Cleanup and unify font handling

First of all, move the remaining user requested fonts to ExtraData.
This was done for QQuickControl, but not for the controls that do not
inherit QQuickControl: QQuickLabel, QQuickTextField & QQuickTextArea.
The ExtraData starts really paying off later when introducing palettes
that propagate similarly to fonts.

Furthermore, give a more explicit name ('font' vs. 'requestedFont')
for the user requested fonts. This lets us use 'font' (instead of just
'f') as an argument name in those various font-helper methods in the
private classes. Furthermore, sync QQuickLabel|TextField|TextArea's
font handling with QQuickControl. It would be best to share the code
somehow, but it's quite tricky due to different base classes, font
members ('resolvedFont' vs. 'sourceFont'), and notifier signals.

Change-Id: I50cc1af160bb033ae604b4239e438c083d83f15d
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

8 files changed, 136 insertions, 60 deletions

diff --git a/src/quicktemplates2/qquickcontrol.cpp b/src/quicktemplates2/qquickcontrol.cpp
index d57c3260..fc0b1b17 100644
--- a/src/quicktemplates2/qquickcontrol.cpp
+++ b/src/quicktemplates2/qquickcontrol.cpp
@@ -351,11 +351,11 @@ void QQuickControlPrivate::resolveFont()
     inheritFont(parentFont(q));
 }
 
-void QQuickControlPrivate::inheritFont(const QFont &f)
+void QQuickControlPrivate::inheritFont(const QFont &font)
 {
     Q_Q(QQuickControl);
-    QFont parentFont = extra.isAllocated() ? extra->font.resolve(f) : f;
-    parentFont.resolve(extra.isAllocated() ? extra->font.resolve() | f.resolve() : f.resolve());
+    QFont parentFont = extra.isAllocated() ? extra->requestedFont.resolve(font) : font;
+    parentFont.resolve(extra.isAllocated() ? extra->requestedFont.resolve() | font.resolve() : font.resolve());
 
     const QFont defaultFont = q->defaultFont();
     const QFont resolvedFont = parentFont.resolve(defaultFont);
@@ -368,35 +368,35 @@ void QQuickControlPrivate::inheritFont(const QFont &f)
 
     Assign \a font to this control, and propagate it to all children.
 */
-void QQuickControlPrivate::updateFont(const QFont &f)
+void QQuickControlPrivate::updateFont(const QFont &font)
 {
     Q_Q(QQuickControl);
-    QFont old = resolvedFont;
-    resolvedFont = f;
+    QFont oldFont = resolvedFont;
+    resolvedFont = font;
 
-    if (old != f)
-        q->fontChange(f, old);
+    if (oldFont != font)
+        q->fontChange(font, oldFont);
 
-    QQuickControlPrivate::updateFontRecur(q, f);
+    QQuickControlPrivate::updateFontRecur(q, font);
 
-    if (old != f)
+    if (oldFont != font)
         emit q->fontChanged();
 }
 
-void QQuickControlPrivate::updateFontRecur(QQuickItem *item, const QFont &f)
+void QQuickControlPrivate::updateFontRecur(QQuickItem *item, const QFont &font)
 {
     const auto childItems = item->childItems();
     for (QQuickItem *child : childItems) {
         if (QQuickControl *control = qobject_cast<QQuickControl *>(child))
-            QQuickControlPrivate::get(control)->inheritFont(f);
+            QQuickControlPrivate::get(control)->inheritFont(font);
         else if (QQuickLabel *label = qobject_cast<QQuickLabel *>(child))
-            QQuickLabelPrivate::get(label)->inheritFont(f);
+            QQuickLabelPrivate::get(label)->inheritFont(font);
         else if (QQuickTextArea *textArea = qobject_cast<QQuickTextArea *>(child))
-            QQuickTextAreaPrivate::get(textArea)->inheritFont(f);
+            QQuickTextAreaPrivate::get(textArea)->inheritFont(font);
         else if (QQuickTextField *textField = qobject_cast<QQuickTextField *>(child))
-            QQuickTextFieldPrivate::get(textField)->inheritFont(f);
+            QQuickTextFieldPrivate::get(textField)->inheritFont(font);
         else
-            QQuickControlPrivate::updateFontRecur(child, f);
+            QQuickControlPrivate::updateFontRecur(child, font);
     }
 }
 
@@ -618,10 +618,10 @@ QFont QQuickControl::font() const
 void QQuickControl::setFont(const QFont &font)
 {
     Q_D(QQuickControl);
-    if (d->extra.value().font.resolve() == font.resolve() && d->extra.value().font == font)
+    if (d->extra.value().requestedFont.resolve() == font.resolve() && d->extra.value().requestedFont == font)
         return;
 
-    d->extra.value().font = font;
+    d->extra.value().requestedFont = font;
     d->resolveFont();
 }
 
diff --git a/src/quicktemplates2/qquickcontrol_p_p.h b/src/quicktemplates2/qquickcontrol_p_p.h
index a6825640..3cd04b17 100644
--- a/src/quicktemplates2/qquickcontrol_p_p.h
+++ b/src/quicktemplates2/qquickcontrol_p_p.h
@@ -101,15 +101,15 @@ public:
     QAccessible::Role accessibleRole() const override;
 #endif
 
-    void updateFont(const QFont &f);
-    static void updateFontRecur(QQuickItem *item, const QFont &f);
-    inline void setFont_helper(const QFont &f) {
-        if (resolvedFont.resolve() == f.resolve() && resolvedFont == f)
+    virtual void resolveFont();
+    void inheritFont(const QFont &font);
+    void updateFont(const QFont &font);
+    static void updateFontRecur(QQuickItem *item, const QFont &font);
+    inline void setFont_helper(const QFont &font) {
+        if (resolvedFont.resolve() == font.resolve() && resolvedFont == font)
             return;
-        updateFont(f);
+        updateFont(font);
     }
-    virtual void resolveFont();
-    void inheritFont(const QFont &f);
     static QFont parentFont(const QQuickItem *item);
     static QFont themeFont(QPlatformTheme::Font type);
 
@@ -127,11 +127,10 @@ public:
 
     struct ExtraData {
         ExtraData();
-        QFont font;
+        QFont requestedFont;
     };
     QLazilyAllocated<ExtraData> extra;
 
-    QFont resolvedFont;
     bool hasTopPadding;
     bool hasLeftPadding;
     bool hasRightPadding;
@@ -150,6 +149,7 @@ public:
     qreal bottomPadding;
     qreal spacing;
     QLocale locale;
+    QFont resolvedFont;
     Qt::FocusPolicy focusPolicy;
     Qt::FocusReason focusReason;
     QQuickItem *background;
diff --git a/src/quicktemplates2/qquicklabel.cpp b/src/quicktemplates2/qquicklabel.cpp
index 45c7e5a4..fdda4542 100644
--- a/src/quicktemplates2/qquicklabel.cpp
+++ b/src/quicktemplates2/qquicklabel.cpp
@@ -108,18 +108,31 @@ void QQuickLabelPrivate::resolveFont()
     inheritFont(QQuickControlPrivate::parentFont(q));
 }
 
-void QQuickLabelPrivate::inheritFont(const QFont &f)
+void QQuickLabelPrivate::inheritFont(const QFont &font)
 {
-    Q_Q(QQuickLabel);
-    QFont parentFont = font.resolve(f);
-    parentFont.resolve(font.resolve() | f.resolve());
+    QFont parentFont = extra.isAllocated() ? extra->requestedFont.resolve(font) : font;
+    parentFont.resolve(extra.isAllocated() ? extra->requestedFont.resolve() | font.resolve() : font.resolve());
 
     const QFont defaultFont = QQuickControlPrivate::themeFont(QPlatformTheme::LabelFont);
     const QFont resolvedFont = parentFont.resolve(defaultFont);
 
-    const bool changed = resolvedFont != sourceFont;
-    q->QQuickText::setFont(resolvedFont);
-    if (changed)
+    setFont_helper(resolvedFont);
+}
+
+/*!
+    \internal
+
+    Assign \a font to this control, and propagate it to all children.
+*/
+void QQuickLabelPrivate::updateFont(const QFont &font)
+{
+    Q_Q(QQuickLabel);
+    QFont oldFont = sourceFont;
+    q->QQuickText::setFont(font);
+
+    QQuickControlPrivate::updateFontRecur(q, font);
+
+    if (oldFont != font)
         emit q->fontChanged();
 }
 
@@ -170,10 +183,10 @@ QFont QQuickLabel::font() const
 void QQuickLabel::setFont(const QFont &font)
 {
     Q_D(QQuickLabel);
-    if (d->font.resolve() == font.resolve() && d->font == font)
+    if (d->extra.value().requestedFont.resolve() == font.resolve() && d->extra.value().requestedFont == font)
         return;
 
-    d->font = font;
+    d->extra.value().requestedFont = font;
     d->resolveFont();
 }
 
diff --git a/src/quicktemplates2/qquicklabel_p_p.h b/src/quicktemplates2/qquicklabel_p_p.h
index c24c855b..dadd63df 100644
--- a/src/quicktemplates2/qquicklabel_p_p.h
+++ b/src/quicktemplates2/qquicklabel_p_p.h
@@ -48,6 +48,7 @@
 // We mean it.
 //
 
+#include <QtQml/private/qlazilyallocated_p.h>
 #include <QtQuick/private/qquicktext_p_p.h>
 
 #if QT_CONFIG(accessibility)
@@ -75,7 +76,13 @@ public:
     }
 
     void resolveFont();
-    void inheritFont(const QFont &f);
+    void inheritFont(const QFont &font);
+    void updateFont(const QFont &font);
+    inline void setFont_helper(const QFont &font) {
+        if (sourceFont.resolve() == font.resolve() && sourceFont == font)
+            return;
+        updateFont(font);
+    }
 
     void textChanged(const QString &text);
 
@@ -84,7 +91,11 @@ public:
     QAccessible::Role accessibleRole() const override;
 #endif
 
-    QFont font;
+    struct ExtraData {
+        QFont requestedFont;
+    };
+    QLazilyAllocated<ExtraData> extra;
+
     QQuickItem *background;
     QQuickAccessibleAttached *accessibleAttached;
 };
diff --git a/src/quicktemplates2/qquicktextarea.cpp b/src/quicktemplates2/qquicktextarea.cpp
index 21d74dd8..3359f6cb 100644
--- a/src/quicktemplates2/qquicktextarea.cpp
+++ b/src/quicktemplates2/qquicktextarea.cpp
@@ -189,18 +189,31 @@ void QQuickTextAreaPrivate::resolveFont()
     inheritFont(QQuickControlPrivate::parentFont(q));
 }
 
-void QQuickTextAreaPrivate::inheritFont(const QFont &f)
+void QQuickTextAreaPrivate::inheritFont(const QFont &font)
 {
-    Q_Q(QQuickTextArea);
-    QFont parentFont = font.resolve(f);
-    parentFont.resolve(font.resolve() | f.resolve());
+    QFont parentFont = extra.isAllocated() ? extra->requestedFont.resolve(font) : font;
+    parentFont.resolve(extra.isAllocated() ? extra->requestedFont.resolve() | font.resolve() : font.resolve());
 
     const QFont defaultFont = QQuickControlPrivate::themeFont(QPlatformTheme::EditorFont);
     const QFont resolvedFont = parentFont.resolve(defaultFont);
 
-    const bool changed = resolvedFont != sourceFont;
-    q->QQuickTextEdit::setFont(resolvedFont);
-    if (changed)
+    setFont_helper(resolvedFont);
+}
+
+/*!
+    \internal
+
+    Assign \a font to this control, and propagate it to all children.
+*/
+void QQuickTextAreaPrivate::updateFont(const QFont &font)
+{
+    Q_Q(QQuickTextArea);
+    QFont oldFont = sourceFont;
+    q->QQuickTextEdit::setFont(font);
+
+    QQuickControlPrivate::updateFontRecur(q, font);
+
+    if (oldFont != font)
         emit q->fontChanged();
 }
 
@@ -419,10 +432,10 @@ QFont QQuickTextArea::font() const
 void QQuickTextArea::setFont(const QFont &font)
 {
     Q_D(QQuickTextArea);
-    if (d->font.resolve() == font.resolve() && d->font == font)
+    if (d->extra.value().requestedFont.resolve() == font.resolve() && d->extra.value().requestedFont == font)
         return;
 
-    d->font = font;
+    d->extra.value().requestedFont = font;
     d->resolveFont();
 }
 
diff --git a/src/quicktemplates2/qquicktextarea_p_p.h b/src/quicktemplates2/qquicktextarea_p_p.h
index 1115b3e9..22ad4b09 100644
--- a/src/quicktemplates2/qquicktextarea_p_p.h
+++ b/src/quicktemplates2/qquicktextarea_p_p.h
@@ -48,6 +48,7 @@
 // We mean it.
 //
 
+#include <QtQml/private/qlazilyallocated_p.h>
 #include <QtQuick/private/qquicktextedit_p_p.h>
 #include <QtQuick/private/qquickitemchangelistener_p.h>
 #include <QtQuickTemplates2/private/qquickpresshandler_p_p.h>
@@ -80,8 +81,15 @@ public:
     }
 
     void resizeBackground();
+
     void resolveFont();
-    void inheritFont(const QFont &f);
+    void inheritFont(const QFont &font);
+    void updateFont(const QFont &font);
+    inline void setFont_helper(const QFont &font) {
+        if (sourceFont.resolve() == font.resolve() && sourceFont == font)
+            return;
+        updateFont(font);
+    }
 
 #if QT_CONFIG(quicktemplates2_hover)
     void updateHoverEnabled(bool h, bool e);
@@ -112,7 +120,12 @@ public:
     bool hovered;
     bool explicitHoverEnabled;
 #endif
-    QFont font;
+
+    struct ExtraData {
+        QFont requestedFont;
+    };
+    QLazilyAllocated<ExtraData> extra;
+
     QQuickItem *background;
     QString placeholder;
     Qt::FocusReason focusReason;
diff --git a/src/quicktemplates2/qquicktextfield.cpp b/src/quicktemplates2/qquicktextfield.cpp
index e6ca2496..241ff922 100644
--- a/src/quicktemplates2/qquicktextfield.cpp
+++ b/src/quicktemplates2/qquicktextfield.cpp
@@ -163,18 +163,31 @@ void QQuickTextFieldPrivate::resolveFont()
     inheritFont(QQuickControlPrivate::parentFont(q));
 }
 
-void QQuickTextFieldPrivate::inheritFont(const QFont &f)
+void QQuickTextFieldPrivate::inheritFont(const QFont &font)
 {
-    Q_Q(QQuickTextField);
-    QFont parentFont = font.resolve(f);
-    parentFont.resolve(font.resolve() | f.resolve());
+    QFont parentFont = extra.isAllocated() ? extra->requestedFont.resolve(font) : font;
+    parentFont.resolve(extra.isAllocated() ? extra->requestedFont.resolve() | font.resolve() : font.resolve());
 
     const QFont defaultFont = QQuickControlPrivate::themeFont(QPlatformTheme::EditorFont);
     const QFont resolvedFont = parentFont.resolve(defaultFont);
 
-    const bool changed = resolvedFont != sourceFont;
-    q->QQuickTextInput::setFont(resolvedFont);
-    if (changed)
+    setFont_helper(resolvedFont);
+}
+
+/*!
+    \internal
+
+    Assign \a font to this control, and propagate it to all children.
+*/
+void QQuickTextFieldPrivate::updateFont(const QFont &font)
+{
+    Q_Q(QQuickTextField);
+    QFont oldFont = sourceFont;
+    q->QQuickTextInput::setFont(font);
+
+    QQuickControlPrivate::updateFontRecur(q, font);
+
+    if (oldFont != font)
         emit q->fontChanged();
 }
 
@@ -288,10 +301,10 @@ QFont QQuickTextField::font() const
 void QQuickTextField::setFont(const QFont &font)
 {
     Q_D(QQuickTextField);
-    if (d->font.resolve() == font.resolve() && d->font == font)
+    if (d->extra.value().requestedFont.resolve() == font.resolve() && d->extra.value().requestedFont == font)
         return;
 
-    d->font = font;
+    d->extra.value().requestedFont = font;
     d->resolveFont();
 }
 
diff --git a/src/quicktemplates2/qquicktextfield_p_p.h b/src/quicktemplates2/qquicktextfield_p_p.h
index e8dc625b..6f36dda4 100644
--- a/src/quicktemplates2/qquicktextfield_p_p.h
+++ b/src/quicktemplates2/qquicktextfield_p_p.h
@@ -48,6 +48,7 @@
 // We mean it.
 //
 
+#include <QtQml/private/qlazilyallocated_p.h>
 #include <QtQuick/private/qquicktextinput_p_p.h>
 #include <QtQuickTemplates2/private/qquickpresshandler_p_p.h>
 
@@ -76,8 +77,15 @@ public:
         return static_cast<QQuickTextFieldPrivate *>(QObjectPrivate::get(item)); }
 
     void resizeBackground();
+
     void resolveFont();
-    void inheritFont(const QFont &f);
+    void inheritFont(const QFont &font);
+    void updateFont(const QFont &font);
+    inline void setFont_helper(const QFont &font) {
+        if (sourceFont.resolve() == font.resolve() && sourceFont == font)
+            return;
+        updateFont(font);
+    }
 
 #if QT_CONFIG(quicktemplates2_hover)
     void updateHoverEnabled(bool h, bool e);
@@ -101,7 +109,12 @@ public:
     bool hovered;
     bool explicitHoverEnabled;
 #endif
-    QFont font;
+
+    struct ExtraData {
+        QFont requestedFont;
+    };
+    QLazilyAllocated<ExtraData> extra;
+
     QQuickItem *background;
     QString placeholder;
     Qt::FocusReason focusReason;