Add QQuickFontMetrics.

This will be a private C++ type that is exposed to QtQuick 2.4 as
FontMetrics.

[ChangeLog][QtQuick] Added QQuickFontMetrics, which provides a subset
of QFontMetricsF's API.

Change-Id: Iac31e5a555bd8f1dc0904b8de0408e5f1a402b25
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>

4 files changed, 455 insertions, 2 deletions

diff --git a/src/quick/util/qquickfontmetrics.cpp b/src/quick/util/qquickfontmetrics.cpp
new file mode 100644
index 0000000000..bf533995a5
--- /dev/null
+++ b/src/quick/util/qquickfontmetrics.cpp
@@ -0,0 +1,334 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtQuick module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 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 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qquickfontmetrics_p.h"
+
+#include <QFont>
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    \qmltype FontMetrics
+    \instantiates QQuickFontMetrics
+    \inqmlmodule QtQuick
+    \ingroup qtquick-text-utility
+    \brief Provides metrics for a given font
+
+    FontMetrics calculates the size of characters and strings for a given font.
+
+    It provides a subset of the C++ \l QFontMetricsF API, with the added
+    ability to change the font that is used for calculations via the \l font
+    property.
+
+    \code
+    FontMetrics {
+        id: fontMetrics
+        font.family: "Arial"
+    }
+
+    Rectangle {
+        width: fontMetrics.height() * 4
+        height: fontMetrics.height() * 2
+    }
+    \endcode
+
+    \sa QFontMetricsF
+*/
+QQuickFontMetrics::QQuickFontMetrics(QObject *parent) :
+    QObject(parent),
+    m_metrics(m_font)
+{
+}
+
+QQuickFontMetrics::~QQuickFontMetrics()
+{
+}
+
+/*!
+    \qmlproperty font QtQuick::FontMetrics::font
+
+    This property holds the font used for the metrics calculations.
+*/
+QFont QQuickFontMetrics::font() const
+{
+    return m_font;
+}
+
+void QQuickFontMetrics::setFont(const QFont &font)
+{
+    if (m_font != font) {
+        m_font = font;
+        m_metrics = QFontMetricsF(m_font);
+        emit fontChanged(m_font);
+    }
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::ascent
+
+    This property holds the ascent of the font.
+
+    \sa {QFontMetricsF::ascent()}, descent, height
+*/
+qreal QQuickFontMetrics::ascent() const
+{
+    return m_metrics.ascent();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::descent
+
+    This property holds the descent of the font.
+
+    \sa {QFontMetricsF::descent()}, ascent, height
+*/
+qreal QQuickFontMetrics::descent() const
+{
+    return m_metrics.descent();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::height
+
+    This property holds the height of the font.
+
+    \sa {QFontMetricsF::height()}
+*/
+qreal QQuickFontMetrics::height() const
+{
+    return m_metrics.height();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::leading
+
+    This property holds the leading of the font.
+
+    \sa {QFontMetricsF::leading()}
+*/
+qreal QQuickFontMetrics::leading() const
+{
+    return m_metrics.leading();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::lineSpacing
+
+    This property holds the distance from one base line to the next.
+
+    \sa {QFontMetricsF::lineSpacing()}
+*/
+qreal QQuickFontMetrics::lineSpacing() const
+{
+    return m_metrics.lineSpacing();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::minimumLeftBearing
+
+    This property holds the minimum left bearing of the font.
+
+    \sa {QFontMetricsF::minLeftBearing()}
+*/
+qreal QQuickFontMetrics::minimumLeftBearing() const
+{
+    return m_metrics.minLeftBearing();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::minimumRightBearing
+
+    This property holds the minimum right bearing of the font.
+
+    \sa {QFontMetricsF::minRightBearing()}
+*/
+qreal QQuickFontMetrics::minimumRightBearing() const
+{
+    return m_metrics.minRightBearing();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::maximumCharacterWidth
+
+    This property holds the width of the widest character in the font.
+
+    \sa {QFontMetricsF::maxWidth()}
+*/
+qreal QQuickFontMetrics::maximumCharacterWidth() const
+{
+    return m_metrics.maxWidth();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::xHeight
+
+    This property holds the 'x' height of the font.
+
+    \sa {QFontMetricsF::xHeight()}
+*/
+qreal QQuickFontMetrics::xHeight() const
+{
+    return m_metrics.xHeight();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::averageCharacterWidth
+
+    This property holds the average width of glyphs in the font.
+
+    \sa {QFontMetricsF::averageCharWidth()}
+*/
+qreal QQuickFontMetrics::averageCharacterWidth() const
+{
+    return m_metrics.averageCharWidth();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::underlinePosition
+
+    This property holds the distance from the base line to where an underscore
+    should be drawn.
+
+    \sa {QFontMetricsF::underlinePos()}, overlinePosition, strikeOutPosition
+*/
+qreal QQuickFontMetrics::underlinePosition() const
+{
+    return m_metrics.underlinePos();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::overlinePosition
+
+    This property holds the distance from the base line to where an overline
+    should be drawn.
+
+    \sa {QFontMetricsF::overlinePos()}, underlinePosition, strikeOutPosition
+*/
+qreal QQuickFontMetrics::overlinePosition() const
+{
+    return m_metrics.overlinePos();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::strikeOutPosition
+
+    This property holds the distance from the base line to where the strikeout
+    line should be drawn.
+
+    \sa {QFontMetricsF::strikeOutPos()}, overlinePosition, underlinePosition
+*/
+qreal QQuickFontMetrics::strikeOutPosition() const
+{
+    return m_metrics.strikeOutPos();
+}
+
+/*!
+    \qmlproperty real QtQuick::FontMetrics::lineWidth
+
+    This property holds the width of the underline and strikeout lines,
+    adjusted for the point size of the font.
+
+    \sa {QFontMetricsF::lineWidth()}
+*/
+qreal QQuickFontMetrics::lineWidth() const
+{
+    return m_metrics.lineWidth();
+}
+
+/*!
+    \qmlmethod qreal QtQuick::FontMetrics::advanceWidth(string text)
+
+    This method returns the advance in pixels of the characters in \a text.
+    This is the distance from the position of the string to where the next
+    string should be drawn.
+
+    \sa {QFontMetricsF::width()}, height()
+*/
+qreal QQuickFontMetrics::advanceWidth(const QString &text) const
+{
+    return m_metrics.width(text);
+}
+
+/*!
+    \qmlmethod rect QtQuick::FontMetrics::boundingRect(string text)
+
+    This method returns the bounding rectangle of the characters in the string
+    specified by \a text.
+
+    \sa {QFontMetricsF::boundingRect()}, tightBoundingRect()
+*/
+QRectF QQuickFontMetrics::boundingRect(const QString &text) const
+{
+    return m_metrics.boundingRect(text);
+}
+
+/*!
+    \qmlmethod rect QtQuick::FontMetrics::tightBoundingRect(string text)
+
+    This method returns a tight bounding rectangle around the characters in the
+    string specified by \a text.
+
+    \sa {QFontMetricsF::tightBoundingRect()}, boundingRect()
+*/
+QRectF QQuickFontMetrics::tightBoundingRect(const QString &text) const
+{
+    return m_metrics.tightBoundingRect(text);
+}
+
+/*!
+    \qmlmethod string QtQuick::FontMetrics::elidedText(string text, enum mode,
+        qreal width, int flags)
+
+    This method returns a returns an elided version of the string (i.e., a
+    string with "..." in it) if the string \a text is wider than \a width.
+    Otherwise, returns the original string.
+
+    The \a flags argument is optional and currently only supports
+    \l {Qt::TextShowMnemonic}.
+
+    \sa {QFontMetricsF::elidedText()}
+*/
+QString QQuickFontMetrics::elidedText(const QString &text, Qt::TextElideMode mode, qreal width, int flags) const
+{
+    return m_metrics.elidedText(text, mode, width, flags);
+}
+
+QT_END_NAMESPACE
diff --git a/src/quick/util/qquickfontmetrics_p.h b/src/quick/util/qquickfontmetrics_p.h
new file mode 100644
index 0000000000..4017fd4061
--- /dev/null
+++ b/src/quick/util/qquickfontmetrics_p.h
@@ -0,0 +1,114 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtQuick module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 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 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQUICKFONTMETRICS_H
+#define QQUICKFONTMETRICS_H
+
+#include <qqml.h>
+
+#include <QtGui/QFontMetricsF>
+#include <QtCore/QObject>
+
+QT_BEGIN_NAMESPACE
+
+class QFont;
+
+class Q_AUTOTEST_EXPORT QQuickFontMetrics : public QObject
+{
+    Q_OBJECT
+
+    Q_PROPERTY(QFont font READ font WRITE setFont NOTIFY fontChanged)
+    Q_PROPERTY(qreal ascent READ ascent NOTIFY fontChanged)
+    Q_PROPERTY(qreal descent READ descent NOTIFY fontChanged)
+    Q_PROPERTY(qreal height READ height NOTIFY fontChanged)
+    Q_PROPERTY(qreal leading READ leading NOTIFY fontChanged)
+    Q_PROPERTY(qreal lineSpacing READ lineSpacing NOTIFY fontChanged)
+    Q_PROPERTY(qreal minimumLeftBearing READ minimumLeftBearing NOTIFY fontChanged)
+    Q_PROPERTY(qreal minimumRightBearing READ minimumRightBearing NOTIFY fontChanged)
+    Q_PROPERTY(qreal maximumCharacterWidth READ maximumCharacterWidth NOTIFY fontChanged)
+    Q_PROPERTY(qreal xHeight READ xHeight NOTIFY fontChanged)
+    Q_PROPERTY(qreal averageCharacterWidth READ averageCharacterWidth NOTIFY fontChanged)
+    Q_PROPERTY(qreal underlinePosition READ underlinePosition NOTIFY fontChanged)
+    Q_PROPERTY(qreal overlinePosition READ overlinePosition NOTIFY fontChanged)
+    Q_PROPERTY(qreal strikeOutPosition READ strikeOutPosition NOTIFY fontChanged)
+    Q_PROPERTY(qreal lineWidth READ lineWidth NOTIFY fontChanged)
+public:
+    explicit QQuickFontMetrics(QObject *parent = 0);
+    ~QQuickFontMetrics();
+
+    QFont font() const;
+    void setFont(const QFont &font);
+
+    qreal ascent() const;
+    qreal descent() const;
+    qreal height() const;
+    qreal leading() const;
+    qreal lineSpacing() const;
+    qreal minimumLeftBearing() const;
+    qreal minimumRightBearing() const;
+    qreal maximumCharacterWidth() const;
+
+    qreal xHeight() const;
+    qreal averageCharacterWidth() const;
+
+    qreal underlinePosition() const;
+    qreal overlinePosition() const;
+    qreal strikeOutPosition() const;
+    qreal lineWidth() const;
+
+    Q_INVOKABLE qreal advanceWidth(const QString &text) const;
+    Q_INVOKABLE QRectF boundingRect(const QString &text) const;
+    Q_INVOKABLE QRectF tightBoundingRect(const QString &text) const;
+    Q_INVOKABLE QString elidedText(const QString &text, Qt::TextElideMode mode, qreal width, int flags = 0) const;
+
+Q_SIGNALS:
+    void fontChanged(const QFont &font);
+
+private:
+    QFont m_font;
+    QFontMetricsF m_metrics;
+};
+
+QT_END_NAMESPACE
+
+QML_DECLARE_TYPE(QQuickFontMetrics)
+
+#endif // QQUICKFONTMETRICS_H
diff --git a/src/quick/util/qquickutilmodule.cpp b/src/quick/util/qquickutilmodule.cpp
index a6e907713a..1d82cfca43 100644
--- a/src/quick/util/qquickutilmodule.cpp
+++ b/src/quick/util/qquickutilmodule.cpp
@@ -45,6 +45,7 @@
 #include "qquickbehavior_p.h"
 #include "qquicksmoothedanimation_p.h"
 #include "qquickfontloader_p.h"
+#include "qquickfontmetrics_p.h"
 #include "qquickpropertychanges_p.h"
 #include "qquickspringanimation_p.h"
 #include "qquickstategroup_p.h"
@@ -106,4 +107,6 @@ void QQuickUtilModule::defineModule()
 
     qRegisterMetaType<QKeySequence::StandardKey>();
     qmlRegisterUncreatableType<QKeySequence, 2>("QtQuick", 2, 2, "StandardKey", QStringLiteral("Cannot create an instance of StandardKey."));
+
+    qmlRegisterType<QQuickFontMetrics>("QtQuick", 2, 4, "FontMetrics");
 }
diff --git a/src/quick/util/util.pri b/src/quick/util/util.pri
index ce409bd10d..35553070dc 100644
--- a/src/quick/util/util.pri
+++ b/src/quick/util/util.pri
@@ -26,7 +26,8 @@ SOURCES += \
     $$PWD/qquickanimator.cpp \
     $$PWD/qquickanimatorjob.cpp \
     $$PWD/qquickanimatorcontroller.cpp \
-    $$PWD/qquickprofiler.cpp
+    $$PWD/qquickprofiler.cpp \
+    $$PWD/qquickfontmetrics.cpp
 
 HEADERS += \
     $$PWD/qquickapplication_p.h\
@@ -60,4 +61,5 @@ HEADERS += \
     $$PWD/qquickanimator_p_p.h \
     $$PWD/qquickanimatorjob_p.h \
     $$PWD/qquickanimatorcontroller_p.h \
-    $$PWD/qquickprofiler_p.h
+    $$PWD/qquickprofiler_p.h \
+    $$PWD/qquickfontmetrics_p.h