Question

我正在尝试创建代码编辑器，并希望在用户键入关键字后更改TextArea中关键字的颜色。我读到textFormat：Text.StyledText可以更改颜色，而无需将整个文本更改为HTML，但是在文本中添加标签不会更改颜色。在这里我使用粗体标记代码-

TextArea{
Layout.alignment: Qt.AlignTop
id:ta
selectByMouse: true
selectByKeyboard: true
Layout.fillWidth:true
Layout.fillHeight: true
font.pointSize: 12
textMargin: 16
font.family:"courier new"
persistentSelection: true
textFormat: Text.StyledText

onActiveFocusChanged: {
menu_trig=0
}
onTextChanged: {
    // check text
        console.log(ta.text.slice(0,ta.text.length-3))
        if(ta.text.slice(ta.text.length-3,ta.text.length)=="def")
                {
          ta_text.text=ta.text.substring(0,ta.text.length-3)+"<b>def</b>"}
            }
Keys.onPressed: {
    if(codeChange==0)
    {codeChange=1
        mainWindow.title=title.toString()+" *"}
}
Component.onCompleted: forceActiveFocus()
// color:"orange"}

Answer 1

您必须使用QSyntaxHighlighter，因为在我看来，您正在尝试使其成为我基于this post实现的python编辑器。

syntaxhighlighter.h

#ifndef SYNTAXHIGHLIGHTER_H
#define SYNTAXHIGHLIGHTER_H

#include <QRegularExpression>
#include <QSyntaxHighlighter>

class QQuickTextDocument;

class HighlightingRule
{
public:
    HighlightingRule(const QString &patternStr, int n, const QTextCharFormat &matchingFormat);
    QString originalRuleStr;
    QRegularExpression pattern;
    int nth;
    QTextCharFormat format;
};

class PythonSyntaxHighlighter : public QSyntaxHighlighter
{
    Q_OBJECT
public:
    PythonSyntaxHighlighter(QTextDocument *parent);
    const QTextCharFormat getTextCharFormat(const QString &colorName, const QString &style = QString());
    void initializeRules();
    bool matchMultiline(const QString &text, const QRegularExpression &delimiter, const int inState, const QTextCharFormat &style);
protected:
    void highlightBlock(const QString &text);
private:
    QStringList keywords;
    QStringList operators;
    QStringList braces;
    QHash<QString, QTextCharFormat> basicStyles;
    QList<HighlightingRule> rules;
    QRegularExpression triSingleQuote;
    QRegularExpression triDoubleQuote;
};

class SyntaxHighlighterHelper: public QObject
{
    Q_OBJECT
    Q_PROPERTY(QQuickTextDocument *quickdocument READ quickdocument WRITE setQuickdocument NOTIFY quickdocumentChanged)
public:
    SyntaxHighlighterHelper(QObject *parent=nullptr):
        QObject(parent),
        m_quickdocument(nullptr)
    {}
    QQuickTextDocument *quickdocument() const;
    void setQuickdocument(QQuickTextDocument *quickdocument);
signals:
    void quickdocumentChanged();
private:
    QQuickTextDocument *m_quickdocument;
};

#endif // SYNTAXHIGHLIGHTER_H

syntaxhighlighter.cpp

#include "syntaxhighlighter.h"
#include <QQuickTextDocument>

HighlightingRule::HighlightingRule(const QString &patternStr, int n, const QTextCharFormat &matchingFormat)
{
    originalRuleStr = patternStr;
    pattern = QRegularExpression(patternStr);
    nth = n;
    format = matchingFormat;
}

PythonSyntaxHighlighter::PythonSyntaxHighlighter(QTextDocument *parent)
    : QSyntaxHighlighter(parent)
{
    keywords = QStringList() << "and" << "assert" << "break" << "class" << "continue" << "def" <<
                                "del" << "elif" << "else" << "except" << "exec" << "finally" <<
                                "for" << "from" << "global" << "if" << "import" << "in" <<
                                "is" << "lambda" << "not" << "or" << "pass" << "print" <<
                                "raise" << "return" << "try" << "while" << "yield" <<
                                "None" << "True" << "False";

    operators = QStringList() << "=" <<
                                 // Comparison
                                 "==" << "!=" << "<" << "<=" << ">" << ">=" <<
                                 // Arithmetic
                                 "\\+" << "-" << "\\*" << "/" << "//" << "%" << "\\*\\*" <<
                                 // In-place
                                 "\\+=" << "-=" << "\\*=" << "/=" << "%=" <<
                                 // Bitwise
                                 "\\^" << "\\|" << "&" << "~" << ">>" << "<<";

    braces = QStringList() << "{" << "}" << "\\(" << "\\)" << "\\[" << "]";

    basicStyles.insert("keyword", getTextCharFormat("blue"));
    basicStyles.insert("operator", getTextCharFormat("red"));
    basicStyles.insert("brace", getTextCharFormat("darkGray"));
    basicStyles.insert("defclass", getTextCharFormat("black", "bold"));
    basicStyles.insert("brace", getTextCharFormat("darkGray"));
    basicStyles.insert("string", getTextCharFormat("magenta"));
    basicStyles.insert("string2", getTextCharFormat("darkMagenta"));
    basicStyles.insert("comment", getTextCharFormat("darkGreen", "italic"));
    basicStyles.insert("self", getTextCharFormat("black", "italic"));
    basicStyles.insert("numbers", getTextCharFormat("brown"));

    triSingleQuote.setPattern("'''");
    triDoubleQuote.setPattern("\"\"\"");

    initializeRules();
}

void PythonSyntaxHighlighter::initializeRules()
{
    for(const QString & currKeyword: keywords)
    {
        rules.append(HighlightingRule(QString("\\b%1\\b").arg(currKeyword), 0, basicStyles.value("keyword")));
    }
    for(const QString & currOperator: operators)
    {
        rules.append(HighlightingRule(QString("%1").arg(currOperator), 0, basicStyles.value("operator")));
    }
    for(const QString &currBrace: braces)
    {
        rules.append(HighlightingRule(QString("%1").arg(currBrace), 0, basicStyles.value("brace")));
    }
    // 'self'
    rules.append(HighlightingRule("\\bself\\b", 0, basicStyles.value("self")));

    // Double-quoted string, possibly containing escape sequences
    // FF: originally in python : r'"[^"\\]*(\\.[^"\\]*)*"'
    rules.append(HighlightingRule("\"[^\"\\\\]*(\\\\.[^\"\\\\]*)*\"", 0, basicStyles.value("string")));
    // Single-quoted string, possibly containing escape sequences
    // FF: originally in python : r"'[^'\\]*(\\.[^'\\]*)*'"
    rules.append(HighlightingRule("'[^'\\\\]*(\\\\.[^'\\\\]*)*'", 0, basicStyles.value("string")));

    // 'def' followed by an identifier
    // FF: originally: r'\bdef\b\s*(\w+)'
    rules.append(HighlightingRule("\\bdef\\b\\s*(\\w+)", 1, basicStyles.value("defclass")));
    //  'class' followed by an identifier
    // FF: originally: r'\bclass\b\s*(\w+)'
    rules.append(HighlightingRule("\\bclass\\b\\s*(\\w+)", 1, basicStyles.value("defclass")));

    // From '#' until a newline
    // FF: originally: r'#[^\\n]*'
    rules.append(HighlightingRule("#[^\\n]*", 0, basicStyles.value("comment")));

    // Numeric literals
    rules.append(HighlightingRule("\\b[+-]?[0-9]+[lL]?\\b", 0, basicStyles.value("numbers"))); // r'\b[+-]?[0-9]+[lL]?\b'
    rules.append(HighlightingRule("\\b[+-]?0[xX][0-9A-Fa-f]+[lL]?\\b", 0, basicStyles.value("numbers"))); // r'\b[+-]?0[xX][0-9A-Fa-f]+[lL]?\b'
    rules.append(HighlightingRule("\\b[+-]?[0-9]+(?:\\.[0-9]+)?(?:[eE][+-]?[0-9]+)?\\b", 0, basicStyles.value("numbers"))); // r'\b[+-]?[0-9]+(?:\.[0-9]+)?(?:[eE][+-]?[0-9]+)?\b'
}

void PythonSyntaxHighlighter::highlightBlock(const QString &text)
{
    for(const HighlightingRule &rule: rules) {
        QRegularExpressionMatchIterator matchIterator = rule.pattern.globalMatch(text);
        while (matchIterator.hasNext()) {
            QRegularExpressionMatch match = matchIterator.next();
            setFormat(match.capturedStart(), match.capturedLength(), rule.format);
        }
    }
    setCurrentBlockState(0);
    bool isInMultilne = matchMultiline(text, triSingleQuote, 1, basicStyles.value("string2"));
    if (!isInMultilne)
        isInMultilne = matchMultiline(text, triDoubleQuote, 2, basicStyles.value("string2"));
}

bool PythonSyntaxHighlighter::matchMultiline(const QString &text, const QRegularExpression &delimiter, const int inState, const QTextCharFormat &style)
{
    QRegularExpressionMatch match;
    int startIndex = 0;
    if (previousBlockState() != 1)
        startIndex = text.indexOf(delimiter);
    while (startIndex >= 0) {
        QRegularExpressionMatch match = delimiter.match(text, startIndex);
        int endIndex = match.capturedStart();
        int commentLength = 0;
        if (endIndex == -1) {
            setCurrentBlockState(1);
            commentLength = text.length() - startIndex;
        } else {
            commentLength = endIndex - startIndex
                    + match.capturedLength();
        }
        setFormat(startIndex, commentLength, style);
        startIndex = text.indexOf(delimiter, startIndex + commentLength);
    }

    return currentBlockState() == inState;
}

const QTextCharFormat PythonSyntaxHighlighter::getTextCharFormat(const QString &colorName, const QString &style)
{
    QTextCharFormat charFormat;
    QColor color(colorName);
    charFormat.setForeground(color);
    if (style.contains("bold", Qt::CaseInsensitive))
        charFormat.setFontWeight(QFont::Bold);
    if (style.contains("italic", Qt::CaseInsensitive))
        charFormat.setFontItalic(true);
    return charFormat;
}

QQuickTextDocument *SyntaxHighlighterHelper::quickdocument() const
{
    return m_quickdocument;
}

void SyntaxHighlighterHelper::setQuickdocument(QQuickTextDocument *quickdocument)
{
    m_quickdocument = quickdocument;
    if(m_quickdocument){
        new PythonSyntaxHighlighter(m_quickdocument->textDocument());
    }
}

main.cpp

// ...
qmlRegisterType<SyntaxHighlighterHelper>("Foo", 1, 0, "SyntaxHighlighterHelper");
// ...

main.qml

// ...
import Foo 1.0
// ...
SyntaxHighlighterHelper{
    quickdocument: ta.textDocument
}

TextArea{
    id:ta
    anchors.fill: parent
    selectByMouse: true
    selectByKeyboard: true
    font.pointSize: 12
    textMargin: 16
    font.family:"courier new"
    persistentSelection: true
    textFormat: Text.StyledText
    tabStopDistance: 4*fontMetrics.advanceWidth(" ")
    FontMetrics {
        id: fontMetrics
        font.family: ta.font
    }
}
// ...

可以在here中找到示例。

没有RichText的QML TextArea中不同单词的颜色不同

1 个答案: