Accessibility: Fix boundaries for text functions in QLineEdit

Make the functions work consistently. For example asking for the line at
the cursor position when the cursor was at the end returned an empty
line before.

Task-number: QTBUG-38500
Change-Id: I60fc78c7be129a59c83efcfce6d8fdd16f2c3f65
Reviewed-by: Jan Arve Sæther <jan-arve.saether@digia.com>

3 files changed, 125 insertions, 31 deletions

diff --git a/src/gui/accessible/qaccessible.cpp b/src/gui/accessible/qaccessible.cpp
index 7584e23f2e..f41afd52ef 100644
--- a/src/gui/accessible/qaccessible.cpp
+++ b/src/gui/accessible/qaccessible.cpp
@@ -1917,14 +1917,9 @@ QString QAccessibleTextInterface::textBeforeOffset(int offset, QAccessible::Text
 {
     const QString txt = text(0, characterCount());
 
-    if (txt.isEmpty() || offset < 0 || offset > txt.length()) {
-        *startOffset = *endOffset = -1;
+    *startOffset = *endOffset = -1;
+    if (txt.isEmpty() || offset <= 0 || offset > txt.length())
         return QString();
-    }
-    if (offset == 0) {
-        *startOffset = *endOffset = offset;
-        return QString();
-    }
 
     QTextBoundaryFinder::BoundaryType type;
     switch (boundaryType) {
@@ -1938,10 +1933,8 @@ QString QAccessibleTextInterface::textBeforeOffset(int offset, QAccessible::Text
         type = QTextBoundaryFinder::Sentence;
         break;
     default:
-        // in any other case return the whole line
-        *startOffset = 0;
-        *endOffset = txt.length();
-        return txt;
+        // return empty, this function currently only supports single lines, so there can be no line before
+        return QString();
     }
 
     // keep behavior in sync with QTextCursor::movePosition()!
@@ -1977,14 +1970,9 @@ QString QAccessibleTextInterface::textAfterOffset(int offset, QAccessible::TextB
 {
     const QString txt = text(0, characterCount());
 
-    if (txt.isEmpty() || offset < 0 || offset > txt.length()) {
-        *startOffset = *endOffset = -1;
-        return QString();
-    }
-    if (offset == txt.length()) {
-        *startOffset = *endOffset = offset;
+    *startOffset = *endOffset = -1;
+    if (txt.isEmpty() || offset < 0 || offset >= txt.length())
         return QString();
-    }
 
     QTextBoundaryFinder::BoundaryType type;
     switch (boundaryType) {
@@ -1998,10 +1986,8 @@ QString QAccessibleTextInterface::textAfterOffset(int offset, QAccessible::TextB
         type = QTextBoundaryFinder::Sentence;
         break;
     default:
-        // in any other case return the whole line
-        *startOffset = 0;
-        *endOffset = txt.length();
-        return txt;
+        // return empty, this function currently only supports single lines, so there can be no line after
+        return QString();
     }
 
     // keep behavior in sync with QTextCursor::movePosition()!
@@ -2009,20 +1995,31 @@ QString QAccessibleTextInterface::textAfterOffset(int offset, QAccessible::TextB
     QTextBoundaryFinder boundary(type, txt);
     boundary.setPosition(offset);
 
-    while (boundary.toNextBoundary() < txt.length()) {
+    while (true) {
+        int toNext = boundary.toNextBoundary();
         if ((boundary.boundaryReasons() & (QTextBoundaryFinder::StartOfItem | QTextBoundaryFinder::EndOfItem)))
             break;
+        if (toNext < 0 || toNext >= txt.length())
+            break; // not found, the boundary might not exist
     }
     Q_ASSERT(boundary.position() <= txt.length());
     *startOffset = boundary.position();
 
-    while (boundary.toNextBoundary() < txt.length()) {
+    while (true) {
+        int toNext = boundary.toNextBoundary();
         if ((boundary.boundaryReasons() & (QTextBoundaryFinder::StartOfItem | QTextBoundaryFinder::EndOfItem)))
             break;
+        if (toNext < 0 || toNext >= txt.length())
+            break; // not found, the boundary might not exist
     }
     Q_ASSERT(boundary.position() <= txt.length());
     *endOffset = boundary.position();
 
+    if ((*startOffset == -1) || (*endOffset == -1) || (*startOffset == *endOffset)) {
+        *endOffset = -1;
+        *startOffset = -1;
+    }
+
     return txt.mid(*startOffset, *endOffset - *startOffset);
 }
 
@@ -2037,14 +2034,12 @@ QString QAccessibleTextInterface::textAtOffset(int offset, QAccessible::TextBoun
 {
     const QString txt = text(0, characterCount());
 
-    if (txt.isEmpty() || offset < 0 || offset > txt.length()) {
-        *startOffset = *endOffset = -1;
+    *startOffset = *endOffset = -1;
+    if (txt.isEmpty() || offset < 0 || offset > txt.length())
         return QString();
-    }
-    if (offset == txt.length()) {
-        *startOffset = *endOffset = offset;
+
+    if (offset == txt.length() && boundaryType == QAccessible::CharBoundary)
         return QString();
-    }
 
     QTextBoundaryFinder::BoundaryType type;
     switch (boundaryType) {
@@ -2058,7 +2053,7 @@ QString QAccessibleTextInterface::textAtOffset(int offset, QAccessible::TextBoun
         type = QTextBoundaryFinder::Sentence;
         break;
     default:
-        // in any other case return the whole line
+        // return the whole line
         *startOffset = 0;
         *endOffset = txt.length();
         return txt;
diff --git a/src/widgets/accessible/simplewidgets.cpp b/src/widgets/accessible/simplewidgets.cpp
index 88d3981391..6fd249f372 100644
--- a/src/widgets/accessible/simplewidgets.cpp
+++ b/src/widgets/accessible/simplewidgets.cpp
@@ -752,6 +752,10 @@ QString QAccessibleLineEdit::textBeforeOffset(int offset, QAccessible::TextBound
         *startOffset = *endOffset = -1;
         return QString();
     }
+    if (offset == -1)
+        offset = lineEdit()->text().length();
+    if (offset == -2)
+        offset = cursorPosition();
     return QAccessibleTextInterface::textBeforeOffset(offset, boundaryType, startOffset, endOffset);
 }
 
@@ -762,6 +766,10 @@ QString QAccessibleLineEdit::textAfterOffset(int offset, QAccessible::TextBounda
         *startOffset = *endOffset = -1;
         return QString();
     }
+    if (offset == -1)
+        offset = lineEdit()->text().length();
+    if (offset == -2)
+        offset = cursorPosition();
     return QAccessibleTextInterface::textAfterOffset(offset, boundaryType, startOffset, endOffset);
 }
 
@@ -772,6 +780,10 @@ QString QAccessibleLineEdit::textAtOffset(int offset, QAccessible::TextBoundaryT
         *startOffset = *endOffset = -1;
         return QString();
     }
+    if (offset == -1)
+        offset = lineEdit()->text().length();
+    if (offset == -2)
+        offset = cursorPosition();
     return QAccessibleTextInterface::textAtOffset(offset, boundaryType, startOffset, endOffset);
 }
 
diff --git a/tests/auto/other/qaccessibility/tst_qaccessibility.cpp b/tests/auto/other/qaccessibility/tst_qaccessibility.cpp
index c9df497b07..88f2120e62 100644
--- a/tests/auto/other/qaccessibility/tst_qaccessibility.cpp
+++ b/tests/auto/other/qaccessibility/tst_qaccessibility.cpp
@@ -264,6 +264,8 @@ private slots:
     void mdiAreaTest();
     void mdiSubWindowTest();
     void lineEditTest();
+    void lineEditTextFunctions_data();
+    void lineEditTextFunctions();
     void groupBoxTest();
     void dialogButtonBoxTest();
     void dialTest();
@@ -2293,6 +2295,91 @@ void tst_QAccessibility::lineEditTest()
     QTestAccessibility::clearEvents();
 }
 
+void tst_QAccessibility::lineEditTextFunctions_data()
+{
+    QTest::addColumn<QString>("text");
+    QTest::addColumn<int>("textFunction"); // before = 0, at = 1, after = 2
+    QTest::addColumn<int>("boundaryType");
+    QTest::addColumn<int>("cursorPosition");
+    QTest::addColumn<int>("offset");
+    QTest::addColumn<int>("expectedStart");
+    QTest::addColumn<int>("expectedEnd");
+    QTest::addColumn<QString>("expectedText");
+
+    // -2 gives cursor position, -1 is length
+    // invalid positions will return empty strings and either -1 and -1 or both the cursor position, both is fine
+    QTest::newRow("char before -2") << "hello" << 0 << (int) QAccessible::CharBoundary << 3 << -2 << 2 << 3 << "l";
+    QTest::newRow("char at -2") << "hello" << 1 << (int) QAccessible::CharBoundary << 3 << -2 << 3 << 4 << "l";
+    QTest::newRow("char after -2") << "hello" << 2 << (int) QAccessible::CharBoundary << 3 << -2 << 4 << 5 << "o";
+    QTest::newRow("char before -1") << "hello" << 0 << (int) QAccessible::CharBoundary << 3 << -1 << 4 << 5 << "o";
+    QTest::newRow("char at -1") << "hello" << 1 << (int) QAccessible::CharBoundary << 3 << -1 << -1 << -1 << "";
+    QTest::newRow("char after -1") << "hello" << 2 << (int) QAccessible::CharBoundary << 3 << -1 << -1 << -1 << "";
+    QTest::newRow("char before 0") << "hello" << 0 << (int) QAccessible::CharBoundary << 0 << 0 << -1 << -1 << "";
+    QTest::newRow("char at 0") << "hello" << 1 << (int) QAccessible::CharBoundary << 0 << 0 << 0 << 1 << "h";
+    QTest::newRow("char after 0") << "hello" << 2 << (int) QAccessible::CharBoundary << 0 << 0 << 1 << 2 << "e";
+    QTest::newRow("char before 1") << "hello" << 0 << (int) QAccessible::CharBoundary << 3 << 1 << 0 << 1 << "h";
+    QTest::newRow("char at 1") << "hello" << 1 << (int) QAccessible::CharBoundary << 3 << 1 << 1 << 2 << "e";
+    QTest::newRow("char after 1") << "hello" << 2 << (int) QAccessible::CharBoundary << 3 << 1 << 2 << 3 << "l";
+    QTest::newRow("char before 4") << "hello" << 0 << (int) QAccessible::CharBoundary << 3 << 4 << 3 << 4 << "l";
+    QTest::newRow("char at 4") << "hello" << 1 << (int) QAccessible::CharBoundary << 3 << 4 << 4 << 5 << "o";
+    QTest::newRow("char after 4") << "hello" << 2 << (int) QAccessible::CharBoundary << 3 << 4 << -1 << -1 << "";
+    QTest::newRow("char before 5") << "hello" << 0 << (int) QAccessible::CharBoundary << 3 << 5 << 4 << 5 << "o";
+    QTest::newRow("char at 5") << "hello" << 1 << (int) QAccessible::CharBoundary << 3 << 5 << -1 << -1 << "";
+    QTest::newRow("char after 5") << "hello" << 2 << (int) QAccessible::CharBoundary << 3 << 5 << -1 << -1 << "";
+    QTest::newRow("char before 6") << "hello" << 0 << (int) QAccessible::CharBoundary << 3 << 6 << -1 << -1 << "";
+    QTest::newRow("char at 6") << "hello" << 1 << (int) QAccessible::CharBoundary << 3 << 6 << -1 << -1 << "";
+    QTest::newRow("char after 6") << "hello" << 2 << (int) QAccessible::CharBoundary << 3 << 6 << -1 << -1 << "";
+
+    for (int i = -2; i < 6; ++i) {
+        QTest::newRow(QString::fromLatin1("line before %1").arg(i).toLocal8Bit().constData()) << "hello" << 0 << (int) QAccessible::LineBoundary << 3 << i << -1 << -1 << "";
+        QTest::newRow(QString::fromLatin1("line at %1").arg(i).toLocal8Bit().constData()) << "hello" << 1 << (int) QAccessible::LineBoundary << 3 << i << 0 << 5 << "hello";
+        QTest::newRow(QString::fromLatin1("line after %1").arg(i).toLocal8Bit().constData()) << "hello" << 2 << (int) QAccessible::LineBoundary << 3 << i << -1 << -1 << "";
+    }
+}
+
+void tst_QAccessibility::lineEditTextFunctions()
+{
+    {
+    QFETCH(QString, text);
+    QFETCH(int, textFunction);
+    QFETCH(int, boundaryType);
+    QFETCH(int, cursorPosition);
+    QFETCH(int, offset);
+    QFETCH(int, expectedStart);
+    QFETCH(int, expectedEnd);
+    QFETCH(QString, expectedText);
+
+    QLineEdit le;
+    le.show();
+    le.setText(text);
+    le.setCursorPosition(cursorPosition);
+
+    QAccessibleInterface *iface = QAccessible::queryAccessibleInterface(&le);
+    QVERIFY(iface);
+    QAccessibleTextInterface *textIface = iface->textInterface();
+    QVERIFY(textIface);
+
+    int start = -33;
+    int end = -33;
+    QString result;
+    switch (textFunction) {
+    case 0:
+        result = textIface->textBeforeOffset(offset, (QAccessible::TextBoundaryType) boundaryType, &start, &end);
+        break;
+    case 1:
+        result = textIface->textAtOffset(offset, (QAccessible::TextBoundaryType) boundaryType, &start, &end);
+        break;
+    case 2:
+        result = textIface->textAfterOffset(offset, (QAccessible::TextBoundaryType) boundaryType, &start, &end);
+        break;
+    }
+    QCOMPARE(result, expectedText);
+    QCOMPARE(start, expectedStart);
+    QCOMPARE(end, expectedEnd);
+    }
+    QTestAccessibility::clearEvents();
+}
+
 void tst_QAccessibility::groupBoxTest()
 {
     {