LanguageClient: move completion rerequest logic

...from the code assistant to the language client specific assist
implementation. This further reduces the complexity of the code
assistant.

Change-Id: I08ba5eecea826d3ccfe7f1f5a8791a085299d6ef
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>

10 files changed, 62 insertions, 114 deletions

diff --git a/src/plugins/texteditor/codeassist/codeassistant.cpp b/src/plugins/texteditor/codeassist/codeassistant.cpp
index 8f583e4d38..db5553b03f 100644
--- a/src/plugins/texteditor/codeassist/codeassistant.cpp
+++ b/src/plugins/texteditor/codeassist/codeassistant.cpp
@@ -77,12 +77,10 @@ private:
 private:
     CodeAssistant *q = nullptr;
     TextEditorWidget *m_editorWidget = nullptr;
-    QMetaObject::Connection m_runnerConnection;
     IAssistProvider *m_requestProvider = nullptr;
     IAssistProcessor *m_processor = nullptr;
     AssistKind m_assistKind = TextEditor::Completion;
     IAssistProposalWidget *m_proposalWidget = nullptr;
-    QScopedPointer<IAssistProposal> m_proposal;
     bool m_receivedContentWhileWaiting = false;
     QTimer m_automaticProposalTimer;
     CompletionSettings m_settings;
@@ -117,12 +115,11 @@ void CodeAssistantPrivate::invoke(AssistKind kind, IAssistProvider *provider)
 {
     stopAutomaticProposalTimer();
 
-    if (isDisplayingProposal() && m_assistKind == kind && !m_proposal->isFragile()
-        && m_proposal->supportsPrefixFiltering(proposalPrefix())) {
+    if (isDisplayingProposal() && m_assistKind == kind && !m_proposalWidget->isFragile()) {
         m_proposalWidget->setReason(ExplicitlyInvoked);
-        m_proposalWidget->updateProposal(m_editorWidget->textAt(
-                        m_proposal->basePosition(),
-                        m_editorWidget->position() - m_proposal->basePosition()));
+        m_proposalWidget->filterProposal(m_editorWidget->textAt(
+                        m_proposalWidget->basePosition(),
+                        m_editorWidget->position() - m_proposalWidget->basePosition()));
     } else {
         requestProposal(ExplicitlyInvoked, kind, provider);
     }
@@ -239,14 +236,12 @@ void CodeAssistantPrivate::displayProposal(IAssistProposal *newProposal, AssistR
         return;
 
     // TODO: The proposal should own the model until someone takes it explicitly away.
-    QScopedPointer<IAssistProposal> proposalCandidate(newProposal);
+    QScopedPointer<IAssistProposal> deleter(newProposal);
 
-    if (isDisplayingProposal() && !m_proposal->isFragile()
-        && !m_proposalWidget->supportsModelUpdate(proposalCandidate->id())) {
+    if (isDisplayingProposal() && !m_proposalWidget->isFragile())
         return;
-    }
 
-    int basePosition = proposalCandidate->basePosition();
+    int basePosition = newProposal->basePosition();
     if (m_editorWidget->position() < basePosition) {
         destroyContext();
         return;
@@ -266,28 +261,16 @@ void CodeAssistantPrivate::displayProposal(IAssistProposal *newProposal, AssistR
         return;
     }
 
-    if (m_proposalWidget
-        && basePosition == proposalCandidate->basePosition()
-        && m_proposalWidget->supportsModelUpdate(proposalCandidate->id())) {
-        m_proposal.reset(proposalCandidate.take());
-        m_proposal->setReason(reason);
-        m_proposalWidget->updateModel(m_proposal->model());
-        m_proposalWidget->updateProposal(prefix);
-        return;
-    }
-
     destroyContext();
 
     clearAbortedPosition();
-    m_proposal.reset(proposalCandidate.take());
-    m_proposal->setReason(reason);
 
-    if (m_proposal->isCorrective(m_editorWidget))
-        m_proposal->makeCorrection(m_editorWidget);
+    if (newProposal->isCorrective(m_editorWidget))
+        newProposal->makeCorrection(m_editorWidget);
 
     m_editorWidget->keepAutoCompletionHighlight(true);
-    basePosition = m_proposal->basePosition();
-    m_proposalWidget = m_proposal->createWidget();
+    basePosition = newProposal->basePosition();
+    m_proposalWidget = newProposal->createWidget();
     connect(m_proposalWidget, &QObject::destroyed,
             this, &CodeAssistantPrivate::finalizeProposal);
     connect(m_proposalWidget, &IAssistProposalWidget::prefixExpanded,
@@ -301,7 +284,7 @@ void CodeAssistantPrivate::displayProposal(IAssistProposal *newProposal, AssistR
     m_proposalWidget->setKind(m_assistKind);
     m_proposalWidget->setBasePosition(basePosition);
     m_proposalWidget->setUnderlyingWidget(m_editorWidget);
-    m_proposalWidget->setModel(m_proposal->model());
+    m_proposalWidget->setModel(newProposal->model());
     m_proposalWidget->setDisplayRect(m_editorWidget->cursorRect(basePosition));
     m_proposalWidget->setIsSynchronized(!m_receivedContentWhileWaiting);
     m_proposalWidget->showProposal(prefix);
@@ -309,9 +292,9 @@ void CodeAssistantPrivate::displayProposal(IAssistProposal *newProposal, AssistR
 
 void CodeAssistantPrivate::processProposalItem(AssistProposalItemInterface *proposalItem)
 {
-    QTC_ASSERT(m_proposal, return);
+    QTC_ASSERT(m_proposalWidget, return);
     TextDocumentManipulator manipulator(m_editorWidget);
-    proposalItem->apply(manipulator, m_proposal->basePosition());
+    proposalItem->apply(manipulator, m_proposalWidget->basePosition());
     destroyContext();
     m_editorWidget->encourageApply();
     if (!proposalItem->isSnippet())
@@ -320,34 +303,33 @@ void CodeAssistantPrivate::processProposalItem(AssistProposalItemInterface *prop
 
 void CodeAssistantPrivate::handlePrefixExpansion(const QString &newPrefix)
 {
-    QTC_ASSERT(m_proposal, return);
+    QTC_ASSERT(m_proposalWidget, return);
 
     QTextCursor cursor(m_editorWidget->document());
-    cursor.setPosition(m_proposal->basePosition());
+    cursor.setPosition(m_proposalWidget->basePosition());
     cursor.movePosition(QTextCursor::EndOfWord);
 
     int currentPosition = m_editorWidget->position();
     const QString textAfterCursor = m_editorWidget->textAt(currentPosition,
                                                        cursor.position() - currentPosition);
     if (!textAfterCursor.startsWith(newPrefix)) {
-        if (newPrefix.indexOf(textAfterCursor, currentPosition - m_proposal->basePosition()) >= 0)
+        if (newPrefix.indexOf(textAfterCursor, currentPosition - m_proposalWidget->basePosition()) >= 0)
             currentPosition = cursor.position();
         const QStringView prefixAddition = QStringView(newPrefix).mid(currentPosition
-                                                                      - m_proposal->basePosition());
+                                                                      - m_proposalWidget->basePosition());
         // If remaining string starts with the prefix addition
         if (textAfterCursor.startsWith(prefixAddition))
             currentPosition += prefixAddition.size();
     }
 
-    m_editorWidget->setCursorPosition(m_proposal->basePosition());
-    m_editorWidget->replace(currentPosition - m_proposal->basePosition(), newPrefix);
+    m_editorWidget->setCursorPosition(m_proposalWidget->basePosition());
+    m_editorWidget->replace(currentPosition - m_proposalWidget->basePosition(), newPrefix);
     notifyChange();
 }
 
 void CodeAssistantPrivate::finalizeProposal()
 {
     stopAutomaticProposalTimer();
-    m_proposal.reset();
     m_proposalWidget = nullptr;
     if (m_receivedContentWhileWaiting)
         m_receivedContentWhileWaiting = false;
@@ -367,8 +349,8 @@ QString CodeAssistantPrivate::proposalPrefix() const
 {
     if (!isDisplayingProposal())
         return {};
-    return m_editorWidget->textAt(m_proposal->basePosition(),
-                                  m_editorWidget->position() - m_proposal->basePosition());
+    return m_editorWidget->textAt(m_proposalWidget->basePosition(),
+                                  m_editorWidget->position() - m_proposalWidget->basePosition());
 }
 
 void CodeAssistantPrivate::invalidateCurrentRequestData()
@@ -409,18 +391,14 @@ void CodeAssistantPrivate::notifyChange()
     stopAutomaticProposalTimer();
 
     if (isDisplayingProposal()) {
-        QTC_ASSERT(m_proposal, return);
-        if (m_editorWidget->position() < m_proposal->basePosition()) {
+        QTC_ASSERT(m_proposalWidget, return);
+        if (m_editorWidget->position() < m_proposalWidget->basePosition()) {
             destroyContext();
         } else {
-            const QString prefix = proposalPrefix();
-            if (m_proposal->supportsPrefixFiltering(prefix)) {
-                m_proposalWidget->updateProposal(prefix);
-                if (!isDisplayingProposal())
-                    requestActivationCharProposal();
-            } else {
-                requestProposal(m_proposal->reason(), m_assistKind, m_requestProvider, true);
-            }
+            m_proposalWidget->updateProposal(
+                m_editorWidget->createAssistInterface(m_assistKind, m_proposalWidget->reason()));
+            if (!isDisplayingProposal())
+                requestActivationCharProposal();
         }
     }
 }
@@ -466,7 +444,7 @@ void CodeAssistantPrivate::automaticProposalTimeout()
 {
     if (isWaitingForProposal()
         || m_editorWidget->multiTextCursor().hasMultipleCursors()
-        || (isDisplayingProposal() && !m_proposal->isFragile())) {
+        || (isDisplayingProposal() && !m_proposalWidget->isFragile())) {
         return;
     }
 
@@ -488,8 +466,8 @@ void CodeAssistantPrivate::updateFromCompletionSettings(
 
 void CodeAssistantPrivate::explicitlyAborted()
 {
-    QTC_ASSERT(m_proposal, return);
-    m_abortedBasePosition = m_proposal->basePosition();
+    QTC_ASSERT(m_proposalWidget, return);
+    m_abortedBasePosition = m_proposalWidget->basePosition();
 }
 
 void CodeAssistantPrivate::clearAbortedPosition()
diff --git a/src/plugins/texteditor/codeassist/functionhintproposal.cpp b/src/plugins/texteditor/codeassist/functionhintproposal.cpp
index 5c713d2330..fcc3b247eb 100644
--- a/src/plugins/texteditor/codeassist/functionhintproposal.cpp
+++ b/src/plugins/texteditor/codeassist/functionhintproposal.cpp
@@ -12,9 +12,7 @@ using namespace TextEditor;
 FunctionHintProposal::FunctionHintProposal(int cursorPos, FunctionHintProposalModelPtr model)
     : IAssistProposal(functionHintId, cursorPos)
     , m_model(model)
-{
-    setFragile(true);
-}
+{}
 
 FunctionHintProposal::~FunctionHintProposal() = default;
 
diff --git a/src/plugins/texteditor/codeassist/functionhintproposalwidget.cpp b/src/plugins/texteditor/codeassist/functionhintproposalwidget.cpp
index 5811c100c8..e6753c4605 100644
--- a/src/plugins/texteditor/codeassist/functionhintproposalwidget.cpp
+++ b/src/plugins/texteditor/codeassist/functionhintproposalwidget.cpp
@@ -138,6 +138,7 @@ FunctionHintProposalWidget::FunctionHintProposalWidget()
     });
 
     setFocusPolicy(Qt::NoFocus);
+    setFragile(true);
 }
 
 FunctionHintProposalWidget::~FunctionHintProposalWidget()
@@ -150,9 +151,6 @@ void FunctionHintProposalWidget::setAssistant(CodeAssistant *assistant)
     d->m_assistant = assistant;
 }
 
-void FunctionHintProposalWidget::setReason(AssistReason)
-{}
-
 void FunctionHintProposalWidget::setKind(AssistKind)
 {}
 
@@ -190,7 +188,7 @@ void FunctionHintProposalWidget::showProposal(const QString &prefix)
     d->m_popupFrame->show();
 }
 
-void FunctionHintProposalWidget::updateProposal(const QString &prefix)
+void FunctionHintProposalWidget::filterProposal(const QString &prefix)
 {
     updateAndCheck(prefix);
 }
diff --git a/src/plugins/texteditor/codeassist/functionhintproposalwidget.h b/src/plugins/texteditor/codeassist/functionhintproposalwidget.h
index 28813ccf8c..97580ede24 100644
--- a/src/plugins/texteditor/codeassist/functionhintproposalwidget.h
+++ b/src/plugins/texteditor/codeassist/functionhintproposalwidget.h
@@ -19,7 +19,6 @@ public:
     ~FunctionHintProposalWidget() override;
 
     void setAssistant(CodeAssistant *assistant) override;
-    void setReason(AssistReason reason) override;
     void setKind(AssistKind kind) override;
     void setUnderlyingWidget(const QWidget *underlyingWidget) override;
     void setModel(ProposalModelPtr model) override;
@@ -27,7 +26,7 @@ public:
     void setIsSynchronized(bool isSync) override;
 
     void showProposal(const QString &prefix) override;
-    void updateProposal(const QString &prefix) override;
+    void filterProposal(const QString &prefix) override;
     void closeProposal() override;
 
     bool proposalIsVisible() const override;
diff --git a/src/plugins/texteditor/codeassist/genericproposalwidget.cpp b/src/plugins/texteditor/codeassist/genericproposalwidget.cpp
index 83fe23404f..9eb3fdcd37 100644
--- a/src/plugins/texteditor/codeassist/genericproposalwidget.cpp
+++ b/src/plugins/texteditor/codeassist/genericproposalwidget.cpp
@@ -249,7 +249,6 @@ public:
     QRect m_displayRect;
     bool m_isSynchronized = true;
     bool m_explicitlySelected = false;
-    AssistReason m_reason = IdleEditor;
     AssistKind m_kind = Completion;
     bool m_justInvoked = false;
     QPointer<GenericProposalInfoFrame> m_infoFrame;
@@ -358,9 +357,9 @@ void GenericProposalWidget::setAssistant(CodeAssistant *assistant)
 
 void GenericProposalWidget::setReason(AssistReason reason)
 {
-    d->m_reason = reason;
-    if (d->m_reason == ExplicitlyInvoked)
+    if (reason == ExplicitlyInvoked)
         d->m_justInvoked = true;
+    IAssistProposalWidget::setReason(reason);
 }
 
 void GenericProposalWidget::setKind(AssistKind kind)
@@ -393,11 +392,6 @@ void GenericProposalWidget::setIsSynchronized(bool isSync)
     d->m_isSynchronized = isSync;
 }
 
-bool GenericProposalWidget::supportsModelUpdate(const Utils::Id &proposalId) const
-{
-    return proposalId == Constants::GENERIC_PROPOSAL_ID;
-}
-
 void GenericProposalWidget::updateModel(ProposalModelPtr model)
 {
     QString currentText;
@@ -418,6 +412,7 @@ void GenericProposalWidget::updateModel(ProposalModelPtr model)
         d->m_completionListView->selectRow(currentRow);
     else
         d->m_explicitlySelected = false;
+    updatePositionAndSize();
 }
 
 void GenericProposalWidget::showProposal(const QString &prefix)
@@ -431,7 +426,7 @@ void GenericProposalWidget::showProposal(const QString &prefix)
     d->m_completionListView->setFocus();
 }
 
-void GenericProposalWidget::updateProposal(const QString &prefix)
+void GenericProposalWidget::filterProposal(const QString &prefix)
 {
     if (!isVisible())
         return;
@@ -470,7 +465,7 @@ bool GenericProposalWidget::updateAndCheck(const QString &prefix)
         if (!prefix.isEmpty())
             d->m_model->filter(prefix);
     }
-    if (!d->m_model->hasItemsToPropose(prefix, d->m_reason)) {
+    if (!d->m_model->hasItemsToPropose(prefix, reason())) {
         d->m_completionListView->reset();
         abort();
         return false;
@@ -660,7 +655,7 @@ bool GenericProposalWidget::eventFilter(QObject *o, QEvent *e)
             AssistProposalItemInterface *item =
                 d->m_model->proposalItem(d->m_completionListView->currentIndex().row());
             if (item->prematurelyApplies(typedChar)
-                    && (d->m_reason == ExplicitlyInvoked || item->text().endsWith(typedChar))) {
+                    && (reason() == ExplicitlyInvoked || item->text().endsWith(typedChar))) {
                 abort();
                 emit proposalItemActivated(item);
                 return true;
diff --git a/src/plugins/texteditor/codeassist/genericproposalwidget.h b/src/plugins/texteditor/codeassist/genericproposalwidget.h
index 901a8b1dfe..c38ccc9f47 100644
--- a/src/plugins/texteditor/codeassist/genericproposalwidget.h
+++ b/src/plugins/texteditor/codeassist/genericproposalwidget.h
@@ -31,11 +31,10 @@ public:
     void setDisplayRect(const QRect &rect) override;
     void setIsSynchronized(bool isSync) override;
 
-    bool supportsModelUpdate(const Utils::Id &proposalId) const override;
-    void updateModel(ProposalModelPtr model) override;
+    void updateModel(ProposalModelPtr model);
 
     void showProposal(const QString &prefix) override;
-    void updateProposal(const QString &prefix) override;
+    void filterProposal(const QString &prefix) override;
     void closeProposal() override;
 
 private:
diff --git a/src/plugins/texteditor/codeassist/iassistproposal.cpp b/src/plugins/texteditor/codeassist/iassistproposal.cpp
index b2c7dffc9f..d6918ba797 100644
--- a/src/plugins/texteditor/codeassist/iassistproposal.cpp
+++ b/src/plugins/texteditor/codeassist/iassistproposal.cpp
@@ -63,16 +63,6 @@ int IAssistProposal::basePosition() const
     return m_basePosition;
 }
 
-bool IAssistProposal::isFragile() const
-{
-    return m_isFragile;
-}
-
-bool IAssistProposal::supportsPrefixFiltering(const QString &prefix) const
-{
-    return !m_prefixChecker || m_prefixChecker(prefix);
-}
-
 /*!
     \fn bool TextEditor::IAssistProposal::isCorrective() const
 
@@ -98,16 +88,6 @@ void IAssistProposal::makeCorrection(TextEditorWidget *editorWidget)
     Q_UNUSED(editorWidget)
 }
 
-void IAssistProposal::setFragile(bool fragile)
-{
-    m_isFragile = fragile;
-}
-
-void IAssistProposal::setPrefixChecker(const PrefixChecker checker)
-{
-    m_prefixChecker = checker;
-}
-
 /*!
     \fn IAssistModel *TextEditor::IAssistProposal::model() const
 
diff --git a/src/plugins/texteditor/codeassist/iassistproposal.h b/src/plugins/texteditor/codeassist/iassistproposal.h
index 5c64a88066..1761fc29bf 100644
--- a/src/plugins/texteditor/codeassist/iassistproposal.h
+++ b/src/plugins/texteditor/codeassist/iassistproposal.h
@@ -22,30 +22,17 @@ public:
     virtual ~IAssistProposal();
 
     int basePosition() const;
-    bool isFragile() const;
-    bool supportsPrefixFiltering(const QString &prefix) const;
     virtual bool hasItemsToPropose(const QString &, AssistReason) const { return true; }
     virtual bool isCorrective(TextEditorWidget *editorWidget) const;
     virtual void makeCorrection(TextEditorWidget *editorWidget);
     virtual TextEditor::ProposalModelPtr model() const = 0;
     virtual IAssistProposalWidget *createWidget() const = 0;
 
-    void setFragile(bool fragile);
-
     Utils::Id id() const { return m_id; }
 
-    AssistReason reason() const { return m_reason; }
-    void setReason(const AssistReason &reason) { m_reason = reason; }
-
-    using PrefixChecker = std::function<bool(const QString &)>;
-    void setPrefixChecker(const PrefixChecker checker);
-
 protected:
     Utils::Id m_id;
     int m_basePosition;
-    bool m_isFragile = false;
-    PrefixChecker m_prefixChecker;
-    AssistReason m_reason = IdleEditor;
 };
 
 } // TextEditor
diff --git a/src/plugins/texteditor/codeassist/iassistproposalwidget.cpp b/src/plugins/texteditor/codeassist/iassistproposalwidget.cpp
index f1ea7428eb..fe5e3d823d 100644
--- a/src/plugins/texteditor/codeassist/iassistproposalwidget.cpp
+++ b/src/plugins/texteditor/codeassist/iassistproposalwidget.cpp
@@ -3,6 +3,8 @@
 
 #include "iassistproposalwidget.h"
 
+#include "assistinterface.h"
+
 using namespace TextEditor;
 
 /*!
@@ -30,6 +32,11 @@ IAssistProposalWidget::IAssistProposalWidget()
     : QFrame(nullptr, Qt::Popup)
 {}
 
+void IAssistProposalWidget::updateProposal(std::unique_ptr<AssistInterface> &&interface)
+{
+    filterProposal(interface->textAt(m_basePosition, interface->position() - m_basePosition));
+}
+
 IAssistProposalWidget::~IAssistProposalWidget() = default;
 
 int IAssistProposalWidget::basePosition() const
diff --git a/src/plugins/texteditor/codeassist/iassistproposalwidget.h b/src/plugins/texteditor/codeassist/iassistproposalwidget.h
index fafe1b48b4..68600b399c 100644
--- a/src/plugins/texteditor/codeassist/iassistproposalwidget.h
+++ b/src/plugins/texteditor/codeassist/iassistproposalwidget.h
@@ -14,8 +14,9 @@ namespace Utils { class Id; }
 
 namespace TextEditor {
 
-class CodeAssistant;
+class AssistInterface;
 class AssistProposalItemInterface;
+class CodeAssistant;
 
 class TEXTEDITOR_EXPORT IAssistProposalWidget  : public QFrame
 {
@@ -26,7 +27,7 @@ public:
     ~IAssistProposalWidget() override;
 
     virtual void setAssistant(CodeAssistant *assistant) = 0;
-    virtual void setReason(AssistReason reason) = 0;
+    virtual void setReason(AssistReason reason) { m_reason = reason; }
     virtual void setKind(AssistKind kind) = 0;
     virtual void setUnderlyingWidget(const QWidget *underlyingWidget) = 0;
     virtual void setModel(ProposalModelPtr model) = 0;
@@ -34,16 +35,20 @@ public:
     virtual void setIsSynchronized(bool isSync) = 0;
 
     virtual void showProposal(const QString &prefix) = 0;
-    virtual void updateProposal(const QString &prefix) = 0;
+    virtual void filterProposal(const QString &prefix) = 0;
+    virtual void updateProposal(std::unique_ptr<AssistInterface> &&interface);
     virtual void closeProposal() = 0;
 
     virtual bool proposalIsVisible() const { return isVisible(); }
-    virtual bool supportsModelUpdate(const Utils::Id &/*proposalId*/) const { return false; }
-    virtual void updateModel(ProposalModelPtr) {}
 
     int basePosition() const;
     void setBasePosition(int basePosition);
 
+    void setFragile(bool fragile) { m_isFragile = fragile; }
+    bool isFragile() const { return m_isFragile; }
+
+    AssistReason reason() const { return m_reason; }
+
 signals:
     void prefixExpanded(const QString &newPrefix);
     void proposalItemActivated(AssistProposalItemInterface *proposalItem);
@@ -51,6 +56,8 @@ signals:
 
 protected:
     int m_basePosition = -1;
+    bool m_isFragile = false;
+    AssistReason m_reason = IdleEditor;
 };
 
 } // TextEditor