4 files changed, 254 insertions, 3 deletions

diff --git a/src/quick/items/qquicktextdocument.cpp b/src/quick/items/qquicktextdocument.cpp
index 81298596b0..432a69b494 100644
--- a/src/quick/items/qquicktextdocument.cpp
+++ b/src/quick/items/qquicktextdocument.cpp
@@ -12,10 +12,33 @@
 #include <QtQml/qqmlcontext.h>
 #include <QtQuick/private/qquickpixmap_p.h>
 
+#include <QtCore/qmimedatabase.h>
 #include <QtCore/qpointer.h>
 
 QT_BEGIN_NAMESPACE
 
+using namespace Qt::StringLiterals;
+
+/*!
+    \qmltype TextDocument
+    \instantiates QQuickTextDocument
+    \inqmlmodule QtQuick
+    \brief A wrapper around TextEdit's backing QTextDocument.
+
+    To load text into the document, set the \l source property. If the user then
+    modifies the text and wants to save the same document, call \l save() to save
+    it to the same source again (only if \l {QUrl::isLocalFile()}{it's a local file}).
+    Or call \l saveAs() to save it to a different file.
+
+    This class cannot be instantiated in QML, but is available from \l TextEdit::textDocument.
+
+    \note All loading and saving is done synchronously for now.
+    This may block the UI if the \l source is a slow network drive.
+    This may be improved in future versions of Qt.
+
+    \note This API is considered tech preview and may change in future versions of Qt.
+*/
+
 /*!
     \class QQuickTextDocument
     \since 5.1
@@ -27,8 +50,6 @@ QT_BEGIN_NAMESPACE
     including document modifications. It can also be used to output content,
     for example with \l{QTextDocumentWriter}), or provide additional formatting,
     for example with \l{QSyntaxHighlighter}.
-
-    This class cannot be instantiated in QML, but is available from \l TextEdit::textDocument.
 */
 
 /*!
@@ -42,6 +63,146 @@ QQuickTextDocument::QQuickTextDocument(QQuickItem *parent)
     Q_ASSERT(parent);
     d->editor = qobject_cast<QQuickTextEdit *>(parent);
     Q_ASSERT(d->editor);
+    connect(textDocument(), &QTextDocument::modificationChanged,
+            this, &QQuickTextDocument::modifiedChanged);
+}
+
+/*!
+    \qmlproperty url QtQuick::TextDocument::source
+    \since 6.7
+
+    QQuickTextDocument can handle any text format supported by Qt, loaded from
+    any URL scheme supported by Qt.
+
+    The URL may be absolute, or relative to the URL of the component.
+
+    The \c source property cannot be changed while the document's \l modified
+    state is \c true. If the user has modified the document contents, you
+    should prompt the user whether to \l save(), or else discard changes by
+    setting \c {modified = false} before setting the \l source property to a
+    different URL.
+
+    \sa QTextDocumentWriter::supportedDocumentFormats()
+*/
+QUrl QQuickTextDocument::source() const
+{
+    Q_D(const QQuickTextDocument);
+    return d->url;
+}
+
+void QQuickTextDocument::setSource(const QUrl &url)
+{
+    Q_D(QQuickTextDocument);
+
+    if (url == d->url)
+        return;
+
+    if (isModified()) {
+        qmlWarning(this) << "Existing document modified: you should save(),"
+                            "or call TextEdit.clear() before setting a different source";
+        return;
+    }
+
+    d->url = url;
+    emit sourceChanged();
+    d->load();
+}
+
+/*!
+    \qmlproperty bool QtQuick::TextDocument::modified
+    \since 6.7
+
+    This property holds whether the document has been modified by the user
+    since the last time it was loaded or saved. By default, this property is
+    \c false.
+
+    As with \l QTextDocument::modified, you can set the modified property:
+    for example, set it to \c false to allow setting the \c source property
+    to a different URL (thus discarding the user's changes).
+
+    \sa QTextDocument::modified
+*/
+bool QQuickTextDocument::isModified() const
+{
+    const auto *doc = textDocument();
+    return doc && doc->isModified();
+}
+
+void QQuickTextDocument::setModified(bool modified)
+{
+    if (auto *doc = textDocument())
+        doc->setModified(modified);
+}
+
+void QQuickTextDocumentPrivate::load()
+{
+    Q_Q(QQuickTextDocument);
+    const QString fileName = QQmlFile::urlToLocalFileOrQrc(url);
+    if (QFile::exists(fileName)) {
+        mimeType = QMimeDatabase().mimeTypeForFile(fileName);
+        QFile file(fileName);
+        if (file.open(QFile::ReadOnly)) {
+            QByteArray data = file.readAll();
+            if (auto *doc = editor->document()) {
+                doc->setBaseUrl(url.adjusted(QUrl::RemoveFilename));
+                if (mimeType.inherits("text/markdown"_L1)) {
+                    doc->setMarkdown(QString::fromUtf8(data));
+                } else if (mimeType.inherits("text/html"_L1)) {
+                    // If a user loads an HTML file, remember the encoding.
+                    // If the user then calls save() later, the same encoding will be used.
+                    encoding = QStringConverter::encodingForHtml(data);
+                    if (encoding) {
+                        QStringDecoder decoder(*encoding);
+                        doc->setHtml(decoder(data));
+                    } else {
+                        // fall back to utf8
+                        doc->setHtml(QString::fromUtf8(data));
+                    }
+                } else {
+                    doc->setPlainText(QString::fromUtf8(data));
+                }
+                doc->setModified(false);
+            }
+        } else {
+            emit q->error(QQuickTextDocument::tr("Cannot load: ") + file.errorString());
+        }
+    }
+}
+
+void QQuickTextDocumentPrivate::writeTo(const QUrl &fileUrl)
+{
+    Q_Q(QQuickTextDocument);
+    auto *doc = editor->document();
+    if (!doc)
+        return;
+
+    const QString filePath = fileUrl.toLocalFile();
+    const bool sameUrl = fileUrl == url;
+    const auto type = (sameUrl ? mimeType : QMimeDatabase().mimeTypeForUrl(fileUrl));
+    const bool isHtml = type.inherits("text/html"_L1);
+    QFile file(filePath);
+    if (!file.open(QFile::WriteOnly | QFile::Truncate | (isHtml ? QFile::NotOpen : QFile::Text))) {
+        emit q->error(QQuickTextDocument::tr("Cannot save: ") + file.errorString());
+        return;
+    }
+    QByteArray raw;
+    if (type.inherits("text/markdown"_L1)) {
+        raw = doc->toMarkdown().toUtf8();
+    } else if (isHtml) {
+        if (sameUrl && encoding) {
+            QStringEncoder enc(*encoding);
+            raw = enc.encode(doc->toHtml());
+        } else {
+            // default to UTF-8 unless the user is saving the same file as previously loaded
+            raw = doc->toHtml().toUtf8();
+        }
+    } else {
+        raw = doc->toPlainText().toUtf8();
+    }
+
+    file.write(raw);
+    file.close();
+    doc->setModified(false);
 }
 
 QTextDocument *QQuickTextDocumentPrivate::document() const
@@ -52,9 +213,16 @@ QTextDocument *QQuickTextDocumentPrivate::document() const
 void QQuickTextDocumentPrivate::setDocument(QTextDocument *doc)
 {
     Q_Q(QQuickTextDocument);
-    if (doc == editor->document())
+    QTextDocument *oldDoc = editor->document();
+    if (doc == oldDoc)
         return;
 
+    if (oldDoc)
+        oldDoc->disconnect(q);
+    if (doc) {
+        q->connect(doc, &QTextDocument::modificationChanged,
+                   q, &QQuickTextDocument::modifiedChanged);
+    }
     editor->setDocument(doc);
     emit q->textDocumentChanged();
 }
@@ -79,6 +247,59 @@ void QQuickTextDocument::setTextDocument(QTextDocument *document)
     d_func()->setDocument(document);
 }
 
+/*!
+    \fn void QQuickTextDocument::textDocumentChanged()
+    \since 6.7
+
+    This signal is emitted when the underlying QTextDocument is
+    replaced with a different instance.
+
+    \sa setTextDocument()
+*/
+
+/*!
+    \qmlmethod void QtQuick::TextDocument::save()
+    \brief Saves the contents to the same file and format specified by \l source.
+    \since 6.7
+
+    \note You can save only to a \l {QUrl::isLocalFile()}{file on a mounted filesystem}.
+
+    \sa source, saveAs()
+*/
+void QQuickTextDocument::save()
+{
+    Q_D(QQuickTextDocument);
+    d->writeTo(d->url);
+}
+
+/*!
+    \qmlmethod void QtQuick::TextDocument::saveAs(url url)
+    \brief Saves the contents to the file and format specified by \a url.
+    \since 6.7
+
+    The file extension in \a url specifies the file format
+    (as determined by QMimeDatabase::mimeTypeForUrl()).
+
+    \note You can save only to a \l {QUrl::isLocalFile()}{file on a mounted filesystem}.
+
+    \sa source, saveAs()
+*/
+void QQuickTextDocument::saveAs(const QUrl &url)
+{
+    Q_D(QQuickTextDocument);
+    if (!url.isLocalFile()) {
+        emit error(tr("Can only save to local files"));
+        return;
+    }
+    d->writeTo(url);
+
+    if (url == d->url)
+        return;
+
+    d->url = url;
+    emit sourceChanged();
+}
+
 QQuickTextImageHandler::QQuickTextImageHandler(QObject *parent)
     : QObject(parent)
 {
@@ -125,6 +346,13 @@ QSizeF QQuickTextImageHandler::intrinsicSize(
     return QSizeF();
 }
 
+/*!
+    \qmlsignal QtQuick::TextDocument::error(string message)
+
+    This signal is emitted when an error \a message (translated string) should
+    be presented to the user, for example with a MessageDialog.
+*/
+
 QT_END_NAMESPACE
 
 #include "moc_qquicktextdocument.cpp"
diff --git a/src/quick/items/qquicktextdocument.h b/src/quick/items/qquicktextdocument.h
index 5ed612b8ae..b2e8137c0a 100644
--- a/src/quick/items/qquicktextdocument.h
+++ b/src/quick/items/qquicktextdocument.h
@@ -13,16 +13,33 @@ class QQuickTextDocumentPrivate;
 class Q_QUICK_EXPORT QQuickTextDocument : public QObject
 {
     Q_OBJECT
+    Q_PROPERTY(QUrl source READ source WRITE setSource NOTIFY sourceChanged REVISION(6, 7) FINAL)
+    Q_PROPERTY(bool modified READ isModified WRITE setModified NOTIFY modifiedChanged REVISION(6, 7) FINAL)
+
     QML_ANONYMOUS
     QML_ADDED_IN_VERSION(2, 0)
 
 public:
     QQuickTextDocument(QQuickItem *parent);
+
+    QUrl source() const;
+    void setSource(const QUrl &url);
+
+    bool isModified() const;
+    void setModified(bool modified);
+
     QTextDocument *textDocument() const;
     void setTextDocument(QTextDocument *document);
 
+    Q_REVISION(6, 7) Q_INVOKABLE void save();
+    Q_REVISION(6, 7) Q_INVOKABLE void saveAs(const QUrl &url);
+
 Q_SIGNALS:
     Q_REVISION(6,7) void textDocumentChanged();
+    Q_REVISION(6, 7) void sourceChanged();
+    Q_REVISION(6, 7) void modifiedChanged();
+
+    Q_REVISION(6, 7) void error(const QString &message);
 
 private:
     Q_DISABLE_COPY(QQuickTextDocument)
diff --git a/src/quick/items/qquicktextdocument_p.h b/src/quick/items/qquicktextdocument_p.h
index 04aa06bb97..8c5bc07a0a 100644
--- a/src/quick/items/qquicktextdocument_p.h
+++ b/src/quick/items/qquicktextdocument_p.h
@@ -60,11 +60,16 @@ public:
     static QQuickTextDocumentPrivate *get(QQuickTextDocument *doc) { return doc->d_func(); }
     static const QQuickTextDocumentPrivate *get(const QQuickTextDocument *doc) { return doc->d_func(); }
 
+    void load();
+    void writeTo(const QUrl &fileUrl);
     QTextDocument *document() const;
     void setDocument(QTextDocument *doc);
 
     // so far the QQuickItem given to the QQuickTextDocument ctor is always a QQuickTextEdit
     QQuickTextEdit *editor = nullptr;
+    QUrl url;
+    QMimeType mimeType;
+    std::optional<QStringConverter::Encoding> encoding; // only relevant for HTML
 };
 
 namespace QtPrivate {
diff --git a/src/quick/items/qquicktextedit.cpp b/src/quick/items/qquicktextedit.cpp
index 9185c11848..ede599cfa3 100644
--- a/src/quick/items/qquicktextedit.cpp
+++ b/src/quick/items/qquicktextedit.cpp
@@ -2646,6 +2646,7 @@ void QQuickTextEditPrivate::init()
     document->setUndoRedoEnabled(false); // flush undo buffer.
     document->setUndoRedoEnabled(true);
     updateDefaultTextOption();
+    document->setModified(false); // we merely changed some defaults: no edits worth saving yet
     q->updateSize();
 #if QT_CONFIG(cursor)
     updateMouseCursorShape();