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>

1 files changed, 34 insertions, 3 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);