TextEditor: correctly highlight preedit text

Fixes: QTCREATORBUG-29134
Change-Id: I8c5cdab8c5b2e5a2380c9e4aeadaf1bd72e60e09
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

4 files changed, 91 insertions, 5 deletions

diff --git a/src/plugins/texteditor/highlighter_test.cpp b/src/plugins/texteditor/highlighter_test.cpp
index f0652a780b3..89b5196a864 100644
--- a/src/plugins/texteditor/highlighter_test.cpp
+++ b/src/plugins/texteditor/highlighter_test.cpp
@@ -185,6 +185,28 @@ void GenerigHighlighterTests::testChange()
         compareFormats(actualFormats.at(i), formatRanges.at(i));
 }
 
+void GenerigHighlighterTests::testPreeditText()
+{
+    QTextBlock block = m_editor->textDocument()->document()->findBlockByNumber(2);
+    QVERIFY(block.isValid());
+
+    block.layout()->setPreeditArea(7, "uaf");
+    m_editor->textDocument()->syntaxHighlighter()->rehighlight();
+
+    const FormatRanges formatRanges = {{0, 4, toFormat(C_VISUAL_WHITESPACE)},
+                                       {4, 3, toFormat(C_TYPE)},
+                                       {10, 3, toFormat(C_TYPE)},
+                                       {13, 1, toFormat(C_FUNCTION)},
+                                       {14, 1, toFormat(C_VISUAL_WHITESPACE)},
+                                       {15, 6, toFormat(C_STRING)},
+                                       {21, 1, toFormat(C_FUNCTION)}};
+    const QList<QTextLayout::FormatRange> actualFormats = block.layout()->formats();
+    // full hash calculation for QTextCharFormat fails so just check the important entries of format
+    QCOMPARE(actualFormats.size(), formatRanges.size());
+    for (int i = 0; i < formatRanges.size(); ++i)
+        compareFormats(actualFormats.at(i), formatRanges.at(i));
+}
+
 void GenerigHighlighterTests::cleanupTestCase()
 {
     if (m_editor)
diff --git a/src/plugins/texteditor/highlighter_test.h b/src/plugins/texteditor/highlighter_test.h
index 30c2848c5c1..3e638783d54 100644
--- a/src/plugins/texteditor/highlighter_test.h
+++ b/src/plugins/texteditor/highlighter_test.h
@@ -17,6 +17,7 @@ private slots:
     void testHighlight_data();
     void testHighlight();
     void testChange();
+    void testPreeditText();
     void cleanupTestCase();
 
 private:
diff --git a/src/plugins/texteditor/syntaxhighlighter.cpp b/src/plugins/texteditor/syntaxhighlighter.cpp
index 6d2616193ef..21db8c0cd32 100644
--- a/src/plugins/texteditor/syntaxhighlighter.cpp
+++ b/src/plugins/texteditor/syntaxhighlighter.cpp
@@ -17,6 +17,12 @@
 
 namespace TextEditor {
 
+enum HighlighterTypeProperty
+{
+    SyntaxHighlight = QTextFormat::UserProperty + 1,
+    SemanticHighlight = QTextFormat::UserProperty + 2
+};
+
 class SyntaxHighlighterPrivate
 {
     SyntaxHighlighter *q_ptr = nullptr;
@@ -98,9 +104,9 @@ void SyntaxHighlighterPrivate::applyFormatChanges(int from, int charsRemoved, in
 
     QVector<QTextLayout::FormatRange> ranges;
     QVector<QTextLayout::FormatRange> oldRanges;
-    std::tie(ranges, oldRanges)
+    std::tie(oldRanges, ranges)
         = Utils::partition(layout->formats(), [](const QTextLayout::FormatRange &range) {
-              return range.format.property(QTextFormat::UserProperty).toBool();
+              return range.format.property(SyntaxHighlight).toBool();
           });
 
     if (currentBlock.contains(from)) {
@@ -129,8 +135,23 @@ void SyntaxHighlighterPrivate::applyFormatChanges(int from, int charsRemoved, in
         while (i < formatChanges.count() && formatChanges.at(i) == r.format)
             ++i;
 
+        r.format.setProperty(SyntaxHighlight, true);
         r.length = i - r.start;
 
+        const QString preeditText = currentBlock.layout()->preeditAreaText();
+        if (!preeditText.isEmpty()) {
+            const int preeditPosition = currentBlock.layout()->preeditAreaPosition();
+            if (r.start >= preeditPosition) {
+                r.start += preeditText.length();
+            } else if (r.start + r.length > preeditPosition) {
+                QTextLayout::FormatRange beforePreeditRange = r;
+                r.start = preeditPosition + preeditText.length();
+                r.length = r.length - (r.start - preeditPosition);
+                beforePreeditRange.length = preeditPosition - beforePreeditRange.start;
+                newRanges << beforePreeditRange;
+            }
+        }
+
         newRanges << r;
     }
 
@@ -656,6 +677,24 @@ void SyntaxHighlighter::setExtraFormats(const QTextBlock &block,
     if (block.layout() == nullptr || blockLength == 0)
         return;
 
+    const QString preeditText = block.layout()->preeditAreaText();
+    if (!preeditText.isEmpty()) {
+        QVector<QTextLayout::FormatRange> additionalRanges;
+        const int preeditPosition = block.layout()->preeditAreaPosition();
+        for (QTextLayout::FormatRange &r : formats) {
+            if (r.start >= preeditPosition) {
+                r.start += preeditText.length();
+            } else if (r.start + r.length > preeditPosition) {
+                QTextLayout::FormatRange afterPreeditRange = r;
+                afterPreeditRange.start = preeditPosition + preeditText.length();
+                afterPreeditRange.length = r.length - (preeditPosition - r.start);
+                additionalRanges << afterPreeditRange;
+                r.length = preeditPosition - r.start;
+            }
+        }
+        formats << additionalRanges;
+    }
+
     Utils::sort(formats, byStartOfRange);
 
     const QVector<QTextLayout::FormatRange> all = block.layout()->formats();
@@ -663,11 +702,11 @@ void SyntaxHighlighter::setExtraFormats(const QTextBlock &block,
     QVector<QTextLayout::FormatRange> formatsToApply;
     std::tie(previousSemanticFormats, formatsToApply)
         = Utils::partition(all, [](const QTextLayout::FormatRange &r) {
-              return r.format.hasProperty(QTextFormat::UserProperty);
+              return r.format.property(SemanticHighlight).toBool();
           });
 
     for (auto &format : formats)
-        format.format.setProperty(QTextFormat::UserProperty, true);
+        format.format.setProperty(SemanticHighlight, true);
 
     if (formats.size() == previousSemanticFormats.size()) {
         Utils::sort(previousSemanticFormats, byStartOfRange);
@@ -694,7 +733,7 @@ void SyntaxHighlighter::clearExtraFormats(const QTextBlock &block)
 
     const QVector<QTextLayout::FormatRange> formatsToApply
         = Utils::filtered(block.layout()->formats(), [](const QTextLayout::FormatRange &r) {
-              return !r.format.hasProperty(QTextFormat::UserProperty);
+              return !r.format.property(SemanticHighlight).toBool();
           });
 
     bool wasInReformatBlocks = d->inReformatBlocks;
diff --git a/tests/auto/texteditor/highlighter/tst_highlighter.cpp b/tests/auto/texteditor/highlighter/tst_highlighter.cpp
index e3f4e3dced6..7c30d3371ea 100644
--- a/tests/auto/texteditor/highlighter/tst_highlighter.cpp
+++ b/tests/auto/texteditor/highlighter/tst_highlighter.cpp
@@ -26,6 +26,7 @@ private slots:
     void test_setExtraAdditionalFormats();
     void test_clearExtraFormats();
     void test_incrementalApplyAdditionalFormats();
+    void test_preeditText();
     void cleanup();
 
 private:
@@ -235,6 +236,7 @@ void tst_highlighter::test_incrementalApplyAdditionalFormats()
                                                                 formatHash);
 
     formats = firstBlock.layout()->formats();
+    QCOMPARE(formats.size(), 1);
     QCOMPARE(formats.at(0).format.fontItalic(), true);
     QCOMPARE(formats.at(0).format.fontOverline(), false);
     QCOMPARE(formats.at(0).start, 0);
@@ -338,6 +340,28 @@ void tst_highlighter::test_incrementalApplyAdditionalFormats()
     QCOMPARE(formats.at(1).length, 2);
 }
 
+void tst_highlighter::test_preeditText()
+{
+    QCOMPARE(doc->blockCount(), 4);
+
+    QTextBlock firstBlock = doc->findBlockByNumber(0);
+    firstBlock.layout()->setPreeditArea(2, "uaf");
+
+    SemanticHighlighter::setExtraAdditionalFormats(highlighter, highlightingResults(), formatHash);
+
+    auto formats = firstBlock.layout()->formats();
+    QCOMPARE(formats.size(), 2);
+    QCOMPARE(formats.at(0).format.fontItalic(), true);
+    QCOMPARE(formats.at(0).format.fontOverline(), false);
+    QCOMPARE(formats.at(0).start, 0);
+    QCOMPARE(formats.at(0).length, 2);
+
+    QCOMPARE(formats.at(1).format.fontItalic(), true);
+    QCOMPARE(formats.at(1).format.fontOverline(), false);
+    QCOMPARE(formats.at(1).start, 5);
+    QCOMPARE(formats.at(1).length, 3);
+}
+
 void tst_highlighter::cleanup()
 {
     delete doc;