1 /****************************************************************************

     2 **

     3 ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

     4 ** All rights reserved.

     5 ** Contact: Nokia Corporation (qt-info@nokia.com)

     6 **

     7 ** This file is part of the examples of the Qt Toolkit.

     8 **

     9 ** $QT_BEGIN_LICENSE:LGPL$

    10 ** No Commercial Usage

    11 ** This file contains pre-release code and may not be distributed.

    12 ** You may use this file in accordance with the terms and conditions

    13 ** contained in the Technology Preview License Agreement accompanying

    14 ** this package.

    15 **

    16 ** GNU Lesser General Public License Usage

    17 ** Alternatively, this file may be used under the terms of the GNU Lesser

    18 ** General Public License version 2.1 as published by the Free Software

    19 ** Foundation and appearing in the file LICENSE.LGPL included in the

    20 ** packaging of this file.  Please review the following information to

    21 ** ensure the GNU Lesser General Public License version 2.1 requirements

    22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

    23 **

    24 ** In addition, as a special exception, Nokia gives you certain additional

    25 ** rights.  These rights are described in the Nokia Qt LGPL Exception

    26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

    27 **

    28 ** If you have questions regarding the use of this file, please contact

    29 ** Nokia at qt-info@nokia.com.

    30 **

    31 **

    32 **

    33 **

    34 **

    35 **

    36 **

    37 **

    38 ** $QT_END_LICENSE$

    39 **

    40 ****************************************************************************/

    41 

    42 #include <QtGui/qplaintextedit.h>

    43 #include <QtGui/qtextedit.h>

    44 #include <QtGui/qabstractkineticscroller.h>

    45 #include <QtGui/qscrollarea.h>

    46 #include <QtDebug>

    47 

    48 #ifndef TEXTEDITAUTORESIZER_H

    49 #define TEXTEDITAUTORESIZER_H

    50 

    51 class TextEditAutoResizer : public QObject

    52 {

    53     Q_OBJECT

    54 public:

    55     TextEditAutoResizer(QWidget *parent)

    56         : QObject(parent), plainTextEdit(qobject_cast<QPlainTextEdit *>(parent)),

    57           textEdit(qobject_cast<QTextEdit *>(parent)), edit(qobject_cast<QFrame *>(parent))

    58     {

    59         // parent must either inherit QPlainTextEdit or  QTextEdit!

    60         Q_ASSERT(plainTextEdit || textEdit);

    61 

    62         connect(parent, SIGNAL(textChanged()), this, SLOT(textEditChanged()));

    63         connect(parent, SIGNAL(cursorPositionChanged()), this, SLOT(textEditChanged()));

    64 

    65         textEditChanged();

    66     }

    67 

    68 private Q_SLOTS:

    69     inline void textEditChanged();

    70 

    71 private:

    72     QPlainTextEdit *plainTextEdit;

    73     QTextEdit *textEdit;

    74     QFrame *edit;

    75 };

    76 

    77 void TextEditAutoResizer::textEditChanged()

    78 {

    79     QTextDocument *doc = textEdit ? textEdit->document() : plainTextEdit->document();

    80     QRect cursor = textEdit ? textEdit->cursorRect() : plainTextEdit->cursorRect();

    81 

    82     QSize s = doc->size().toSize();

    83     if (plainTextEdit)

    84         s.setHeight((s.height() + 2) * edit->fontMetrics().lineSpacing());

    85 

    86     const QRect fr = edit->frameRect();

    87     const QRect cr = edit->contentsRect();

    88 

    89     edit->setMinimumHeight(qMax(70, s.height() + (fr.height() - cr.height() - 1)));

    90 

    91     // make sure the cursor is visible in case we have a QAbstractScrollArea parent

    92     QPoint pos = edit->pos();

    93     QWidget *pw = edit->parentWidget();

    94     while (pw) {

    95         if (qobject_cast<QScrollArea *>(pw))

    96             break;

    97         pw = pw->parentWidget();

    98     }

    99 

   100     if (pw) {

   101         QScrollArea *area = static_cast<QScrollArea *>(pw);

   102         QPoint scrollto = area->widget()->mapFrom(edit, cursor.center());

   103         QPoint margin(10 + cursor.width(), 2 * cursor.height());

   104 

   105         if (QAbstractKineticScroller *scroller = area->property("kineticScroller").value<QAbstractKineticScroller *>()) {

   106             scroller->ensureVisible(scrollto, margin.x(), margin.y());

   107         } else {

   108             area->ensureVisible(scrollto.x(), scrollto.y(), margin.x(), margin.y());

   109         }

   110     }

   111 }

   112 

   113 #endif