From 57fbd2fe0146f3445ebdd4bb9b35d320a55fbce9 Mon Sep 17 00:00:00 2001
From: James Turner <zakalawe@mac.com>
Date: Sun, 24 Jun 2018 11:34:28 +0100
Subject: [PATCH] Remote-canvas: QPainter rendering mode

---
 utils/fgqcanvas/CMakeLists.txt           |   2 +
 utils/fgqcanvas/canvaspainteddisplay.cpp | 130 +++++++++++++++++++++++
 utils/fgqcanvas/canvaspainteddisplay.h   |  74 +++++++++++++
 utils/fgqcanvas/fgcanvaselement.cpp      |   5 +-
 utils/fgqcanvas/fgcanvastext.cpp         |   8 +-
 utils/fgqcanvas/main.cpp                 |   3 +
 utils/fgqcanvas/qml/CanvasFrame.qml      |  21 +++-
 7 files changed, 235 insertions(+), 8 deletions(-)
 create mode 100644 utils/fgqcanvas/canvaspainteddisplay.cpp
 create mode 100644 utils/fgqcanvas/canvaspainteddisplay.h

diff --git a/utils/fgqcanvas/CMakeLists.txt b/utils/fgqcanvas/CMakeLists.txt
index c672c3107..fd8f0277c 100644
--- a/utils/fgqcanvas/CMakeLists.txt
+++ b/utils/fgqcanvas/CMakeLists.txt
@@ -53,6 +53,8 @@ set(SOURCES
   applicationcontroller.h
   canvasdisplay.cpp
   canvasdisplay.h
+  canvaspainteddisplay.cpp
+  canvaspainteddisplay.h
 )
 
 qt5_add_resources(qrc_sources fgqcanvas_resources.qrc)
diff --git a/utils/fgqcanvas/canvaspainteddisplay.cpp b/utils/fgqcanvas/canvaspainteddisplay.cpp
new file mode 100644
index 000000000..dd3203b27
--- /dev/null
+++ b/utils/fgqcanvas/canvaspainteddisplay.cpp
@@ -0,0 +1,130 @@
+//
+// Copyright (C) 2018 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 "canvaspainteddisplay.h"
+
+#include <QDebug>
+
+#include "canvasconnection.h"
+#include "fgcanvasgroup.h"
+#include "fgcanvaspaintcontext.h"
+#include "localprop.h"
+
+CanvasPaintedDisplay::CanvasPaintedDisplay(QQuickItem* parent) :
+    QQuickPaintedItem(parent)
+{
+    setTransformOrigin(QQuickItem::TopLeft);
+    setAntialiasing(true);
+}
+
+CanvasPaintedDisplay::~CanvasPaintedDisplay()
+{
+}
+
+void CanvasPaintedDisplay::paint(QPainter *painter)
+{
+    if (!m_rootElement)
+        return;
+
+    const double xScaleFactor = width() / m_sourceSize.width();
+    const double yScaleFactor =  height() / m_sourceSize.height();
+    const double f = std::min(xScaleFactor, yScaleFactor);
+    painter->scale(f, f);
+
+    FGCanvasPaintContext context(painter);
+    m_rootElement->paint(&context);
+}
+
+void CanvasPaintedDisplay::geometryChanged(const QRectF &newGeometry, const QRectF &)
+{
+    Q_UNUSED(newGeometry);
+    update();
+}
+
+void CanvasPaintedDisplay::setCanvas(CanvasConnection *canvas)
+{
+    if (m_connection == canvas)
+        return;
+
+    if (m_connection) {
+        disconnect(m_connection, nullptr, this, nullptr);
+        m_rootElement.reset();
+    }
+
+    m_connection = canvas;
+    emit canvasChanged(m_connection);
+
+    if (m_connection) {
+        connect(m_connection, &QObject::destroyed,
+                this, &CanvasPaintedDisplay::onConnectionDestroyed);
+        connect(m_connection, &CanvasConnection::statusChanged,
+                this, &CanvasPaintedDisplay::onConnectionStatusChanged);
+        connect(m_connection, &CanvasConnection::updated,
+                this, &CanvasPaintedDisplay::onConnectionUpdated);
+
+        onConnectionStatusChanged();
+    }
+
+}
+
+void CanvasPaintedDisplay::onConnectionDestroyed()
+{
+    m_connection = nullptr;
+    emit canvasChanged(m_connection);
+
+    m_rootElement.reset();
+}
+
+void CanvasPaintedDisplay::onConnectionStatusChanged()
+{
+    if ((m_connection->status() == CanvasConnection::Connected) ||
+            (m_connection->status() == CanvasConnection::Snapshot))
+    {
+        m_rootElement.reset(new FGCanvasGroup(nullptr, m_connection->propertyRoot()));
+        // this is important to elements can discover their connection
+        // by walking their parent chain
+        m_rootElement->setParent(m_connection);
+
+        connect(m_rootElement.get(), &FGCanvasGroup::canvasSizeChanged,
+                this, &CanvasPaintedDisplay::onCanvasSizeChanged);
+
+        onCanvasSizeChanged();
+
+        if (m_connection->status() == CanvasConnection::Snapshot) {
+            m_connection->propertyRoot()->recursiveNotifyRestored();
+            m_rootElement->polish();
+            update();
+        }
+    }
+}
+
+void CanvasPaintedDisplay::onConnectionUpdated()
+{
+    if (m_rootElement) {
+        m_rootElement->polish();
+        update();
+    }
+}
+
+void CanvasPaintedDisplay::onCanvasSizeChanged()
+{
+    m_sourceSize = QSizeF(m_connection->propertyRoot()->value("size", 256).toDouble(),
+                          m_connection->propertyRoot()->value("size[1]", 256).toDouble());
+    setImplicitSize(m_sourceSize.width(), m_sourceSize.height());
+    update();
+}
+
diff --git a/utils/fgqcanvas/canvaspainteddisplay.h b/utils/fgqcanvas/canvaspainteddisplay.h
new file mode 100644
index 000000000..feea4ff97
--- /dev/null
+++ b/utils/fgqcanvas/canvaspainteddisplay.h
@@ -0,0 +1,74 @@
+//
+// Copyright (C) 2018 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 CANVAS_PAINTED_DISPLAY_H
+#define CANVAS_PAINTED_DISPLAY_H
+
+#include <memory>
+
+#include <QQuickPaintedItem>
+
+class CanvasConnection;
+class FGCanvasGroup;
+class QQuickItem;
+
+class CanvasPaintedDisplay : public QQuickPaintedItem
+{
+    Q_OBJECT
+
+    Q_PROPERTY(CanvasConnection* canvas READ canvas WRITE setCanvas NOTIFY canvasChanged)
+
+public:
+    CanvasPaintedDisplay(QQuickItem* parent = nullptr);
+    ~CanvasPaintedDisplay();
+
+    CanvasConnection* canvas() const
+    {
+        return m_connection;
+    }
+
+    void paint(QPainter *painter) override;
+signals:
+
+    void canvasChanged(CanvasConnection* canvas);
+
+public slots:
+
+    void setCanvas(CanvasConnection* canvas);
+
+protected:
+
+    void geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry) override;
+
+private slots:
+    void onConnectionStatusChanged();
+
+    void onConnectionUpdated();
+
+    void onCanvasSizeChanged();
+    void onConnectionDestroyed();
+
+private:
+    void recomputeScaling();
+
+    CanvasConnection* m_connection = nullptr;
+    std::unique_ptr<FGCanvasGroup> m_rootElement;
+   // QQuickItem* m_rootItem = nullptr;
+    QSizeF m_sourceSize;
+};
+
+#endif // CANVAS_PAINTED_DISPLAY_H
diff --git a/utils/fgqcanvas/fgcanvaselement.cpp b/utils/fgqcanvas/fgcanvaselement.cpp
index 333962724..133af82cd 100644
--- a/utils/fgqcanvas/fgcanvaselement.cpp
+++ b/utils/fgqcanvas/fgcanvaselement.cpp
@@ -171,7 +171,10 @@ void FGCanvasElement::paint(FGCanvasPaintContext *context) const
     if (_hasClip)
     {
         // clip is defined in the global coordinate system
-#if 0
+        if (_clipFrame != ReferenceFrame::GLOBAL) {
+            qWarning() << Q_FUNC_INFO << "implement support for non-global clips";
+        }
+#if defined(DEBUG_PAINTING)
         p->save();
         p->setTransform(context->globalCoordinateTransform());
         p->setPen(Qt::yellow);
diff --git a/utils/fgqcanvas/fgcanvastext.cpp b/utils/fgqcanvas/fgcanvastext.cpp
index 102594b98..e32e91968 100644
--- a/utils/fgqcanvas/fgcanvastext.cpp
+++ b/utils/fgqcanvas/fgcanvastext.cpp
@@ -130,13 +130,13 @@ protected:
         return QPointF(x,y);
     }
 
-    void geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry)
+    void geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry) override
     {
         QQuickItem::geometryChanged(newGeometry, oldGeometry);
         update();
     }
 
-    QRectF boundingRect() const
+    QRectF boundingRect() const override
     {
         if ((width() == 0.0) || (height() == 0.0)) {
             return m_layout.boundingRect();
@@ -229,8 +229,8 @@ void FGCanvasText::doPaint(FGCanvasPaintContext *context) const
 
     context->painter()->drawText(rect, _alignment, _text);
 
-    context->painter()->setPen(Qt::cyan);
-    context->painter()->drawRect(rect);
+   // context->painter()->setPen(Qt::cyan);
+   // context->painter()->drawRect(rect);
 }
 
 void FGCanvasText::doPolish()
diff --git a/utils/fgqcanvas/main.cpp b/utils/fgqcanvas/main.cpp
index 3558a1858..041ffa93b 100644
--- a/utils/fgqcanvas/main.cpp
+++ b/utils/fgqcanvas/main.cpp
@@ -24,6 +24,7 @@
 #include "applicationcontroller.h"
 #include "canvasdisplay.h"
 #include "canvasconnection.h"
+#include "canvaspainteddisplay.h"
 
 int main(int argc, char *argv[])
 {
@@ -38,6 +39,8 @@ int main(int argc, char *argv[])
 
     qmlRegisterType<CanvasItem>("FlightGear", 1, 0, "CanvasItem");
     qmlRegisterType<CanvasDisplay>("FlightGear", 1, 0, "CanvasDisplay");
+    qmlRegisterType<CanvasPaintedDisplay>("FlightGear", 1, 0, "PaintedCanvasDisplay");
+
     qmlRegisterUncreatableType<CanvasConnection>("FlightGear", 1, 0, "CanvasConnection", "Don't create me");
     qmlRegisterUncreatableType<ApplicationController>("FlightGear", 1, 0, "Application", "Can't create");
 
diff --git a/utils/fgqcanvas/qml/CanvasFrame.qml b/utils/fgqcanvas/qml/CanvasFrame.qml
index 3b7d0887c..67004593e 100644
--- a/utils/fgqcanvas/qml/CanvasFrame.qml
+++ b/utils/fgqcanvas/qml/CanvasFrame.qml
@@ -4,7 +4,7 @@ import FlightGear 1.0 as FG
 Item {
     id: root
     property bool showDecorations: true
-    property alias canvas: canvasDisplay.canvas
+    property alias canvas: paintedDisplay.canvas
     property bool showUi: true
 
     Component.onCompleted: {
@@ -27,9 +27,24 @@ Item {
         anchors.fill: parent
         clip: true
 
-        FG.CanvasDisplay {
-            id: canvasDisplay
+//        FG.CanvasDisplay {
+//            id: canvasDisplay
+//            anchors.fill: parent
+
+//            onCanvasChanged: {
+//                if (canvas) {
+//                    root.width = canvas.size.width
+//                    root.height = canvas.size.height
+//                    root.x = canvas.origin.x
+//                    root.y = canvas.origin.y
+//                }
+//            }
+//        }
+
+        FG.PaintedCanvasDisplay {
+            id: paintedDisplay
             anchors.fill: parent
+         //   canvas: canvasDisplay.canvas
 
             onCanvasChanged: {
                 if (canvas) {