Create and init QQuickTheme from QtQuickControls2Plugin

Instead of creating and setting the QQuickTheme instance from each
style plugin (e.g. QtQuickControls2MaterialStylePlugin), create the
QQuickTheme instance in QtQuickControls2Plugin when the style is
being resolved, and just pass the instance to be initialized by the
style plugin(s). This avoids the problem that QQuickTheme API was
virtual, and sub-classes created from plugins would have vtables
destroyed before the QQuickTheme was destroyed.

Task-number: QTBUG-67062
Task-number: QTBUG-68087
Change-Id: I19e9ced5296b708c2668c30163389cb3da6be7cf
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

3 files changed, 3 insertions, 34 deletions

diff --git a/src/quicktemplates2/qquicktheme.cpp b/src/quicktemplates2/qquicktheme.cpp
index b8ced7b9..1ea0cef2 100644
--- a/src/quicktemplates2/qquicktheme.cpp
+++ b/src/quicktemplates2/qquicktheme.cpp
@@ -94,26 +94,6 @@ static QPlatformTheme::Palette platformPalette(QQuickTheme::Scope scope)
     }
 }
 
-const QFont *QQuickThemePrivate::resolveThemeFont(QQuickTheme::Scope scope)
-{
-    Q_Q(QQuickTheme);
-    if (!hasResolved) {
-        q->resolve();
-        hasResolved = true;
-    }
-    return fonts[scope].data();
-}
-
-const QPalette *QQuickThemePrivate::resolveThemePalette(QQuickTheme::Scope scope)
-{
-    Q_Q(QQuickTheme);
-    if (!hasResolved) {
-        q->resolve();
-        hasResolved = true;
-    }
-    return palettes[scope].data();
-}
-
 QQuickTheme::QQuickTheme()
     : d_ptr(new QQuickThemePrivate)
 {
@@ -133,7 +113,7 @@ QFont QQuickTheme::font(Scope scope)
 {
     const QFont *font = nullptr;
     if (QQuickTheme *theme = instance())
-        font = QQuickThemePrivate::get(theme)->resolveThemeFont(scope);
+        font = QQuickThemePrivate::get(theme)->fonts[scope].data();
     else if (QPlatformTheme *theme = QGuiApplicationPrivate::platformTheme())
         font = theme->font(platformFont(scope));
 
@@ -154,7 +134,7 @@ QPalette QQuickTheme::palette(Scope scope)
 {
     const QPalette *palette = nullptr;
     if (QQuickTheme *theme = instance())
-        palette = QQuickThemePrivate::get(theme)->resolveThemePalette(scope);
+        palette = QQuickThemePrivate::get(theme)->palettes[scope].data();
     else if (QPlatformTheme *theme = QGuiApplicationPrivate::platformTheme())
         palette = theme->palette(platformPalette(scope));
 
@@ -183,8 +163,4 @@ void QQuickTheme::setPalette(Scope scope, const QPalette &palette)
     d->palettes[scope] = QSharedPointer<QPalette>::create(d->defaultPalette ? d->defaultPalette->resolve(palette) : palette);
 }
 
-void QQuickTheme::resolve()
-{
-}
-
 QT_END_NAMESPACE
diff --git a/src/quicktemplates2/qquicktheme_p.h b/src/quicktemplates2/qquicktheme_p.h
index 44610c09..d51cc5b6 100644
--- a/src/quicktemplates2/qquicktheme_p.h
+++ b/src/quicktemplates2/qquicktheme_p.h
@@ -61,7 +61,7 @@ class Q_QUICKTEMPLATES2_PRIVATE_EXPORT QQuickTheme
 {
 public:
     QQuickTheme();
-    virtual ~QQuickTheme();
+    ~QQuickTheme();
 
     static QQuickTheme *instance();
 
@@ -90,12 +90,9 @@ public:
     static QFont font(Scope scope);
     static QPalette palette(Scope scope);
 
-protected:
     void setFont(Scope scope, const QFont &font);
     void setPalette(Scope scope, const QPalette &palette);
 
-    virtual void resolve();
-
 private:
     Q_DISABLE_COPY(QQuickTheme)
     Q_DECLARE_PRIVATE(QQuickTheme)
diff --git a/src/quicktemplates2/qquicktheme_p_p.h b/src/quicktemplates2/qquicktheme_p_p.h
index 6a32440f..c7421677 100644
--- a/src/quicktemplates2/qquicktheme_p_p.h
+++ b/src/quicktemplates2/qquicktheme_p_p.h
@@ -62,14 +62,10 @@ public:
         return theme->d_func();
     }
 
-    const QFont *resolveThemeFont(QQuickTheme::Scope scope);
-    const QPalette *resolveThemePalette(QQuickTheme::Scope scope);
-
     static QScopedPointer<QQuickTheme> instance;
 
     static const int NScopes = QQuickTheme::Tumbler + 1;
 
-    bool hasResolved = false;
     QScopedPointer<const QFont> defaultFont;
     QScopedPointer<const QPalette> defaultPalette;
     QSharedPointer<QFont> fonts[NScopes];