Speed up TextEdit construction time.

Defer setting content on the QTextDocument until componentComplete()
to avoid unnecessary layouts and move one time setup for the
text document from setContent to the constructor.

Reduces the construction time of a TextEdit with RichText textFormat
by about a third.

Change-Id: Idde0772063bf769cde984efddd68589c55a7431a
Reviewed-by: Martin Jones <martin.jones@nokia.com>

1 files changed, 26 insertions, 51 deletions

diff --git a/src/quick/items/qquicktextcontrol.cpp b/src/quick/items/qquicktextcontrol.cpp
index 23bf2a779e..d2ff4dc649 100644
--- a/src/quick/items/qquicktextcontrol.cpp
+++ b/src/quick/items/qquicktextcontrol.cpp
@@ -71,6 +71,8 @@
 #include <qstylehints.h>
 #include <qmetaobject.h>
 
+#include <private/qqmlglobal_p.h>
+
 // ### these should come from QStyleHints
 const int textCursorWidth = 1;
 const bool fullWidthSelection = true;
@@ -279,16 +281,7 @@ void QQuickTextControlPrivate::updateCurrentCharFormat()
     cursorRectangleChanged = true;
 }
 
-void QQuickTextControlPrivate::init(Qt::TextFormat format, const QString &text, QTextDocument *document)
-{
-    Q_Q(QQuickTextControl);
-    setContent(format, text, document);
-
-    doc->setUndoRedoEnabled(interactionFlags & Qt::TextEditable);
-    q->setCursorWidth(-1);
-}
-
-void QQuickTextControlPrivate::setContent(Qt::TextFormat format, const QString &text, QTextDocument *document)
+void QQuickTextControlPrivate::setContent(Qt::TextFormat format, const QString &text)
 {
     Q_Q(QQuickTextControl);
 
@@ -298,33 +291,11 @@ void QQuickTextControlPrivate::setContent(Qt::TextFormat format, const QString &
     // set char format then.
     const QTextCharFormat charFormatForInsertion = cursor.charFormat();
 
-    bool clearDocument = true;
-    if (!doc) {
-        if (document) {
-            doc = document;
-            clearDocument = false;
-        } else {
-            doc = new QTextDocument(q);
-        }
-        _q_documentLayoutChanged();
-        cursor = QTextCursor(doc);
-
-// ####        doc->documentLayout()->setPaintDevice(viewport);
-
-        QObject::connect(doc, SIGNAL(contentsChanged()), q, SLOT(_q_updateCurrentCharFormatAndSelection()));
-        QObject::connect(doc, SIGNAL(cursorPositionChanged(QTextCursor)), q, SLOT(_q_emitCursorPosChanged(QTextCursor)));
-        QObject::connect(doc, SIGNAL(documentLayoutChanged()), q, SLOT(_q_documentLayoutChanged()));
-    }
-
     bool previousUndoRedoState = doc->isUndoRedoEnabled();
-    if (!document)
-        doc->setUndoRedoEnabled(false);
+    doc->setUndoRedoEnabled(false);
 
-    //Saving the index save some time.
-    static int contentsChangedIndex = QMetaMethod::fromSignal(&QTextDocument::contentsChanged).methodIndex();
-    static int textChangedIndex = QMetaMethod::fromSignal(&QQuickTextControl::textChanged).methodIndex();
     // avoid multiple textChanged() signals being emitted
-    QMetaObject::disconnect(doc, contentsChangedIndex, q, textChangedIndex);
+    qmlobject_disconnect(doc, QTextDocument, SIGNAL(contentsChanged()), q, QQuickTextControl, SIGNAL(textChanged()));
 
     if (!text.isEmpty()) {
         // clear 'our' cursor for insertion to prevent
@@ -354,18 +325,16 @@ void QQuickTextControlPrivate::setContent(Qt::TextFormat format, const QString &
             doc->setUndoRedoEnabled(false);
         }
         cursor = QTextCursor(doc);
-    } else if (clearDocument) {
+    } else {
         doc->clear();
     }
     cursor.setCharFormat(charFormatForInsertion);
 
-    QMetaObject::connect(doc, contentsChangedIndex, q, textChangedIndex);
+    qmlobject_connect(doc, QTextDocument, SIGNAL(contentsChanged()), q, QQuickTextControl, SIGNAL(textChanged()));
     emit q->textChanged();
-    if (!document)
-        doc->setUndoRedoEnabled(previousUndoRedoState);
+    doc->setUndoRedoEnabled(previousUndoRedoState);
     _q_updateCurrentCharFormatAndSelection();
-    if (!document)
-        doc->setModified(false);
+    doc->setModified(false);
 
     q->updateCursorRectangle(true);
     emit q->cursorPositionChanged();
@@ -474,16 +443,6 @@ void QQuickTextControlPrivate::_q_emitCursorPosChanged(const QTextCursor &someCu
     }
 }
 
-void QQuickTextControlPrivate::_q_documentLayoutChanged()
-{
-    Q_Q(QQuickTextControl);
-    QAbstractTextDocumentLayout *layout = doc->documentLayout();
-    QObject::connect(layout, SIGNAL(update(QRectF)), q, SIGNAL(updateRequest()));
-    QObject::connect(layout, SIGNAL(updateBlock(QTextBlock)), q, SIGNAL(updateRequest()));
-    QObject::connect(layout, SIGNAL(documentSizeChanged(QSizeF)), q, SIGNAL(documentSizeChanged(QSizeF)));
-
-}
-
 void QQuickTextControlPrivate::setBlinkingCursorEnabled(bool enable)
 {
     Q_Q(QQuickTextControl);
@@ -611,7 +570,23 @@ QQuickTextControl::QQuickTextControl(QTextDocument *doc, QObject *parent)
     : QObject(*new QQuickTextControlPrivate, parent)
 {
     Q_D(QQuickTextControl);
-    d->init(Qt::PlainText, QString(), doc);
+    Q_ASSERT(doc);
+
+    QAbstractTextDocumentLayout *layout = doc->documentLayout();
+    qmlobject_connect(layout, QAbstractTextDocumentLayout, SIGNAL(update(QRectF)), this, QQuickTextControl, SIGNAL(updateRequest()));
+    qmlobject_connect(layout, QAbstractTextDocumentLayout, SIGNAL(updateBlock(QTextBlock)), this, QQuickTextControl, SIGNAL(updateRequest()));
+    qmlobject_connect(doc, QTextDocument, SIGNAL(contentsChanged()), this, QQuickTextControl, SIGNAL(textChanged()));
+    qmlobject_connect(doc, QTextDocument, SIGNAL(contentsChanged()), this, QQuickTextControl, SLOT(_q_updateCurrentCharFormatAndSelection()));
+    qmlobject_connect(doc, QTextDocument, SIGNAL(cursorPositionChanged(QTextCursor)), this, QQuickTextControl, SLOT(_q_emitCursorPosChanged(QTextCursor)));
+
+    layout->setProperty("cursorWidth", textCursorWidth);
+
+    d->doc = doc;
+    d->cursor = QTextCursor(doc);
+    d->lastCharFormat = d->cursor.charFormat();
+    doc->setPageSize(QSizeF(0, 0));
+    doc->setModified(false);
+    doc->setUndoRedoEnabled(true);
 }
 
 QQuickTextControl::~QQuickTextControl()