Support tentative commit string with input method.

Tentative commit string allows input method to notify editor
what is expected to be committed in the place of preedit.
This commit adds such support in QLineEdit.

Change-Id: If855619bc6843652db0d6254f7e7063bb8ad0936
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

src/gui/kernel/qevent.cpp

@@ -1643,6 +1643,17 @@ void QInputMethodEvent::setCommitString(const QString &commitString, int replace
     replace_length = replaceLength;
 }
 
+/*!
+    Sets the tentative commit string to \a tentativeCommitString.
+
+    The tentative commit string is what the preedit string is expected to be committed as.
+    The string can be used within the editor to trigger code that reacts on text changes such as validators.
+*/
+void QInputMethodEvent::setTentativeCommitString(const QString &tentativeCommitString)
+{
+    tentativeCommit = tentativeCommitString;
+}
+
 /*!
     \fn const QList<Attribute> &QInputMethodEvent::attributes() const
 
@@ -1692,6 +1703,14 @@ void QInputMethodEvent::setCommitString(const QString &commitString, int replace
     \sa replacementStart(), setCommitString()
 */
 
+/*!
+    \fn const QString &tentativeCommitString() const
+
+    Returns the text as which preedit string is expected to be committed as.
+    The string can be used within the editor to trigger code that reacts on text changes such as validators.
+
+    \sa setTentativeCommitString()
+*/
 
 /*! \class QInputMethodQueryEvent
 

src/gui/kernel/qevent.h

@@ -428,6 +428,7 @@ public:
     QInputMethodEvent();
     QInputMethodEvent(const QString &preeditText, const QList<Attribute> &attributes);
     void setCommitString(const QString &commitString, int replaceFrom = 0, int replaceLength = 0);
+    void setTentativeCommitString(const QString &tentativeCommitString);
 
     inline const QList<Attribute> &attributes() const { return attrs; }
     inline const QString &preeditString() const { return preedit; }
@@ -435,6 +436,7 @@ public:
     inline const QString &commitString() const { return commit; }
     inline int replacementStart() const { return replace_from; }
     inline int replacementLength() const { return replace_length; }
+    inline const QString &tentativeCommitString() const { return tentativeCommit; }
 
     QInputMethodEvent(const QInputMethodEvent &other);
 
@@ -444,6 +446,7 @@ private:
     QString commit;
     int replace_from;
     int replace_length;
+    QString tentativeCommit;
 };
 
 class Q_GUI_EXPORT QInputMethodQueryEvent : public QEvent

src/widgets/widgets/qlineedit.cpp

@@ -1631,7 +1631,7 @@ QVariant QLineEdit::inputMethodQuery(Qt::InputMethodQuery property) const
     case Qt::ImCursorPosition:
         return QVariant(d->control->cursor());
     case Qt::ImSurroundingText:
-        return QVariant(text());
+        return QVariant(d->control->realText());
     case Qt::ImCurrentSelection:
         return QVariant(selectedText());
     case Qt::ImMaximumTextLength:

src/widgets/widgets/qwidgetlinecontrol.cpp

@@ -429,7 +429,7 @@ void QWidgetLineControl::moveCursor(int pos, bool mark)
 */
 void QWidgetLineControl::processInputMethodEvent(QInputMethodEvent *event)
 {
-    int priorState = 0;
+    int priorState = -1;
     bool isGettingInput = !event->commitString().isEmpty()
             || event->preeditString() != preeditAreaText()
             || event->replacementLength() > 0;
@@ -514,8 +514,16 @@ void QWidgetLineControl::processInputMethodEvent(QInputMethodEvent *event)
         emitCursorPositionChanged();
     else if (m_preeditCursor != oldPreeditCursor)
         emit updateMicroFocus();
-    if (isGettingInput)
+
+    bool tentativeCommitChanged = (m_tentativeCommit != event->tentativeCommitString());
+    if (tentativeCommitChanged) {
+        m_textDirty = true;
+        m_tentativeCommit = event->tentativeCommitString();
+    }
+
+    if (isGettingInput || tentativeCommitChanged)
         finishChange(priorState);
+
     if (selectionChange)
         emit selectionChanged();
 }
@@ -612,7 +620,6 @@ bool QWidgetLineControl::finishChange(int validateFromState, bool update, bool e
         m_validInput = true;
 #ifndef QT_NO_VALIDATOR
         if (m_validator) {
-            m_validInput = false;
             QString textCopy = m_text;
             int cursorCopy = m_cursor;
             m_validInput = (m_validator->validate(textCopy, cursorCopy) != QValidator::Invalid);
@@ -622,6 +629,15 @@ bool QWidgetLineControl::finishChange(int validateFromState, bool update, bool e
                     return true;
                 }
                 m_cursor = cursorCopy;
+
+                if (!m_tentativeCommit.isEmpty()) {
+                    textCopy.insert(m_cursor, m_tentativeCommit);
+                    bool validInput = (m_validator->validate(textCopy, cursorCopy) != QValidator::Invalid);
+                    if (!validInput)
+                        m_tentativeCommit.clear();
+                }
+            } else {
+                m_tentativeCommit.clear();
             }
         }
 #endif

src/widgets/widgets/qwidgetlinecontrol_p.h

@@ -214,11 +214,27 @@ public:
     void setReadOnly(bool enable) { m_readOnly = enable; }
 
     QString text() const
+    {
+        QString content = m_text;
+        if (!m_tentativeCommit.isEmpty())
+            content.insert(m_cursor, m_tentativeCommit);
+        QString res = m_maskData ? stripString(content) : content;
+        return (res.isNull() ? QString::fromLatin1("") : res);
+    }
+    // like text() but doesn't include preedit
+    QString realText() const
     {
         QString res = m_maskData ? stripString(m_text) : m_text;
         return (res.isNull() ? QString::fromLatin1("") : res);
     }
-    void setText(const QString &txt) { internalSetText(txt, -1, false); }
+    void setText(const QString &txt)
+    {
+        if (composeMode())
+            qApp->inputPanel()->reset();
+        m_tentativeCommit.clear();
+        internalSetText(txt, -1, false);
+    }
+
     QString displayText() const { return m_textLayout.text(); }
 
     void backspace();
@@ -379,6 +395,7 @@ private:
     int m_cursor;
     int m_preeditCursor;
     int m_cursorWidth;
+    QString m_tentativeCommit;
     Qt::LayoutDirection m_layoutDirection;
     uint m_hideCursor : 1; // used to hide the m_cursor inside preedit areas
     uint m_separator : 1;

tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp

@@ -279,6 +279,7 @@ private slots:
 
     void selectAndCursorPosition();
     void inputMethodSelection();
+    void inputMethodTentativeCommit();
 
 protected slots:
     void editingFinished();
@@ -3831,5 +3832,30 @@ void tst_QLineEdit::inputMethodSelection()
     QCOMPARE(testWidget->selectionStart(), 12);
 }
 
+void tst_QLineEdit::inputMethodTentativeCommit()
+{
+    // test that basic tentative commit gets to text property on preedit state
+    QList<QInputMethodEvent::Attribute> attributes;
+    QInputMethodEvent event("test", attributes);
+    event.setTentativeCommitString("test");
+    QApplication::sendEvent(testWidget, &event);
+    QCOMPARE(testWidget->text(), QString("test"));
+
+    // tentative commit not allowed present in surrounding text
+    QInputMethodQueryEvent queryEvent(Qt::ImSurroundingText);
+    QApplication::sendEvent(testWidget, &queryEvent);
+    QCOMPARE(queryEvent.value(Qt::ImSurroundingText).toString(), QString(""));
+
+    // if text with tentative commit does not validate, not allowed to be part of text property
+    testWidget->setText(""); // ensure input state is reset
+    QValidator *validator = new QIntValidator(0, 100);
+    testWidget->setValidator(validator);
+    QApplication::sendEvent(testWidget, &event);
+    QCOMPARE(testWidget->text(), QString(""));
+    testWidget->setValidator(0);
+    delete validator;
+}
+
+
 QTEST_MAIN(tst_QLineEdit)
 #include "tst_qlineedit.moc"