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** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt Creator.
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** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
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#include "textdocument.h"

#include "extraencodingsettings.h"
#include "fontsettings.h"
#include "indenter.h"
#include "storagesettings.h"
#include "syntaxhighlighter.h"
#include "tabsettings.h"
#include "textdocumentlayout.h"
#include "texteditor.h"
#include "texteditorconstants.h"
#include "typingsettings.h"
#include <texteditor/generichighlighter/highlighter.h>
#include <coreplugin/diffservice.h>
#include <coreplugin/editormanager/editormanager.h>
#include <coreplugin/editormanager/documentmodel.h>
#include <extensionsystem/pluginmanager.h>
#include <utils/textutils.h>
#include <utils/guard.h>
#include <utils/mimetypes/mimedatabase.h>

#include <QAction>
#include <QApplication>
#include <QDir>
#include <QFileInfo>
#include <QFutureInterface>
#include <QScrollBar>
#include <QStringList>
#include <QTextCodec>
#include <QTimer>

#include <coreplugin/coreconstants.h>
#include <coreplugin/icore.h>
#include <coreplugin/progressmanager/progressmanager.h>
#include <utils/qtcassert.h>

using namespace Core;

/*!
    \class TextEditor::BaseTextDocument
    \brief The BaseTextDocument class is the base class for QTextDocument based documents.

    It is the base class for documents used by implementations of the BaseTextEditor class,
    and contains basic functions for retrieving text content and markers (like bookmarks).

    Subclasses of BaseTextEditor can either use BaseTextDocument as is (and this is the default),
    or created subclasses of BaseTextDocument if they have special requirements.
*/

namespace TextEditor {

class TextDocumentPrivate
{
public:
    TextDocumentPrivate()
        : m_indenter(new Indenter)
    {
    }

    QTextCursor indentOrUnindent(const QTextCursor &textCursor, bool doIndent,
                                 bool blockSelection = false, int column = 0,
                                 int *offset = nullptr);
    void resetRevisions();
    void updateRevisions();

public:
    QString m_defaultPath;
    QString m_suggestedFileName;
    TypingSettings m_typingSettings;
    StorageSettings m_storageSettings;
    TabSettings m_tabSettings;
    ExtraEncodingSettings m_extraEncodingSettings;
    FontSettings m_fontSettings;
    bool m_fontSettingsNeedsApply = false; // for applying font settings delayed till an editor becomes visible
    QTextDocument m_document;
    SyntaxHighlighter *m_highlighter = nullptr;
    CompletionAssistProvider *m_completionAssistProvider = nullptr;
    QScopedPointer<Indenter> m_indenter;

    bool m_fileIsReadOnly = false;
    int m_autoSaveRevision = -1;

    TextMarks m_marksCache; // Marks not owned
    Utils::Guard m_modificationChangedGuard;
};

QTextCursor TextDocumentPrivate::indentOrUnindent(const QTextCursor &textCursor, bool doIndent,
                                                  bool blockSelection, int columnIn, int *offset)
{
    QTextCursor cursor = textCursor;
    cursor.beginEditBlock();

    TabSettings &ts = m_tabSettings;

    // Indent or unindent the selected lines
    int pos = cursor.position();
    int column = blockSelection ? columnIn
               : ts.columnAt(cursor.block().text(), cursor.positionInBlock());
    int anchor = cursor.anchor();
    int start = qMin(anchor, pos);
    int end = qMax(anchor, pos);
    bool modified = true;

    QTextBlock startBlock = m_document.findBlock(start);
    QTextBlock endBlock = m_document.findBlock(blockSelection ? end : qMax(end - 1, 0)).next();
    const bool cursorAtBlockStart = (textCursor.position() == startBlock.position());
    const bool anchorAtBlockStart = (textCursor.anchor() == startBlock.position());
    const bool oneLinePartial = (startBlock.next() == endBlock)
                              && (start > startBlock.position() || end < endBlock.position() - 1);

    // Make sure one line selection will get processed in "for" loop
    if (startBlock == endBlock)
        endBlock = endBlock.next();

    if (cursor.hasSelection() && !blockSelection && !oneLinePartial) {
        for (QTextBlock block = startBlock; block != endBlock; block = block.next()) {
            const QString text = block.text();
            int indentPosition = ts.lineIndentPosition(text);
            if (!doIndent && !indentPosition)
                indentPosition = ts.firstNonSpace(text);
            int targetColumn = ts.indentedColumn(ts.columnAt(text, indentPosition), doIndent);
            cursor.setPosition(block.position() + indentPosition);
            cursor.insertText(ts.indentationString(0, targetColumn, 0, block));
            cursor.setPosition(block.position());
            cursor.setPosition(block.position() + indentPosition, QTextCursor::KeepAnchor);
            cursor.removeSelectedText();
        }
        // make sure that selection that begins in first column stays at first column
        // even if we insert text at first column
        if (cursorAtBlockStart) {
            cursor = textCursor;
            cursor.setPosition(startBlock.position(), QTextCursor::KeepAnchor);
        } else if (anchorAtBlockStart) {
            cursor = textCursor;
            cursor.setPosition(startBlock.position(), QTextCursor::MoveAnchor);
            cursor.setPosition(textCursor.position(), QTextCursor::KeepAnchor);
        } else {
            modified = false;
        }
    } else if (cursor.hasSelection() && !blockSelection && oneLinePartial) {
        // Only one line partially selected.
        cursor.removeSelectedText();
    } else {
        // Indent or unindent at cursor position
        for (QTextBlock block = startBlock; block != endBlock; block = block.next()) {
            QString text = block.text();

            int blockColumn = ts.columnAt(text, text.size());
            if (blockColumn < column) {
                cursor.setPosition(block.position() + text.size());
                cursor.insertText(ts.indentationString(blockColumn, column, 0, block));
                text = block.text();
            }

            int indentPosition = ts.positionAtColumn(text, column, nullptr, true);
            int spaces = ts.spacesLeftFromPosition(text, indentPosition);
            int startColumn = ts.columnAt(text, indentPosition - spaces);
            int targetColumn = ts.indentedColumn(ts.columnAt(text, indentPosition), doIndent);
            cursor.setPosition(block.position() + indentPosition);
            cursor.setPosition(block.position() + indentPosition - spaces, QTextCursor::KeepAnchor);
            cursor.removeSelectedText();
            cursor.insertText(ts.indentationString(startColumn, targetColumn, 0, block));
        }
        // Preserve initial anchor of block selection
        if (blockSelection) {
            end = cursor.position();
            if (offset)
                *offset = ts.columnAt(cursor.block().text(), cursor.positionInBlock()) - column;
            cursor.setPosition(start);
            cursor.setPosition(end, QTextCursor::KeepAnchor);
        }
    }

    cursor.endEditBlock();

    return modified ? cursor : textCursor;
}

void TextDocumentPrivate::resetRevisions()
{
    TextDocumentLayout *documentLayout = qobject_cast<TextDocumentLayout*>(m_document.documentLayout());
    QTC_ASSERT(documentLayout, return);
    documentLayout->lastSaveRevision = m_document.revision();

    for (QTextBlock block = m_document.begin(); block.isValid(); block = block.next())
        block.setRevision(documentLayout->lastSaveRevision);
}

void TextDocumentPrivate::updateRevisions()
{
    TextDocumentLayout *documentLayout = qobject_cast<TextDocumentLayout*>(m_document.documentLayout());
    QTC_ASSERT(documentLayout, return);
    int oldLastSaveRevision = documentLayout->lastSaveRevision;
    documentLayout->lastSaveRevision = m_document.revision();

    if (oldLastSaveRevision != documentLayout->lastSaveRevision) {
        for (QTextBlock block = m_document.begin(); block.isValid(); block = block.next()) {
            if (block.revision() < 0 || block.revision() != oldLastSaveRevision)
                block.setRevision(-documentLayout->lastSaveRevision - 1);
            else
                block.setRevision(documentLayout->lastSaveRevision);
        }
    }
}

///////////////////////////////////////////////////////////////////////
//
// BaseTextDocument
//
///////////////////////////////////////////////////////////////////////

TextDocument::TextDocument(Id id)
    : d(new TextDocumentPrivate)
{
    connect(&d->m_document, &QTextDocument::modificationChanged,
            this, &TextDocument::modificationChanged);
    connect(&d->m_document, &QTextDocument::contentsChanged,
            this, &Core::IDocument::contentsChanged);
    connect(&d->m_document, &QTextDocument::contentsChange,
            this, &TextDocument::contentsChangedWithPosition);

    // set new document layout
    QTextOption opt = d->m_document.defaultTextOption();
    opt.setTextDirection(Qt::LeftToRight);
    opt.setFlags(opt.flags() | QTextOption::IncludeTrailingSpaces
            | QTextOption::AddSpaceForLineAndParagraphSeparators
            );
    d->m_document.setDefaultTextOption(opt);
    d->m_document.setDocumentLayout(new TextDocumentLayout(&d->m_document));

    if (id.isValid())
        setId(id);

    setSuspendAllowed(true);
}

TextDocument::~TextDocument()
{
    delete d;
}

QMap<QString, QString> TextDocument::openedTextDocumentContents()
{
    QMap<QString, QString> workingCopy;
    foreach (IDocument *document, DocumentModel::openedDocuments()) {
        TextDocument *textEditorDocument = qobject_cast<TextDocument *>(document);
        if (!textEditorDocument)
            continue;
        QString fileName = textEditorDocument->filePath().toString();
        workingCopy[fileName] = textEditorDocument->plainText();
    }
    return workingCopy;
}

QMap<QString, QTextCodec *> TextDocument::openedTextDocumentEncodings()
{
    QMap<QString, QTextCodec *> workingCopy;
    foreach (IDocument *document, DocumentModel::openedDocuments()) {
        TextDocument *textEditorDocument = qobject_cast<TextDocument *>(document);
        if (!textEditorDocument)
            continue;
        QString fileName = textEditorDocument->filePath().toString();
        workingCopy[fileName] = const_cast<QTextCodec *>(textEditorDocument->codec());
    }
    return workingCopy;
}

TextDocument *TextDocument::currentTextDocument()
{
    return qobject_cast<TextDocument *>(EditorManager::currentDocument());
}

QString TextDocument::plainText() const
{
    return document()->toPlainText();
}

QString TextDocument::textAt(int pos, int length) const
{
    return Utils::Text::textAt(QTextCursor(document()), pos, length);
}

QChar TextDocument::characterAt(int pos) const
{
    return document()->characterAt(pos);
}

void TextDocument::setTypingSettings(const TypingSettings &typingSettings)
{
    d->m_typingSettings = typingSettings;
}

void TextDocument::setStorageSettings(const StorageSettings &storageSettings)
{
    d->m_storageSettings = storageSettings;
}

const TypingSettings &TextDocument::typingSettings() const
{
    return d->m_typingSettings;
}

const StorageSettings &TextDocument::storageSettings() const
{
    return d->m_storageSettings;
}

void TextDocument::setTabSettings(const TabSettings &tabSettings)
{
    if (tabSettings == d->m_tabSettings)
        return;
    d->m_tabSettings = tabSettings;

    if (Highlighter *highlighter = qobject_cast<Highlighter *>(d->m_highlighter))
        highlighter->setTabSettings(tabSettings);

    emit tabSettingsChanged();
}

const TabSettings &TextDocument::tabSettings() const
{
    return d->m_tabSettings;
}

void TextDocument::setFontSettings(const FontSettings &fontSettings)
{
    if (fontSettings == d->m_fontSettings)
        return;
    d->m_fontSettings = fontSettings;
    d->m_fontSettingsNeedsApply = true;
    emit fontSettingsChanged();
}

QAction *TextDocument::createDiffAgainstCurrentFileAction(
    QObject *parent, const std::function<Utils::FileName()> &filePath)
{
    const auto diffAgainstCurrentFile = [filePath]() {
        auto diffService = DiffService::instance();
        auto textDocument = TextEditor::TextDocument::currentTextDocument();
        const QString leftFilePath = textDocument ? textDocument->filePath().toString() : QString();
        const QString rightFilePath = filePath().toString();
        if (diffService && !leftFilePath.isEmpty() && !rightFilePath.isEmpty())
            diffService->diffFiles(leftFilePath, rightFilePath);
    };
    auto diffAction = new QAction(tr("Diff Against Current File"), parent);
    QObject::connect(diffAction, &QAction::triggered, parent, diffAgainstCurrentFile);
    return diffAction;
}

void TextDocument::triggerPendingUpdates()
{
    if (d->m_fontSettingsNeedsApply)
        applyFontSettings();
}

void TextDocument::setCompletionAssistProvider(CompletionAssistProvider *provider)
{
    d->m_completionAssistProvider = provider;
}

CompletionAssistProvider *TextDocument::completionAssistProvider() const
{
    return d->m_completionAssistProvider;
}

IAssistProvider *TextDocument::quickFixAssistProvider() const
{
    return nullptr;
}

void TextDocument::applyFontSettings()
{
    d->m_fontSettingsNeedsApply = false;
    if (d->m_highlighter) {
        d->m_highlighter->setFontSettings(d->m_fontSettings);
        d->m_highlighter->rehighlight();
    }
}

const FontSettings &TextDocument::fontSettings() const
{
    return d->m_fontSettings;
}

void TextDocument::setExtraEncodingSettings(const ExtraEncodingSettings &extraEncodingSettings)
{
    d->m_extraEncodingSettings = extraEncodingSettings;
}

void TextDocument::autoIndent(const QTextCursor &cursor, QChar typedChar)
{
    d->m_indenter->indent(&d->m_document, cursor, typedChar, d->m_tabSettings);
}

void TextDocument::autoReindent(const QTextCursor &cursor)
{
    d->m_indenter->reindent(&d->m_document, cursor, d->m_tabSettings);
}

QTextCursor TextDocument::indent(const QTextCursor &cursor, bool blockSelection, int column,
                                 int *offset)
{
    return d->indentOrUnindent(cursor, true, blockSelection, column, offset);
}

QTextCursor TextDocument::unindent(const QTextCursor &cursor, bool blockSelection, int column,
                                   int *offset)
{
    return d->indentOrUnindent(cursor, false, blockSelection, column, offset);
}

const ExtraEncodingSettings &TextDocument::extraEncodingSettings() const
{
    return d->m_extraEncodingSettings;
}

void TextDocument::setIndenter(Indenter *indenter)
{
    // clear out existing code formatter data
    for (QTextBlock it = document()->begin(); it.isValid(); it = it.next()) {
        TextBlockUserData *userData = TextDocumentLayout::testUserData(it);
        if (userData)
            userData->setCodeFormatterData(nullptr);
    }
    d->m_indenter.reset(indenter);
}

Indenter *TextDocument::indenter() const
{
    return d->m_indenter.data();
}

bool TextDocument::isSaveAsAllowed() const
{
    return true;
}

QString TextDocument::fallbackSaveAsPath() const
{
    return d->m_defaultPath;
}

QString TextDocument::fallbackSaveAsFileName() const
{
    return d->m_suggestedFileName;
}

void TextDocument::setFallbackSaveAsPath(const QString &defaultPath)
{
    d->m_defaultPath = defaultPath;
}

void TextDocument::setFallbackSaveAsFileName(const QString &suggestedFileName)
{
    d->m_suggestedFileName = suggestedFileName;
}

QTextDocument *TextDocument::document() const
{
    return &d->m_document;
}

SyntaxHighlighter *TextDocument::syntaxHighlighter() const
{
    return d->m_highlighter;
}

/*!
 * Saves the document to the file specified by \a fileName. If errors occur,
 * \a errorString contains their cause.
 * \a autoSave returns whether this function was called by the automatic save routine.
 * If \a autoSave is true, the cursor will be restored and some signals suppressed
 * and we do not clean up the text file (cleanWhitespace(), ensureFinalNewLine()).
 */
bool TextDocument::save(QString *errorString, const QString &saveFileName, bool autoSave)
{
    QTextCursor cursor(&d->m_document);

    // When autosaving, we don't want to modify the document/location under the user's fingers.
    TextEditorWidget *editorWidget = nullptr;
    int savedPosition = 0;
    int savedAnchor = 0;
    int savedVScrollBarValue = 0;
    int savedHScrollBarValue = 0;
    int undos = d->m_document.availableUndoSteps();

    // When saving the current editor, make sure to maintain the cursor and scroll bar
    // positions for undo
    if (BaseTextEditor *editor = BaseTextEditor::currentTextEditor()) {
        if (editor->document() == this) {
            editorWidget = editor->editorWidget();
            QTextCursor cur = editor->textCursor();
            savedPosition = cur.position();
            savedAnchor = cur.anchor();
            savedVScrollBarValue = editorWidget->verticalScrollBar()->value();
            savedHScrollBarValue = editorWidget->horizontalScrollBar()->value();
            cursor.setPosition(cur.position());
        }
    }

    if (!autoSave) {
        cursor.beginEditBlock();
        cursor.movePosition(QTextCursor::Start);

        if (d->m_storageSettings.m_cleanWhitespace)
          cleanWhitespace(cursor, d->m_storageSettings.m_cleanIndentation, d->m_storageSettings.m_inEntireDocument);
        if (d->m_storageSettings.m_addFinalNewLine)
          ensureFinalNewLine(cursor);
        cursor.endEditBlock();
      }

    QString fName = filePath().toString();
    if (!saveFileName.isEmpty())
        fName = saveFileName;

    // check if UTF8-BOM has to be added or removed
    Utils::TextFileFormat saveFormat = format();
    if (saveFormat.codec->name() == "UTF-8" && supportsUtf8Bom()) {
        switch (d->m_extraEncodingSettings.m_utf8BomSetting) {
        case ExtraEncodingSettings::AlwaysAdd:
            saveFormat.hasUtf8Bom = true;
            break;
        case ExtraEncodingSettings::OnlyKeep:
            break;
        case ExtraEncodingSettings::AlwaysDelete:
            saveFormat.hasUtf8Bom = false;
            break;
        }
    }

    const bool ok = write(fName, saveFormat, d->m_document.toPlainText(), errorString);

    // restore text cursor and scroll bar positions
    if (autoSave && undos < d->m_document.availableUndoSteps()) {
        d->m_document.undo();
        if (editorWidget) {
            QTextCursor cur = editorWidget->textCursor();
            cur.setPosition(savedAnchor);
            cur.setPosition(savedPosition, QTextCursor::KeepAnchor);
            editorWidget->verticalScrollBar()->setValue(savedVScrollBarValue);
            editorWidget->horizontalScrollBar()->setValue(savedHScrollBarValue);
            editorWidget->setTextCursor(cur);
        }
    }

    if (!ok)
        return false;
    d->m_autoSaveRevision = d->m_document.revision();
    if (autoSave)
        return true;

    // inform about the new filename
    const QFileInfo fi(fName);
    d->m_document.setModified(false); // also triggers update of the block revisions
    setFilePath(Utils::FileName::fromUserInput(fi.absoluteFilePath()));
    emit changed();
    return true;
}

QByteArray TextDocument::contents() const
{
    return plainText().toUtf8();
}

bool TextDocument::setContents(const QByteArray &contents)
{
    return setPlainText(QString::fromUtf8(contents));
}

bool TextDocument::shouldAutoSave() const
{
    return d->m_autoSaveRevision != d->m_document.revision();
}

void TextDocument::setFilePath(const Utils::FileName &newName)
{
    if (newName == filePath())
        return;
    IDocument::setFilePath(Utils::FileName::fromUserInput(newName.toFileInfo().absoluteFilePath()));
}

bool TextDocument::isFileReadOnly() const
{
    if (filePath().isEmpty()) //have no corresponding file, so editing is ok
        return false;
    return d->m_fileIsReadOnly;
}

bool TextDocument::isModified() const
{
    return d->m_document.isModified();
}

void TextDocument::checkPermissions()
{
    bool previousReadOnly = d->m_fileIsReadOnly;
    if (!filePath().isEmpty()) {
        d->m_fileIsReadOnly = !filePath().toFileInfo().isWritable();
    } else {
        d->m_fileIsReadOnly = false;
    }
    if (previousReadOnly != d->m_fileIsReadOnly)
        emit changed();
}

Core::IDocument::OpenResult TextDocument::open(QString *errorString, const QString &fileName,
                                               const QString &realFileName)
{
    emit aboutToOpen(fileName, realFileName);
    OpenResult success = openImpl(errorString, fileName, realFileName, /*reload =*/ false);
    if (success == OpenResult::Success) {
        setMimeType(Utils::mimeTypeForFile(fileName).name());
        emit openFinishedSuccessfully();
    }
    return success;
}

Core::IDocument::OpenResult TextDocument::openImpl(QString *errorString, const QString &fileName,
                                                   const QString &realFileName, bool reload)
{
    QStringList content;

    ReadResult readResult = Utils::TextFileFormat::ReadIOError;

    if (!fileName.isEmpty()) {
        const QFileInfo fi(fileName);
        d->m_fileIsReadOnly = !fi.isWritable();
        readResult = read(realFileName, &content, errorString);
        const int chunks = content.size();

        // Don't call setUndoRedoEnabled(true) when reload is true and filenames are different,
        // since it will reset the undo's clear index
        if (!reload || fileName == realFileName)
            d->m_document.setUndoRedoEnabled(reload);

        QTextCursor c(&d->m_document);
        c.beginEditBlock();
        if (reload) {
            c.select(QTextCursor::Document);
            c.removeSelectedText();
        } else {
            d->m_document.clear();
        }

        if (chunks == 1) {
            c.insertText(content.at(0));
        } else if (chunks > 1) {
            QFutureInterface<void> interface;
            interface.setProgressRange(0, chunks);
            ProgressManager::addTask(interface.future(), tr("Opening File"),
                                     Constants::TASK_OPEN_FILE);
            interface.reportStarted();

            for (int i = 0; i < chunks; ++i) {
                c.insertText(content.at(i));
                interface.setProgressValue(i + 1);
                QApplication::processEvents(QEventLoop::ExcludeUserInputEvents);
            }

            interface.reportFinished();
        }

        c.endEditBlock();

        // Don't call setUndoRedoEnabled(true) when reload is true and filenames are different,
        // since it will reset the undo's clear index
        if (!reload || fileName == realFileName)
            d->m_document.setUndoRedoEnabled(true);

        TextDocumentLayout *documentLayout =
            qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
        QTC_ASSERT(documentLayout, return OpenResult::CannotHandle);
        documentLayout->lastSaveRevision = d->m_autoSaveRevision = d->m_document.revision();
        d->updateRevisions();
        d->m_document.setModified(fileName != realFileName);
        setFilePath(Utils::FileName::fromUserInput(fi.absoluteFilePath()));
    }
    if (readResult == Utils::TextFileFormat::ReadIOError)
        return OpenResult::ReadError;
    return OpenResult::Success;
}

bool TextDocument::reload(QString *errorString, QTextCodec *codec)
{
    QTC_ASSERT(codec, return false);
    setCodec(codec);
    return reload(errorString);
}

bool TextDocument::reload(QString *errorString)
{
    return reload(errorString, filePath().toString());
}

bool TextDocument::reload(QString *errorString, const QString &realFileName)
{
    emit aboutToReload();
    TextDocumentLayout *documentLayout =
        qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
    TextMarks marks;
    if (documentLayout)
        marks = documentLayout->documentClosing(); // removes text marks non-permanently

    const QString &file = filePath().toString();
    bool success = openImpl(errorString, file, realFileName, /*reload =*/ true) == OpenResult::Success;

    if (documentLayout)
        documentLayout->documentReloaded(marks, this); // re-adds text marks
    emit reloadFinished(success);
    return success;
}

bool TextDocument::setPlainText(const QString &text)
{
    if (text.size() > EditorManager::maxTextFileSize()) {
        document()->setPlainText(TextEditorWidget::msgTextTooLarge(text.size()));
        d->resetRevisions();
        document()->setModified(false);
        return false;
    }
    document()->setPlainText(text);
    d->resetRevisions();
    document()->setModified(false);
    return true;
}

bool TextDocument::reload(QString *errorString, ReloadFlag flag, ChangeType type)
{
    if (flag == FlagIgnore) {
        if (type != TypeContents)
            return true;

        const bool wasModified = document()->isModified();
        {
            Utils::GuardLocker locker(d->m_modificationChangedGuard);
            // hack to ensure we clean the clear state in QTextDocument
            document()->setModified(false);
            document()->setModified(true);
        }
        if (!wasModified)
            modificationChanged(true);
        return true;
    }
    if (type == TypePermissions) {
        checkPermissions();
        return true;
    } else {
        return reload(errorString);
    }
}

void TextDocument::setSyntaxHighlighter(SyntaxHighlighter *highlighter)
{
    if (d->m_highlighter)
        delete d->m_highlighter;
    d->m_highlighter = highlighter;
    d->m_highlighter->setParent(this);
    d->m_highlighter->setDocument(&d->m_document);
}

void TextDocument::cleanWhitespace(const QTextCursor &cursor)
{
    bool hasSelection = cursor.hasSelection();
    QTextCursor copyCursor = cursor;
    copyCursor.setVisualNavigation(false);
    copyCursor.beginEditBlock();
    cleanWhitespace(copyCursor, true, true);
    if (!hasSelection)
        ensureFinalNewLine(copyCursor);
    copyCursor.endEditBlock();
}

void TextDocument::cleanWhitespace(QTextCursor &cursor, bool cleanIndentation, bool inEntireDocument)
{
    TextDocumentLayout *documentLayout = qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
    Q_ASSERT(cursor.visualNavigation() == false);

    QTextBlock block = d->m_document.findBlock(cursor.selectionStart());
    QTextBlock end;
    if (cursor.hasSelection())
        end = d->m_document.findBlock(cursor.selectionEnd()-1).next();

    QVector<QTextBlock> blocks;
    while (block.isValid() && block != end) {
        if (inEntireDocument || block.revision() != documentLayout->lastSaveRevision)
            blocks.append(block);
        block = block.next();
    }
    if (blocks.isEmpty())
        return;

    const IndentationForBlock &indentations =
            d->m_indenter->indentationForBlocks(blocks, d->m_tabSettings);

    foreach (block, blocks) {
        QString blockText = block.text();
        d->m_tabSettings.removeTrailingWhitespace(cursor, block);
        const int indent = indentations[block.blockNumber()];
        if (cleanIndentation && !d->m_tabSettings.isIndentationClean(block, indent)) {
            cursor.setPosition(block.position());
            int firstNonSpace = d->m_tabSettings.firstNonSpace(blockText);
            if (firstNonSpace == blockText.length()) {
                cursor.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
                cursor.removeSelectedText();
            } else {
                int column = d->m_tabSettings.columnAt(blockText, firstNonSpace);
                cursor.movePosition(QTextCursor::NextCharacter, QTextCursor::KeepAnchor, firstNonSpace);
                QString indentationString = d->m_tabSettings.indentationString(0, column, column - indent, block);
                cursor.insertText(indentationString);
            }
        }
    }
}

void TextDocument::ensureFinalNewLine(QTextCursor& cursor)
{
    cursor.movePosition(QTextCursor::End, QTextCursor::MoveAnchor);
    bool emptyFile = !cursor.movePosition(QTextCursor::PreviousCharacter, QTextCursor::KeepAnchor);

    if (!emptyFile && cursor.selectedText().at(0) != QChar::ParagraphSeparator)
    {
        cursor.movePosition(QTextCursor::End, QTextCursor::MoveAnchor);
        cursor.insertText(QLatin1String("\n"));
    }
}

void TextDocument::modificationChanged(bool modified)
{
    if (d->m_modificationChangedGuard.isLocked())
        return;
    // we only want to update the block revisions when going back to the saved version,
    // e.g. with undo
    if (!modified)
        d->updateRevisions();
    emit changed();
}

void TextDocument::updateLayout() const
{
    auto documentLayout = qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
    QTC_ASSERT(documentLayout, return);
    documentLayout->requestUpdate();
}

TextMarks TextDocument::marks() const
{
    return d->m_marksCache;
}

bool TextDocument::addMark(TextMark *mark)
{
    if (mark->baseTextDocument())
        return false;
    QTC_ASSERT(mark->lineNumber() >= 1, return false);
    int blockNumber = mark->lineNumber() - 1;
    auto documentLayout = qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
    QTC_ASSERT(documentLayout, return false);
    QTextBlock block = d->m_document.findBlockByNumber(blockNumber);

    if (block.isValid()) {
        TextBlockUserData *userData = TextDocumentLayout::userData(block);
        userData->addMark(mark);
        d->m_marksCache.append(mark);
        mark->updateLineNumber(blockNumber + 1);
        QTC_CHECK(mark->lineNumber() == blockNumber + 1); // Checks that the base class is called
        mark->updateBlock(block);
        mark->setBaseTextDocument(this);
        if (!mark->isVisible())
            return true;
        // Update document layout
        double newMaxWidthFactor = qMax(mark->widthFactor(), documentLayout->maxMarkWidthFactor);
        bool fullUpdate =  newMaxWidthFactor > documentLayout->maxMarkWidthFactor || !documentLayout->hasMarks;
        documentLayout->hasMarks = true;
        documentLayout->maxMarkWidthFactor = newMaxWidthFactor;
        if (fullUpdate)
            documentLayout->requestUpdate();
        else
            documentLayout->requestExtraAreaUpdate();
        return true;
    }
    return false;
}

TextMarks TextDocument::marksAt(int line) const
{
    QTC_ASSERT(line >= 1, return TextMarks());
    int blockNumber = line - 1;
    QTextBlock block = d->m_document.findBlockByNumber(blockNumber);

    if (block.isValid()) {
        if (TextBlockUserData *userData = TextDocumentLayout::testUserData(block))
            return userData->marks();
    }
    return TextMarks();
}

void TextDocument::removeMarkFromMarksCache(TextMark *mark)
{
    auto documentLayout = qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
    QTC_ASSERT(documentLayout, return);
    d->m_marksCache.removeAll(mark);

    auto scheduleLayoutUpdate = [documentLayout](){
        // make sure all destructors that may directly or indirectly call this function are
        // completed before updating.
        QTimer::singleShot(0, documentLayout, &QPlainTextDocumentLayout::requestUpdate);
    };

    if (d->m_marksCache.isEmpty()) {
        documentLayout->hasMarks = false;
        documentLayout->maxMarkWidthFactor = 1.0;
        scheduleLayoutUpdate();
        return;
    }

    if (!mark->isVisible())
        return;

    if (documentLayout->maxMarkWidthFactor == 1.0
            || mark->widthFactor() == 1.0
            || mark->widthFactor() < documentLayout->maxMarkWidthFactor) {
        // No change in width possible
        documentLayout->requestExtraAreaUpdate();
    } else {
        double maxWidthFactor = 1.0;
        foreach (const TextMark *mark, marks()) {
            if (!mark->isVisible())
                continue;
            maxWidthFactor = qMax(mark->widthFactor(), maxWidthFactor);
            if (maxWidthFactor == documentLayout->maxMarkWidthFactor)
                break; // Still a mark with the maxMarkWidthFactor
        }

        if (maxWidthFactor != documentLayout->maxMarkWidthFactor) {
            documentLayout->maxMarkWidthFactor = maxWidthFactor;
            scheduleLayoutUpdate();
        } else {
            documentLayout->requestExtraAreaUpdate();
        }
    }
}

void TextDocument::removeMark(TextMark *mark)
{
    QTextBlock block = d->m_document.findBlockByNumber(mark->lineNumber() - 1);
    if (TextBlockUserData *data = static_cast<TextBlockUserData *>(block.userData())) {
        if (!data->removeMark(mark))
            qDebug() << "Could not find mark" << mark << "on line" << mark->lineNumber();
    }

    removeMarkFromMarksCache(mark);
    emit markRemoved(mark);
    mark->setBaseTextDocument(nullptr);
    updateLayout();
}

void TextDocument::updateMark(TextMark *mark)
{
    QTextBlock block = d->m_document.findBlockByNumber(mark->lineNumber() - 1);
    if (block.isValid()) {
        TextBlockUserData *userData = TextDocumentLayout::userData(block);
        // re-evaluate priority
        userData->removeMark(mark);
        userData->addMark(mark);
    }
    updateLayout();
}

void TextDocument::moveMark(TextMark *mark, int previousLine)
{
    QTextBlock block = d->m_document.findBlockByNumber(previousLine - 1);
    if (TextBlockUserData *data = TextDocumentLayout::testUserData(block)) {
        if (!data->removeMark(mark))
            qDebug() << "Could not find mark" << mark << "on line" << previousLine;
    }
    removeMarkFromMarksCache(mark);
    mark->setBaseTextDocument(nullptr);
    addMark(mark);
}

} // namespace TextEditor