qmljs: add option to disable builtin codemodel

Add an option in the QML Language Server settings to disable the code
model, for now it allows to use qmlls for renaming and find usages
operations.
Some of the checkboxes in the qmlls settings were not making a lot of
sense, rephrased them to be easier to understand for the user.

TODOs for later commits:
* use qmlls for 'go to definition' aka 'follow symbol under cursor'
* add extra action to the context menu for 'go to type definition' and
  implement it using the language client
  * also, remove builtin codemode stuff from the context menu when the
    builtin model is disabled

Task-number: QTCREATORBUG-29567
Change-Id: I6283d99bd2b5dc8aef7df49994eb313bfbb854c6
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

src/plugins/qmljseditor/qmljseditingsettingspage.cpp

@@ -33,6 +33,7 @@ const char QML_CONTEXTPANEPIN_KEY[] = "QmlJSEditor.ContextPanePinned";
 const char FOLD_AUX_DATA[] = "QmlJSEditor.FoldAuxData";
 const char USE_QMLLS[] = "QmlJSEditor.UseQmlls";
 const char USE_LATEST_QMLLS[] = "QmlJSEditor.UseLatestQmlls";
+const char DISABLE_BUILTIN_CODEMODEL[] = "QmlJSEditor.DisableBuiltinCodemodel";
 const char UIQML_OPEN_MODE[] = "QmlJSEditor.openUiQmlMode";
 const char FORMAT_COMMAND[] = "QmlJSEditor.formatCommand";
 const char FORMAT_COMMAND_OPTIONS[] = "QmlJSEditor.formatCommandOptions";
@@ -101,6 +102,8 @@ void QmlJsEditingSettings::fromSettings(QSettings *settings)
     m_uiQmlOpenMode = settings->value(UIQML_OPEN_MODE, "").toString();
     m_qmllsSettings.useQmlls = settings->value(USE_QMLLS, QVariant(false)).toBool();
     m_qmllsSettings.useLatestQmlls = settings->value(USE_LATEST_QMLLS, QVariant(false)).toBool();
+    m_qmllsSettings.disableBuiltinCodemodel
+        = settings->value(DISABLE_BUILTIN_CODEMODEL, QVariant(false)).toBool();
     m_formatCommand = settings->value(FORMAT_COMMAND, {}).toString();
     m_formatCommandOptions = settings->value(FORMAT_COMMAND_OPTIONS, {}).toString();
     m_useCustomFormatCommand = settings->value(CUSTOM_COMMAND, QVariant(false)).toBool();
@@ -128,6 +131,7 @@ void QmlJsEditingSettings::toSettings(QSettings *settings) const
     settings->setValue(UIQML_OPEN_MODE, m_uiQmlOpenMode);
     settings->setValue(USE_QMLLS, m_qmllsSettings.useQmlls);
     settings->setValue(USE_LATEST_QMLLS, m_qmllsSettings.useLatestQmlls);
+    settings->setValue(DISABLE_BUILTIN_CODEMODEL, m_qmllsSettings.disableBuiltinCodemodel);
     Utils::QtcSettings::setValueWithDefault(settings, FORMAT_COMMAND, m_formatCommand, {});
     Utils::QtcSettings::setValueWithDefault(settings,
                                             FORMAT_COMMAND_OPTIONS,
@@ -396,13 +400,19 @@ public:
         uiQmlOpenComboBox->setSizePolicy(QSizePolicy::Maximum, QSizePolicy::Preferred);
         uiQmlOpenComboBox->setSizeAdjustPolicy(QComboBox::QComboBox::AdjustToContents);
 
-        useQmlls = new QCheckBox(Tr::tr("Use qmlls (EXPERIMENTAL!)"));
+        useQmlls = new QCheckBox(Tr::tr("Enable QML Language Server (EXPERIMENTAL!)"));
         useQmlls->setChecked(s.qmllsSettings().useQmlls);
-        useLatestQmlls = new QCheckBox(Tr::tr("Always use latest qmlls"));
+        disableBuiltInCodemodel = new QCheckBox(
+            Tr::tr("Use QML Language Server advanced features (renaming, find usages and co.) "
+                   "(EXPERIMENTAL!)"));
+        disableBuiltInCodemodel->setChecked(s.qmllsSettings().disableBuiltinCodemodel);
+        disableBuiltInCodemodel->setEnabled(s.qmllsSettings().useQmlls);
+        useLatestQmlls = new QCheckBox(Tr::tr("Use QML Language Server from latest Qt version"));
         useLatestQmlls->setChecked(s.qmllsSettings().useLatestQmlls);
         useLatestQmlls->setEnabled(s.qmllsSettings().useQmlls);
         QObject::connect(useQmlls, &QCheckBox::stateChanged, this, [this](int checked) {
             useLatestQmlls->setEnabled(checked != Qt::Unchecked);
+            disableBuiltInCodemodel->setEnabled(checked != Qt::Unchecked);
         });
 
         useCustomAnalyzer = new QCheckBox(Tr::tr("Use customized static analyzer"));
@@ -454,8 +464,8 @@ public:
                 },
             },
             Group{
-                title(Tr::tr("Language Server")),
-                Column{useQmlls, useLatestQmlls},
+                title(Tr::tr("QML Language Server")),
+                Column{useQmlls, disableBuiltInCodemodel , useLatestQmlls},
             },
             Group {
                 title(Tr::tr("Static Analyzer")),
@@ -499,6 +509,7 @@ public:
         s.setFoldAuxData(foldAuxData->isChecked());
         s.setUiQmlOpenMode(uiQmlOpenComboBox->currentData().toString());
         s.qmllsSettings().useQmlls = useQmlls->isChecked();
+        s.qmllsSettings().disableBuiltinCodemodel = disableBuiltInCodemodel->isChecked();
         s.qmllsSettings().useLatestQmlls = useLatestQmlls->isChecked();
         s.setUseCustomAnalyzer(useCustomAnalyzer->isChecked());
         QSet<int> disabled;
@@ -557,6 +568,7 @@ private:
     QCheckBox *foldAuxData;
     QCheckBox *useQmlls;
     QCheckBox *useLatestQmlls;
+    QCheckBox *disableBuiltInCodemodel;
     QComboBox *uiQmlOpenComboBox;
     QCheckBox *useCustomAnalyzer;
     QTreeView *analyzerMessagesView;

src/plugins/qmljseditor/qmljseditor.cpp

@@ -60,6 +60,10 @@
 #include <utils/qtcassert.h>
 #include <utils/uncommentselection.h>
 
+#include <languageclient/languageclientmanager.h>
+#include <languageclient/locatorfilter.h>
+#include <languageclient/languageclientsymbolsupport.h>
+
 #include <QComboBox>
 #include <QCoreApplication>
 #include <QFileInfo>
@@ -855,14 +859,39 @@ void QmlJSEditorWidget::findLinkAt(const QTextCursor &cursor,
     processLinkCallback(Utils::Link());
 }
 
+static LanguageClient::Client *getQmllsClient(const Utils::FilePath &fileName)
+{
+    // the value in disableBuiltinCodemodel is only valid when useQmlls is enabled
+    if (QmlJsEditingSettings::get().qmllsSettings().useQmlls
+        && !QmlJsEditingSettings::get().qmllsSettings().disableBuiltinCodemodel)
+        return nullptr;
+
+    auto client = LanguageClient::LanguageClientManager::clientForFilePath(fileName);
+    return client;
+}
+
 void QmlJSEditorWidget::findUsages()
 {
-    m_findReferences->findUsages(textDocument()->filePath(), textCursor().position());
+    const Utils::FilePath fileName = textDocument()->filePath();
+
+    if (auto client = getQmllsClient(fileName)) {
+        client->symbolSupport().findUsages(textDocument(), textCursor());
+    } else {
+        const int offset = textCursor().position();
+        m_findReferences->findUsages(fileName, offset);
+    }
 }
 
 void QmlJSEditorWidget::renameSymbolUnderCursor()
 {
-    m_findReferences->renameUsages(textDocument()->filePath(), textCursor().position());
+    const Utils::FilePath fileName = textDocument()->filePath();
+
+    if (auto client = getQmllsClient(fileName)) {
+        client->symbolSupport().renameSymbol(textDocument(), textCursor(), QString());
+    } else {
+        const int offset = textCursor().position();
+        m_findReferences->renameUsages(fileName, offset);
+    }
 }
 
 void QmlJSEditorWidget::showContextPane()

src/plugins/qmljseditor/qmllssettings.h

@@ -15,10 +15,12 @@ struct QmllsSettings
 {
     bool useQmlls = true;
     bool useLatestQmlls = false;
+    bool disableBuiltinCodemodel = false;
 
     friend bool operator==(const QmllsSettings &s1, const QmllsSettings &s2)
     {
-        return s1.useQmlls == s2.useQmlls && s1.useLatestQmlls == s2.useLatestQmlls;
+        return s1.useQmlls == s2.useQmlls && s1.useLatestQmlls == s2.useLatestQmlls
+               && s1.disableBuiltinCodemodel == s2.disableBuiltinCodemodel;
     }
     friend bool operator!=(const QmllsSettings &s1, const QmllsSettings &s2) { return !(s1 == s2); }
 };