q3textedit.cpp

奇趣公司比较新的qt/emd版本

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#include "q3textedit.h"

#ifndef QT_NO_TEXTEDIT

#include <private/q3richtext_p.h>
#include "qpainter.h"
#include "qpen.h"
#include "qbrush.h"
#include "qpixmap.h"
#include "qfont.h"
#include "qcolor.h"
#include "qstyle.h"
#include "qsize.h"
#include "qevent.h"
#include "qtimer.h"
#include "qapplication.h"
#include "q3listbox.h"
#include "qclipboard.h"
#include "qcolordialog.h"
#include "q3stylesheet.h"
#include "q3dragobject.h"
#include "qurl.h"
#include "qcursor.h"
#include "qregexp.h"
#include "q3popupmenu.h"
#include "qstack.h"
#include "qmetaobject.h"
#include "q3textbrowser.h"
#include "private/q3syntaxhighlighter_p.h"
#include "qtextformat.h"
#ifndef QT_NO_IM
#include <qinputcontext.h>
#endif

#ifndef QT_NO_ACCEL
#include <qkeysequence.h>
#define ACCEL_KEY(k) QLatin1Char('\t') + QString(QKeySequence(Qt::CTRL | Qt::Key_ ## k))
#else
#define ACCEL_KEY(k) QLatin1Char('\t' )+ QString(QLatin1String("Ctrl+" #k))
#endif

#ifdef QT_TEXTEDIT_OPTIMIZATION
#define LOGOFFSET(i) d->logOffset + i
#endif

struct QUndoRedoInfoPrivate
{
    Q3TextString text;
};

class Q3TextEditPrivate
{
public:
    Q3TextEditPrivate()
        :preeditStart(-1),preeditLength(-1),numPreeditSelections(0),ensureCursorVisibleInShowEvent(false),
         tabChangesFocus(false),
#ifndef QT_NO_CLIPBOARD
         clipboard_mode(QClipboard::Clipboard),
#endif
#ifdef QT_TEXTEDIT_OPTIMIZATION
         od(0), optimMode(false),
         maxLogLines(-1),
         logOffset(0),
#endif
         autoFormatting((uint)Q3TextEdit::AutoAll),
         cursorRepaintMode(false),
         cursorBlinkActive(false)

    {
        for (int i=0; i<7; i++)
            id[i] = 0;
    }
    int id[7];
    int preeditStart;
    int preeditLength;
    int numPreeditSelections;
    uint ensureCursorVisibleInShowEvent : 1;
    uint tabChangesFocus : 1;
    QString scrollToAnchor; // used to deferr scrollToAnchor() until the show event when we are resized
    QString pressedName;
    QString onName;
#ifndef QT_NO_CLIPBOARD
    QClipboard::Mode clipboard_mode;
#endif
    QTimer *trippleClickTimer;
    QPoint trippleClickPoint;
#ifdef QT_TEXTEDIT_OPTIMIZATION
    Q3TextEditOptimPrivate * od;
    bool optimMode : 1;
    int maxLogLines;
    int logOffset;
#endif
    Q3TextEdit::AutoFormatting autoFormatting;
    uint cursorRepaintMode : 1;
    uint cursorBlinkActive : 1;
};

#ifndef QT_NO_MIME
class Q3RichTextDrag : public Q3TextDrag
{
public:
    Q3RichTextDrag(QWidget *dragSource = 0, const char *name = 0);

    void setPlainText(const QString &txt) { setText(txt); }
    void setRichText(const QString &txt) { richTxt = txt; }

    virtual QByteArray encodedData(const char *mime) const;
    virtual const char* format(int i) const;

    static bool decode(QMimeSource *e, QString &str, const QString &mimetype,
                        const QString &subtype);
    static bool canDecode(QMimeSource* e);

private:
    QString richTxt;

};

Q3RichTextDrag::Q3RichTextDrag(QWidget *dragSource, const char *name)
    : Q3TextDrag(dragSource, name)
{
}

QByteArray Q3RichTextDrag::encodedData(const char *mime) const
{
    if (qstrcmp("application/x-qrichtext", mime) == 0) {
        return richTxt.toUtf8(); // #### perhaps we should use USC2 instead?
    } else
        return Q3TextDrag::encodedData(mime);
}

bool Q3RichTextDrag::decode(QMimeSource *e, QString &str, const QString &mimetype,
                            const QString &subtype)
{
    if (mimetype == QLatin1String("application/x-qrichtext")) {
        // do richtext decode
        const char *mime;
        int i;
        for (i = 0; (mime = e->format(i)); ++i) {
            if (qstrcmp("application/x-qrichtext", mime) != 0)
                continue;
            str = QString::fromUtf8(e->encodedData(mime));
            return true;
        }
        return false;
    }

    // do a regular text decode
    QString st = subtype;
    return Q3TextDrag::decode(e, str, st);
}

bool Q3RichTextDrag::canDecode(QMimeSource* e)
{
    if (e->provides("application/x-qrichtext"))
        return true;
    return Q3TextDrag::canDecode(e);
}

const char* Q3RichTextDrag::format(int i) const
{
    if (Q3TextDrag::format(i))
        return Q3TextDrag::format(i);
    if (Q3TextDrag::format(i-1))
        return "application/x-qrichtext";
    return 0;
}

#endif

static bool block_set_alignment = false;

/*!
    \class Q3TextEdit qtextedit.h
    \brief The Q3TextEdit widget provides a powerful single-page rich text editor.

    \compat

    \tableofcontents

    \section1 Introduction and Concepts

    Q3TextEdit 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.

    Q3TextEdit has four modes of operation:
    \table
    \header \i Mode \i Command \i Notes
    \row \i Plain Text Editor \i setTextFormat(Qt::PlainText)
         \i Set text with setText(); text() returns plain text. Text
         attributes (e.g. colors) can be set, but plain text is always
         returned.
    \row \i Rich Text Editor \i setTextFormat(Qt::RichText)
         \i Set text with setText(); text() returns rich text. Rich
         text editing is fairly limited. You can't set margins or
         insert images for example (although you can read and
         correctly display files that have margins set and that
         include images). This mode is mostly useful for editing small
         amounts of rich text.
    \row \i Text Viewer \i setReadOnly(true)
         \i Set text with setText() or append() (which has no undo
         history so is faster and uses less memory); text() returns
         plain or rich text depending on the textFormat(). This mode
         can correctly display a large subset of HTML tags.
    \row \i Log Viewer \i setTextFormat(Qt::LogText)
         \i Append text using append(). The widget is set to be read
         only and rich text support is disabled although a few HTML
         tags (for color, bold, italic and underline) may be used.
         (See \link #logtextmode Qt::LogText mode\endlink for details.)
    \endtable

    Q3TextEdit can be used as a syntax highlighting editor when used in
    conjunction with QSyntaxHighlighter.

    We recommend that you always call setTextFormat() to set the mode
    you want to use. If you use Qt::AutoText then setText() and
    append() will try to determine whether the text they are given is
    plain text or rich text. If you use Qt::RichText then setText() and
    append() will assume that the text they are given is rich text.
    insert() simply inserts the text it is given.

    Q3TextEdit 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
    signify a paragraph. A document consists of zero or more
    paragraphs, indexed from 0. Characters are indexed on a
    per-paragraph basis, also indexed from 0. 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.

    The text edit documentation uses the following concepts:
    \list
    \i \e{current format} --
    this is the format at the current cursor position, \e and it
    is the format of the selected text if any.
    \i \e{current paragraph} -- the paragraph which contains the
    cursor.
    \endlist

    Q3TextEdit can display images (using Q3MimeSourceFactory), 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). The
    rendering style and the set of valid tags are defined by a
    styleSheet(). Custom tags can be created and placed in a custom
    style sheet. Change the style sheet with \l{setStyleSheet()}; see
    Q3StyleSheet for details. The images identified by image tags are
    displayed if they can be interpreted using the text edit's
    \l{Q3MimeSourceFactory}; see setMimeSourceFactory().

    If you want a text browser with more navigation use QTextBrowser.
    If you just need to display a small piece of rich text use QLabel
    or QSimpleRichText.

    If you create a new Q3TextEdit, and want to allow the user to edit
    rich text, call setTextFormat(Qt::RichText) to ensure that the
    text is treated as rich text. (Rich text uses HTML tags to set
    text formatting attributes. See Q3StyleSheet for information on the
    HTML tags that are supported.). If you don't call setTextFormat()
    explicitly the text edit will guess from the text itself whether
    it is rich text or plain text. This means that if the text looks
    like HTML or XML it will probably be interpreted as rich text, so
    you should call setTextFormat(Qt::PlainText) to preserve such
    text.

    Note that we do not intend to add a full-featured web browser
    widget to Qt (because that would easily double Qt's size and only
    a few applications would benefit from it). 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.

    \section1 Using Q3TextEdit as a Display Widget

    Q3TextEdit can display a large HTML subset, including tables and
    images.

    The text is set or replaced using setText() which deletes any
    existing text and replaces it with the text passed in the
    setText() call. If you call setText() with legacy HTML (with
    setTextFormat(Qt::RichText) in force), and then call text(), the text
    that is returned may have different markup, but will render the
    same. Text can be inserted with insert(), paste(), pasteSubType()
    and append(). Text that is appended does not go into the undo
    history; this makes append() faster and consumes less memory. Text
    can also be cut(). The entire text is deleted with clear() and the
    selected text is deleted with removeSelectedText(). Selected
    (marked) text can also be deleted with del() (which will delete
    the character to the right of the cursor if no text is selected).

    Loading and saving text is achieved using setText() and text(),
    for example:
    \code
    QFile file(fileName); // Read the text from a file
    if (file.open(IO_ReadOnly)) {
        QTextStream stream(&file);
        textEdit->setText(stream.read());
    }

    QFile file(fileName); // Write the text to a file
    if (file.open(IO_WriteOnly)) {
        QTextStream stream(&file);
        stream << textEdit->text();
        textEdit->setModified(false);
    }
    \endcode

    By default the text edit wraps words at whitespace to fit within
    the text edit widget. The setWordWrap() function is used to
    specify the kind of word wrap you want, or \c NoWrap if you don't
    want any wrapping. Call setWordWrap() to set a fixed pixel width
    \c FixedPixelWidth, or character column (e.g. 80 column) \c
    FixedColumnWidth with the pixels or columns specified with
    setWrapColumnOrWidth(). If you use word wrap to the widget's width
    \c WidgetWidth, you can specify whether to break on whitespace or
    anywhere with setWrapPolicy().

    The background color is set differently than other widgets, using
    setPaper(). You specify a brush style which could be a plain color
    or a complex pixmap.

    Hypertext links are automatically underlined; this can be changed
    with setLinkUnderline(). The tab stop width is set with
    setTabStopWidth().

    The zoomIn() and zoomOut() functions can be used to resize the
    text by increasing (decreasing for zoomOut()) the point size used.
    Images are not affected by the zoom functions.

    The lines() function returns the number of lines in the text and
    paragraphs() returns the number of paragraphs. The number of lines
    within a particular paragraph is returned by linesOfParagraph().
    The length of the entire text in characters is returned by
    length().