogStateController.hxx>
+#include <GUI/DialogStateController.hxx>
 #include <GUI/FGQQWindowManager.hxx>
 #include <GUI/FGQmlInstance.hxx>
 #include <GUI/FGQmlPropertyNode.hxx>
-#include <Viewer/OSGQtAdaption.hxx>
-
 #include <Main/fg_props.hxx>
 #include <Main/globals.hxx>
+#include <Viewer/OSGQtAdaption.hxx>
 #include <simgear/structure/commands.hxx>
 
 #if defined(HAVE_PUI)
@@ -464,7 +463,7 @@ QQuickDrawable::QQuickDrawable() : d(new QQuickDrawablePrivate)
 
         // QML types
         qmlRegisterType<FGQmlPropertyNode>("FlightGear", 1, 0, "Property");
-        //qmlRegisterType<DialogStateController>("FlightGear", 1, 0, "DialogStateController");
+        qmlRegisterType<DialogStateController>("FlightGear", 1, 0, "DialogStateController");
     }
 }
 

src/GUI/StackController.cxx

@@ -31,9 +31,29 @@ QUrl StackController::currentPageSource() const
     return m_stack.front();
 }
 
-void StackController::push(QUrl page)
+QString StackController::currentPageTitle() const
+{
+    if (m_stack.empty())
+        return {};
+    return m_titles.front();
+}
+
+QString StackController::previousPageTitle() const
+{
+    if (m_titles.size() < 2)
+        return {};
+    return m_titles.at(1);
+}
+
+bool StackController::canGoBack() const
+{
+    return (m_stack.size() > 1);
+}
+
+void StackController::push(QUrl page, QString title)
 {
     m_stack.push_front(page);
+    m_titles.push_front(title);
     emit currentPageChanged();
 }
 
@@ -42,12 +62,16 @@ void StackController::pop()
     if (m_stack.empty())
         return;
     m_stack.pop_front();
+    m_titles.pop_front();
     emit currentPageChanged();
 }
 
-void StackController::replace(QUrl url)
+void StackController::replace(QUrl url, QString title)
 {
     m_stack.clear();
     m_stack.push_back(url);
+    m_titles.clear();
+    m_titles.push_back(title);
+
     emit currentPageChanged();
 }

src/GUI/StackController.hxx

@@ -32,20 +32,30 @@ class StackController : public QObject
 
     Q_PROPERTY(QUrl currentPageSource READ currentPageSource NOTIFY currentPageChanged)
 
+    Q_PROPERTY(bool canGoBack READ canGoBack NOTIFY currentPageChanged)
+
+    Q_PROPERTY(QString currentPageTitle READ currentPageTitle NOTIFY currentPageChanged)
+    Q_PROPERTY(QString previousPageTitle READ previousPageTitle NOTIFY currentPageChanged)
+
 public:
     StackController();
 
-    Q_INVOKABLE void push(QUrl page);
+    Q_INVOKABLE void push(QUrl page, QString title);
     Q_INVOKABLE void pop();
-    Q_INVOKABLE void replace(QUrl url);
+    Q_INVOKABLE void replace(QUrl url, QString title);
 
     QUrl currentPageSource() const;
 
+    bool canGoBack() const;
+    QString currentPageTitle() const;
+    QString previousPageTitle() const;
+
 signals:
     void currentPageChanged();
 
 private:
     QVector<QUrl> m_stack;
+    QVector<QString> m_titles;
 };
 
 #endif // FG_GUI_STACK_CONTROLLER_HXX