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#include <QtGui/qplaintextedit.h>

#include <QtGui/qtextedit.h>

#include <QtGui/qabstractkineticscroller.h>

#include <QtGui/qscrollarea.h>

#include <QtDebug>

#ifndef TEXTEDITAUTORESIZER_H

#define TEXTEDITAUTORESIZER_H

class TextEditAutoResizer : public QObject

{

    Q_OBJECT

public:

    TextEditAutoResizer(QWidget *parent)

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

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

    {

        // parent must either inherit QPlainTextEdit or  QTextEdit!

        Q_ASSERT(plainTextEdit || textEdit);

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

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

        textEditChanged();

    }

private Q_SLOTS:

    inline void textEditChanged();

private:

    QPlainTextEdit *plainTextEdit;

    QTextEdit *textEdit;

    QFrame *edit;

};

void TextEditAutoResizer::textEditChanged()

{

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

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

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

    if (plainTextEdit)

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

    const QRect fr = edit->frameRect();

    const QRect cr = edit->contentsRect();

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

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

    QPoint pos = edit->pos();

    QWidget *pw = edit->parentWidget();

    while (pw) {

        if (qobject_cast<QScrollArea *>(pw))

            break;

        pw = pw->parentWidget();

    }

    if (pw) {

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

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

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

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

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

        } else {

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

        }

    }

}

#endif