Make QSGTextNode back-end for QML's TextInput and TextEdit

Use the general QSGTextNode class as back-end for all text
elements in QML to make all text elements look the same and
use the same text rasterization back-end. This requires a
few rewrites in the text node to support e.g. selections.

Crashes seen with threaded renderer in TextEdit and TextInput on
Mac are also fixed by this.

Reviewed-by: Jiang Jiang
Task-number: QTBUG-18019, QTBUG-20017
Change-Id: I4207faf180c83422e5f8b726741321af395bd724
Reviewed-on: http://codereview.qt.nokia.com/2865
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@nokia.com>

4 files changed, 185 insertions, 15 deletions

diff --git a/tests/auto/declarative/qsgtext/tst_qsgtext.cpp b/tests/auto/declarative/qsgtext/tst_qsgtext.cpp
index 48d679bfa7..747ea51f41 100644
--- a/tests/auto/declarative/qsgtext/tst_qsgtext.cpp
+++ b/tests/auto/declarative/qsgtext/tst_qsgtext.cpp
@@ -45,6 +45,7 @@
 #include <private/qsgtext_p.h>
 #include <private/qsgtext_p_p.h>
 #include <private/qdeclarativevaluetype_p.h>
+#include <private/qsgdistancefieldglyphcache_p.h>
 #include <QFontMetrics>
 #include <QGraphicsSceneMouseEvent>
 #include <qmath.h>
@@ -61,6 +62,8 @@
 #define SRCDIR "."
 #endif
 
+DEFINE_BOOL_CONFIG_OPTION(qmlDisableDistanceField, QML_DISABLE_DISTANCEFIELD)
+
 class tst_qsgtext : public QObject
 
 {
@@ -261,14 +264,42 @@ void tst_qsgtext::width()
         delete textObject;
     }
 
+    bool requiresUnhintedMetrics = !qmlDisableDistanceField();
+
     for (int i = 0; i < standard.size(); i++)
     {
         QVERIFY(!Qt::mightBeRichText(standard.at(i))); // self-test
 
         QFont f;
-        QFontMetricsF fm(f);
-        qreal metricWidth = fm.size(Qt::TextExpandTabs && Qt::TextShowMnemonic, standard.at(i)).width();
-        metricWidth = qCeil(metricWidth);
+        qreal metricWidth = 0.0;
+
+        if (requiresUnhintedMetrics) {
+            QString s = standard.at(i);
+            s.replace(QLatin1Char('\n'), QChar::LineSeparator);
+
+            QTextLayout layout(s);
+            layout.setFlags(Qt::TextExpandTabs | Qt::TextShowMnemonic);
+            {
+                QTextOption option;
+                option.setUseDesignMetrics(true);
+                layout.setTextOption(option);
+            }
+
+            layout.beginLayout();
+            forever {
+                QTextLine line = layout.createLine();
+                if (!line.isValid())
+                    break;
+            }
+
+            layout.endLayout();
+
+            metricWidth = qCeil(layout.boundingRect().width());
+        } else {
+            QFontMetricsF fm(f);
+            qreal metricWidth = fm.size(Qt::TextExpandTabs && Qt::TextShowMnemonic, standard.at(i)).width();
+            metricWidth = qCeil(metricWidth);
+        }
 
         QString componentStr = "import QtQuick 2.0\nText { text: \"" + standard.at(i) + "\" }";
         QDeclarativeComponent textComponent(&engine);
diff --git a/tests/auto/declarative/qsgtextedit/tst_qsgtextedit.cpp b/tests/auto/declarative/qsgtextedit/tst_qsgtextedit.cpp
index 3492ac2138..2a94e20d3f 100644
--- a/tests/auto/declarative/qsgtextedit/tst_qsgtextedit.cpp
+++ b/tests/auto/declarative/qsgtextedit/tst_qsgtextedit.cpp
@@ -51,6 +51,7 @@
 #include <QtDeclarative/qdeclarativecomponent.h>
 #include <private/qsgtextedit_p.h>
 #include <private/qsgtextedit_p_p.h>
+#include <private/qsgdistancefieldglyphcache_p.h>
 #include <QFontMetrics>
 #include <QSGView>
 #include <QDir>
@@ -72,6 +73,7 @@
 #endif
 
 Q_DECLARE_METATYPE(QSGTextEdit::SelectionMode)
+DEFINE_BOOL_CONFIG_OPTION(qmlDisableDistanceField, QML_DISABLE_DISTANCEFIELD)
 
 QString createExpectedFileIfNotFound(const QString& filebasename, const QImage& actual)
 {
@@ -280,12 +282,40 @@ void tst_qsgtextedit::width()
         QCOMPARE(textEditObject->width(), 0.0);
     }
 
+    bool requiresUnhintedMetrics = !qmlDisableDistanceField();
+
     for (int i = 0; i < standard.size(); i++)
     {
         QFont f;
-        QFontMetricsF fm(f);
-        qreal metricWidth = fm.size(Qt::TextExpandTabs && Qt::TextShowMnemonic, standard.at(i)).width();
-        metricWidth = ceil(metricWidth);
+        qreal metricWidth = 0.0;
+
+        if (requiresUnhintedMetrics) {
+            QString s = standard.at(i);
+            s.replace(QLatin1Char('\n'), QChar::LineSeparator);
+
+            QTextLayout layout(s);
+            layout.setFlags(Qt::TextExpandTabs | Qt::TextShowMnemonic);
+            {
+                QTextOption option;
+                option.setUseDesignMetrics(true);
+                layout.setTextOption(option);
+            }
+
+            layout.beginLayout();
+            forever {
+                QTextLine line = layout.createLine();
+                if (!line.isValid())
+                    break;
+            }
+
+            layout.endLayout();
+
+            metricWidth = ceil(layout.boundingRect().width());
+        } else {
+            QFontMetricsF fm(f);
+            metricWidth = fm.size(Qt::TextExpandTabs | Qt::TextShowMnemonic, standard.at(i)).width();
+            metricWidth = ceil(metricWidth);
+        }
 
         QString componentStr = "import QtQuick 2.0\nTextEdit { text: \"" + standard.at(i) + "\" }";
         QDeclarativeComponent texteditComponent(&engine);
@@ -301,6 +331,8 @@ void tst_qsgtextedit::width()
         QTextDocument document;
         document.setHtml(richText.at(i));
         document.setDocumentMargin(0);
+        if (requiresUnhintedMetrics)
+            document.setUseDesignMetrics(true);
 
         int documentWidth = ceil(document.idealWidth());
 
@@ -455,7 +487,6 @@ void tst_qsgtextedit::hAlign()
 
 void tst_qsgtextedit::hAlign_RightToLeft()
 {
-    QSKIP("QTBUG-20017", SkipAll);
     QSGView canvas(QUrl::fromLocalFile(SRCDIR "/data/horizontalAlignment_RightToLeft.qml"));
     QSGTextEdit *textEdit = canvas.rootObject()->findChild<QSGTextEdit*>("text");
     QVERIFY(textEdit != 0);
@@ -1471,7 +1502,28 @@ void tst_qsgtextedit::positionAt()
     const int y1 = fm.height() * 3 / 2;
 
     int pos = texteditObject->positionAt(texteditObject->width()/2, y0);
-    int diff = abs(int(fm.width(texteditObject->text().left(pos))-texteditObject->width()/2));
+    int width = 0;
+    if (!qmlDisableDistanceField()) {
+        QTextLayout layout(texteditObject->text().left(pos));
+
+        {
+            QTextOption option;
+            option.setUseDesignMetrics(true);
+            layout.setTextOption(option);
+        }
+
+        layout.beginLayout();
+        QTextLine line = layout.createLine();
+        layout.endLayout();
+
+        width = ceil(line.horizontalAdvance());
+
+    } else {
+        width = fm.width(texteditObject->text().left(pos));
+    }
+
+
+    int diff = abs(int(width-texteditObject->width()/2));
 
     // some tollerance for different fonts.
 #ifdef Q_OS_LINUX
diff --git a/tests/auto/declarative/qsgtextinput/data/positionAt.qml b/tests/auto/declarative/qsgtextinput/data/positionAt.qml
index 7611376e13..1840462c87 100644
--- a/tests/auto/declarative/qsgtextinput/data/positionAt.qml
+++ b/tests/auto/declarative/qsgtextinput/data/positionAt.qml
@@ -4,5 +4,5 @@ TextInput{
     focus: true
     objectName: "myInput"
     width: 50
-    text: "This is a long piece of text"
+    text: "AAAAAAAAAAAAAAAAAAAAAAAAAAAA"
 }
diff --git a/tests/auto/declarative/qsgtextinput/tst_qsgtextinput.cpp b/tests/auto/declarative/qsgtextinput/tst_qsgtextinput.cpp
index 93e8ad21fd..744717cd80 100644
--- a/tests/auto/declarative/qsgtextinput/tst_qsgtextinput.cpp
+++ b/tests/auto/declarative/qsgtextinput/tst_qsgtextinput.cpp
@@ -51,7 +51,9 @@
 #include <QStyle>
 #include <QInputContext>
 #include <private/qapplication_p.h>
+#include <private/qsgdistancefieldglyphcache_p.h>
 #include <QtOpenGL/QGLShaderProgram>
+#include <math.h>
 
 #ifdef Q_OS_SYMBIAN
 // In Symbian OS test data is located in applications private dir
@@ -59,6 +61,7 @@
 #endif
 
 Q_DECLARE_METATYPE(QSGTextInput::SelectionMode)
+DEFINE_BOOL_CONFIG_OPTION(qmlDisableDistanceField, QML_DISABLE_DISTANCEFIELD)
 
 QString createExpectedFileIfNotFound(const QString& filebasename, const QImage& actual)
 {
@@ -221,11 +224,38 @@ void tst_qsgtextinput::width()
         delete textinputObject;
     }
 
+    bool requiresUnhintedMetrics = !qmlDisableDistanceField();
+
     for (int i = 0; i < standard.size(); i++)
     {
         QFont f;
-        QFontMetricsF fm(f);
-        qreal metricWidth = fm.width(standard.at(i));
+        qreal metricWidth = 0.0;
+        if (requiresUnhintedMetrics) {
+            QString s = standard.at(i);
+            s.replace(QLatin1Char('\n'), QChar::LineSeparator);
+
+            QTextLayout layout(s);
+            layout.setFlags(Qt::TextExpandTabs | Qt::TextShowMnemonic);
+            {
+                QTextOption option;
+                option.setUseDesignMetrics(true);
+                layout.setTextOption(option);
+            }
+
+            layout.beginLayout();
+            forever {
+                QTextLine line = layout.createLine();
+                if (!line.isValid())
+                    break;
+            }
+
+            layout.endLayout();
+
+            metricWidth = ceil(layout.boundingRect().width());
+        } else {
+            QFontMetricsF fm(f);
+            metricWidth = fm.width(standard.at(i));
+        }
 
         QString componentStr = "import QtQuick 2.0\nTextInput { text: \"" + standard.at(i) + "\" }";
         QDeclarativeComponent textinputComponent(&engine);
@@ -1048,7 +1078,6 @@ void tst_qsgtextinput::horizontalAlignment()
 
 void tst_qsgtextinput::horizontalAlignment_RightToLeft()
 {
-    QSKIP("QTBUG-20017", SkipAll);
     QSGView canvas(QUrl::fromLocalFile(SRCDIR "/data/horizontalAlignment_RightToLeft.qml"));
     QSGTextInput *textInput = canvas.rootObject()->findChild<QSGTextInput*>("text");
     QVERIFY(textInput != 0);
@@ -1161,7 +1190,45 @@ void tst_qsgtextinput::positionAt()
     QFontMetrics fm(textinputObject->font());
 
     int pos = textinputObject->positionAt(textinputObject->width()/2);
-    int diff = abs(int(fm.width(textinputObject->text()) - (fm.width(textinputObject->text().left(pos))+textinputObject->width()/2)));
+    int textWidth = 0;
+    int textLeftWidth = 0;
+    if (!qmlDisableDistanceField()) {
+        {
+            QTextLayout layout(textinputObject->text().left(pos));
+
+            {
+                QTextOption option;
+                option.setUseDesignMetrics(true);
+                layout.setTextOption(option);
+            }
+
+            layout.beginLayout();
+            QTextLine line = layout.createLine();
+            layout.endLayout();
+
+            textLeftWidth = ceil(line.horizontalAdvance());
+        }
+        {
+            QTextLayout layout(textinputObject->text());
+
+            {
+                QTextOption option;
+                option.setUseDesignMetrics(true);
+                layout.setTextOption(option);
+            }
+
+            layout.beginLayout();
+            QTextLine line = layout.createLine();
+            layout.endLayout();
+
+            textWidth = ceil(line.horizontalAdvance());
+        }
+    } else {
+        textWidth = fm.width(textinputObject->text());
+        textLeftWidth = fm.width(textinputObject->text().left(pos));
+    }
+
+    int diff = abs(textWidth - (textLeftWidth+textinputObject->width()/2));
 
     // some tollerance for different fonts.
 #ifdef Q_OS_LINUX
@@ -1177,7 +1244,28 @@ void tst_qsgtextinput::positionAt()
     // Check without autoscroll...
     textinputObject->setAutoScroll(false);
     pos = textinputObject->positionAt(textinputObject->width()/2);
-    diff = abs(int(fm.width(textinputObject->text().left(pos))-textinputObject->width()/2));
+
+    if (!qmlDisableDistanceField()) {
+        {
+            QTextLayout layout(textinputObject->text().left(pos));
+
+            {
+                QTextOption option;
+                option.setUseDesignMetrics(true);
+                layout.setTextOption(option);
+            }
+
+            layout.beginLayout();
+            QTextLine line = layout.createLine();
+            layout.endLayout();
+
+            textLeftWidth = ceil(line.horizontalAdvance());
+        }
+    } else {
+        textLeftWidth = fm.width(textinputObject->text().left(pos));
+    }
+
+    diff = abs(int(textLeftWidth-textinputObject->width()/2));
 
     // some tollerance for different fonts.
 #ifdef Q_OS_LINUX
@@ -1442,7 +1530,6 @@ void tst_qsgtextinput::navigation()
 
 void tst_qsgtextinput::navigation_RTL()
 {
-    QSKIP("QTBUG-20017", SkipAll);
     QSGView canvas(QUrl::fromLocalFile(SRCDIR "/data/navigation.qml"));
     canvas.show();
     canvas.setFocus();