Fix theme ownership

Theme ownership now uses similar model as axis and inputhandler
ownership: Graph can own multiple themes, but only one is active
at the time.

Task-number: QTRD-2623

Change-Id: I7134384df6f8cc465cc28fbebb454b7d2e254f83
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@digia.com>

10 files changed, 71 insertions, 50 deletions

diff --git a/examples/audiolevels/audiolevels.cpp b/examples/audiolevels/audiolevels.cpp
index 3677c1f1..259274d9 100644
--- a/examples/audiolevels/audiolevels.cpp
+++ b/examples/audiolevels/audiolevels.cpp
@@ -46,12 +46,12 @@ AudioLevels::AudioLevels(Q3DBars *graph, QObject *parent)
     m_graph->setShadowQuality(QDataVis::ShadowQualityNone);
     m_graph->setSelectionMode(QDataVis::SelectionNone);
     m_graph->scene()->activeCamera()->setCameraPosition(-25.0f, 10.0f, 190.0f);
-    m_graph->setTheme(new Q3DTheme(Q3DTheme::ThemeIsabelle));
-    m_graph->theme()->setGridEnabled(true);
-    m_graph->theme()->setBackgroundEnabled(false);
-    QFont font = m_graph->theme()->font();
+    m_graph->setActiveTheme(new Q3DTheme(Q3DTheme::ThemeIsabelle));
+    m_graph->activeTheme()->setGridEnabled(true);
+    m_graph->activeTheme()->setBackgroundEnabled(false);
+    QFont font = m_graph->activeTheme()->font();
     font.setPointSize(10);
-    m_graph->theme()->setFont(font);
+    m_graph->activeTheme()->setFont(font);
     QBar3DSeries *series = new QBar3DSeries;
     series->setMesh(QAbstract3DSeries::MeshBar);
     m_graph->addSeries(series);
diff --git a/examples/bars/graphmodifier.cpp b/examples/bars/graphmodifier.cpp
index 13e4d3e7..09fec65d 100644
--- a/examples/bars/graphmodifier.cpp
+++ b/examples/bars/graphmodifier.cpp
@@ -54,9 +54,9 @@ GraphModifier::GraphModifier(Q3DBars *bargraph)
 {
     //! [2]
     m_graph->setShadowQuality(QDataVis::ShadowQualitySoftMedium);
-    m_graph->theme()->setBackgroundEnabled(false);
-    m_graph->theme()->setFont(QFont("Times New Roman", m_fontSize));
-    m_graph->theme()->setLabelBackgroundEnabled(true);
+    m_graph->activeTheme()->setBackgroundEnabled(false);
+    m_graph->activeTheme()->setFont(QFont("Times New Roman", m_fontSize));
+    m_graph->activeTheme()->setLabelBackgroundEnabled(true);
     //! [2]
 
     m_months << "January" << "February" << "March" << "April" << "May" << "June" << "July" << "August" << "September" << "October" << "November" << "December";
@@ -185,16 +185,20 @@ void GraphModifier::changePresetCamera()
 
 void GraphModifier::changeTheme(int theme)
 {
-    m_graph->setTheme(new Q3DTheme(Q3DTheme::Theme(theme)));
-    emit backgroundEnabledChanged(m_graph->theme()->isBackgroundEnabled());
-    emit gridEnabledChanged(m_graph->theme()->isGridEnabled());
-    emit fontChanged(m_graph->theme()->font());
-    emit fontSizeChanged(m_graph->theme()->font().pointSize());
+    Q3DTheme *currentTheme = m_graph->activeTheme();
+    m_graph->releaseTheme(currentTheme);
+    delete currentTheme;
+    currentTheme = new Q3DTheme(Q3DTheme::Theme(theme));
+    m_graph->setActiveTheme(currentTheme);
+    emit backgroundEnabledChanged(currentTheme->isBackgroundEnabled());
+    emit gridEnabledChanged(currentTheme->isGridEnabled());
+    emit fontChanged(currentTheme->font());
+    emit fontSizeChanged(currentTheme->font().pointSize());
 }
 
 void GraphModifier::changeLabelBackground()
 {
-    m_graph->theme()->setLabelBackgroundEnabled(!m_graph->theme()->isLabelBackgroundEnabled());
+    m_graph->activeTheme()->setLabelBackgroundEnabled(!m_graph->activeTheme()->isLabelBackgroundEnabled());
 }
 
 void GraphModifier::changeSelectionMode(int selectionMode)
@@ -209,15 +213,15 @@ void GraphModifier::changeSelectionMode(int selectionMode)
 void GraphModifier::changeFont(const QFont &font)
 {
     QFont newFont = font;
-    m_graph->theme()->setFont(newFont);
+    m_graph->activeTheme()->setFont(newFont);
 }
 
 void GraphModifier::changeFontSize(int fontsize)
 {
     m_fontSize = fontsize;
-    QFont font = m_graph->theme()->font();
+    QFont font = m_graph->activeTheme()->font();
     font.setPointSize(m_fontSize);
-    m_graph->theme()->setFont(font);
+    m_graph->activeTheme()->setFont(font);
 }
 
 void GraphModifier::shadowQualityUpdatedByVisual(QDataVis::ShadowQuality sq)
@@ -250,12 +254,12 @@ void GraphModifier::rotateY(int rotation)
 
 void GraphModifier::setBackgroundEnabled(int enabled)
 {
-    m_graph->theme()->setBackgroundEnabled(bool(enabled));
+    m_graph->activeTheme()->setBackgroundEnabled(bool(enabled));
 }
 
 void GraphModifier::setGridEnabled(int enabled)
 {
-    m_graph->theme()->setGridEnabled(bool(enabled));
+    m_graph->activeTheme()->setGridEnabled(bool(enabled));
 }
 
 void GraphModifier::setSmoothBars(int smooth)
diff --git a/examples/custominput/scatterdatamodifier.cpp b/examples/custominput/scatterdatamodifier.cpp
index aabb1b3a..aeef4c98 100644
--- a/examples/custominput/scatterdatamodifier.cpp
+++ b/examples/custominput/scatterdatamodifier.cpp
@@ -32,7 +32,7 @@ ScatterDataModifier::ScatterDataModifier(Q3DScatter *scatter)
     : m_graph(scatter),
       m_inputHandler(new CustomInputHandler())
 {
-    m_graph->setTheme(new Q3DTheme(Q3DTheme::ThemeDigia));
+    m_graph->setActiveTheme(new Q3DTheme(Q3DTheme::ThemeDigia));
     m_graph->setShadowQuality(QDataVis::ShadowQualityMedium);
     m_graph->scene()->activeCamera()->setCameraPreset(Q3DCamera::CameraPresetFront);
 
diff --git a/examples/customproxy/rainfallgraph.cpp b/examples/customproxy/rainfallgraph.cpp
index ad45d016..57e1d0ea 100644
--- a/examples/customproxy/rainfallgraph.cpp
+++ b/examples/customproxy/rainfallgraph.cpp
@@ -72,10 +72,10 @@ RainfallGraph::RainfallGraph(Q3DBars *rainfall)
     m_graph->setSelectionMode(QDataVis::SelectionItemAndColumn | QDataVis::SelectionSlice);
 
     // Set theme
-    m_graph->setTheme(new Q3DTheme(Q3DTheme::ThemeArmyBlue));
+    m_graph->setActiveTheme(new Q3DTheme(Q3DTheme::ThemeArmyBlue));
 
     // Set font to theme
-    m_graph->theme()->setFont(QFont("Century Gothic", 30));
+    m_graph->activeTheme()->setFont(QFont("Century Gothic", 30));
 
     // Set camera position and zoom
     m_graph->scene()->activeCamera()->setCameraPreset(Q3DCamera::CameraPresetIsometricRightHigh);
diff --git a/examples/itemmodel/main.cpp b/examples/itemmodel/main.cpp
index 46aa8bb8..015470d1 100644
--- a/examples/itemmodel/main.cpp
+++ b/examples/itemmodel/main.cpp
@@ -107,10 +107,10 @@ GraphDataGenerator::GraphDataGenerator(Q3DBars *bargraph, QTableWidget *tableWid
     //! [7]
 
     // Set theme
-    m_graph->setTheme(new Q3DTheme(Q3DTheme::ThemeDigia));
+    m_graph->setActiveTheme(new Q3DTheme(Q3DTheme::ThemeDigia));
 
     // Set font
-    m_graph->theme()->setFont(QFont("Impact", 20));
+    m_graph->activeTheme()->setFont(QFont("Impact", 20));
 
     // Set preset camera position
     m_graph->scene()->activeCamera()->setCameraPreset(Q3DCamera::CameraPresetFront);
diff --git a/examples/qmlscatter/doc/src/qmlscatter.qdoc b/examples/qmlscatter/doc/src/qmlscatter.qdoc
index 0a758751..19559f4c 100644
--- a/examples/qmlscatter/doc/src/qmlscatter.qdoc
+++ b/examples/qmlscatter/doc/src/qmlscatter.qdoc
@@ -112,9 +112,13 @@
 
     \snippet ../examples/qmlscatter/qml/qmlscatter/main.qml 3
 
-    We added a built-in Theme3D and changed the font in it. We also changed the shadow quality.
+    We added a customized theme and changed the shadow quality.
     We're happy with the other visual properties, so we won't change them.
 
+    The custom theme is based on a predefined theme, but we change the font in it:
+
+    \snippet ../examples/qmlscatter/qml/qmlscatter/main.qml 13
+
     Then it's time to start feeding the graph some data.
 
     \section1 Adding data to the graph
diff --git a/examples/qmlscatter/qml/qmlscatter/main.qml b/examples/qmlscatter/qml/qmlscatter/main.qml
index e0a7f26b..50164c50 100644
--- a/examples/qmlscatter/qml/qmlscatter/main.qml
+++ b/examples/qmlscatter/qml/qmlscatter/main.qml
@@ -33,6 +33,21 @@ Item {
         id: seriesData
     }
     //! [4]
+
+    //! [13]
+    Theme3D {
+        id: themeIsabelle
+        type: Theme3D.ThemeIsabelle
+        font.family: "Lucida Handwriting"
+        font.pointSize: 40
+    }
+    //! [13]
+
+    Theme3D {
+        id : themeArmyBlue
+        type: Theme3D.ThemeArmyBlue
+    }
+
     //! [8]
     //! [9]
     Item {
@@ -50,11 +65,7 @@ Item {
             height: dataView.height
             //! [2]
             //! [3]
-            theme: Theme3D {
-                type: Theme3D.ThemeIsabelle
-                font.family: "Lucida Handwriting"
-                font.pointSize: 40
-            }
+            theme: themeIsabelle
             shadowQuality: AbstractGraph3D.ShadowQualitySoftLow
             //! [3]
             //! [6]
@@ -179,14 +190,9 @@ Item {
             text: "Change Theme"
             onClicked: {
                 if (scatterGraph.theme.type === Theme3D.ThemeArmyBlue) {
-                    // Ownership of the theme is transferred and old theme is destroyed when setting
-                    // a new one, so we need to create them dynamically
-                    scatterGraph.theme = Qt.createQmlObject('import QtDataVisualization 1.0;
-                        Theme3D {type: Theme3D.ThemeIsabelle; font.family: "Lucida Handwriting";
-                        font.pointSize: 40}', parent);
+                    scatterGraph.theme = themeIsabelle
                 } else {
-                    scatterGraph.theme = Qt.createQmlObject('import QtDataVisualization 1.0;
-                        Theme3D {type: Theme3D.ThemeArmyBlue}', parent);
+                    scatterGraph.theme = themeArmyBlue
                 }
             }
         }
diff --git a/examples/scatter/scatterdatamodifier.cpp b/examples/scatter/scatterdatamodifier.cpp
index 6cdb1458..964da977 100644
--- a/examples/scatter/scatterdatamodifier.cpp
+++ b/examples/scatter/scatterdatamodifier.cpp
@@ -39,10 +39,10 @@ ScatterDataModifier::ScatterDataModifier(Q3DScatter *scatter)
       m_smooth(true)
 {
     //! [0]
-    m_graph->setTheme(new Q3DTheme(Q3DTheme::ThemeEbony));
-    QFont font = m_graph->theme()->font();
+    m_graph->setActiveTheme(new Q3DTheme(Q3DTheme::ThemeEbony));
+    QFont font = m_graph->activeTheme()->font();
     font.setPointSize(m_fontSize);
-    m_graph->theme()->setFont(font);
+    m_graph->activeTheme()->setFont(font);
     m_graph->setShadowQuality(QDataVis::ShadowQualitySoftLow);
     m_graph->scene()->activeCamera()->setCameraPreset(Q3DCamera::CameraPresetFront);
     //! [0]
@@ -131,10 +131,14 @@ void ScatterDataModifier::setSmoothDots(int smooth)
 
 void ScatterDataModifier::changeTheme(int theme)
 {
-    m_graph->setTheme(new Q3DTheme(Q3DTheme::Theme(theme)));
-    emit backgroundEnabledChanged(m_graph->theme()->isBackgroundEnabled());
-    emit gridEnabledChanged(m_graph->theme()->isGridEnabled());
-    emit fontChanged(m_graph->theme()->font());
+    Q3DTheme *currentTheme = m_graph->activeTheme();
+    m_graph->releaseTheme(currentTheme);
+    delete currentTheme;
+    currentTheme = new Q3DTheme(Q3DTheme::Theme(theme));
+    m_graph->setActiveTheme(currentTheme);
+    emit backgroundEnabledChanged(currentTheme->isBackgroundEnabled());
+    emit gridEnabledChanged(currentTheme->isGridEnabled());
+    emit fontChanged(currentTheme->font());
 }
 
 void ScatterDataModifier::changePresetCamera()
@@ -149,14 +153,14 @@ void ScatterDataModifier::changePresetCamera()
 
 void ScatterDataModifier::changeLabelStyle()
 {
-    m_graph->theme()->setLabelBackgroundEnabled(!m_graph->theme()->isLabelBackgroundEnabled());
+    m_graph->activeTheme()->setLabelBackgroundEnabled(!m_graph->activeTheme()->isLabelBackgroundEnabled());
 }
 
 void ScatterDataModifier::changeFont(const QFont &font)
 {
     QFont newFont = font;
     newFont.setPointSizeF(m_fontSize);
-    m_graph->theme()->setFont(newFont);
+    m_graph->activeTheme()->setFont(newFont);
 }
 
 void ScatterDataModifier::shadowQualityUpdatedByVisual(QDataVis::ShadowQuality sq)
@@ -173,12 +177,12 @@ void ScatterDataModifier::changeShadowQuality(int quality)
 
 void ScatterDataModifier::setBackgroundEnabled(int enabled)
 {
-    m_graph->theme()->setBackgroundEnabled((bool)enabled);
+    m_graph->activeTheme()->setBackgroundEnabled((bool)enabled);
 }
 
 void ScatterDataModifier::setGridEnabled(int enabled)
 {
-    m_graph->theme()->setGridEnabled((bool)enabled);
+    m_graph->activeTheme()->setGridEnabled((bool)enabled);
 }
 //! [8]
 
diff --git a/examples/surface/doc/src/surface.qdoc b/examples/surface/doc/src/surface.qdoc
index 6f49a3dc..dd334d01 100644
--- a/examples/surface/doc/src/surface.qdoc
+++ b/examples/surface/doc/src/surface.qdoc
@@ -124,7 +124,7 @@
 
     Q3DSurface supports all the themes Qt Data Visualization has. The example has a pull
     down menu for selecting the theme. The following method is connected to the
-    menu to activate the selected theme.
+    menu to activate the selected theme. The old theme is released and deleted:
 
     \snippet ../examples/surface/surfacegraph.cpp 6
 
diff --git a/examples/surface/surfacegraph.cpp b/examples/surface/surfacegraph.cpp
index 7ebb6b72..3770906e 100644
--- a/examples/surface/surfacegraph.cpp
+++ b/examples/surface/surfacegraph.cpp
@@ -229,7 +229,10 @@ void SurfaceGraph::setAxisZRange(float min, float max)
 //! [6]
 void SurfaceGraph::changeTheme(int theme)
 {
-    m_graph->setTheme(new Q3DTheme(Q3DTheme::Theme(theme)));
+    Q3DTheme *currentTheme = m_graph->activeTheme();
+    m_graph->releaseTheme(currentTheme);
+    delete currentTheme;
+    m_graph->setActiveTheme(new Q3DTheme(Q3DTheme::Theme(theme)));
 }
 //! [6]