LanguageClient: Add option to start server when needed

Until now all servers where startet on creator startup. Change this
default to start server when first file that matches the configured
filter is opened. Additionally add an option that restores the old
behavior of always on servers.

Change-Id: I595e0ede1cf136cc803181377155bcd58ca1a83c
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/languageclient/client.cpp

@@ -663,7 +663,7 @@ void Client::setSupportedLanguage(const LanguageFilter &filter)
 bool Client::isSupportedDocument(const Core::IDocument *document) const
 {
     QTC_ASSERT(document, return false);
-    return m_languagFilter.isSupported(document->filePath(), document->mimeType());
+    return m_languagFilter.isSupported(document);
 }
 
 bool Client::isSupportedFile(const Utils::FileName &filePath, const QString &mimeType) const
@@ -673,8 +673,8 @@ bool Client::isSupportedFile(const Utils::FileName &filePath, const QString &mim
 
 bool Client::isSupportedUri(const DocumentUri &uri) const
 {
-    return isSupportedFile(uri.toFileName(),
-                           Utils::mimeTypeForFile(uri.toFileName().fileName()).name());
+    return m_languagFilter.isSupported(uri.toFileName(),
+                                       Utils::mimeTypeForFile(uri.toFileName().fileName()).name());
 }
 
 bool Client::needsRestart(const BaseSettings *settings) const

src/plugins/languageclient/languageclientmanager.cpp

@@ -231,6 +231,10 @@ void LanguageClientManager::editorOpened(Core::IEditor *editor)
 
 void LanguageClientManager::documentOpened(Core::IDocument *document)
 {
+    for (StdIOSettings *setting : LanguageClientSettings::currentSettings()) {
+        if (setting->m_client.isNull() && setting->m_languageFilter.isSupported(document))
+            setting->startClient();
+    }
     for (Client *interface : reachableClients())
         interface->openDocument(document);
 }

src/plugins/languageclient/languageclientsettings.cpp

@@ -30,7 +30,9 @@
 #include "languageclient_global.h"
 #include "languageclientinterface.h"
 
+#include <coreplugin/editormanager/documentmodel.h>
 #include <coreplugin/icore.h>
+#include <coreplugin/idocument.h>
 #include <coreplugin/variablechooser.h>
 #include <utils/algorithm.h>
 #include <utils/delegates.h>
@@ -58,6 +60,7 @@
 
 constexpr char nameKey[] = "name";
 constexpr char enabledKey[] = "enabled";
+constexpr char alwaysOnKey[] = "alwaysOn";
 constexpr char mimeTypeKey[] = "mimeType";
 constexpr char filePatternKey[] = "filePattern";
 constexpr char executableKey[] = "executable";
@@ -271,11 +274,15 @@ void LanguageClientSettingsPage::apply()
         }
     }
     for (StdIOSettings *setting : restarts) {
-        if (setting && setting->isValid() && setting->m_enabled) {
-            if (auto client = setting->createClient()) {
-                setting->m_client = client;
-                LanguageClientManager::startClient(client);
-            }
+        if (setting->isValid() && setting->m_enabled) {
+            const bool start = setting->m_alwaysOn
+                               || Utils::anyOf(Core::DocumentModel::openedDocuments(),
+                                               [filter = setting->m_languageFilter](
+                                                   Core::IDocument *doc) {
+                                                   return filter.isSupported(doc);
+                                               });
+            if (start)
+                setting->startClient();
         }
     }
 
@@ -386,6 +393,7 @@ void BaseSettings::applyFromSettingsWidget(QWidget *widget)
     if (auto settingsWidget = qobject_cast<BaseSettingsWidget *>(widget)) {
         m_name = settingsWidget->name();
         m_languageFilter = settingsWidget->filter();
+        m_alwaysOn = settingsWidget->alwaysOn();
     }
 }
 
@@ -404,16 +412,17 @@ bool BaseSettings::isValid() const
     return !m_name.isEmpty();
 }
 
-Client *BaseSettings::createClient() const
+void BaseSettings::startClient()
 {
+    if (!isValid() || !m_enabled)
+        return;
     BaseClientInterface *interface = createInterface();
-    if (QTC_GUARD(interface)) {
-        auto *client = new Client(interface);
-        client->setName(Utils::globalMacroExpander()->expand(m_name));
-        client->setSupportedLanguage(m_languageFilter);
-        return client;
-    }
-    return nullptr;
+    QTC_ASSERT(interface, return);
+    auto *client = new Client(interface);
+    client->setName(Utils::globalMacroExpander()->expand(m_name));
+    client->setSupportedLanguage(m_languageFilter);
+    m_client = client;
+    LanguageClientManager::startClient(client);
 }
 
 QVariantMap BaseSettings::toMap() const
@@ -421,6 +430,7 @@ QVariantMap BaseSettings::toMap() const
     QVariantMap map;
     map.insert(nameKey, m_name);
     map.insert(enabledKey, m_enabled);
+    map.insert(alwaysOnKey, m_alwaysOn);
     map.insert(mimeTypeKey, m_languageFilter.mimeTypes);
     map.insert(filePatternKey, m_languageFilter.filePattern);
     return map;
@@ -430,6 +440,7 @@ void BaseSettings::fromMap(const QVariantMap &map)
 {
     m_name = map[nameKey].toString();
     m_enabled = map[enabledKey].toBool();
+    m_alwaysOn = map.value(alwaysOnKey, false).toBool();
     m_languageFilter.mimeTypes = map[mimeTypeKey].toStringList();
     m_languageFilter.filePattern = map[filePatternKey].toStringList();
 }
@@ -546,6 +557,7 @@ BaseSettingsWidget::BaseSettingsWidget(const BaseSettings *settings, QWidget *pa
     , m_name(new QLineEdit(settings->m_name, this))
     , m_mimeTypes(new QLabel(settings->m_languageFilter.mimeTypes.join(filterSeparator), this))
     , m_filePattern(new QLineEdit(settings->m_languageFilter.filePattern.join(filterSeparator), this))
+    , m_alwaysOn(new QCheckBox())
 {
     int row = 0;
     auto *mainLayout = new QGridLayout;
@@ -562,6 +574,9 @@ BaseSettingsWidget::BaseSettingsWidget(const BaseSettings *settings, QWidget *pa
     mainLayout->addLayout(mimeLayout, row, 1);
     m_filePattern->setPlaceholderText(tr("File pattern"));
     mainLayout->addWidget(m_filePattern, ++row, 1);
+    mainLayout->addWidget(new QLabel(tr("Always On:")), ++row, 0);
+    mainLayout->addWidget(m_alwaysOn, row, 1);
+    m_alwaysOn->setChecked(settings->m_alwaysOn);
 
     connect(addMimeTypeButton, &QPushButton::pressed,
             this, &BaseSettingsWidget::showAddMimeTypeDialog);
@@ -604,6 +619,11 @@ LanguageFilter BaseSettingsWidget::filter() const
                 m_filePattern->text().split(filterSeparator)};
 }
 
+bool BaseSettingsWidget::alwaysOn() const
+{
+    return m_alwaysOn->isChecked();
+}
+
 class MimeTypeModel : public QStringListModel
 {
 public:
@@ -741,4 +761,9 @@ bool LanguageFilter::isSupported(const Utils::FileName &filePath, const QString
     });
 }
 
+bool LanguageFilter::isSupported(const Core::IDocument *document) const
+{
+    return isSupported(document->filePath(), document->mimeType());
+}
+
 } // namespace LanguageClient

src/plugins/languageclient/languageclientsettings.h

@@ -42,6 +42,8 @@ class FileName;
 class PathChooser;
 } // namespace Utils
 
+namespace Core { class IDocument; }
+
 namespace LanguageClient {
 
 constexpr char noLanguageFilter[] = "No Filter";
@@ -54,6 +56,7 @@ struct LanguageFilter
     QStringList mimeTypes;
     QStringList filePattern;
     bool isSupported(const Utils::FileName &filePath, const QString &mimeType) const;
+    bool isSupported(const Core::IDocument *document) const;
 };
 
 class BaseSettings
@@ -65,6 +68,7 @@ public:
 
     QString m_name = QString("New Language Server");
     bool m_enabled = true;
+    bool m_alwaysOn = false;
     LanguageFilter m_languageFilter;
     QPointer<Client> m_client; // not owned
 
@@ -73,7 +77,7 @@ public:
     virtual BaseSettings *copy() const { return new BaseSettings(*this); }
     virtual bool needsRestart() const;
     virtual bool isValid() const ;
-    Client *createClient() const;
+    void startClient();
     virtual QVariantMap toMap() const;
     virtual void fromMap(const QVariantMap &map);
 
@@ -135,6 +139,7 @@ public:
 
     QString name() const;
     LanguageFilter filter() const;
+    bool alwaysOn() const;
 
 private:
     void showAddMimeTypeDialog();
@@ -142,6 +147,7 @@ private:
     QLineEdit *m_name = nullptr;
     QLabel *m_mimeTypes = nullptr;
     QLineEdit *m_filePattern = nullptr;
+    QCheckBox *m_alwaysOn = nullptr;
 
     static constexpr char filterSeparator = ';';
 };