beginnings of fancy snippet editing support

src/plugins/texteditor/basetexteditor.cpp

@@ -175,6 +175,7 @@ BaseTextEditor::BaseTextEditor(QWidget *parent)
     setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
 
     d->m_overlay = new TextEditorOverlay(this);
+    d->m_snippetOverlay = new TextEditorOverlay(this);
     d->m_searchResultOverlay = new TextEditorOverlay(this);
 
     d->setupDocumentSignals(d->m_document);
@@ -1080,6 +1081,11 @@ void BaseTextEditor::keyPressEvent(QKeyEvent *e)
     case Qt::Key_Tab:
     case Qt::Key_Backtab: {
         if (ro) break;
+        if (d->m_snippetOverlay->isVisible() && !d->m_snippetOverlay->isEmpty()) {
+            d->snippetTabOrBacktab(e->key() == Qt::Key_Tab);
+            e->accept();
+            return;
+        }
         QTextCursor cursor = textCursor();
         int newPosition;
         if (d->m_document->tabSettings().tabShouldIndent(document(), cursor, &newPosition)) {
@@ -1172,6 +1178,12 @@ void BaseTextEditor::keyPressEvent(QKeyEvent *e)
         }
     }
 
+    if (e->key() == Qt::Key_H && e->modifiers() == Qt::ControlModifier) {
+        universalHelper();
+        e->accept();
+        return;
+    }
+
     if (ro || e->text().isEmpty() || !e->text().at(0).isPrint()) {
         QPlainTextEdit::keyPressEvent(e);
     } else if ((e->modifiers() & (Qt::ControlModifier|Qt::AltModifier)) != Qt::ControlModifier){
@@ -1189,6 +1201,9 @@ void BaseTextEditor::keyPressEvent(QKeyEvent *e)
             }
         }
 
+        if (d->m_snippetOverlay->isVisible())
+            d->snippetCheckCursor(cursor);
+
         bool doEditBlock = !(electricChar.isNull() && autoText.isEmpty());
         if (doEditBlock)
             cursor.beginEditBlock();
@@ -1221,6 +1236,28 @@ skip_event:
         delete e;
 }
 
+void BaseTextEditor::universalHelper()
+{
+    QList<QTextEdit::ExtraSelection> selections;
+    QTextCursor cursor = textCursor();
+    cursor.beginEditBlock();
+    int pos = cursor.position();
+    cursor.insertText("if (condition){\n        \n    }\n");
+    QTextCursor c = cursor;
+    c.setPosition(pos + 3); // condition-1;
+    c.setPosition(c.position() + 10, QTextCursor::KeepAnchor);
+    QTextEdit::ExtraSelection selection;
+    selection.cursor = c;
+    selection.format.setBackground(Qt::darkCyan);
+    selections.append(selection);
+    c.setPosition(pos + 24); // contents
+    selection.cursor = c;
+    selection.format.setBackground(Qt::darkMagenta);
+    selections.append(selection);
+    cursor.endEditBlock();
+    setExtraSelections(BaseTextEditor::SnippetPlaceholderSelection, selections);
+}
+
 void BaseTextEditor::setTextCursor(const QTextCursor &cursor)
 {
     // workaround for QTextControl bug
@@ -1611,6 +1648,55 @@ void BaseTextEditorPrivate::setupDocumentSignals(BaseTextDocument *document)
     q->slotUpdateExtraAreaWidth();
 }
 
+
+void BaseTextEditorPrivate::snippetCheckCursor(const QTextCursor &cursor)
+{
+    if (cursor.hasSelection())
+        return;
+    if (!m_snippetOverlay->isVisible() || m_snippetOverlay->isEmpty())
+        return;
+    if (!m_snippetOverlay->hasCursorInSelection(cursor)) {
+        m_snippetOverlay->setVisible(false);
+        m_snippetOverlay->clear();
+    }
+}
+
+void BaseTextEditorPrivate::snippetTabOrBacktab(bool forward)
+{
+    if (!m_snippetOverlay->isVisible() || m_snippetOverlay->isEmpty())
+        return;
+    QTextCursor cursor = q->textCursor();
+    OverlaySelection final;
+    if (forward) {
+        for (int i = 0; i < m_snippetOverlay->m_selections.count(); ++i){
+            const OverlaySelection &selection = m_snippetOverlay->m_selections.at(i);
+            if (selection.m_cursor_begin.position() > cursor.position()) {
+                final = selection;
+                break;
+            }
+        }
+    } else {
+        for (int i = m_snippetOverlay->m_selections.count()-1; i >= 0; --i){
+            const OverlaySelection &selection = m_snippetOverlay->m_selections.at(i);
+            if (selection.m_cursor_end.position() < cursor.position()) {
+                final = selection;
+                break;
+            }
+        }
+
+    }
+    if (final.m_cursor_begin.isNull())
+        final = forward ? m_snippetOverlay->m_selections.first() : m_snippetOverlay->m_selections.last();
+
+    if (final.m_cursor_begin.position() == final.m_cursor_end.position()) { // empty tab stop
+        cursor.setPosition(final.m_cursor_end.position());
+    } else {
+        cursor.setPosition(final.m_cursor_begin.position()+1);
+        cursor.setPosition(final.m_cursor_end.position(), QTextCursor::KeepAnchor);
+    }
+    q->setTextCursor(cursor);
+}
+
 bool Parenthesis::hasClosingCollapse(const Parentheses &parentheses)
 {
     return closeCollapseAtPos(parentheses) >= 0;
@@ -1906,9 +1992,10 @@ void BaseTextEditorPrivate::highlightSearchResults(const QTextBlock &block,
             overlay->addOverlaySelection(blockPosition + idx,
                                          blockPosition + idx + l,
                                          m_searchResultFormat.background().color().darker(120),
-                                         QColor(), false,
+                                         QColor(),
                                          (idx == cursor.selectionStart() - blockPosition
-                                          && idx + l == cursor.selectionEnd() - blockPosition));
+                                          && idx + l == cursor.selectionEnd() - blockPosition)?
+                                         TextEditorOverlay::DropShadow : 0);
 
         }
     }
@@ -2516,6 +2603,9 @@ void BaseTextEditor::paintEvent(QPaintEvent *e)
 
     if (d->m_overlay && d->m_overlay->isVisible())
         d->m_overlay->paint(&painter, e->rect());
+
+    if (d->m_snippetOverlay && d->m_snippetOverlay->isVisible())
+        d->m_snippetOverlay->paint(&painter, e->rect());
     
     if (!d->m_searchResultOverlay->isEmpty()) {
         d->m_searchResultOverlay->paint(&painter, e->rect());
@@ -4578,14 +4668,22 @@ void BaseTextEditor::setExtraSelections(ExtraSelectionKind kind, const QList<QTe
             d->m_overlay->addOverlaySelection(selection.cursor,
                                               selection.format.background().color(),
                                               selection.format.background().color(),
-                                              true);
+                                              TextEditorOverlay::LockSize);
         }
         d->m_overlay->setVisible(!d->m_overlay->isEmpty());
-
+    } else if (kind == SnippetPlaceholderSelection) {
+        d->m_snippetOverlay->clear();
+        foreach (const QTextEdit::ExtraSelection &selection, d->m_extraSelections[kind]) {
+            d->m_snippetOverlay->addOverlaySelection(selection.cursor,
+                                              selection.format.background().color(),
+                                              selection.format.background().color(),
+                                              TextEditorOverlay::ExpandBegin);
+        }
+        d->m_snippetOverlay->setVisible(!d->m_snippetOverlay->isEmpty());
     } else {
         QList<QTextEdit::ExtraSelection> all;
         for (int i = 0; i < NExtraSelectionKinds; ++i) {
-            if (i == CodeSemanticsSelection)
+            if (i == CodeSemanticsSelection || i == SnippetPlaceholderSelection)
                 continue;
             all += d->m_extraSelections[i];
         }

src/plugins/texteditor/basetexteditor.h

@@ -482,6 +482,7 @@ public:
         UnusedSymbolSelection,
         FakeVimSelection,
         OtherSelection,
+        SnippetPlaceholderSelection,
         NExtraSelectionKinds
     };
     void setExtraSelections(ExtraSelectionKind kind, const QList<QTextEdit::ExtraSelection> &selections);
@@ -635,6 +636,8 @@ private:
     void showLink(const Link &);
     void clearLink();
 
+    void universalHelper(); // test function for development
+
     // parentheses matcher
 private slots:
     void _q_matchParentheses();

src/plugins/texteditor/basetexteditor_p.h

@@ -194,7 +194,10 @@ public:
     int extraAreaHighlightCollapseColumn;
 
     TextEditorOverlay *m_overlay;
+    TextEditorOverlay *m_snippetOverlay;
     TextEditorOverlay *m_searchResultOverlay;
+    void snippetCheckCursor(const QTextCursor &cursor);
+    void snippetTabOrBacktab(bool forward);
 
     QBasicTimer collapsedBlockTimer;
     int visibleCollapsedBlockNumber;

src/plugins/texteditor/texteditoroverlay.cpp

@@ -57,8 +57,8 @@ void TextEditorOverlay::setVisible(bool b)
 {
     if (m_visible == b)
         return;
-    m_visible = b;
     update();
+    m_visible = b;
 }
 
 void TextEditorOverlay::clear()
@@ -71,8 +71,7 @@ void TextEditorOverlay::clear()
 
 void TextEditorOverlay::addOverlaySelection(int begin, int end,
                                             const QColor &fg, const QColor &bg,
-                                            bool lockSize,
-                                            bool dropShadow)
+                                            uint overlaySelectionFlags)
 {
     if (end < begin)
         return;
@@ -83,26 +82,31 @@ void TextEditorOverlay::addOverlaySelection(int begin, int end,
     selection.m_fg = fg;
     selection.m_bg = bg;
 
+    if (overlaySelectionFlags & ExpandBegin) {
+        if (begin > 0 && begin < end) { // not empty
+            selection.m_expandBegin = true;
+        }
+    }
+
     selection.m_cursor_begin = QTextCursor(document->docHandle(), begin);
     selection.m_cursor_end = QTextCursor(document->docHandle(), end);
 
-    if (lockSize)
+    if (overlaySelectionFlags & LockSize)
         selection.m_fixedLength = (end - begin);
 
-    selection.m_dropShadow = dropShadow;
 
-    if (dropShadow)
-        m_selections.append(selection);
-    else
-        m_selections.prepend(selection);
+    selection.m_dropShadow = (overlaySelectionFlags & DropShadow);
+
+    m_selections.append(selection);
     update();
 }
 
 
 void TextEditorOverlay::addOverlaySelection(const QTextCursor &cursor,
-                                            const QColor &fg, const QColor &bg, bool lockSize)
+                                            const QColor &fg, const QColor &bg,
+                                            uint overlaySelectionFlags)
 {
-    addOverlaySelection(cursor.selectionStart(), cursor.selectionEnd(), fg, bg, lockSize);
+    addOverlaySelection(cursor.selectionStart(), cursor.selectionEnd(), fg, bg, overlaySelectionFlags);
 }
 
 QRect TextEditorOverlay::rect() const
@@ -296,13 +300,18 @@ void TextEditorOverlay::paintSelection(QPainter *painter,
                                        const OverlaySelection &selection)
 {
 
-    const QTextCursor &begin = selection.m_cursor_begin;
+    QTextCursor begin = selection.m_cursor_begin;
+    if (selection.m_expandBegin)
+        begin.setPosition(begin.position() + 1);
+
     const QTextCursor &end= selection.m_cursor_end;
     const QColor &fg = selection.m_fg;
     const QColor &bg = selection.m_bg;
 
 
-    if (begin.isNull() || end.isNull() || begin.position() > end.position())
+    if (begin.isNull()
+        || end.isNull()
+        || begin.position() > end.position())
         return;
 
     QPainterPath path = createSelectionPath(begin, end, m_editor->viewport()->rect());
@@ -377,8 +386,21 @@ void TextEditorOverlay::fillSelection(QPainter *painter,
 void TextEditorOverlay::paint(QPainter *painter, const QRect &clip)
 {
     Q_UNUSED(clip);
-    for (int i = 0; i < m_selections.size(); ++i) {
+    for (int i = m_selections.size()-1; i >= 0; --i) {
         const OverlaySelection &selection = m_selections.at(i);
+        if (selection.m_dropShadow)
+            continue;
+        if (selection.m_fixedLength >= 0
+            && selection.m_cursor_end.position() - selection.m_cursor_begin.position()
+            != selection.m_fixedLength)
+            continue;
+
+        paintSelection(painter, selection);
+    }
+    for (int i = m_selections.size()-1; i >= 0; --i) {
+        const OverlaySelection &selection = m_selections.at(i);
+        if (!selection.m_dropShadow)
+            continue;
         if (selection.m_fixedLength >= 0
             && selection.m_cursor_end.position() - selection.m_cursor_begin.position()
             != selection.m_fixedLength)
@@ -391,8 +413,21 @@ void TextEditorOverlay::paint(QPainter *painter, const QRect &clip)
 void TextEditorOverlay::fill(QPainter *painter, const QColor &color, const QRect &clip)
 {
     Q_UNUSED(clip);
-    for (int i = 0; i < m_selections.size(); ++i) {
+    for (int i = m_selections.size()-1; i >= 0; --i) {
+        const OverlaySelection &selection = m_selections.at(i);
+        if (selection.m_dropShadow)
+            continue;
+        if (selection.m_fixedLength >= 0
+            && selection.m_cursor_end.position() - selection.m_cursor_begin.position()
+            != selection.m_fixedLength)
+            continue;
+
+        fillSelection(painter, selection, color);
+    }
+    for (int i = m_selections.size()-1; i >= 0; --i) {
         const OverlaySelection &selection = m_selections.at(i);
+        if (!selection.m_dropShadow)
+            continue;
         if (selection.m_fixedLength >= 0
             && selection.m_cursor_end.position() - selection.m_cursor_begin.position()
             != selection.m_fixedLength)
@@ -402,3 +437,13 @@ void TextEditorOverlay::fill(QPainter *painter, const QColor &color, const QRect
     }
 }
 
+bool TextEditorOverlay::hasCursorInSelection(const QTextCursor &cursor) const
+{
+    for (int i = 0; i < m_selections.size(); ++i) {
+        const OverlaySelection &selection = m_selections.at(i);
+        if (cursor.position() > selection.m_cursor_begin.position()
+            && cursor.position() <= selection.m_cursor_end.position())
+            return true;
+    }
+    return false;
+}

src/plugins/texteditor/texteditoroverlay.h

@@ -37,13 +37,14 @@ namespace TextEditor {
 namespace Internal {
 
 struct TEXTEDITOR_EXPORT OverlaySelection {
-    OverlaySelection():m_fixedLength(-1), m_dropShadow(false){}
+    OverlaySelection():m_fixedLength(-1), m_dropShadow(false), m_expandBegin(false){}
     QTextCursor m_cursor_begin;
     QTextCursor m_cursor_end;
     QColor m_fg;
     QColor m_bg;
     int m_fixedLength;
     bool m_dropShadow;
+    bool m_expandBegin;
 };
 
 class TEXTEDITOR_EXPORT TextEditorOverlay : public QObject
@@ -78,13 +79,24 @@ public:
     void setAlpha(bool enabled) { m_alpha = enabled; }
 
     void clear();
-    void addOverlaySelection(const QTextCursor &cursor, const QColor &fg, const QColor &bg, bool lockSize = false);
-    void addOverlaySelection(int begin, int end, const QColor &fg, const QColor &bg, bool lockSize = false, bool dropShadow = false);
+
+    enum OverlaySelectionFlags {
+        LockSize = 1,
+        DropShadow = 2,
+        ExpandBegin = 4
+    };
+
+    void addOverlaySelection(const QTextCursor &cursor, const QColor &fg, const QColor &bg,
+                             uint overlaySelectionFlags = 0);
+    void addOverlaySelection(int begin, int end, const QColor &fg, const QColor &bg,
+                             uint overlaySelectionFlags = 0);
 
     inline bool isEmpty() const { return m_selections.isEmpty(); }
 
     inline int dropShadowWidth() const { return m_dropShadowWidth; }
 
+    bool hasCursorInSelection(const QTextCursor &cursor) const;
+
 private:
     QPainterPath createSelectionPath(const QTextCursor &begin, const QTextCursor &end, const QRect& clip);
     void paintSelection(QPainter *painter, const OverlaySelection &selection);