Clang: Remove TextEditorWidget from AssistProposalItemInterface

Change-Id: I0ac924f88c1347d1b0027c47118b7ed21daf4869
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>
Reviewed-by: David Schulz <david.schulz@theqtcompany.com>

src/plugins/clangcodemodel/clangassistproposalitem.cpp

@@ -66,22 +66,7 @@ bool ClangAssistProposalItem::implicitlyApplies() const
     return false;
 }
 
-static bool hasOnlyBlanksBeforeCursorInLine(QTextCursor textCursor)
-{
-    textCursor.movePosition(QTextCursor::StartOfLine, QTextCursor::KeepAnchor);
-
-    const auto textBeforeCursor = textCursor.selectedText();
-
-    const auto nonSpace = std::find_if(textBeforeCursor.cbegin(),
-                                       textBeforeCursor.cend(),
-                                       [] (const QChar &signBeforeCursor) {
-        return !signBeforeCursor.isSpace();
-    });
-
-    return nonSpace == textBeforeCursor.cend();
-}
-
-void ClangAssistProposalItem::apply(TextEditor::TextEditorWidget *editorWidget,
+void ClangAssistProposalItem::apply(TextEditor::TextDocumentManipulatorInterface &manipulator,
                                     int basePosition) const
 {
     const CodeCompletion ccr = codeCompletion();
@@ -134,7 +119,7 @@ void ClangAssistProposalItem::apply(TextEditor::TextEditorWidget *editorWidget,
 
             // If the function doesn't return anything, automatically place the semicolon,
             // unless we're doing a scope completion (then it might be function definition).
-            const QChar characterAtCursor = editorWidget->characterAt(editorWidget->position());
+            const QChar characterAtCursor = manipulator.characterAt(manipulator.currentPosition());
             bool endWithSemicolon = m_typedCharacter == QLatin1Char(';')/*
                                             || (function->returnType()->isVoidType() && m_completionOperator != T_COLON_COLON)*/; //###
             const QChar semicolon = m_typedCharacter.isNull() ? QLatin1Char(';') : m_typedCharacter;
@@ -152,7 +137,7 @@ void ClangAssistProposalItem::apply(TextEditor::TextEditorWidget *editorWidget,
                     m_typedCharacter = QChar();
                 }
             } else if (autoParenthesesEnabled) {
-                const QChar lookAhead = editorWidget->characterAt(editorWidget->position() + 1);
+                const QChar lookAhead = manipulator.characterAt(manipulator.currentPosition() + 1);
                 if (MatchingText::shouldInsertMatchingText(lookAhead)) {
                     extraCharacters += QLatin1Char(')');
                     --cursorOffset;
@@ -187,12 +172,12 @@ void ClangAssistProposalItem::apply(TextEditor::TextEditorWidget *editorWidget,
     }
 
     // Avoid inserting characters that are already there
-    const int endsPosition = editorWidget->position(TextEditor::EndOfLinePosition);
-    const QString existingText = editorWidget->textAt(editorWidget->position(), endsPosition - editorWidget->position());
+    const int endsPosition = manipulator.positionAt(TextEditor::EndOfLinePosition);
+    const QString existingText = manipulator.textAt(manipulator.currentPosition(), endsPosition - manipulator.currentPosition());
     int existLength = 0;
     if (!existingText.isEmpty() && ccr.completionKind() != CodeCompletion::KeywordCompletionKind) {
         // Calculate the exist length in front of the extra chars
-        existLength = textToBeInserted.length() - (editorWidget->position() - basePosition);
+        existLength = textToBeInserted.length() - (manipulator.currentPosition() - basePosition);
         while (!existingText.startsWith(textToBeInserted.right(existLength))) {
             if (--existLength == 0)
                 break;
@@ -200,7 +185,7 @@ void ClangAssistProposalItem::apply(TextEditor::TextEditorWidget *editorWidget,
     }
     for (int i = 0; i < extraCharacters.length(); ++i) {
         const QChar a = extraCharacters.at(i);
-        const QChar b = editorWidget->characterAt(editorWidget->position() + i + existLength);
+        const QChar b = manipulator.characterAt(manipulator.currentPosition() + i + existLength);
         if (a == b)
             ++extraLength;
         else
@@ -209,27 +194,15 @@ void ClangAssistProposalItem::apply(TextEditor::TextEditorWidget *editorWidget,
 
     textToBeInserted += extraCharacters;
 
-    // Insert the remainder of the name
-    const int length = editorWidget->position() - basePosition + existLength + extraLength;
-    const auto textToBeReplaced = editorWidget->textAt(basePosition, length);
+    const int length = manipulator.currentPosition() - basePosition + existLength + extraLength;
 
-    if (textToBeReplaced != textToBeInserted) {
-        editorWidget->setCursorPosition(basePosition);
-        editorWidget->replace(length, textToBeInserted);
+    const bool isReplaced = manipulator.replace(basePosition, length, textToBeInserted);
+    if (isReplaced) {
         if (cursorOffset)
-            editorWidget->setCursorPosition(editorWidget->position() + cursorOffset);
+            manipulator.setCursorPosition(manipulator.currentPosition() + cursorOffset);
 
-        // indent the statement
-        if (ccr.completionKind() == CodeCompletion::KeywordCompletionKind) {
-            auto selectionCursor = editorWidget->textCursor();
-            selectionCursor.setPosition(basePosition);
-            selectionCursor.setPosition(basePosition + textToBeInserted.size(), QTextCursor::KeepAnchor);
-
-            auto basePositionCursor = editorWidget->textCursor();
-            basePositionCursor.setPosition(basePosition);
-            if (hasOnlyBlanksBeforeCursorInLine(basePositionCursor))
-                editorWidget->textDocument()->autoIndent(selectionCursor);
-        }
+        if (ccr.completionKind() == CodeCompletion::KeywordCompletionKind)
+            manipulator.autoIndent(basePosition, textToBeInserted.size());
     }
 }
 

src/plugins/clangcodemodel/clangassistproposalitem.h

@@ -41,7 +41,7 @@ class ClangAssistProposalItem final : public TextEditor::AssistProposalItemInter
 public:
     bool prematurelyApplies(const QChar &typedCharacter) const final;
     bool implicitlyApplies() const final;
-    void apply(TextEditor::TextEditorWidget *editorWidget, int basePosition) const final;
+    void apply(TextEditor::TextDocumentManipulatorInterface &manipulator, int basePosition) const final;
 
     void setText(const QString &text);
     QString text() const final;

src/plugins/clangcodemodel/clangpreprocessorassistproposalitem.cpp

@@ -49,7 +49,7 @@ bool ClangPreprocessorAssistProposalItem::implicitlyApplies() const
     return false;
 }
 
-void ClangPreprocessorAssistProposalItem::apply(TextEditor::TextEditorWidget *editorWidget,
+void ClangPreprocessorAssistProposalItem::apply(TextEditor::TextDocumentManipulatorInterface &manipulator,
                                                 int basePosition) const
 {
     // TODO move in an extra class under tests
@@ -76,12 +76,12 @@ void ClangPreprocessorAssistProposalItem::apply(TextEditor::TextEditorWidget *ed
     }
 
     // Avoid inserting characters that are already there
-    const int endsPosition = editorWidget->position(TextEditor::EndOfLinePosition);
-    const QString existingText = editorWidget->textAt(editorWidget->position(), endsPosition - editorWidget->position());
+    const int endsPosition = manipulator.positionAt(TextEditor::EndOfLinePosition);
+    const QString existingText = manipulator.textAt(manipulator.currentPosition(), endsPosition - manipulator.currentPosition());
     int existLength = 0;
     if (!existingText.isEmpty()) {
         // Calculate the exist length in front of the extra chars
-        existLength = textToBeInserted.length() - (editorWidget->position() - basePosition);
+        existLength = textToBeInserted.length() - (manipulator.currentPosition() - basePosition);
         while (!existingText.startsWith(textToBeInserted.right(existLength))) {
             if (--existLength == 0)
                 break;
@@ -89,7 +89,7 @@ void ClangPreprocessorAssistProposalItem::apply(TextEditor::TextEditorWidget *ed
     }
     for (int i = 0; i < extraCharacters.length(); ++i) {
         const QChar a = extraCharacters.at(i);
-        const QChar b = editorWidget->characterAt(editorWidget->position() + i + existLength);
+        const QChar b = manipulator.characterAt(manipulator.currentPosition() + i + existLength);
         if (a == b)
             ++extraLength;
         else
@@ -99,15 +99,11 @@ void ClangPreprocessorAssistProposalItem::apply(TextEditor::TextEditorWidget *ed
     textToBeInserted += extraCharacters;
 
     // Insert the remainder of the name
-    const int length = editorWidget->position() - basePosition + existLength + extraLength;
-    const auto textToBeReplaced = editorWidget->textAt(basePosition, length);
+    const int length = manipulator.currentPosition() - basePosition + existLength + extraLength;
 
-    if (textToBeReplaced != textToBeInserted) {
-        editorWidget->setCursorPosition(basePosition);
-        editorWidget->replace(length, textToBeInserted);
-        if (cursorOffset)
-            editorWidget->setCursorPosition(editorWidget->position() + cursorOffset);
-    }
+    const bool isReplaced = manipulator.replace(basePosition, length, textToBeInserted);
+    if (isReplaced && cursorOffset)
+            manipulator.setCursorPosition(manipulator.currentPosition() + cursorOffset);
 }
 
 void ClangPreprocessorAssistProposalItem::setText(const QString &text)

src/plugins/clangcodemodel/clangpreprocessorassistproposalitem.h

@@ -38,7 +38,8 @@ class ClangPreprocessorAssistProposalItem final : public TextEditor::AssistPropo
 public:
     bool prematurelyApplies(const QChar &typedChar) const final;
     virtual bool implicitlyApplies() const final;
-    void apply(TextEditor::TextEditorWidget *editorWidget, int basePosition) const final;
+    void apply(TextEditor::TextDocumentManipulatorInterface &manipulator,
+               int basePosition) const final;
 
     void setText(const QString &text);
     QString text() const final;

src/plugins/cpptools/cppcompletionassist.cpp

@@ -87,7 +87,7 @@ public:
         m_isOverloaded(false) {}
 
     bool prematurelyApplies(const QChar &c) const override;
-    void applyContextualContent(TextEditorWidget *editorWidget, int basePosition) const override;
+    void applyContextualContent(TextDocumentManipulatorInterface &manipulator, int basePosition) const override;
 
     bool isOverloaded() const { return m_isOverloaded; }
     void markAsOverloaded() { m_isOverloaded = true; }
@@ -161,9 +161,9 @@ bool CppAssistProposalItem::prematurelyApplies(const QChar &typedChar) const
     return false;
 }
 
-static bool isDereferenced(TextEditorWidget *editorWidget, int basePosition)
+static bool isDereferenced(TextDocumentManipulatorInterface &manipulator, int basePosition)
 {
-    QTextCursor cursor = editorWidget->textCursor();
+    QTextCursor cursor = manipulator.textCursorAt(basePosition);
     cursor.setPosition(basePosition);
 
     BackwardsScanner scanner(cursor, LanguageFeatures());
@@ -191,7 +191,7 @@ quint64 CppAssistProposalItem::hash() const
     return 0;
 }
 
-void CppAssistProposalItem::applyContextualContent(TextEditorWidget *editorWidget, int basePosition) const
+void CppAssistProposalItem::applyContextualContent(TextDocumentManipulatorInterface &manipulator, int basePosition) const
 {
     Symbol *symbol = 0;
 
@@ -241,7 +241,7 @@ void CppAssistProposalItem::applyContextualContent(TextEditorWidget *editorWidge
                     if (function->argumentCount() == 0)
                         extraChars += QLatin1Char('<');
 #endif
-                } else if (!isDereferenced(editorWidget, basePosition) && !function->isAmbiguous()) {
+                } else if (!isDereferenced(manipulator, basePosition) && !function->isAmbiguous()) {
                     // When the user typed the opening parenthesis, he'll likely also type the closing one,
                     // in which case it would be annoying if we put the cursor after the already automatically
                     // inserted closing parenthesis.
@@ -255,7 +255,7 @@ void CppAssistProposalItem::applyContextualContent(TextEditorWidget *editorWidge
 
                     // If the function doesn't return anything, automatically place the semicolon,
                     // unless we're doing a scope completion (then it might be function definition).
-                    const QChar characterAtCursor = editorWidget->characterAt(editorWidget->position());
+                    const QChar characterAtCursor = manipulator.characterAt(manipulator.currentPosition());
                     bool endWithSemicolon = m_typedChar == QLatin1Char(';')
                             || (function->returnType()->isVoidType() && m_completionOperator != T_COLON_COLON);
                     const QChar semicolon = m_typedChar.isNull() ? QLatin1Char(';') : m_typedChar;
@@ -273,7 +273,7 @@ void CppAssistProposalItem::applyContextualContent(TextEditorWidget *editorWidge
                             m_typedChar = QChar();
                         }
                     } else if (autoParenthesesEnabled) {
-                        const QChar lookAhead = editorWidget->characterAt(editorWidget->position() + 1);
+                        const QChar lookAhead = manipulator.characterAt(manipulator.currentPosition() + 1);
                         if (MatchingText::shouldInsertMatchingText(lookAhead)) {
                             extraChars += QLatin1Char(')');
                             --cursorOffset;
@@ -311,11 +311,12 @@ void CppAssistProposalItem::applyContextualContent(TextEditorWidget *editorWidge
 
     // Determine the length of characters that should just be kept on the editor, but do
     // not consider content that ends as an identifier (which could be undesired).
-    const int lineEnd = editorWidget->position(EndOfLinePosition);
-    const QString inEditor = editorWidget->textAt(editorWidget->position(), lineEnd - editorWidget->position());
+    const int lineEnd = manipulator.positionAt(EndOfLinePosition);
+    const QString inEditor = manipulator.textAt(manipulator.currentPosition(),
+                                                lineEnd - manipulator.currentPosition());
     int preserveLength = 0;
     if (!inEditor.isEmpty()) {
-        preserveLength = toInsert.length() - (editorWidget->position() - basePosition);
+        preserveLength = toInsert.length() - (manipulator.currentPosition() - basePosition);
         const int inEditorLength = inEditor.length();
         while (preserveLength > 0) {
             if (inEditor.startsWith(toInsert.right(preserveLength))
@@ -329,7 +330,7 @@ void CppAssistProposalItem::applyContextualContent(TextEditorWidget *editorWidge
 
     for (int i = 0; i < extraChars.length(); ++i) {
         const QChar a = extraChars.at(i);
-        const QChar b = editorWidget->characterAt(editorWidget->position() + i + preserveLength);
+        const QChar b = manipulator.characterAt(manipulator.currentPosition() + i + preserveLength);
         if (a == b)
             ++extraLength;
         else
@@ -339,11 +340,10 @@ void CppAssistProposalItem::applyContextualContent(TextEditorWidget *editorWidge
     toInsert += extraChars;
 
     // Insert the remainder of the name
-    const int length = editorWidget->position() - basePosition + preserveLength + extraLength;
-    editorWidget->setCursorPosition(basePosition);
-    editorWidget->replace(length, toInsert);
+    const int length = manipulator.currentPosition() - basePosition + preserveLength + extraLength;
+    manipulator.replace(basePosition, length, toInsert);
     if (cursorOffset)
-        editorWidget->setCursorPosition(editorWidget->position() + cursorOffset);
+        manipulator.setCursorPosition(manipulator.currentPosition() + cursorOffset);
 }
 
 // --------------------

src/plugins/fakevim/fakevimplugin.cpp

@@ -933,7 +933,7 @@ public:
         return text() == m_provider->needle();
     }
 
-    void applyContextualContent(TextEditorWidget *, int) const override
+    void applyContextualContent(TextDocumentManipulatorInterface &, int) const override
     {
         QTC_ASSERT(m_provider->handler(), return);
         m_provider->handler()->handleReplay(text().mid(m_provider->needle().size()));

src/plugins/qmljseditor/qmljscompletionassist.cpp

@@ -348,12 +348,11 @@ bool QmlJSAssistProposalItem::prematurelyApplies(const QChar &c) const
             || (text().endsWith(QLatin1Char('.')) && c == QLatin1Char('.'));
 }
 
-void QmlJSAssistProposalItem::applyContextualContent(TextEditorWidget *editorWidget,
+void QmlJSAssistProposalItem::applyContextualContent(TextEditor::TextDocumentManipulatorInterface &manipulator,
                                                      int basePosition) const
 {
-    const int currentPosition = editorWidget->position();
-    editorWidget->setCursorPosition(basePosition);
-    editorWidget->remove(currentPosition - basePosition);
+    const int currentPosition = manipulator.currentPosition();
+    manipulator.replace(basePosition, currentPosition - basePosition, QString());
 
     QString content = text();
     int cursorOffset = 0;
@@ -372,16 +371,16 @@ void QmlJSAssistProposalItem::applyContextualContent(TextEditorWidget *editorWid
     int replacedLength = 0;
     for (int i = 0; i < replaceable.length(); ++i) {
         const QChar a = replaceable.at(i);
-        const QChar b = editorWidget->characterAt(editorWidget->position() + i);
+        const QChar b = manipulator.characterAt(manipulator.currentPosition() + i);
         if (a == b)
             ++replacedLength;
         else
             break;
     }
-    const int length = editorWidget->position() - basePosition + replacedLength;
-    editorWidget->replace(length, content);
+    const int length = manipulator.currentPosition() - basePosition + replacedLength;
+    manipulator.replace(basePosition, length, content);
     if (cursorOffset)
-        editorWidget->setCursorPosition(editorWidget->position() + cursorOffset);
+        manipulator.setCursorPosition(manipulator.currentPosition() + cursorOffset);
 }
 
 // -------------------------

src/plugins/qmljseditor/qmljscompletionassist.h

@@ -49,12 +49,12 @@ class QmlJSCompletionAssistInterface;
 
 namespace Internal {
 
-class QmlJSAssistProposalItem : public TextEditor::AssistProposalItem
+class QmlJSAssistProposalItem final : public TextEditor::AssistProposalItem
 {
 public:
-    bool prematurelyApplies(const QChar &c) const override;
-    void applyContextualContent(TextEditor::TextEditorWidget *editorWidget,
-                                int basePosition) const override;
+    bool prematurelyApplies(const QChar &c) const final;
+    void applyContextualContent(TextEditor::TextDocumentManipulatorInterface &manipulator,
+                                int basePosition) const final;
 };
 
 

src/plugins/texteditor/circularclipboardassist.cpp

@@ -58,7 +58,7 @@ public:
         setText(text);
     }
 
-    void apply(TextEditorWidget *editorWidget, int /*basePosition*/) const override
+    void apply(TextDocumentManipulatorInterface &manipulator, int /*basePosition*/) const override
     {
 
         //Move to last in circular clipboard
@@ -72,7 +72,7 @@ public:
                     TextEditorWidget::duplicateMimeData(m_mimeData.data()));
 
         //Paste
-        editorWidget->paste();
+        manipulator.paste();
     }
 
 private:

src/plugins/texteditor/codeassist/assistproposalitem.cpp

@@ -126,35 +126,33 @@ bool AssistProposalItem::prematurelyApplies(const QChar &c) const
     return false;
 }
 
-void AssistProposalItem::apply(TextEditorWidget *editorWidget, int basePosition) const
+void AssistProposalItem::apply(TextDocumentManipulatorInterface &manipulator, int basePosition) const
 {
     if (data().canConvert<QString>()) {
-        applySnippet(editorWidget, basePosition);
+        applySnippet(manipulator, basePosition);
     } else if (data().canConvert<QuickFixOperation::Ptr>()) {
-        applyQuickFix(editorWidget, basePosition);
+        applyQuickFix(manipulator, basePosition);
     } else {
-        applyContextualContent(editorWidget, basePosition);
-        editorWidget->encourageApply();
+        applyContextualContent(manipulator, basePosition);
+        manipulator.encourageApply();
     }
 }
 
-void AssistProposalItem::applyContextualContent(TextEditorWidget *editorWidget, int basePosition) const
+void AssistProposalItem::applyContextualContent(TextDocumentManipulatorInterface &manipulator, int basePosition) const
 {
-    const int currentPosition = editorWidget->position();
-    editorWidget->setCursorPosition(basePosition);
-    editorWidget->replace(currentPosition - basePosition, text());
+    const int currentPosition = manipulator.currentPosition();
+    manipulator.replace(basePosition, currentPosition - basePosition, text());
+
 }
 
-void AssistProposalItem::applySnippet(TextEditorWidget *editorWidget, int basePosition) const
+void AssistProposalItem::applySnippet(TextDocumentManipulatorInterface &manipulator, int basePosition) const
 {
-    QTextCursor tc = editorWidget->textCursor();
-    tc.setPosition(basePosition, QTextCursor::KeepAnchor);
-    editorWidget->insertCodeSnippet(tc, data().toString());
+    manipulator.insertCodeSnippet(basePosition, data().toString());
 }
 
-void AssistProposalItem::applyQuickFix(TextEditorWidget *editorWidget, int basePosition) const
+void AssistProposalItem::applyQuickFix(TextDocumentManipulatorInterface &manipulator, int basePosition) const
 {
-    Q_UNUSED(editorWidget)
+    Q_UNUSED(manipulator)
     Q_UNUSED(basePosition)
 
     QuickFixOperation::Ptr op = data().value<QuickFixOperation::Ptr>();

src/plugins/texteditor/codeassist/assistproposalitem.h

@@ -44,7 +44,7 @@ public:
     QString text() const override;
     bool implicitlyApplies() const override;
     bool prematurelyApplies(const QChar &c) const override;
-    void apply(TextEditorWidget *editorWidget, int basePosition) const override;
+    void apply(TextDocumentManipulatorInterface &manipulator, int basePosition) const override;
 
     void setIcon(const QIcon &icon);
     QIcon icon() const final;
@@ -61,9 +61,9 @@ public:
     bool isValid() const final;
     quint64 hash() const;
 
-    virtual void applyContextualContent(TextEditorWidget *editorWidget, int basePosition) const;
-    virtual void applySnippet(TextEditorWidget *editorWidget, int basePosition) const;
-    virtual void applyQuickFix(TextEditorWidget *editorWidget, int basePosition) const;
+    virtual void applyContextualContent(TextDocumentManipulatorInterface &manipulator, int basePosition) const;
+    virtual void applySnippet(TextDocumentManipulatorInterface &manipulator, int basePosition) const;
+    virtual void applyQuickFix(TextDocumentManipulatorInterface &manipulator, int basePosition) const;
 
 private:
     QIcon m_icon;

src/plugins/texteditor/codeassist/assistproposaliteminterface.h

@@ -26,10 +26,9 @@
 #ifndef TEXTEDITOR_ASSISTPROPOSALITEMINTERFACE_H
 #define TEXTEDITOR_ASSISTPROPOSALITEMINTERFACE_H
 
-#include <texteditor/texteditor_global.h>
+#include "textdocumentmanipulatorinterface.h"
 
 QT_BEGIN_NAMESPACE
-class QChar;
 class QIcon;
 class QString;
 class QVariant;
@@ -49,7 +48,7 @@ public:
     virtual QString text() const = 0;
     virtual bool implicitlyApplies() const = 0;
     virtual bool prematurelyApplies(const QChar &typedCharacter) const = 0;
-    virtual void apply(TextEditorWidget *editorWidget, int basePosition) const = 0;
+    virtual void apply(TextDocumentManipulatorInterface &manipulator, int basePosition) const = 0;
     virtual QIcon icon() const = 0;
     virtual QString detail() const = 0;
     virtual bool isSnippet() const = 0;

src/plugins/texteditor/codeassist/codeassistant.cpp

@@ -34,6 +34,7 @@
 #include "assistinterface.h"
 #include "assistproposalitem.h"
 #include "runner.h"
+#include "textdocumentmanipulator.h"
 
 #include <texteditor/texteditor.h>
 #include <texteditor/texteditorsettings.h>
@@ -357,7 +358,8 @@ void CodeAssistantPrivate::displayProposal(IAssistProposal *newProposal, AssistR
 void CodeAssistantPrivate::processProposalItem(AssistProposalItemInterface *proposalItem)
 {
     QTC_ASSERT(m_proposal, return);
-    proposalItem->apply(m_editorWidget, m_proposal->basePosition());
+    TextDocumentManipulator manipulator(m_editorWidget);
+    proposalItem->apply(manipulator, m_proposal->basePosition());
     destroyContext();
     process();
 }

src/plugins/texteditor/codeassist/keywordscompletionassist.cpp

@@ -92,20 +92,22 @@ bool KeywordsAssistProposalItem::prematurelyApplies(const QChar &c) const
     return c == QLatin1Char('(') && m_isFunction;
 }
 
-void KeywordsAssistProposalItem::applyContextualContent(TextEditorWidget *editorWidget,
+void KeywordsAssistProposalItem::applyContextualContent(TextDocumentManipulatorInterface &manipulator,
                                                         int basePosition) const
 {
     const CompletionSettings &settings = TextEditorSettings::completionSettings();
 
-    int replaceLength = editorWidget->position() - basePosition;
+    int replaceLength = manipulator.currentPosition() - basePosition;
     QString toInsert = text();
     int cursorOffset = 0;
+    const QChar characterAtCurrentPosition = manipulator.characterAt(manipulator.currentPosition());
+
     if (m_isFunction && settings.m_autoInsertBrackets) {
         if (settings.m_spaceAfterFunctionName) {
-            if (editorWidget->textAt(editorWidget->position(), 2) == QLatin1String(" (")) {
+            if (manipulator.textAt(manipulator.currentPosition(), 2) == QLatin1String(" (")) {
                 cursorOffset = 2;
-            } else if (editorWidget->characterAt(editorWidget->position()) == QLatin1Char('(')
-                       || editorWidget->characterAt(editorWidget->position()) == QLatin1Char(' ')) {
+            } else if ( characterAtCurrentPosition == QLatin1Char('(')
+                       || characterAtCurrentPosition == QLatin1Char(' ')) {
                 replaceLength += 1;
                 toInsert += QLatin1String(" (");
             } else {
@@ -113,7 +115,7 @@ void KeywordsAssistProposalItem::applyContextualContent(TextEditorWidget *editor
                 cursorOffset = -1;
             }
         } else {
-            if (editorWidget->characterAt(editorWidget->position()) == QLatin1Char('(')) {
+            if (characterAtCurrentPosition == QLatin1Char('(')) {
                 cursorOffset = 1;
             } else {
                 toInsert += QLatin1String("()");
@@ -122,10 +124,9 @@ void KeywordsAssistProposalItem::applyContextualContent(TextEditorWidget *editor
         }
     }
 
-    editorWidget->setCursorPosition(basePosition);
-    editorWidget->replace(replaceLength, toInsert);
+    manipulator.replace(basePosition, replaceLength, toInsert);
     if (cursorOffset)
-        editorWidget->setCursorPosition(editorWidget->position() + cursorOffset);
+        manipulator.setCursorPosition(manipulator.currentPosition() + cursorOffset);
 }
 
 // -------------------------

src/plugins/texteditor/codeassist/keywordscompletionassist.h

@@ -58,7 +58,7 @@ public:
     ~KeywordsAssistProposalItem();
 
     bool prematurelyApplies(const QChar &c) const override;
-    void applyContextualContent(TextEditorWidget *editorWidget, int basePosition) const override;
+    void applyContextualContent(TextDocumentManipulatorInterface &manipulator, int basePosition) const override;
 private:
     bool m_isFunction;
 };

src/plugins/texteditor/codeassist/textdocumentmanipulator.cpp

@@ -0,0 +1,143 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 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 "textdocumentmanipulator.h"
+
+#include <texteditor/texteditor.h>
+#include <texteditor/textdocument.h>
+
+namespace TextEditor {
+
+TextDocumentManipulator::TextDocumentManipulator(TextEditorWidget *textEditorWidget)
+    : m_textEditorWidget(textEditorWidget)
+{
+}
+
+int TextDocumentManipulator::currentPosition() const
+{
+    return m_textEditorWidget->position();
+}
+
+int TextDocumentManipulator::positionAt(TextPositionOperation textPositionOperation) const
+{
+    return m_textEditorWidget->position(textPositionOperation);
+}
+
+QChar TextDocumentManipulator::characterAt(int position) const
+{
+    return m_textEditorWidget->characterAt(position);
+}
+
+QString TextDocumentManipulator::textAt(int position, int length) const
+{
+    return m_textEditorWidget->textAt(position, length);
+}
+
+QTextCursor TextDocumentManipulator::textCursorAt(int position) const
+{
+    auto cursor = m_textEditorWidget->textCursor();
+    cursor.setPosition(position);
+
+    return cursor;
+}
+
+void TextDocumentManipulator::setCursorPosition(int position)
+{
+    m_textEditorWidget->setCursorPosition(position);
+}
+
+bool TextDocumentManipulator::replace(int position, int length, const QString &text)
+{
+    bool textWillBeReplaced = textIsDifferentAt(position, length, text);
+
+    if (textWillBeReplaced)
+        replaceWithoutCheck(position, length, text);
+
+    return textWillBeReplaced;
+}
+
+void TextDocumentManipulator::insertCodeSnippet(int position, const QString &text)
+{
+    auto cursor = m_textEditorWidget->textCursor();
+    cursor.setPosition(position);
+    m_textEditorWidget->insertCodeSnippet(cursor, text);
+}
+
+void TextDocumentManipulator::paste()
+{
+    m_textEditorWidget->paste();
+}
+
+void TextDocumentManipulator::encourageApply()
+{
+    m_textEditorWidget->encourageApply();
+}
+
+namespace {
+
+bool hasOnlyBlanksBeforeCursorInLine(QTextCursor textCursor)
+{
+    textCursor.movePosition(QTextCursor::StartOfLine, QTextCursor::KeepAnchor);
+
+    const auto textBeforeCursor = textCursor.selectedText();
+
+    const auto nonSpace = std::find_if(textBeforeCursor.cbegin(),
+                                       textBeforeCursor.cend(),
+                                       [] (const QChar &signBeforeCursor) {
+        return !signBeforeCursor.isSpace();
+    });
+
+    return nonSpace == textBeforeCursor.cend();
+}
+
+}
+
+void TextDocumentManipulator::autoIndent(int position, int length)
+{
+    auto cursor = m_textEditorWidget->textCursor();
+    cursor.setPosition(position);
+    if (hasOnlyBlanksBeforeCursorInLine(cursor)) {
+        cursor.setPosition(position + length, QTextCursor::KeepAnchor);
+
+        m_textEditorWidget->textDocument()->autoIndent(cursor);
+    }
+}
+
+bool TextDocumentManipulator::textIsDifferentAt(int position, int length, const QString &text) const
+{
+    const auto textToBeReplaced = m_textEditorWidget->textAt(position, length);
+
+    return text != textToBeReplaced;
+}
+
+void TextDocumentManipulator::replaceWithoutCheck(int position, int length, const QString &text)
+{
+    auto cursor = m_textEditorWidget->textCursor();
+    cursor.setPosition(position);
+    cursor.setPosition(position + length, QTextCursor::KeepAnchor);
+    cursor.insertText(text);
+}
+
+} // namespace TextEditor

src/plugins/texteditor/codeassist/textdocumentmanipulator.h

@@ -0,0 +1,63 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 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.
+**
+****************************************************************************/
+
+#ifndef TEXTDOCUMENTMANIPULATOR_H
+#define TEXTDOCUMENTMANIPULATOR_H
+
+#include "textdocumentmanipulatorinterface.h"
+
+namespace TextEditor {
+
+class TextEditorWidget;
+
+class TextDocumentManipulator final : public TextDocumentManipulatorInterface
+{
+public:
+    TextDocumentManipulator(TextEditorWidget *textEditorWidget);
+
+    int currentPosition() const final;
+    int positionAt(TextPositionOperation textPositionOperation) const final;
+    QChar characterAt(int position) const final;
+    QString textAt(int position, int length) const final;
+    QTextCursor textCursorAt(int position) const final;
+
+    void setCursorPosition(int position) final;
+    bool replace(int position, int length, const QString &text) final;
+    void insertCodeSnippet(int position, const QString &text) final;
+    void paste() final;
+    void encourageApply() final;
+    void autoIndent(int position, int length);
+
+private:
+    bool textIsDifferentAt(int position, int length, const QString &text) const;
+    void replaceWithoutCheck(int position, int length, const QString &text);
+
+private:
+    TextEditorWidget *m_textEditorWidget;
+};
+
+} // namespace TextEditor
+
+#endif // TEXTDOCUMENTMANIPULATOR_H

src/plugins/texteditor/codeassist/textdocumentmanipulatorinterface.h

@@ -0,0 +1,60 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 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.
+**
+****************************************************************************/
+
+#ifndef TEXTDOCUMENTMANIPULATORINTERFACE_H
+#define TEXTDOCUMENTMANIPULATORINTERFACE_H
+
+#include <texteditor/texteditor_global.h>
+
+QT_BEGIN_NAMESPACE
+class QChar;
+class QString;
+class QTextCursor;
+QT_END_NAMESPACE
+
+namespace TextEditor {
+
+class TEXTEDITOR_EXPORT TextDocumentManipulatorInterface
+{
+public:
+    virtual ~TextDocumentManipulatorInterface() = default;
+
+    virtual int currentPosition() const = 0;
+    virtual int positionAt(TextPositionOperation textPositionOperation) const = 0;
+    virtual QChar characterAt(int position) const = 0;
+    virtual QString textAt(int position, int length) const = 0;
+    virtual QTextCursor textCursorAt(int position) const = 0;
+
+    virtual void setCursorPosition(int position) = 0;
+    virtual bool replace(int position, int length, const QString &text) = 0;
+    virtual void insertCodeSnippet(int position, const QString &text) = 0;
+    virtual void paste() = 0;
+    virtual void encourageApply() = 0;
+    virtual void autoIndent(int position, int length) = 0;
+};
+
+} // namespace TextEditor
+
+#endif // TEXTDOCUMENTMANIPULATORINTERFACE_H

src/plugins/texteditor/texteditor.h

@@ -87,15 +87,6 @@ class MarginSettings;
 class StorageSettings;
 class TypingSettings;
 
-enum TextPositionOperation
-{
-    CurrentPosition = 1,
-    EndOfLinePosition = 2,
-    StartOfLinePosition = 3,
-    AnchorPosition = 4,
-    EndOfDocPosition = 5
-};
-
 enum TextMarkRequestKind
 {
     BreakpointRequest,

src/plugins/texteditor/texteditor.pro

@@ -87,6 +87,7 @@ SOURCES += texteditorplugin.cpp \
     codeassist/genericproposal.cpp \
     codeassist/genericproposalwidget.cpp \
     codeassist/iassistproposalmodel.cpp \
+    codeassist/textdocumentmanipulator.cpp \
     tabsettingswidget.cpp \
     simplecodestylepreferences.cpp \
     simplecodestylepreferenceswidget.cpp \
@@ -197,6 +198,8 @@ HEADERS += texteditorplugin.h \
     codeassist/genericproposal.h \
     codeassist/genericproposalwidget.h \
     codeassist/iassistproposalmodel.h \
+    codeassist/textdocumentmanipulator.h \
+    codeassist/textdocumentmanipulatorinterface.h \
     tabsettingswidget.h \
     simplecodestylepreferences.h \
     simplecodestylepreferenceswidget.h \

src/plugins/texteditor/texteditor.qbs

@@ -115,6 +115,9 @@ QtcPlugin {
         "textdocument.h",
         "textdocumentlayout.cpp",
         "textdocumentlayout.h",
+        "textdocumentmanipulator.cpp",
+        "textdocumentmanipulator.h",
+        "textdocumentmanipulatorinterface.h",
         "texteditor.cpp",
         "texteditor.h",
         "texteditor.qrc",

src/plugins/texteditor/texteditor_global.h

@@ -34,4 +34,17 @@
 #  define TEXTEDITOR_EXPORT Q_DECL_IMPORT
 #endif
 
+namespace TextEditor {
+
+enum TextPositionOperation
+{
+    CurrentPosition = 1,
+    EndOfLinePosition = 2,
+    StartOfLinePosition = 3,
+    AnchorPosition = 4,
+    EndOfDocPosition = 5
+};
+
+} // namespace TextEditor
+
 #endif // TEXTEDITOR_GLOBAL_H