Make QQuickIcon a value type

QQuickIcon no longer inherits QObject, but becomes a light-weight
implicitly shared Q_GADGET-type, that is passed by value the same
way fonts and colors are.

Before:

  SUB: OS:          Fedora 25 (Workstation Edition)
  SUB: QPA:         xcb
  SUB: GL_VENDOR:   Intel Open Source Technology Center
  SUB: GL_RENDERER: Mesa DRI Intel(R) Haswell Desktop
  SUB: GL_VERSION:  3.0 Mesa 13.0.4
  SUB: running: benchmarks/auto/creation/controls/delegates_buttoncontrol2.qml
  SUB:     110 frames
  SUB:     109 frames
  SUB:     109 frames
  SUB:     109 frames
  SUB:     109 frames
  SUB:     Average:
  SUB: 109.2  frames; using  samples; MedianAll=109; StdDev=0.447214, CoV=0.00409536

After:

  [...]
  SUB: running: benchmarks/auto/creation/controls/delegates_buttoncontrol2.qml
  SUB:     123 frames
  SUB:     124 frames
  SUB:     124 frames
  SUB:     122 frames
  SUB:     125 frames
  SUB:     Average:
  SUB: 123.6  frames; using  samples; MedianAll=124; StdDev=1.14018, CoV=0.00922472

Change-Id: I604532204fb94fc0726d0c9b8b6097f9ebc265e8
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

3 files changed, 18 insertions, 37 deletions

diff --git a/src/quickcontrols2/qquickiconlabel.cpp b/src/quickcontrols2/qquickiconlabel.cpp
index 61151f28..1cfceda2 100644
--- a/src/quickcontrols2/qquickiconlabel.cpp
+++ b/src/quickcontrols2/qquickiconlabel.cpp
@@ -41,7 +41,6 @@
 #include <QtGui/private/qguiapplication_p.h>
 #include <QtQuick/private/qquickitem_p.h>
 #include <QtQuick/private/qquicktext_p.h>
-#include <QtQuickTemplates2/private/qquickicon_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -66,7 +65,6 @@ QQuickIconLabelPrivate::QQuickIconLabelPrivate()
       leftPadding(0),
       rightPadding(0),
       bottomPadding(0),
-      icon(nullptr),
       image(nullptr),
       label(nullptr)
 {
@@ -74,7 +72,7 @@ QQuickIconLabelPrivate::QQuickIconLabelPrivate()
 
 bool QQuickIconLabelPrivate::hasIcon() const
 {
-    return display != QQuickIconLabel::TextOnly && icon && (!icon->name().isEmpty() || !icon->source().isEmpty());
+    return display != QQuickIconLabel::TextOnly && !icon.isEmpty();
 }
 
 bool QQuickIconLabelPrivate::hasText() const
@@ -92,10 +90,10 @@ bool QQuickIconLabelPrivate::createImage()
     watchChanges(image);
     beginClass(image);
     image->setObjectName(QStringLiteral("image"));
-    image->setName(icon->name());
-    image->setSource(icon->source());
-    image->setSourceSize(QSize(icon->width(), icon->height()));
-    image->setColor(icon->color());
+    image->setName(icon.name());
+    image->setSource(icon.source());
+    image->setSourceSize(QSize(icon.width(), icon.height()));
+    image->setColor(icon.color());
     QQmlEngine::setContextForObject(image, qmlContext(q));
     if (componentComplete)
         completeComponent(image);
@@ -122,11 +120,11 @@ bool QQuickIconLabelPrivate::updateImage()
 
 void QQuickIconLabelPrivate::syncImage()
 {
-    if (!image || !icon)
+    if (!image || icon.isEmpty())
         return;
 
-    image->setName(icon->name());
-    image->setSource(icon->source());
+    image->setName(icon.name());
+    image->setSource(icon.source());
 }
 
 void QQuickIconLabelPrivate::updateOrSyncImage()
@@ -200,11 +198,11 @@ void QQuickIconLabelPrivate::updateOrSyncLabel()
 
 void QQuickIconLabelPrivate::updateIcon()
 {
-    if (!image || !icon)
+    if (!image || icon.isEmpty())
         return;
 
-    image->setColor(icon->color());
-    image->setSourceSize(QSize(icon->width(), icon->height()));
+    image->setColor(icon.color());
+    image->setSourceSize(QSize(icon.width(), icon.height()));
 }
 
 void QQuickIconLabelPrivate::updateImplicitSize()
@@ -395,35 +393,19 @@ QQuickIconLabel::~QQuickIconLabel()
         d->unwatchChanges(d->label);
 }
 
-QQuickIcon *QQuickIconLabel::icon() const
+QQuickIcon QQuickIconLabel::icon() const
 {
     Q_D(const QQuickIconLabel);
     return d->icon;
 }
 
-void QQuickIconLabel::setIcon(QQuickIcon *icon)
+void QQuickIconLabel::setIcon(const QQuickIcon &icon)
 {
     Q_D(QQuickIconLabel);
     if (d->icon == icon)
         return;
 
-    if (QQuickIcon *oldIcon = d->icon) {
-        QObjectPrivate::disconnect(oldIcon, &QQuickIcon::nameChanged, d, &QQuickIconLabelPrivate::updateOrSyncImage);
-        QObjectPrivate::disconnect(oldIcon, &QQuickIcon::sourceChanged, d, &QQuickIconLabelPrivate::updateOrSyncImage);
-        QObjectPrivate::disconnect(oldIcon, &QQuickIcon::colorChanged, d, &QQuickIconLabelPrivate::updateIcon);
-        QObjectPrivate::disconnect(oldIcon, &QQuickIcon::widthChanged, d, &QQuickIconLabelPrivate::updateIcon);
-        QObjectPrivate::disconnect(oldIcon, &QQuickIcon::heightChanged, d, &QQuickIconLabelPrivate::updateIcon);
-    }
-
     d->icon = icon;
-    if (icon) {
-        QObjectPrivate::connect(icon, &QQuickIcon::nameChanged, d, &QQuickIconLabelPrivate::updateOrSyncImage);
-        QObjectPrivate::connect(icon, &QQuickIcon::sourceChanged, d, &QQuickIconLabelPrivate::updateOrSyncImage);
-        QObjectPrivate::connect(icon, &QQuickIcon::colorChanged, d, &QQuickIconLabelPrivate::updateIcon);
-        QObjectPrivate::connect(icon, &QQuickIcon::widthChanged, d, &QQuickIconLabelPrivate::updateIcon);
-        QObjectPrivate::connect(icon, &QQuickIcon::heightChanged, d, &QQuickIconLabelPrivate::updateIcon);
-    }
-
     d->updateOrSyncImage();
 }
 
diff --git a/src/quickcontrols2/qquickiconlabel_p.h b/src/quickcontrols2/qquickiconlabel_p.h
index 63b7fbd2..df79dbf2 100644
--- a/src/quickcontrols2/qquickiconlabel_p.h
+++ b/src/quickcontrols2/qquickiconlabel_p.h
@@ -50,16 +50,16 @@
 
 #include <QtQuick/qquickitem.h>
 #include <QtQuickControls2/private/qtquickcontrols2global_p.h>
+#include <QtQuickTemplates2/private/qquickicon_p.h>
 
 QT_BEGIN_NAMESPACE
 
-class QQuickIcon;
 class QQuickIconLabelPrivate;
 
 class Q_QUICKCONTROLS2_PRIVATE_EXPORT QQuickIconLabel : public QQuickItem
 {
     Q_OBJECT
-    Q_PROPERTY(QQuickIcon *icon READ icon WRITE setIcon FINAL)
+    Q_PROPERTY(QQuickIcon icon READ icon WRITE setIcon FINAL)
     Q_PROPERTY(QString text READ text WRITE setText FINAL)
     Q_PROPERTY(QFont font READ font WRITE setFont FINAL)
     Q_PROPERTY(QColor color READ color WRITE setColor FINAL)
@@ -84,8 +84,8 @@ public:
     explicit QQuickIconLabel(QQuickItem *parent = nullptr);
     ~QQuickIconLabel();
 
-    QQuickIcon *icon() const;
-    void setIcon(QQuickIcon *icon);
+    QQuickIcon icon() const;
+    void setIcon(const QQuickIcon &icon);
 
     QString text() const;
     void setText(const QString text);
diff --git a/src/quickcontrols2/qquickiconlabel_p_p.h b/src/quickcontrols2/qquickiconlabel_p_p.h
index 00c2d404..b02b5400 100644
--- a/src/quickcontrols2/qquickiconlabel_p_p.h
+++ b/src/quickcontrols2/qquickiconlabel_p_p.h
@@ -55,7 +55,6 @@
 QT_BEGIN_NAMESPACE
 
 class QQuickText;
-class QQuickIcon;
 class QQuickIconImage;
 
 class QQuickIconLabelPrivate : public QQuickItemPrivate, public QQuickItemChangeListener
@@ -105,7 +104,7 @@ public:
     QFont font;
     QColor color;
     QString text;
-    QQuickIcon *icon;
+    QQuickIcon icon;
     QQuickIconImage *image;
     QQuickText *label;
 };