LanguageClient: add hover handler

Change-Id: Iddf30828ef26a157ab935d0abe708087ab123dd6
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

7 files changed, 233 insertions, 0 deletions

diff --git a/src/plugins/languageclient/client.cpp b/src/plugins/languageclient/client.cpp
index 52f63cc07b..b6eecb4fdb 100644
--- a/src/plugins/languageclient/client.cpp
+++ b/src/plugins/languageclient/client.cpp
@@ -96,6 +96,7 @@ Client::Client(BaseClientInterface *clientInterface)
     , m_quickFixProvider(this)
     , m_clientInterface(clientInterface)
     , m_documentSymbolCache(this)
+    , m_hoverHandler(this)
 {
     m_contentHandler.insert(JsonRpcMessageHandler::jsonRpcMimeType(),
                             &JsonRpcMessageHandler::parseContent);
@@ -129,6 +130,7 @@ Client::~Client()
         if (auto textEditor = qobject_cast<BaseTextEditor *>(editor)) {
             TextEditorWidget *widget = textEditor->editorWidget();
             widget->setRefactorMarkers(RefactorMarker::filterOutType(widget->refactorMarkers(), id()));
+            widget->removeHoverHandler(&m_hoverHandler);
         }
     }
     for (const DocumentUri &uri : m_diagnostics.keys())
@@ -204,6 +206,12 @@ static ClientCapabilities generateClientCapabilities()
             CodeActionKind(QList<QString>{"*"}));
     codeActionCapabilities.setCodeActionLiteralSupport(literalSupport);
     documentCapabilities.setCodeAction(codeActionCapabilities);
+
+    TextDocumentClientCapabilities::HoverCapabilities hover;
+    hover.setContentFormat({MarkupKind::plaintext});
+    hover.setDynamicRegistration(true);
+    documentCapabilities.setHover(hover);
+
     documentCapabilities.setReferences(allowDynamicRegistration);
     documentCapabilities.setDocumentHighlight(allowDynamicRegistration);
     documentCapabilities.setDefinition(allowDynamicRegistration);
@@ -915,6 +923,11 @@ DocumentSymbolCache *Client::documentSymbolCache()
     return &m_documentSymbolCache;
 }
 
+HoverHandler *Client::hoverHandler()
+{
+    return &m_hoverHandler;
+}
+
 void Client::log(const ShowMessageParams &message,
                      Core::MessageManager::PrintToOutputPaneFlag flag)
 {
@@ -1113,6 +1126,10 @@ void Client::intializeCallback(const InitializeRequest::Response &initResponse)
                 updateEditorToolBar(editor);
         }
     }
+    for (Core::IEditor *editor : Core::DocumentModel::editorsForOpenedDocuments()) {
+        if (auto textEditor = qobject_cast<TextEditor::BaseTextEditor *>(editor))
+            textEditor->editorWidget()->addHoverHandler(&m_hoverHandler);
+    }
     emit initialized(m_serverCapabilities);
 }
 
diff --git a/src/plugins/languageclient/client.h b/src/plugins/languageclient/client.h
index bd679ead93..81bb101d14 100644
--- a/src/plugins/languageclient/client.h
+++ b/src/plugins/languageclient/client.h
@@ -30,6 +30,7 @@
 #include "languageclientcompletionassist.h"
 #include "languageclientquickfix.h"
 #include "languageclientsettings.h"
+#include "languageclienthoverhandler.h"
 
 #include <coreplugin/id.h>
 #include <coreplugin/messagemanager.h>
@@ -155,6 +156,7 @@ public:
     const DynamicCapabilities &dynamicCapabilities() const;
     const BaseClientInterface *clientInterface() const;
     DocumentSymbolCache *documentSymbolCache();
+    HoverHandler *hoverHandler();
 
 signals:
     void initialized(LanguageServerProtocol::ServerCapabilities capabilities);
@@ -205,6 +207,7 @@ private:
     QScopedPointer<BaseClientInterface> m_clientInterface;
     QMap<LanguageServerProtocol::DocumentUri, QList<TextMark *>> m_diagnostics;
     DocumentSymbolCache m_documentSymbolCache;
+    HoverHandler m_hoverHandler;
     const ProjectExplorer::Project *m_project = nullptr;
 };
 
diff --git a/src/plugins/languageclient/languageclient.pro b/src/plugins/languageclient/languageclient.pro
index 7ff9bf3574..e3bfd5870a 100644
--- a/src/plugins/languageclient/languageclient.pro
+++ b/src/plugins/languageclient/languageclient.pro
@@ -8,6 +8,7 @@ HEADERS += \
     dynamiccapabilities.h \
     languageclient_global.h \
     languageclientcompletionassist.h \
+    languageclienthoverhandler.h \
     languageclientinterface.h \
     languageclientmanager.h \
     languageclientoutline.h \
@@ -23,6 +24,7 @@ SOURCES += \
     documentsymbolcache.cpp \
     dynamiccapabilities.cpp \
     languageclientcompletionassist.cpp \
+    languageclienthoverhandler.cpp \
     languageclientinterface.cpp \
     languageclientmanager.cpp \
     languageclientoutline.cpp \
diff --git a/src/plugins/languageclient/languageclient.qbs b/src/plugins/languageclient/languageclient.qbs
index b743675c09..13cba8201b 100644
--- a/src/plugins/languageclient/languageclient.qbs
+++ b/src/plugins/languageclient/languageclient.qbs
@@ -22,6 +22,8 @@ QtcPlugin {
         "dynamiccapabilities.h",
         "languageclient.qrc",
         "languageclient_global.h",
+        "languageclienthoverhandler.cpp",
+        "languageclienthoverhandler.h",
         "languageclientinterface.cpp",
         "languageclientinterface.h",
         "languageclientcompletionassist.cpp",
diff --git a/src/plugins/languageclient/languageclienthoverhandler.cpp b/src/plugins/languageclient/languageclienthoverhandler.cpp
new file mode 100644
index 0000000000..166fdc3049
--- /dev/null
+++ b/src/plugins/languageclient/languageclienthoverhandler.cpp
@@ -0,0 +1,148 @@
+/****************************************************************************
+**
+** 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 "languageclienthoverhandler.h"
+
+#include "client.h"
+
+#include <texteditor/textdocument.h>
+#include <texteditor/texteditor.h>
+#include <utils/mimetypes/mimedatabase.h>
+#include <utils/qtcassert.h>
+#include <utils/tooltip/tooltip.h>
+
+using namespace LanguageServerProtocol;
+
+namespace LanguageClient {
+
+HoverHandler::HoverHandler(Client *client)
+    : m_client(client)
+{}
+
+HoverHandler::~HoverHandler()
+{
+    abort();
+}
+
+void HoverHandler::abort()
+{
+    if (m_client && m_client->reachable() && m_currentRequest.has_value())
+        m_client->cancelRequest(*m_currentRequest);
+    m_currentRequest.reset();
+}
+
+void HoverHandler::identifyMatch(TextEditor::TextEditorWidget *editorWidget,
+                                 int pos,
+                                 TextEditor::BaseHoverHandler::ReportPriority report)
+{
+    if (m_currentRequest.has_value())
+        abort();
+    if (m_client.isNull()
+        || !m_client->documentOpen(editorWidget->textDocument())
+        || !m_client->capabilities().hoverProvider().value_or(false)) {
+        report(Priority_None);
+        return;
+    }
+
+    bool sendMessage = m_client->capabilities().hoverProvider().value_or(false);
+    if (Utils::optional<bool> registered = m_client->dynamicCapabilities().isRegistered(
+            HoverRequest::methodName)) {
+        sendMessage = registered.value();
+        if (sendMessage) {
+            const TextDocumentRegistrationOptions option(
+                m_client->dynamicCapabilities().option(HoverRequest::methodName).toObject());
+            if (option.isValid(nullptr)) {
+                sendMessage = option.filterApplies(editorWidget->textDocument()->filePath(),
+                                                   Utils::mimeTypeForName(
+                                                       editorWidget->textDocument()->mimeType()));
+            }
+        }
+    }
+    if (!sendMessage) {
+        report(Priority_None);
+        return;
+    }
+
+    m_report = report;
+    auto uri = DocumentUri::fromFileName(editorWidget->textDocument()->filePath());
+    QTextCursor cursor = editorWidget->textCursor();
+    cursor.setPosition(pos);
+    TextDocumentPositionParams params(uri, Position(cursor));
+    HoverRequest request(params);
+    request.setResponseCallback(
+        [this](const HoverRequest::Response &response) { handleResponse(response); });
+    m_client->sendContent(request);
+}
+
+void HoverHandler::operateTooltip(TextEditor::TextEditorWidget *editorWidget, const QPoint &point)
+{
+    if (toolTip().isEmpty())
+        Utils::ToolTip::hide();
+    else
+        Utils::ToolTip::show(point, toolTip(), editorWidget);
+}
+
+void HoverHandler::handleResponse(const HoverRequest::Response &response)
+{
+    m_currentRequest.reset();
+    if (Utils::optional<HoverRequest::Response::Error> error = response.error()) {
+        if (m_client)
+            m_client->log(error.value());
+    }
+    if (Utils::optional<Hover> result = response.result())
+        setContent(result.value().content());
+    m_report(priority());
+}
+
+static QString toolTipForMarkedStrings(const QList<MarkedString> &markedStrings)
+{
+    QString tooltip;
+    for (const MarkedString &markedString : markedStrings) {
+        if (!tooltip.isEmpty())
+            tooltip += '\n';
+        if (auto string = Utils::get_if<QString>(&markedString))
+            tooltip += *string;
+        else if (auto string = Utils::get_if<MarkedLanguageString>(&markedString))
+            tooltip += string->value() + " [" + string->language() + ']';
+    }
+    return tooltip;
+}
+
+void HoverHandler::setContent(const HoverContent &hoverContent)
+{
+    if (auto markupContent = Utils::get_if<MarkupContent>(&hoverContent)) {
+        const QString &content = markupContent->content();
+        if (markupContent->kind() == MarkupKind::plaintext)
+            setToolTip(content);
+        else if (m_client)
+            m_client->log(tr("Got unsupported markup hover content: ") + content);
+    } else if (auto markedString = Utils::get_if<MarkedString>(&hoverContent)) {
+        setToolTip(toolTipForMarkedStrings({*markedString}));
+    } else if (auto markedStrings = Utils::get_if<QList<MarkedString>>(&hoverContent)) {
+        setToolTip(toolTipForMarkedStrings(*markedStrings));
+    }
+}
+
+} // namespace LanguageClient
diff --git a/src/plugins/languageclient/languageclienthoverhandler.h b/src/plugins/languageclient/languageclienthoverhandler.h
new file mode 100644
index 0000000000..88a439e211
--- /dev/null
+++ b/src/plugins/languageclient/languageclienthoverhandler.h
@@ -0,0 +1,59 @@
+/****************************************************************************
+**
+** 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.
+**
+****************************************************************************/
+
+#pragma once
+
+#include <languageserverprotocol/languagefeatures.h>
+#include <texteditor/basehoverhandler.h>
+
+namespace LanguageClient {
+
+class Client;
+
+class HoverHandler : public TextEditor::BaseHoverHandler
+{
+    Q_DECLARE_TR_FUNCTIONS(HoverHandler)
+public:
+    explicit HoverHandler(Client *client);
+    ~HoverHandler() override;
+
+    void abort() override;
+
+protected:
+    void identifyMatch(TextEditor::TextEditorWidget *editorWidget,
+                       int pos,
+                       ReportPriority report) override;
+    void operateTooltip(TextEditor::TextEditorWidget *editorWidget, const QPoint &point) override;
+
+private:
+    void handleResponse(const LanguageServerProtocol::HoverRequest::Response &response);
+    void setContent(const LanguageServerProtocol::HoverContent &content);
+
+    QPointer<Client> m_client;
+    Utils::optional<LanguageServerProtocol::MessageId> m_currentRequest;
+    TextEditor::BaseHoverHandler::ReportPriority m_report;
+};
+
+} // namespace LanguageClient
diff --git a/src/plugins/languageclient/languageclientmanager.cpp b/src/plugins/languageclient/languageclientmanager.cpp
index 45b91674fe..b519c13fef 100644
--- a/src/plugins/languageclient/languageclientmanager.cpp
+++ b/src/plugins/languageclient/languageclientmanager.cpp
@@ -362,6 +362,8 @@ void LanguageClientManager::editorOpened(Core::IEditor *editor)
                         });
                     });
             updateEditorToolBar(editor);
+            for (auto client : reachableClients())
+                widget->addHoverHandler(client->hoverHandler());
         }
     }
 }