LanguageClient: add lsp based auto formatter

Change-Id: I2a7347961b4633868aa3b033c351a1e709c3597e
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/languageclient/languageclientformatter.cpp

@@ -0,0 +1,146 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "languageclientformatter.h"
+
+#include "languageclientutils.h"
+
+#include <texteditor/tabsettings.h>
+#include <texteditor/textdocument.h>
+#include <utils/mimetypes/mimedatabase.h>
+
+#include <QTextDocument>
+
+using namespace LanguageServerProtocol;
+using namespace Utils;
+
+namespace LanguageClient {
+
+LanguageClientFormatter::LanguageClientFormatter(TextEditor::TextDocument *document, Client *client)
+    : m_client(client)
+    , m_document(document)
+{
+    m_cancelConnection = QObject::connect(document->document(),
+                                          &QTextDocument::contentsChanged,
+                                          [this]() {
+        if (m_ignoreCancel)
+            m_ignoreCancel = false;
+        else
+            cancelCurrentRequest();
+    });
+}
+
+LanguageClientFormatter::~LanguageClientFormatter()
+{
+    QObject::disconnect(m_cancelConnection);
+    cancelCurrentRequest();
+}
+
+static const FormattingOptions formattingOptions(const TextEditor::TabSettings &settings)
+{
+    FormattingOptions options;
+    options.setTabSize(settings.m_tabSize);
+    options.setInsertSpace(settings.m_tabPolicy == TextEditor::TabSettings::SpacesOnlyTabPolicy);
+    return options;
+}
+
+QFutureWatcher<Utils::Text::Replacements> *LanguageClientFormatter::format(
+        const QTextCursor &cursor, const TextEditor::TabSettings &tabSettings)
+{
+    cancelCurrentRequest();
+    m_progress = QFutureInterface<Utils::Text::Replacements>();
+
+    const FilePath &filePath = m_document->filePath();
+    const DynamicCapabilities dynamicCapabilities = m_client->dynamicCapabilities();
+    const QString method(DocumentRangeFormattingRequest::methodName);
+    if (Utils::optional<bool> registered = dynamicCapabilities.isRegistered(method)) {
+        if (!registered.value())
+            return nullptr;
+        const TextDocumentRegistrationOptions option(dynamicCapabilities.option(method).toObject());
+        if (option.isValid(nullptr)
+                && !option.filterApplies(filePath, Utils::mimeTypeForName(m_document->mimeType()))) {
+            return nullptr;
+        }
+    } else if (!m_client->capabilities().documentRangeFormattingProvider().value_or(false)) {
+        return nullptr;
+    }
+    DocumentRangeFormattingParams params;
+    const DocumentUri uri = DocumentUri::fromFilePath(filePath);
+    params.setTextDocument(uri);
+    params.setOptions(formattingOptions(tabSettings));
+    if (!cursor.hasSelection()) {
+        QTextCursor c = cursor;
+        c.select(QTextCursor::LineUnderCursor);
+        params.setRange(Range(c));
+    } else {
+        params.setRange(Range(cursor));
+    }
+    DocumentRangeFormattingRequest request(params);
+    request.setResponseCallback([this](const DocumentRangeFormattingRequest::Response &response) {
+        handleResponse(response);
+    });
+    m_currentRequest = request.id();
+    m_client->sendContent(request);
+    // ignore first contents changed, because this function is called inside a begin/endEdit block
+    m_ignoreCancel = true;
+    m_progress.reportStarted();
+    auto watcher = new QFutureWatcher<Text::Replacements>();
+    watcher->setFuture(m_progress.future());
+    QObject::connect(watcher, &QFutureWatcher<Text::Replacements>::canceled, [this]() {
+        cancelCurrentRequest();
+    });
+    return watcher;
+}
+
+void LanguageClientFormatter::cancelCurrentRequest()
+{
+    if (m_currentRequest.has_value()) {
+        m_progress.reportCanceled();
+        m_progress.reportFinished();
+        m_client->cancelRequest(*m_currentRequest);
+        m_ignoreCancel = false;
+        m_currentRequest = nullopt;
+    }
+}
+
+void LanguageClientFormatter::handleResponse(const DocumentRangeFormattingRequest::Response &response)
+{
+    m_currentRequest = nullopt;
+    if (const optional<DocumentRangeFormattingRequest::Response::Error> &error = response.error())
+        m_client->log(*error);
+    Text::Replacements replacements;
+    if (optional<LanguageClientArray<TextEdit>> result = response.result()) {
+        if (!result->isNull()) {
+            const QList<TextEdit> results = result->toList();
+            replacements.reserve(results.size());
+            for (const TextEdit &edit : results)
+                replacements.emplace_back(edit.toReplacement(m_document->document()));
+        }
+    }
+    m_progress.reportResult(replacements);
+    m_progress.reportFinished();
+}
+
+} // namespace LanguageClient