/****************************************************************************

**

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

** All rights reserved.

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

**

** This file is part of the QtGui module of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

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

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

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

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

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

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

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

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

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

**

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

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

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

**

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

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

**

**

**

**

**

**

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#include "qtextedit_p.h"

#include "qlineedit.h"

#include "qtextbrowser.h"

#ifndef QT_NO_TEXTEDIT

#include <qfont.h>

#include <qpainter.h>

#include <qevent.h>

#include <qdebug.h>

#include <qmime.h>

#include <qdrag.h>

#include <qclipboard.h>

#include <qmenu.h>

#include <qstyle.h>

#include <qtimer.h>

#include "private/qtextdocumentlayout_p.h"

#include "qtextdocument.h"

#include "private/qtextdocument_p.h"

#include "qtextlist.h"

#include "private/qtextcontrol_p.h"

#include <qtextformat.h>

#include <qdatetime.h>

#include <qapplication.h>

#include <limits.h>

#include <qtexttable.h>

#include <qvariant.h>

#include <qinputcontext.h>

#endif

QT_BEGIN_NAMESPACE

#ifndef QT_NO_TEXTEDIT

static inline bool shouldEnableInputMethod(QTextEdit *textedit)

{

    return !textedit->isReadOnly();

}

class QTextEditControl : public QTextControl

{

public:

    inline QTextEditControl(QObject *parent) : QTextControl(parent) {}

    virtual QMimeData *createMimeDataFromSelection() const {

        QTextEdit *ed = qobject_cast<QTextEdit *>(parent());

        if (!ed)

            return QTextControl::createMimeDataFromSelection();

        return ed->createMimeDataFromSelection();

    }

    virtual bool canInsertFromMimeData(const QMimeData *source) const {

        QTextEdit *ed = qobject_cast<QTextEdit *>(parent());

        if (!ed)

            return QTextControl::canInsertFromMimeData(source);

        return ed->canInsertFromMimeData(source);

    }

    virtual void insertFromMimeData(const QMimeData *source) {

        QTextEdit *ed = qobject_cast<QTextEdit *>(parent());

        if (!ed)

            QTextControl::insertFromMimeData(source);

        else

            ed->insertFromMimeData(source);

    }

};

QTextEditPrivate::QTextEditPrivate()

    : control(0),

      autoFormatting(QTextEdit::AutoNone), tabChangesFocus(false),

      lineWrap(QTextEdit::WidgetWidth), lineWrapColumnOrWidth(0),

      wordWrap(QTextOption::WrapAtWordBoundaryOrAnywhere), clickCausedFocus(0),

      textFormat(Qt::AutoText)

{

    ignoreAutomaticScrollbarAdjustment = false;

    preferRichText = false;

    showCursorOnInitialShow = true;

    inDrag = false;

}

void QTextEditPrivate::createAutoBulletList()

{

    QTextCursor cursor = control->textCursor();

    cursor.beginEditBlock();

    QTextBlockFormat blockFmt = cursor.blockFormat();

    QTextListFormat listFmt;

    listFmt.setStyle(QTextListFormat::ListDisc);

    listFmt.setIndent(blockFmt.indent() + 1);

    blockFmt.setIndent(0);

    cursor.setBlockFormat(blockFmt);

    cursor.createList(listFmt);

    cursor.endEditBlock();

    control->setTextCursor(cursor);

}

void QTextEditPrivate::init(const QString &html)

{

    Q_Q(QTextEdit);

    control = new QTextEditControl(q);

    control->setPalette(q->palette());

    QObject::connect(control, SIGNAL(microFocusChanged()), q, SLOT(updateMicroFocus()));

    QObject::connect(control, SIGNAL(documentSizeChanged(QSizeF)), q, SLOT(_q_adjustScrollbars()));

    QObject::connect(control, SIGNAL(updateRequest(QRectF)), q, SLOT(_q_repaintContents(QRectF)));

    QObject::connect(control, SIGNAL(visibilityRequest(QRectF)), q, SLOT(_q_ensureVisible(QRectF)));

    QObject::connect(control, SIGNAL(currentCharFormatChanged(QTextCharFormat)),

                     q, SLOT(_q_currentCharFormatChanged(QTextCharFormat)));

    QObject::connect(control, SIGNAL(textChanged()), q, SIGNAL(textChanged()));

    QObject::connect(control, SIGNAL(undoAvailable(bool)), q, SIGNAL(undoAvailable(bool)));

    QObject::connect(control, SIGNAL(redoAvailable(bool)), q, SIGNAL(redoAvailable(bool)));

    QObject::connect(control, SIGNAL(copyAvailable(bool)), q, SIGNAL(copyAvailable(bool)));

    QObject::connect(control, SIGNAL(selectionChanged()), q, SIGNAL(selectionChanged()));

    QObject::connect(control, SIGNAL(cursorPositionChanged()), q, SIGNAL(cursorPositionChanged()));

    QObject::connect(control, SIGNAL(textChanged()), q, SLOT(updateMicroFocus()));

    QTextDocument *doc = control->document();

    // set a null page size initially to avoid any relayouting until the textedit

    // is shown. relayoutDocument() will take care of setting the page size to the

    // viewport dimensions later.

    doc->setPageSize(QSize(0, 0));

    doc->documentLayout()->setPaintDevice(viewport);

    doc->setDefaultFont(q->font());

    doc->setUndoRedoEnabled(false); // flush undo buffer.

    doc->setUndoRedoEnabled(true);

    if (!html.isEmpty())

        control->setHtml(html);

    hbar->setSingleStep(20);

    vbar->setSingleStep(20);

    viewport->setBackgroundRole(QPalette::Base);

    q->setAcceptDrops(true);

    q->setFocusPolicy(Qt::WheelFocus);

    q->setAttribute(Qt::WA_KeyCompression);

    q->setAttribute(Qt::WA_InputMethodEnabled);

#ifndef QT_NO_CURSOR

    viewport->setCursor(Qt::IBeamCursor);

#endif

#ifdef Q_WS_WIN

    setSingleFingerPanEnabled(true);

#endif

}

void QTextEditPrivate::_q_repaintContents(const QRectF &contentsRect)

{

    if (!contentsRect.isValid()) {

        viewport->update();

        return;

    }

    const int xOffset = horizontalOffset();

    const int yOffset = verticalOffset();

    const QRectF visibleRect(xOffset, yOffset, viewport->width(), viewport->height());

    QRect r = contentsRect.intersected(visibleRect).toAlignedRect();

    if (r.isEmpty())

        return;

    r.translate(-xOffset, -yOffset);

    viewport->update(r);

}

void QTextEditPrivate::pageUpDown(QTextCursor::MoveOperation op, QTextCursor::MoveMode moveMode)

{

    QTextCursor cursor = control->textCursor();

    bool moved = false;

    qreal lastY = control->cursorRect(cursor).top();

    qreal distance = 0;

    // move using movePosition to keep the cursor's x

    do {

        qreal y = control->cursorRect(cursor).top();

        distance += qAbs(y - lastY);

        lastY = y;

        moved = cursor.movePosition(op, moveMode);

    } while (moved && distance < viewport->height());

    if (moved) {

        if (op == QTextCursor::Up) {

            cursor.movePosition(QTextCursor::Down, moveMode);

            vbar->triggerAction(QAbstractSlider::SliderPageStepSub);

        } else {

            cursor.movePosition(QTextCursor::Up, moveMode);

            vbar->triggerAction(QAbstractSlider::SliderPageStepAdd);

        }

    }

    control->setTextCursor(cursor);

}

#ifndef QT_NO_SCROLLBAR

static QSize documentSize(QTextControl *control)

{

    QTextDocument *doc = control->document();

    QAbstractTextDocumentLayout *layout = doc->documentLayout();

    QSize docSize;

    if (QTextDocumentLayout *tlayout = qobject_cast<QTextDocumentLayout *>(layout)) {

        docSize = tlayout->dynamicDocumentSize().toSize();

        int percentageDone = tlayout->layoutStatus();

        // extrapolate height

        if (percentageDone > 0)

            docSize.setHeight(docSize.height() * 100 / percentageDone);

    } else {

        docSize = layout->documentSize().toSize();

    }

    return docSize;

}

void QTextEditPrivate::_q_adjustScrollbars()

{

    if (ignoreAutomaticScrollbarAdjustment)

        return;

    ignoreAutomaticScrollbarAdjustment = true; // avoid recursion, #106108

    QSize viewportSize = viewport->size();

    QSize docSize = documentSize(control);

    // due to the recursion guard we have to repeat this step a few times,

    // as adding/removing a scroll bar will cause the document or viewport

    // size to change

    // ideally we should loop until the viewport size and doc size stabilize,

    // but in corner cases they might fluctuate, so we need to limit the

    // number of iterations

    for (int i = 0; i < 4; ++i) {

        hbar->setRange(0, docSize.width() - viewportSize.width());

        hbar->setPageStep(viewportSize.width());

        vbar->setRange(0, docSize.height() - viewportSize.height());

        vbar->setPageStep(viewportSize.height());

        // if we are in left-to-right mode widening the document due to

        // lazy layouting does not require a repaint. If in right-to-left

        // the scroll bar has the value zero and it visually has the maximum

        // value (it is visually at the right), then widening the document

        // keeps it at value zero but visually adjusts it to the new maximum

        // on the right, hence we need an update.

        if (q_func()->isRightToLeft())

            viewport->update();

        _q_showOrHideScrollBars();

        const QSize oldViewportSize = viewportSize;

        const QSize oldDocSize = docSize;

        // make sure the document is layouted if the viewport width changes

        viewportSize = viewport->size();

        if (viewportSize.width() != oldViewportSize.width())

            relayoutDocument();

        docSize = documentSize(control);

        if (viewportSize == oldViewportSize && docSize == oldDocSize)

            break;

    }

    ignoreAutomaticScrollbarAdjustment = false;

}

#endif

// rect is in content coordinates

void QTextEditPrivate::_q_ensureVisible(const QRectF &_rect)

{

    const QRect rect = _rect.toRect();

    if ((vbar->isVisible() && vbar->maximum() < rect.bottom())

        || (hbar->isVisible() && hbar->maximum() < rect.right()))

        _q_adjustScrollbars();

    const int visibleWidth = viewport->width();

    const int visibleHeight = viewport->height();

    const bool rtl = q_func()->isRightToLeft();

    if (rect.x() < horizontalOffset()) {

        if (rtl)

            hbar->setValue(hbar->maximum() - rect.x());

        else

            hbar->setValue(rect.x());

    } else if (rect.x() + rect.width() > horizontalOffset() + visibleWidth) {

        if (rtl)

            hbar->setValue(hbar->maximum() - (rect.x() + rect.width() - visibleWidth));

        else

            hbar->setValue(rect.x() + rect.width() - visibleWidth);

    }

    if (rect.y() < verticalOffset())

        vbar->setValue(rect.y());

    else if (rect.y() + rect.height() > verticalOffset() + visibleHeight)

        vbar->setValue(rect.y() + rect.height() - visibleHeight);

}

/*!

    \class QTextEdit

    \brief The QTextEdit class provides a widget that is used to edit and display

    both plain and rich text.

    \ingroup richtext-processing

    \tableofcontents

    \section1 Introduction and Concepts

    QTextEdit is an advanced WYSIWYG viewer/editor supporting rich

    text formatting using HTML-style tags. It is optimized to handle

    large documents and to respond quickly to user input.

    QTextEdit works on paragraphs and characters. A paragraph is a

    formatted string which is word-wrapped to fit into the width of

    the widget. By default when reading plain text, one newline

    signifies a paragraph. A document consists of zero or more

    paragraphs. The words in the paragraph are aligned in accordance

    with the paragraph's alignment. Paragraphs are separated by hard

    line breaks. Each character within a paragraph has its own

    attributes, for example, font and color.

    QTextEdit can display images, lists and tables. If the text is

    too large to view within the text edit's viewport, scroll bars will

    appear. The text edit can load both plain text and HTML files (a

    subset of HTML 3.2 and 4).

    If you just need to display a small piece of rich text use QLabel.

    The rich text support in Qt is designed to provide a fast, portable and

    efficient way to add reasonable online help facilities to

    applications, and to provide a basis for rich text editors. If

    you find the HTML support insufficient for your needs you may consider

    the use of QtWebKit, which provides a full-featured web browser

    widget.

    The shape of the mouse cursor on a QTextEdit is Qt::IBeamCursor by default.

    It can be changed through the viewport()'s cursor property.

    \section1 Using QTextEdit as a Display Widget

    QTextEdit can display a large HTML subset, including tables and

    images.

    The text is set or replaced using setHtml() which deletes any

    existing text and replaces it with the text passed in the

    setHtml() call. If you call setHtml() with legacy HTML, and then

    call toHtml(), the text that is returned may have different markup,

    but will render the same. The entire text can be deleted with clear().

    Text itself can be inserted using the QTextCursor class or using the

    convenience functions insertHtml(), insertPlainText(), append() or

    paste(). QTextCursor is also able to insert complex objects like tables

    or lists into the document, and it deals with creating selections

    and applying changes to selected text.

    By default the text edit wraps words at whitespace to fit within

    the text edit widget. The setLineWrapMode() function is used to

    specify the kind of line wrap you want, or \l NoWrap if you don't

    want any wrapping. Call setLineWrapMode() to set a fixed pixel width

    \l FixedPixelWidth, or character column (e.g. 80 column) \l

    FixedColumnWidth with the pixels or columns specified with

    setLineWrapColumnOrWidth(). If you use word wrap to the widget's width

    \l WidgetWidth, you can specify whether to break on whitespace or

    anywhere with setWordWrapMode().

    The find() function can be used to find and select a given string

    within the text.

    If you want to limit the total number of paragraphs in a QTextEdit,

    as it is for example open useful in a log viewer, then you can use

    QTextDocument's maximumBlockCount property for that.

    \section2 Read-only Key Bindings

    When QTextEdit is used read-only the key bindings are limited to

    navigation, and text may only be selected with the mouse:

    \table

    \header \i Keypresses \i Action

    \row \i Up        \i Moves one line up.

    \row \i Down        \i Moves one line down.

    \row \i Left        \i Moves one character to the left.

    \row \i Right        \i Moves one character to the right.

    \row \i PageUp        \i Moves one (viewport) page up.

    \row \i PageDown        \i Moves one (viewport) page down.

    \row \i Home        \i Moves to the beginning of the text.

    \row \i End                \i Moves to the end of the text.

    \row \i Alt+Wheel

         \i Scrolls the page horizontally (the Wheel is the mouse wheel).

    \row \i Ctrl+Wheel        \i Zooms the text.

    \row \i Ctrl+A            \i Selects all text.

    \endtable

    The text edit may be able to provide some meta-information. For

    example, the documentTitle() function will return the text from

    within HTML \c{<title>} tags.

    \section1 Using QTextEdit as an Editor

    All the information about using QTextEdit as a display widget also

    applies here.

    The current char format's attributes are set with setFontItalic(),

    setFontWeight(), setFontUnderline(), setFontFamily(),

    setFontPointSize(), setTextColor() and setCurrentFont(). The current

    paragraph's alignment is set with setAlignment().

    Selection of text is handled by the QTextCursor class, which provides

    functionality for creating selections, retrieving the text contents or

    deleting selections. You can retrieve the object that corresponds with

    the user-visible cursor using the textCursor() method. If you want to set

    a selection in QTextEdit just create one on a QTextCursor object and

    then make that cursor the visible cursor using setTextCursor(). The selection

    can be copied to the clipboard with copy(), or cut to the clipboard with

    cut(). The entire text can be selected using selectAll().

    When the cursor is moved and the underlying formatting attributes change,

    the currentCharFormatChanged() signal is emitted to reflect the new attributes

    at the new cursor position.

    QTextEdit holds a QTextDocument object which can be retrieved using the

    document() method. You can also set your own document object using setDocument().

    QTextDocument emits a textChanged() signal if the text changes and it also

    provides a isModified() function which will return true if the text has been

    modified since it was either loaded or since the last call to setModified

    with false as argument. In addition it provides methods for undo and redo.

    \section2 Drag and Drop

    QTextEdit also supports custom drag and drop behavior. By default,

    QTextEdit will insert plain text, HTML and rich text when the user drops

    data of these MIME types onto a document. Reimplement

    canInsertFromMimeData() and insertFromMimeData() to add support for

    additional MIME types.

    For example, to allow the user to drag and drop an image onto a QTextEdit,

    you could the implement these functions in the following way:

    \snippet doc/src/snippets/textdocument-imagedrop/textedit.cpp 0

    We add support for image MIME types by returning true. For all other

    MIME types, we use the default implementation.

    \snippet doc/src/snippets/textdocument-imagedrop/textedit.cpp 1

    We unpack the image from the QVariant held by the MIME source and insert

    it into the document as a resource.

    \section2 Editing Key Bindings

    The list of key bindings which are implemented for editing:

    \table

    \header \i Keypresses \i Action

    \row \i Backspace \i Deletes the character to the left of the cursor.

    \row \i Delete \i Deletes the character to the right of the cursor.

    \row \i Ctrl+C \i Copy the selected text to the clipboard.

    \row \i Ctrl+Insert \i Copy the selected text to the clipboard.

    \row \i Ctrl+K \i Deletes to the end of the line.

    \row \i Ctrl+V \i Pastes the clipboard text into text edit.

    \row \i Shift+Insert \i Pastes the clipboard text into text edit.

    \row \i Ctrl+X \i Deletes the selected text and copies it to the clipboard.

    \row \i Shift+Delete \i Deletes the selected text and copies it to the clipboard.

    \row \i Ctrl+Z \i Undoes the last operation.

    \row \i Ctrl+Y \i Redoes the last operation.

    \row \i Left \i Moves the cursor one character to the left.

    \row \i Ctrl+Left \i Moves the cursor one word to the left.

    \row \i Right \i Moves the cursor one character to the right.

    \row \i Ctrl+Right \i Moves the cursor one word to the right.

    \row \i Up \i Moves the cursor one line up.

    \row \i Down \i Moves the cursor one line down.

    \row \i PageUp \i Moves the cursor one page up.

    \row \i PageDown \i Moves the cursor one page down.

    \row \i Home \i Moves the cursor to the beginning of the line.

    \row \i Ctrl+Home \i Moves the cursor to the beginning of the text.

    \row \i End \i Moves the cursor to the end of the line.

    \row \i Ctrl+End \i Moves the cursor to the end of the text.

    \row \i Alt+Wheel \i Scrolls the page horizontally (the Wheel is the mouse wheel).

    \endtable

    To select (mark) text hold down the Shift key whilst pressing one

    of the movement keystrokes, for example, \e{Shift+Right}

    will select the character to the right, and \e{Shift+Ctrl+Right} will select the word to the right, etc.

    \sa QTextDocument, QTextCursor, {Application Example},

        {Syntax Highlighter Example}, {Rich Text Processing}

*/

/*!

    \property QTextEdit::plainText

    \since 4.3