Add QQuickStyle

Now that we have a good place for it, we can share a common base class
for QQuickMaterialStyle and QQuickUniversalStyle. QQuickStyle implements
the inheritance pattern for attached styles, in one place.

Change-Id: I459d98f96ce7c6de1ce7ef716e859f459278d8ad
Reviewed-by: Mitch Curtis <mitch.curtis@theqtcompany.com>

3 files changed, 42 insertions, 70 deletions

diff --git a/src/imports/controls/universal/qquickuniversalstyle.cpp b/src/imports/controls/universal/qquickuniversalstyle.cpp
index 10c4e812..f2bfd70d 100644
--- a/src/imports/controls/universal/qquickuniversalstyle.cpp
+++ b/src/imports/controls/universal/qquickuniversalstyle.cpp
@@ -35,10 +35,9 @@
 ****************************************************************************/
 
 #include "qquickuniversalstyle_p.h"
-#include "qquickstyle_p.h"
 
-#include <QtGui/qguiapplication.h>
-#include <QtQuick/private/qquickitem_p.h>
+#include <QtCore/qdebug.h>
+#include <QtLabsControls/private/qquickstyle_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -134,34 +133,15 @@ static QColor qquickuniversal_accent_color(QQuickUniversalStyle::Accent accent)
     return colors[accent];
 }
 
-QQuickUniversalStyle::QQuickUniversalStyle(QObject *parent) : QObject(parent),
+QQuickUniversalStyle::QQuickUniversalStyle(QObject *parent) : QQuickStyle(parent),
     m_hasTheme(false), m_hasAccent(false), m_theme(DefaultTheme), m_accent(DefaultAccent)
 {
-    QQuickItem *item = qobject_cast<QQuickItem *>(parent);
-    if (item)
-        QQuickItemPrivate::get(item)->addItemChangeListener(this, QQuickItemPrivate::Parent);
-}
-
-QQuickUniversalStyle::~QQuickUniversalStyle()
-{
-    QQuickItem *item = qobject_cast<QQuickItem *>(parent());
-    if (item)
-        QQuickItemPrivate::get(item)->removeItemChangeListener(this, QQuickItemPrivate::Parent);
-
-    reparent(Q_NULLPTR);
+    init(); // TODO: lazy init?
 }
 
 QQuickUniversalStyle *QQuickUniversalStyle::qmlAttachedProperties(QObject *object)
 {
-    QQuickUniversalStyle *style = new QQuickUniversalStyle(object);
-    QQuickUniversalStyle *parentStyle = QQuickStyle::findParent<QQuickUniversalStyle>(object);
-    if (parentStyle)
-        style->reparent(parentStyle);
-
-    QList<QQuickUniversalStyle *> children = QQuickStyle::findChildren<QQuickUniversalStyle>(object);
-    foreach (QQuickUniversalStyle *child, children)
-        child->reparent(style);
-    return style;
+    return new QQuickUniversalStyle(object);
 }
 
 QQuickUniversalStyle::Theme QQuickUniversalStyle::theme() const
@@ -174,8 +154,7 @@ void QQuickUniversalStyle::setTheme(Theme theme)
     m_hasTheme = true;
     if (m_theme != theme) {
         m_theme = theme;
-        foreach (QQuickUniversalStyle *child, m_childStyles)
-            child->inheritTheme(theme);
+        propagateTheme();
         emit themeChanged();
         emit paletteChanged();
     }
@@ -185,19 +164,27 @@ void QQuickUniversalStyle::inheritTheme(Theme theme)
 {
     if (!m_hasTheme && m_theme != theme) {
         m_theme = theme;
-        foreach (QQuickUniversalStyle *child, m_childStyles)
-            child->inheritTheme(theme);
+        propagateTheme();
         emit themeChanged();
         emit paletteChanged();
     }
 }
 
+void QQuickUniversalStyle::propagateTheme()
+{
+    foreach (QQuickStyle *child, childStyles()) {
+        QQuickUniversalStyle *universal = qobject_cast<QQuickUniversalStyle *>(child);
+        if (universal)
+            universal->inheritTheme(m_theme);
+    }
+}
+
 void QQuickUniversalStyle::resetTheme()
 {
     if (m_hasTheme) {
         m_hasTheme = false;
-        QQuickUniversalStyle *parentStyle = QQuickStyle::findParent<QQuickUniversalStyle>(parent());
-        inheritTheme(parentStyle ? parentStyle->theme() : DefaultTheme);
+        QQuickUniversalStyle *universal = qobject_cast<QQuickUniversalStyle *>(parentStyle());
+        inheritTheme(universal ? universal->theme() : DefaultTheme);
     }
 }
 
@@ -215,8 +202,7 @@ void QQuickUniversalStyle::setAccent(Accent accent)
     m_hasAccent = true;
     if (m_accent != accent) {
         m_accent = accent;
-        foreach (QQuickUniversalStyle *child, m_childStyles)
-            child->inheritAccent(accent);
+        propagateAccent();
         emit accentChanged();
     }
 }
@@ -225,18 +211,26 @@ void QQuickUniversalStyle::inheritAccent(Accent accent)
 {
     if (!m_hasAccent && m_accent != accent) {
         m_accent = accent;
-        foreach (QQuickUniversalStyle *child, m_childStyles)
-            child->inheritAccent(accent);
+        propagateAccent();
         emit accentChanged();
     }
 }
 
+void QQuickUniversalStyle::propagateAccent()
+{
+    foreach (QQuickStyle *child, childStyles()) {
+        QQuickUniversalStyle *universal = qobject_cast<QQuickUniversalStyle *>(child);
+        if (universal)
+            universal->inheritAccent(m_accent);
+    }
+}
+
 void QQuickUniversalStyle::resetAccent()
 {
     if (m_hasAccent) {
         m_hasAccent = false;
-        QQuickUniversalStyle *parentStyle = QQuickStyle::findParent<QQuickUniversalStyle>(parent());
-        inheritAccent(parentStyle ? parentStyle->accent() : DefaultAccent);
+        QQuickUniversalStyle *universal = qobject_cast<QQuickUniversalStyle *>(parentStyle());
+        inheritAccent(universal ? universal->accent() : DefaultAccent);
     }
 }
 
@@ -370,27 +364,13 @@ QColor QQuickUniversalStyle::getColor(SystemColor role) const
     return m_theme == QQuickUniversalStyle::Dark ? qquickuniversal_dark_color(role) : qquickuniversal_light_color(role);
 }
 
-void QQuickUniversalStyle::reparent(QQuickUniversalStyle *style)
-{
-    if (m_parentStyle != style) {
-        if (m_parentStyle)
-            m_parentStyle->m_childStyles.remove(this);
-        m_parentStyle = style;
-        if (style) {
-            style->m_childStyles.insert(this);
-            inheritTheme(style->theme());
-            inheritAccent(style->accent());
-        }
-    }
-}
-
-void QQuickUniversalStyle::itemParentChanged(QQuickItem *item, QQuickItem *parent)
+void QQuickUniversalStyle::parentStyleChange(QQuickStyle *newParent, QQuickStyle *oldParent)
 {
-    QQuickUniversalStyle *style = QQuickStyle::instance<QQuickUniversalStyle>(item);
-    if (style) {
-        QQuickUniversalStyle *parentStyle = QQuickStyle::findParent<QQuickUniversalStyle>(parent);
-        if (parentStyle)
-            style->reparent(parentStyle);
+    Q_UNUSED(oldParent);
+    QQuickUniversalStyle *universal = qobject_cast<QQuickUniversalStyle *>(newParent);
+    if (universal) {
+        inheritTheme(universal->theme());
+        inheritAccent(universal->accent());
     }
 }
 
diff --git a/src/imports/controls/universal/qquickuniversalstyle_p.h b/src/imports/controls/universal/qquickuniversalstyle_p.h
index e8e9eafb..3bf0bb5d 100644
--- a/src/imports/controls/universal/qquickuniversalstyle_p.h
+++ b/src/imports/controls/universal/qquickuniversalstyle_p.h
@@ -48,18 +48,14 @@
 // We mean it.
 //
 
-#include <QtCore/qset.h>
-#include <QtCore/qpointer.h>
-#include <QtCore/qobject.h>
 #include <QtGui/qcolor.h>
-#include <QtQml/qqml.h>
-#include <QtQuick/private/qquickitemchangelistener_p.h>
+#include <QtLabsControls/private/qquickstyle_p.h>
 
 QT_BEGIN_NAMESPACE
 
 class QQuickUniversalStylePrivate;
 
-class QQuickUniversalStyle : public QObject, public QQuickItemChangeListener
+class QQuickUniversalStyle : public QQuickStyle
 {
     Q_OBJECT
     Q_PROPERTY(Theme theme READ theme WRITE setTheme RESET resetTheme NOTIFY themeChanged FINAL)
@@ -93,7 +89,6 @@ class QQuickUniversalStyle : public QObject, public QQuickItemChangeListener
 
 public:
     explicit QQuickUniversalStyle(QObject *parent = Q_NULLPTR);
-    ~QQuickUniversalStyle();
 
     static QQuickUniversalStyle *qmlAttachedProperties(QObject *object);
 
@@ -103,6 +98,7 @@ public:
     Theme theme() const;
     void setTheme(Theme theme);
     void inheritTheme(Theme theme);
+    void propagateTheme();
     void resetTheme();
 
     enum Accent {
@@ -132,10 +128,10 @@ public:
     Accent accent() const;
     void setAccent(Accent accent);
     void inheritAccent(Accent accent);
+    void propagateAccent();
     void resetAccent();
 
     QColor accentColor() const;
-
     QColor altHighColor() const;
     QColor altLowColor() const;
     QColor altMediumColor() const;
@@ -196,16 +192,13 @@ Q_SIGNALS:
     void paletteChanged();
 
 protected:
-    void reparent(QQuickUniversalStyle *parent);
-    void itemParentChanged(QQuickItem *item, QQuickItem *parent) Q_DECL_OVERRIDE;
+    void parentStyleChange(QQuickStyle *newParent, QQuickStyle *oldParent) Q_DECL_OVERRIDE;
 
 private:
     bool m_hasTheme;
     bool m_hasAccent;
     QQuickUniversalStyle::Theme m_theme;
     QQuickUniversalStyle::Accent m_accent;
-    QPointer<QQuickUniversalStyle> m_parentStyle;
-    QSet<QQuickUniversalStyle *> m_childStyles;
 };
 
 QT_END_NAMESPACE
diff --git a/src/imports/controls/universal/universal.pro b/src/imports/controls/universal/universal.pro
index 4e96256b..41cef97d 100644
--- a/src/imports/controls/universal/universal.pro
+++ b/src/imports/controls/universal/universal.pro
@@ -17,7 +17,6 @@ RESOURCES += \
     $$PWD/qtlabsuniversalstyleplugin.qrc
 
 include(universal.pri)
-include(../shared/shared.pri)
 
 CONFIG += no_cxx_module
 load(qml_plugin)