QQuickControl: add font property

When the font of a QQuickControl subclass is set, it will
propagate it to all children that are also derived from
QQuickControl, as well as TextField and TextArea.

Change-Id: I7c851f84b89609094d9a81d239ade0f0ac212985
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>

10 files changed, 405 insertions, 35 deletions

diff --git a/src/controls/controls.pri b/src/controls/controls.pri
index af65c841..e7e8f65d 100644
--- a/src/controls/controls.pri
+++ b/src/controls/controls.pri
@@ -31,7 +31,9 @@ HEADERS += \
     $$PWD/qquicktabbar_p.h \
     $$PWD/qquicktabbutton_p.h \
     $$PWD/qquicktextarea_p.h \
+    $$PWD/qquicktextarea_p_p.h \
     $$PWD/qquicktextfield_p.h \
+    $$PWD/qquicktextfield_p_p.h \
     $$PWD/qquicktogglebutton_p.h \
     $$PWD/qquicktoolbar_p.h \
     $$PWD/qquicktoolbutton_p.h
diff --git a/src/controls/qquickcontrol.cpp b/src/controls/qquickcontrol.cpp
index 1b41c352..e91149e3 100644
--- a/src/controls/qquickcontrol.cpp
+++ b/src/controls/qquickcontrol.cpp
@@ -37,6 +37,12 @@
 #include "qquickcontrol_p.h"
 #include "qquickcontrol_p_p.h"
 
+#include <QtGui/qguiapplication.h>
+#include "qquicktextarea_p.h"
+#include "qquicktextarea_p_p.h"
+#include "qquicktextfield_p.h"
+#include "qquicktextfield_p_p.h"
+
 QT_BEGIN_NAMESPACE
 
 /*!
@@ -143,6 +149,78 @@ void QQuickControlPrivate::resizeContent()
     }
 }
 
+/*!
+    \internal
+
+    Returns the font that the control w inherits from its ancestors and
+    QGuiApplication::font.
+*/
+QFont QQuickControlPrivate::naturalControlFont(const QQuickItem *q)
+{
+    QFont naturalFont = QGuiApplication::font();
+    QQuickItem *p = q->parentItem();
+    while (p) {
+        if (QQuickControl *qc = qobject_cast<QQuickControl *>(p)) {
+            naturalFont = qc->font();
+            break;
+        }
+
+        p = p->parentItem();
+    }
+
+    naturalFont.resolve(0);
+    return naturalFont;
+}
+
+/*!
+    \internal
+
+    Determine which font is implicitly imposed on this control by its ancestors
+    and QGuiApplication::font, resolve this against its own font (attributes from
+    the implicit font are copied over). Then propagate this font to this
+    control's children.
+*/
+void QQuickControlPrivate::resolveFont()
+{
+    Q_Q(const QQuickControl);
+    QFont naturalFont = QQuickControlPrivate::naturalControlFont(q);
+    QFont resolvedFont = font.resolve(naturalFont);
+    setFont_helper(resolvedFont);
+}
+
+/*!
+    \internal
+
+    Assign \a font to this control, and propagate it to all children.
+*/
+void QQuickControlPrivate::updateFont(const QFont &f)
+{
+    Q_Q(QQuickControl);
+    font = f;
+
+    QQuickControlPrivate::updateFontRecur(q, f);
+
+    emit q->fontChanged();
+}
+
+void QQuickControlPrivate::updateFontRecur(QQuickItem *i, const QFont &f)
+{
+    foreach (QQuickItem *child, i->childItems()) {
+        if (QQuickControl *qc = qobject_cast<QQuickControl *>(child)) {
+            QQuickControlPrivate *qcp = qc->d_func();
+            qcp->resolveFont();
+        } else if (QQuickTextArea *qta = qobject_cast<QQuickTextArea *>(child)) {
+            QQuickTextAreaPrivate *qtap = QQuickTextAreaPrivate::get(qta);
+            qtap->resolveFont();
+        } else if (QQuickTextField *qtf = qobject_cast<QQuickTextField *>(child)) {
+            QQuickTextFieldPrivate *qtfp = QQuickTextFieldPrivate::get(qtf);
+            qtfp->resolveFont();
+        } else {
+            QQuickControlPrivate::updateFontRecur(child, f);
+        }
+    }
+}
+
 QQuickControl::QQuickControl(QQuickItem *parent) :
     QQuickItem(*(new QQuickControlPrivate), parent)
 {
@@ -153,6 +231,40 @@ QQuickControl::QQuickControl(QQuickControlPrivate &dd, QQuickItem *parent) :
 {
 }
 
+void QQuickControl::itemChange(QQuickItem::ItemChange change, const QQuickItem::ItemChangeData &value)
+{
+    Q_D(QQuickControl);
+    QQuickItem::itemChange(change, value);
+    if (change == ItemParentHasChanged)
+        d->resolveFont();
+}
+
+QFont QQuickControl::font() const
+{
+    Q_D(const QQuickControl);
+    return d->font;
+}
+
+void QQuickControl::setFont(const QFont &f)
+{
+    Q_D(QQuickControl);
+    if (d->font == f)
+        return;
+
+    // Determine which font is inherited from this control's ancestors and
+    // QGuiApplication::font, resolve this against \a font (attributes from the
+    // inherited font are copied over). Then propagate this font to this
+    // control's children.
+    QFont naturalFont = QQuickControlPrivate::naturalControlFont(this);
+    QFont resolvedFont = f.resolve(naturalFont);
+    d->setFont_helper(resolvedFont);
+}
+
+void QQuickControl::resetFont()
+{
+    setFont(QFont());
+}
+
 /*!
     \qmlproperty real QtQuickControls2::Control::availableWidth
 
diff --git a/src/controls/qquickcontrol_p.h b/src/controls/qquickcontrol_p.h
index 9da4235e..9b2ede50 100644
--- a/src/controls/qquickcontrol_p.h
+++ b/src/controls/qquickcontrol_p.h
@@ -58,6 +58,7 @@ class QQuickControlPrivate;
 class Q_QUICKCONTROLS_EXPORT QQuickControl : public QQuickItem
 {
     Q_OBJECT
+    Q_PROPERTY(QFont font READ font WRITE setFont RESET resetFont NOTIFY fontChanged)
     Q_PROPERTY(qreal availableWidth READ availableWidth NOTIFY availableWidthChanged FINAL)
     Q_PROPERTY(qreal availableHeight READ availableHeight NOTIFY availableHeightChanged FINAL)
     Q_PROPERTY(qreal padding READ padding WRITE setPadding RESET resetPadding NOTIFY paddingChanged FINAL)
@@ -75,6 +76,10 @@ class Q_QUICKCONTROLS_EXPORT QQuickControl : public QQuickItem
 public:
     explicit QQuickControl(QQuickItem *parent = Q_NULLPTR);
 
+    QFont font() const;
+    void setFont(const QFont &);
+    void resetFont();
+
     qreal availableWidth() const;
     qreal availableHeight() const;
 
@@ -115,6 +120,7 @@ public:
     void setContentItem(QQuickItem *item);
 
 Q_SIGNALS:
+    void fontChanged();
     void availableWidthChanged();
     void availableHeightChanged();
     void paddingChanged();
@@ -132,6 +138,8 @@ Q_SIGNALS:
 protected:
     QQuickControl(QQuickControlPrivate &dd, QQuickItem *parent);
 
+    void itemChange(ItemChange change, const ItemChangeData &value) Q_DECL_OVERRIDE;
+
     void mousePressEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
     void mouseMoveEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
     void mouseReleaseEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
diff --git a/src/controls/qquickcontrol_p_p.h b/src/controls/qquickcontrol_p_p.h
index 273ca6c9..2861c067 100644
--- a/src/controls/qquickcontrol_p_p.h
+++ b/src/controls/qquickcontrol_p_p.h
@@ -69,6 +69,17 @@ public:
     void resizeBackground();
     void resizeContent();
 
+    void updateFont(const QFont &);
+    static void updateFontRecur(QQuickItem *item, const QFont &);
+    inline void setFont_helper(const QFont &f) {
+        if (font.resolve() == f.resolve() && font == f)
+            return;
+        updateFont(f);
+    }
+    void resolveFont();
+    static QFont naturalControlFont(const QQuickItem *);
+
+    QFont font;
     bool hasTopPadding;
     bool hasLeftPadding;
     bool hasRightPadding;
diff --git a/src/controls/qquicktextarea.cpp b/src/controls/qquicktextarea.cpp
index a670f893..b9e4e4f8 100644
--- a/src/controls/qquicktextarea.cpp
+++ b/src/controls/qquicktextarea.cpp
@@ -35,12 +35,14 @@
 ****************************************************************************/
 
 #include "qquicktextarea_p.h"
-#include "qquickpressandholdhelper_p.h"
+#include "qquicktextarea_p_p.h"
+#include "qquickcontrol_p.h"
+#include "qquickcontrol_p_p.h"
 
+#include <QtGui/qguiapplication.h>
 #include <QtQuick/private/qquickitem_p.h>
 #include <QtQuick/private/qquicktext_p.h>
 #include <QtQuick/private/qquickclipnode_p.h>
-#include <QtQuick/private/qquicktextedit_p_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -64,20 +66,6 @@ QT_BEGIN_NAMESPACE
     \sa TextField, {Customizing TextArea}
 */
 
-class QQuickTextAreaPrivate : public QQuickTextEditPrivate
-{
-    Q_DECLARE_PUBLIC(QQuickTextArea)
-
-public:
-    QQuickTextAreaPrivate() : background(Q_NULLPTR), placeholder(Q_NULLPTR) { }
-
-    void resizeBackground();
-
-    QQuickItem *background;
-    QQuickText *placeholder;
-    QQuickPressAndHoldHelper pressAndHoldHelper;
-};
-
 void QQuickTextAreaPrivate::resizeBackground()
 {
     Q_Q(QQuickTextArea);
@@ -106,6 +94,47 @@ QQuickTextArea::~QQuickTextArea()
 }
 
 /*!
+    \internal
+
+    Determine which font is implicitly imposed on this control by its ancestors
+    and QGuiApplication::font, resolve this against its own font (attributes from
+    the implicit font are copied over). Then propagate this font to this
+    control's children.
+*/
+void QQuickTextAreaPrivate::resolveFont()
+{
+    Q_Q(const QQuickTextArea);
+    QFont naturalFont = QQuickControlPrivate::naturalControlFont(q);
+    QFont resolvedFont = sourceFont.resolve(naturalFont);
+    setFont_helper(resolvedFont);
+}
+
+QFont QQuickTextArea::font() const
+{
+    Q_D(const QQuickTextArea);
+    return d->sourceFont;
+}
+
+void QQuickTextArea::setFont(const QFont &font)
+{
+    Q_D(QQuickTextArea);
+    if (d->sourceFont == font)
+        return;
+
+    // Determine which font is inherited from this control's ancestors and
+    // QGuiApplication::font, resolve this against \a font (attributes from the
+    // inherited font are copied over). Then propagate this font to this
+    // control's children.
+    QFont naturalFont = QQuickControlPrivate::naturalControlFont(this);
+    QFont resolvedFont = font.resolve(naturalFont);
+    d->setFont_helper(resolvedFont);
+
+    QQuickTextEdit::setFont(font);
+
+    emit fontChanged();
+}
+
+/*!
     \qmlproperty Item QtQuickControls2::TextArea::background
 
     This property holds the background item.
diff --git a/src/controls/qquicktextarea_p.h b/src/controls/qquicktextarea_p.h
index f952f304..239fa559 100644
--- a/src/controls/qquicktextarea_p.h
+++ b/src/controls/qquicktextarea_p.h
@@ -60,6 +60,7 @@ class QQuickMouseEvent;
 class Q_QUICKCONTROLS_EXPORT QQuickTextArea : public QQuickTextEdit
 {
     Q_OBJECT
+    Q_PROPERTY(QFont font READ font WRITE setFont NOTIFY fontChanged) // override
     Q_PROPERTY(QQuickItem *background READ background WRITE setBackground NOTIFY backgroundChanged FINAL)
     Q_PROPERTY(QQuickText *placeholder READ placeholder WRITE setPlaceholder NOTIFY placeholderChanged FINAL)
 
@@ -67,6 +68,9 @@ public:
     explicit QQuickTextArea(QQuickItem *parent = Q_NULLPTR);
     ~QQuickTextArea();
 
+    QFont font() const;
+    void setFont(const QFont &font);
+
     QQuickItem *background() const;
     void setBackground(QQuickItem *background);
 
@@ -74,6 +78,7 @@ public:
     void setPlaceholder(QQuickText *placeholder);
 
 Q_SIGNALS:
+    void fontChanged();
     void backgroundChanged();
     void placeholderChanged();
     void pressAndHold(QQuickMouseEvent *event);
diff --git a/src/controls/qquicktextarea_p_p.h b/src/controls/qquicktextarea_p_p.h
new file mode 100644
index 00000000..83194ef1
--- /dev/null
+++ b/src/controls/qquicktextarea_p_p.h
@@ -0,0 +1,85 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Quick Controls module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQUICKTEXTAREA_P_P_H
+#define QQUICKTEXTAREA_P_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtQuick/private/qquicktextedit_p_p.h>
+#include <QtQuickControls/private/qquickpressandholdhelper_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQuickTextAreaPrivate : public QQuickTextEditPrivate
+{
+    Q_DECLARE_PUBLIC(QQuickTextArea)
+
+public:
+    QQuickTextAreaPrivate() : background(Q_NULLPTR), placeholder(Q_NULLPTR) { }
+
+    static QQuickTextAreaPrivate *get(QQuickTextArea *item) {
+        return static_cast<QQuickTextAreaPrivate *>(QObjectPrivate::get(item)); }
+
+    void resizeBackground();
+
+    inline void setFont_helper(const QFont &f) {
+        // In QQuickTextEditPrivate, sourceFont was used, instead of font...
+        if (sourceFont.resolve() == f.resolve() && sourceFont == f)
+            return;
+        sourceFont = f;
+    }
+    void resolveFont();
+
+    QQuickItem *background;
+    QQuickText *placeholder;
+    QQuickPressAndHoldHelper pressAndHoldHelper;
+};
+
+Q_DECLARE_TYPEINFO(QQuickTextAreaPrivate, Q_COMPLEX_TYPE);
+
+QT_END_NAMESPACE
+
+#endif // QQUICKTEXTAREA_P_P_H
diff --git a/src/controls/qquicktextfield.cpp b/src/controls/qquicktextfield.cpp
index e8b4086c..01b26cf7 100644
--- a/src/controls/qquicktextfield.cpp
+++ b/src/controls/qquicktextfield.cpp
@@ -35,13 +35,14 @@
 ****************************************************************************/
 
 #include "qquicktextfield_p.h"
-#include "qquickpressandholdhelper_p.h"
+#include "qquicktextfield_p_p.h"
+#include "qquickcontrol_p.h"
+#include "qquickcontrol_p_p.h"
 
 #include <QtCore/qbasictimer.h>
 #include <QtQuick/private/qquickitem_p.h>
 #include <QtQuick/private/qquicktext_p.h>
 #include <QtQuick/private/qquickclipnode_p.h>
-#include <QtQuick/private/qquicktextinput_p_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -82,23 +83,6 @@ QT_BEGIN_NAMESPACE
     position of the press, and which button is pressed.
 */
 
-class QQuickTextFieldPrivate : public QQuickTextInputPrivate
-{
-    Q_DECLARE_PUBLIC(QQuickTextField)
-
-public:
-    QQuickTextFieldPrivate()
-        : background(Q_NULLPTR)
-        , placeholder(Q_NULLPTR)
-    { }
-
-    void resizeBackground();
-
-    QQuickItem *background;
-    QQuickText *placeholder;
-    QQuickPressAndHoldHelper pressAndHoldHelper;
-};
-
 void QQuickTextFieldPrivate::resizeBackground()
 {
     Q_Q(QQuickTextField);
@@ -127,6 +111,47 @@ QQuickTextField::~QQuickTextField()
 }
 
 /*!
+    \internal
+
+    Determine which font is implicitly imposed on this control by its ancestors
+    and QGuiApplication::font, resolve this against its own font (attributes from
+    the implicit font are copied over). Then propagate this font to this
+    control's children.
+*/
+void QQuickTextFieldPrivate::resolveFont()
+{
+    Q_Q(QQuickTextField);
+    QFont naturalFont = QQuickControlPrivate::naturalControlFont(q);
+    QFont resolvedFont = sourceFont.resolve(naturalFont);
+    setFont_helper(resolvedFont);
+}
+
+QFont QQuickTextField::font() const
+{
+    Q_D(const QQuickTextField);
+    return d->sourceFont;
+}
+
+void QQuickTextField::setFont(const QFont &font)
+{
+    Q_D(QQuickTextField);
+    if (d->sourceFont == font)
+        return;
+
+    // Determine which font is inherited from this control's ancestors and
+    // QGuiApplication::font, resolve this against \a font (attributes from the
+    // inherited font are copied over). Then propagate this font to this
+    // control's children.
+    QFont naturalFont = QQuickControlPrivate::naturalControlFont(this);
+    QFont resolvedFont = font.resolve(naturalFont);
+    d->setFont_helper(resolvedFont);
+
+    QQuickTextInput::setFont(font);
+
+    emit fontChanged();
+}
+
+/*!
     \qmlproperty Item QtQuickControls2::TextField::background
 
     This property holds the background item.
diff --git a/src/controls/qquicktextfield_p.h b/src/controls/qquicktextfield_p.h
index a3b0fa8d..6f22cdd5 100644
--- a/src/controls/qquicktextfield_p.h
+++ b/src/controls/qquicktextfield_p.h
@@ -60,6 +60,7 @@ class QQuickMouseEvent;
 class Q_QUICKCONTROLS_EXPORT QQuickTextField : public QQuickTextInput
 {
     Q_OBJECT
+    Q_PROPERTY(QFont font READ font WRITE setFont NOTIFY fontChanged) // override
     Q_PROPERTY(QQuickItem *background READ background WRITE setBackground NOTIFY backgroundChanged FINAL)
     Q_PROPERTY(QQuickText *placeholder READ placeholder WRITE setPlaceholder NOTIFY placeholderChanged FINAL)
 
@@ -67,6 +68,9 @@ public:
     explicit QQuickTextField(QQuickItem *parent = Q_NULLPTR);
     ~QQuickTextField();
 
+    QFont font() const;
+    void setFont(const QFont &font);
+
     QQuickItem *background() const;
     void setBackground(QQuickItem *background);
 
@@ -74,6 +78,7 @@ public:
     void setPlaceholder(QQuickText *placeholder);
 
 Q_SIGNALS:
+    void fontChanged();
     void backgroundChanged();
     void placeholderChanged();
     void pressAndHold(QQuickMouseEvent *mouse);
diff --git a/src/controls/qquicktextfield_p_p.h b/src/controls/qquicktextfield_p_p.h
new file mode 100644
index 00000000..ceefb91e
--- /dev/null
+++ b/src/controls/qquicktextfield_p_p.h
@@ -0,0 +1,88 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Quick Controls module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQUICKTEXTFIELD_P_P_H
+#define QQUICKTEXTFIELD_P_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtQuick/private/qquicktextinput_p_p.h>
+#include <QtQuickControls/private/qquickpressandholdhelper_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQuickTextFieldPrivate : public QQuickTextInputPrivate
+{
+    Q_DECLARE_PUBLIC(QQuickTextField)
+
+public:
+    QQuickTextFieldPrivate()
+        : background(Q_NULLPTR)
+        , placeholder(Q_NULLPTR)
+    { }
+
+    static QQuickTextFieldPrivate *get(QQuickTextField *item) {
+        return static_cast<QQuickTextFieldPrivate *>(QObjectPrivate::get(item)); }
+
+    void resizeBackground();
+
+    inline void setFont_helper(const QFont &f) {
+        // In QQuickTextInputPrivate, sourceFont was used, instead of font...
+        if (sourceFont.resolve() == f.resolve() && sourceFont == f)
+            return;
+        sourceFont = f;
+    }
+    void resolveFont();
+
+    QQuickItem *background;
+    QQuickText *placeholder;
+    QQuickPressAndHoldHelper pressAndHoldHelper;
+};
+
+Q_DECLARE_TYPEINFO(QQuickTextFieldPrivate, Q_COMPLEX_TYPE);
+
+QT_END_NAMESPACE
+
+#endif // QQUICKTEXTFIELD_P_P_H