Fix for clipped Vietnamese characters when typed with VKB

Adding tone marks with VKB to Vietnamese vowels caused them to be
clipped from top.

Added character conversion to Symbian VKB handling so that correct
characters without clipping are used.

Task-Number: ou1cimx1#981433
Change-Id: Iaf9f2ce9f5cf42e74cac100658025eb6e20e6487
Reviewed-by: Juha Kukkonen <ext-juha.kukkonen@nokia.com>
Reviewed-by: Pasi Pentikäinen <ext-pasi.a.pentikainen@nokia.com>
(cherry picked from commit 6e5d6d292ba6bcd686367077228b17d02160bee9)

2 files changed, 109 insertions, 0 deletions

diff --git a/src/gui/inputmethod/qcoefepinputcontext_p.h b/src/gui/inputmethod/qcoefepinputcontext_p.h
index 4b36da314d..1b62a256f4 100644
--- a/src/gui/inputmethod/qcoefepinputcontext_p.h
+++ b/src/gui/inputmethod/qcoefepinputcontext_p.h
@@ -132,6 +132,7 @@ private:
     void commitTemporaryPreeditString();
     bool isWidgetVisible(QWidget *widget, int offset = 0);
     bool isPartialKeyboardSupported();
+    bool vietCharConversion(const QEvent *event);
 
 private Q_SLOTS:
     void ensureInputCapabilitiesChanged();
diff --git a/src/gui/inputmethod/qcoefepinputcontext_s60.cpp b/src/gui/inputmethod/qcoefepinputcontext_s60.cpp
index 44a54a321f..5ced556e51 100644
--- a/src/gui/inputmethod/qcoefepinputcontext_s60.cpp
+++ b/src/gui/inputmethod/qcoefepinputcontext_s60.cpp
@@ -101,6 +101,49 @@
 
 _LIT(KAvkonResourceFile, "z:\\resource\\avkon.rsc" );
 
+// Vietnamese tone tables
+const int VietToneMarks = 5;
+
+const QChar VietToneList[VietToneMarks] = {
+        0x0301, 0x0300, 0x0309, 0x0303, 0x0323
+};
+
+const QChar VietVowelList[] = {
+        0x0041, 0x0061, 0x0102, 0x0103, 0x00c2,
+        0x00e2, 0x0045, 0x0065, 0x00ca, 0x00ea,
+        0x0049, 0x0069, 0x004f, 0x006f, 0x00d4,
+        0x00f4, 0x01a0, 0x01a1, 0x0055, 0x0075,
+        0x01af, 0x01b0, 0x0059, 0x0079
+};
+
+const QChar VietToneMatrix[][VietToneMarks] = {
+        // Matrix for each vowel (row) after applying certain tone mark (column)
+        0x00c1, 0x00c0, 0x1ea2, 0x00c3, 0x1ea0,
+        0x00e1, 0x00e0, 0x1ea3, 0x00e3, 0x1ea1,
+        0x1eae, 0x1eb0, 0x1eb2, 0x1eb4, 0x1eb6,
+        0x1eaf, 0x1eb1, 0x1eb3, 0x1eb5, 0x1eb7,
+        0x1ea4, 0x1ea6, 0x1ea8, 0x1eaa, 0x1eac,
+        0x1ea5, 0x1ea7, 0x1ea9, 0x1eab, 0x1ead,
+        0x00c9, 0x00c8, 0x1eba, 0x1ebc, 0x1eb8,
+        0x00e9, 0x00e8, 0x1ebb, 0x1ebd, 0x1eb9,
+        0x1ebe, 0x1ec0, 0x1ec2, 0x1ec4, 0x1ec6,
+        0x1ebf, 0x1ec1, 0x1ec3, 0x1ec5, 0x1ec7,
+        0x00cd, 0x00cc, 0x1ec8, 0x0128, 0x1eca,
+        0x00ed, 0x00ec, 0x1ec9, 0x0129, 0x1ecb,
+        0x00d3, 0x00d2, 0x1ece, 0x00d5, 0x1ecc,
+        0x00f3, 0x00f2, 0x1ecf, 0x00f5, 0x1ecd,
+        0x1ed0, 0x1ed2, 0x1ed4, 0x1ed6, 0x1ed8,
+        0x1ed1, 0x1ed3, 0x1ed5, 0x1ed7, 0x1ed9,
+        0x1eda, 0x1edc, 0x1ede, 0x1ee0, 0x1ee2,
+        0x1edb, 0x1edd, 0x1edf, 0x1ee1, 0x1ee3,
+        0x00da, 0x00d9, 0x1ee6, 0x0168, 0x1ee4,
+        0x00fa, 0x00f9, 0x1ee7, 0x0169, 0x1ee5,
+        0x1ee8, 0x1eea, 0x1eec, 0x1eee, 0x1ef0,
+        0x1ee9, 0x1eeb, 0x1eed, 0x1eef, 0x1ef1,
+        0x00dd, 0x1ef2, 0x1ef6, 0x1ef8, 0x1ef4,
+        0x00fd, 0x1ef3, 0x1ef7, 0x1ef9, 0x1ef5
+};
+
 QT_BEGIN_NAMESPACE
 
 static QWidget* getFocusedChild(const QList<QObject*>& objectList)
@@ -572,11 +615,76 @@ bool QCoeFepInputContext::needsInputPanel()
     }
 }
 
+bool QCoeFepInputContext::vietCharConversion(const QEvent *event)
+{
+    const QKeyEvent *keyEvent = static_cast<const QKeyEvent *>(event);
+    const uint VietVowelListCount = sizeof(VietVowelList)/sizeof(VietVowelList[0]);
+    for (int tone = 0; tone < VietToneMarks; tone++) {
+        if (keyEvent->key() == VietToneList[tone]) {
+            // Vietnamese vowel tone mark pressed, check previous character
+            const int cursor = focusWidget()->inputMethodQuery(Qt::ImCursorPosition).toInt();
+            if (cursor > 0) {
+                QString widgetText = focusWidget()->inputMethodQuery(Qt::ImSurroundingText).toString();
+                for (int vowel = 0; vowel < VietVowelListCount; vowel++) {
+                    if (widgetText[cursor-1].unicode() == VietVowelList[vowel]) {
+                        // Previous character is Vietnamese vowel, replace it from matrix
+                        QList<QInputMethodEvent::Attribute> attributes;
+                        if (event->type() == QEvent::KeyPress) {
+                            QInputMethodEvent imEvent(QString(VietToneMatrix[vowel][tone]), attributes);
+                            sendEvent(imEvent);
+                        } else {
+                            // event->type() == QEvent::KeyRelease
+                            QInputMethodEvent imEvent(QLatin1String(""), attributes);
+                            imEvent.setCommitString(QString(VietToneMatrix[vowel][tone]), -1, 1);
+                            sendEvent(imEvent);
+                        }
+                        return true;
+                    }
+                }
+            }
+            return false;
+        }
+    }
+    if (keyEvent->key() == Qt::Key_Backspace) {
+        // Backspace pressed, check previous character
+        const int cursor = focusWidget()->inputMethodQuery(Qt::ImCursorPosition).toInt();
+        if (cursor > 0) {
+            QString widgetText = focusWidget()->inputMethodQuery(Qt::ImSurroundingText).toString();
+            for (int vowel = 0; vowel < VietVowelListCount; vowel++) {
+                for (int tone = 0; tone < VietToneMarks; tone++) {
+                    if (widgetText[cursor-1].unicode() == VietToneMatrix[vowel][tone]) {
+                        // Previous character is Vietnamese vowel with tone, replace it with plain vowel
+                        QList<QInputMethodEvent::Attribute> attributes;
+                        if (event->type() == QEvent::KeyPress) {
+                            QInputMethodEvent imEvent(QString(VietVowelList[vowel]), attributes);
+                            sendEvent(imEvent);
+                        } else {
+                            // event->type() == QEvent::KeyRelease
+                            QInputMethodEvent imEvent(QLatin1String(""), attributes);
+                            imEvent.setCommitString(QString(VietVowelList[vowel]), -1, 1);
+                            sendEvent(imEvent);
+                        }
+                        return true;
+                    }
+                }
+            }
+        }
+    }
+    return false;
+}
+
 bool QCoeFepInputContext::filterEvent(const QEvent *event)
 {
     if (!focusWidget())
         return false;
 
+    if ((event->type() == QEvent::KeyPress || event->type() == QEvent::KeyRelease) &&
+            QApplication::keyboardInputLocale().language() == QLocale::Vietnamese) {
+        // Vietnamese character conversions
+        if (vietCharConversion(event))
+            return true;
+    }
+
     switch (event->type()) {
     case QEvent::KeyPress:
         commitTemporaryPreeditString();