Introduce QStaticText API

Much of the time in drawText() is used on text layouting, which is
wasted time when the text is not updated every frame. QStaticText is
meant to cache the relevant parts of this work. It currently uses
a copy-paste of the layout code in QPainter::drawText() and 99% of the
time in QPainter::drawStaticText() is spent in drawTextItem(). We can
use QTextLayout here instead without losing much.

6 files changed, 222 insertions, 2 deletions

diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index a98ac10..f5bd2c5 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -69,6 +69,7 @@
 #include <private/qwidget_p.h>
 #include <private/qpaintengine_raster_p.h>
 #include <private/qmath_p.h>
+#include <private/qstatictext_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -5703,6 +5704,37 @@ void QPainter::drawText(const QPointF &p, const QString &str)
     drawText(p, str, 0, 0);
 }
 
+void QPainter::drawStaticText(const QPointF &p, const QStaticText &staticText)
+{
+    const QStaticTextPrivate *staticText_d = QStaticTextPrivate::get(&staticText);
+    const QTextEngine &engine = staticText_d->engine;
+    const QVarLengthArray<int> &visualOrder = staticText_d->visualOrder;
+
+    QFixed x = QFixed::fromReal(p.x());
+    QFixed ox = x;
+
+    int nItems = engine.layoutData->items.size();
+    for (int i = 0; i < nItems; ++i) {
+        int item = visualOrder[i];
+        const QScriptItem &si = engine.layoutData->items.at(item);
+        if (si.analysis.flags >= QScriptAnalysis::TabOrObject) {
+            x += si.width;
+            continue;
+        }
+        QFont f = engine.font(si);
+        QTextItemInt gf(si, &f);
+        gf.glyphs = engine.shapedGlyphs(&si);
+        gf.chars = engine.layoutData->string.unicode() + si.position;
+        gf.num_chars = engine.length(item);
+        gf.width = si.width;
+        gf.logClusters = engine.logClusters(&si);
+
+        drawTextItem(QPointF(x.toReal(), p.y()), gf);
+
+        x += si.width;
+    }
+}
+
 /*!
    \internal
 */
diff --git a/src/gui/painting/qpainter.h b/src/gui/painting/qpainter.h
index ffddcba..f2be36f 100644
--- a/src/gui/painting/qpainter.h
+++ b/src/gui/painting/qpainter.h
@@ -50,6 +50,7 @@
 #include <QtGui/qimage.h>
 #include <QtGui/qtextoption.h>
 #include <QtGui/qdrawutil.h>
+#include <QtGui/qstatictext.h>
 
 #ifndef QT_INCLUDE_COMPAT
 #include <QtGui/qpolygon.h>
@@ -369,6 +370,8 @@ public:
     void setLayoutDirection(Qt::LayoutDirection direction);
     Qt::LayoutDirection layoutDirection() const;
 
+    void drawStaticText(const QPointF &p, const QStaticText &staticText);
+
     void drawText(const QPointF &p, const QString &s);
     inline void drawText(const QPoint &p, const QString &s);
     inline void drawText(int x, int y, const QString &s);
diff --git a/src/gui/text/qstatictext.cpp b/src/gui/text/qstatictext.cpp
new file mode 100644
index 0000000..90b1145
--- /dev/null
+++ b/src/gui/text/qstatictext.cpp
@@ -0,0 +1,91 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** 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, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, 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.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qstatictext.h"
+#include "qstatictext_p.h"
+
+QT_BEGIN_NAMESPACE
+
+QStaticText::QStaticText(const QString &text, const QFont &font)
+    : d_ptr(new QStaticTextPrivate) 
+{
+    Q_D(QStaticText);
+    d->init(text, font);
+}
+
+QStaticTextPrivate *QStaticTextPrivate::get(const QStaticText *q)
+{
+    return q->d_ptr;
+}
+
+void QStaticTextPrivate::init(const QString &text, const QFont &font)
+{
+    engine.text = text; 
+    engine.fnt = font;
+
+    /*engine.option.setTextDirection(d->state->layoutDirection);
+    if (tf & (Qt::TextForceLeftToRight|Qt::TextForceRightToLeft)) {
+        engine.ignoreBidi = true;
+        engine.option.setTextDirection((tf & Qt::TextForceLeftToRight) ? Qt::LeftToRight : Qt::RightToLeft);
+    }*/
+
+    engine.itemize();
+    QScriptLine line;
+    line.length = text.length();
+    engine.shapeLine(line);
+
+    int nItems = engine.layoutData->items.size();
+    visualOrder = QVarLengthArray<int>(nItems);
+    QVarLengthArray<uchar> levels(nItems);
+    for (int i = 0; i < nItems; ++i)
+        levels[i] = engine.layoutData->items[i].analysis.bidiLevel;
+    QTextEngine::bidiReorder(nItems, levels.data(), visualOrder.data());
+
+    /*if (justificationPadding > 0) {
+        engine.option.setAlignment(Qt::AlignJustify);
+        engine.forceJustification = true;
+        // this works because justify() is only interested in the difference between width and textWidth
+        line.width = justificationPadding;
+        engine.justify(line);
+    }*/
+}
+
+QT_END_NAMESPACE
diff --git a/src/gui/text/qstatictext.h b/src/gui/text/qstatictext.h
new file mode 100644
index 0000000..4d39e23
--- /dev/null
+++ b/src/gui/text/qstatictext.h
@@ -0,0 +1,69 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** 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, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, 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.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QSTATICTEXT_H
+#define QSTATICTEXT_H
+
+#include <QtCore/qstring.h>
+#include <QtGui/qfont.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+QT_MODULE(Gui)
+
+class QStaticTextPrivate;
+class Q_GUI_EXPORT QStaticText
+{
+    Q_DECLARE_PRIVATE(QStaticText);
+public:
+    QStaticText(const QString &text, const QFont &font);
+
+private:
+    QStaticTextPrivate *d_ptr;
+};
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QSTATICTEXT_H
diff --git a/src/gui/text/qstatictext_p.h b/src/gui/text/qstatictext_p.h
new file mode 100644
index 0000000..ad70b1e
--- /dev/null
+++ b/src/gui/text/qstatictext_p.h
@@ -0,0 +1,22 @@
+#ifndef QSTATICTEXT_P_H
+#define QSTATICTEXT_P_H
+
+QT_BEGIN_NAMESPACE
+
+#include <private/qtextengine_p.h>
+
+class QStaticText;
+class QStaticTextPrivate
+{
+public:
+    void init(const QString &text, const QFont &font);
+
+    QTextEngine engine;
+    QVarLengthArray<int> visualOrder;
+    
+    static QStaticTextPrivate *get(const QStaticText *q);
+};
+
+QT_END_NAMESPACE
+
+#endif // QSTATICTEXT_P_H
diff --git a/src/gui/text/text.pri b/src/gui/text/text.pri
index b7615a4..026e6c6 100644
--- a/src/gui/text/text.pri
+++ b/src/gui/text/text.pri
@@ -37,7 +37,9 @@ HEADERS += \
 	text/qtexttable_p.h \
 	text/qzipreader_p.h \
 	text/qzipwriter_p.h \
-	text/qtextodfwriter_p.h
+	text/qtextodfwriter_p.h \
+	text/qstatictext.h \
+	text/qstatictext_p.h
 
 SOURCES += \
 	text/qfont.cpp \
@@ -66,7 +68,8 @@ SOURCES += \
 	text/qsyntaxhighlighter.cpp \
 	text/qcssparser.cpp \
 	text/qzip.cpp \
-	text/qtextodfwriter.cpp
+	text/qtextodfwriter.cpp \
+	text/qstatictext.cpp
 
 win32 {
 	SOURCES += \