TextEditor: Add option to display annotation between lines

Task-number: QTCREATORBUG-19181
Change-Id: I9b3957c678c08ca2f3ddf9cfa5ff272241547471
Reviewed-by: Marco Bubke <marco.bubke@qt.io>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

doc/src/editors/creator-editors.qdoc

@@ -204,9 +204,11 @@
 
     To specify the position where the annotations are displayed, select
     \uicontrol Tools > \uicontrol Options > \uicontrol {Text Editor} >
-    \uicontrol Display > \uicontrol {Annotations next to lines}, and then
+    \uicontrol Display > \uicontrol {Line annotations}, and then
     select whether to display the annotations directly next to the code,
-    aligned to the right of the code, or in the right margin.
+    aligned to the right of the code, or in the right margin. Showing annotations
+    between lines can be useful if there is usually not enough space to
+    display annotations next to the text.
 
     If you hide the annotations by deselecting the check box, you can move the
     mouse pointer over an icon to view them.

src/plugins/texteditor/displaysettings.h

@@ -40,7 +40,8 @@ enum class AnnotationAlignment
 {
     NextToContent,
     NextToMargin,
-    RightSide
+    RightSide,
+    BetweenLines
 };
 
 class TEXTEDITOR_EXPORT DisplaySettings

src/plugins/texteditor/displaysettingspage.cpp

@@ -126,6 +126,8 @@ void DisplaySettingsPage::settingsFromUI(DisplaySettings &displaySettings,
         displaySettings.m_annotationAlignment = AnnotationAlignment::NextToMargin;
     else if (d->m_page->rightAligned->isChecked())
         displaySettings.m_annotationAlignment = AnnotationAlignment::RightSide;
+    else if (d->m_page->betweenLines->isChecked())
+        displaySettings.m_annotationAlignment = AnnotationAlignment::BetweenLines;
 }
 
 void DisplaySettingsPage::settingsToUI()
@@ -154,6 +156,7 @@ void DisplaySettingsPage::settingsToUI()
     case AnnotationAlignment::NextToContent: d->m_page->leftAligned->setChecked(true); break;
     case AnnotationAlignment::NextToMargin: d->m_page->atMargin->setChecked(true); break;
     case AnnotationAlignment::RightSide: d->m_page->rightAligned->setChecked(true); break;
+    case AnnotationAlignment::BetweenLines: d->m_page->betweenLines->setChecked(true); break;
     }
 }
 

src/plugins/texteditor/displaysettingspage.ui

@@ -187,7 +187,7 @@
    <item row="2" column="0">
     <widget class="QGroupBox" name="displayAnnotations">
      <property name="title">
-      <string>Annotations next to lines</string>
+      <string>Line annotations</string>
      </property>
      <property name="checkable">
       <bool>true</bool>
@@ -217,6 +217,13 @@
         </property>
        </widget>
       </item>
+      <item>
+       <widget class="QRadioButton" name="betweenLines">
+        <property name="text">
+         <string>Between lines</string>
+        </property>
+       </widget>
+      </item>
      </layout>
     </widget>
    </item>

src/plugins/texteditor/textdocumentlayout.cpp

@@ -634,6 +634,14 @@ void TextDocumentLayout::updateMarksBlock(const QTextBlock &block)
             mrk->updateBlock(block);
 }
 
+QRectF TextDocumentLayout::blockBoundingRect(const QTextBlock &block) const
+{
+    QRectF boundingRect = QPlainTextDocumentLayout::blockBoundingRect(block);
+    if (TextBlockUserData *userData = testUserData(block))
+        boundingRect.adjust(0, 0, 0, userData->additionalAnnotationHeight());
+    return boundingRect;
+}
+
 TextDocumentLayout::FoldValidator::FoldValidator()
     : m_layout(0)
     , m_requestDocUpdate(false)

src/plugins/texteditor/textdocumentlayout.h

@@ -126,6 +126,9 @@ public:
     inline int lexerState() const { return m_lexerState; }
     inline void setLexerState(int state) {m_lexerState = state; }
 
+    inline void setAdditionalAnnotationHeight(int annotationHeight)
+    { m_additionalAnnotationHeight = annotationHeight; }
+    inline int additionalAnnotationHeight() const { return m_additionalAnnotationHeight; }
 
     CodeFormatterData *codeFormatterData() const { return m_codeFormatterData; }
     void setCodeFormatterData(CodeFormatterData *data);
@@ -138,6 +141,7 @@ private:
     uint m_lexerState : 8;
     uint m_foldingStartIncluded : 1;
     uint m_foldingEndIncluded : 1;
+    int m_additionalAnnotationHeight = 0;
     Parentheses m_parentheses;
     CodeFormatterData *m_codeFormatterData;
 };
@@ -210,7 +214,8 @@ public:
 
     void setRequiredWidth(int width);
 
-    QSizeF documentSize() const;
+    QSizeF documentSize() const override;
+    QRectF blockBoundingRect(const QTextBlock &block) const override;
 
     TextMarks documentClosing();
     void documentReloaded(TextMarks marks, TextDocument *baseextDocument);

src/plugins/texteditor/texteditor.cpp

@@ -459,7 +459,9 @@ public:
                            bool expanded,
                            bool active,
                            bool hovered) const;
-    void updateLineAnnotation(const PaintEventData &data, QPainter &painter);
+    bool updateAnnotationBounds(TextBlockUserData *blockUserData, bool annotationsVisible);
+    void updateLineAnnotation(const PaintEventData &data, const PaintEventBlockData &blockData,
+                              QPainter &painter);
     void paintRightMarginArea(PaintEventData &data, QPainter &painter) const;
     void paintRightMarginLine(const PaintEventData &data, QPainter &painter) const;
     void paintBlockHighlight(const PaintEventData &data, QPainter &painter) const;
@@ -3965,7 +3967,20 @@ QRectF TextEditorWidgetPrivate::getLastLineLineRect(const QTextBlock &block)
     return line.naturalTextRect().translated(contentOffset.x(), top).adjusted(0, 0, -1, -1);
 }
 
+bool TextEditorWidgetPrivate::updateAnnotationBounds(TextBlockUserData *blockUserData, bool annotationsVisible)
+{
+    const bool additionalHeightNeeded = annotationsVisible
+            && m_displaySettings.m_annotationAlignment == AnnotationAlignment::BetweenLines;
+    const int additionalHeight = additionalHeightNeeded ? q->fontMetrics().lineSpacing() : 0;
+    if (blockUserData->additionalAnnotationHeight() == additionalHeight)
+        return false;
+    blockUserData->setAdditionalAnnotationHeight(additionalHeight);
+    q->viewport()->update();
+    return true;
+}
+
 void TextEditorWidgetPrivate::updateLineAnnotation(const PaintEventData &data,
+                                                   const PaintEventBlockData &blockData,
                                                    QPainter &painter)
 {
     m_annotationRects.remove(data.block.blockNumber());
@@ -3978,7 +3993,12 @@ void TextEditorWidgetPrivate::updateLineAnnotation(const PaintEventData &data,
         return;
 
     TextMarks marks = blockUserData->marks();
-    if (marks.isEmpty())
+
+    const bool annotationsVisible = Utils::anyOf(marks, [](const TextMark* mark) {
+        return !mark->lineAnnotation().isEmpty();
+    });
+
+    if (updateAnnotationBounds(blockUserData, annotationsVisible) || !annotationsVisible)
         return;
 
     const QRectF lineRect = getLastLineLineRect(data.block);
@@ -3990,14 +4010,20 @@ void TextEditorWidgetPrivate::updateLineAnnotation(const PaintEventData &data,
     });
 
     const qreal itemOffset = q->fontMetrics().lineSpacing();
-    const qreal initialOffset = itemOffset * 2;
+    const qreal initialOffset = m_displaySettings.m_annotationAlignment == AnnotationAlignment::BetweenLines ? itemOffset / 2 : itemOffset * 2;
     const qreal minimalContentWidth = q->fontMetrics().width('X')
             * m_displaySettings.m_minimalAnnotationContent;
-    QRectF boundingRect(lineRect.topLeft().x(), lineRect.topLeft().y(),
-                        q->viewport()->width() - lineRect.right(), lineRect.height());
     qreal offset = initialOffset;
+    qreal x = 0;
     if (marks.isEmpty())
         return;
+    QRectF boundingRect;
+    if (m_displaySettings.m_annotationAlignment == AnnotationAlignment::BetweenLines) {
+        boundingRect = QRectF(lineRect.bottomLeft(), blockData.boundingRect.bottomRight());
+    } else {
+        boundingRect = QRectF(lineRect.topLeft().x(), lineRect.topLeft().y(),
+                              q->viewport()->width() - lineRect.right(), lineRect.height());
+        x = lineRect.right();
         if (m_displaySettings.m_annotationAlignment == AnnotationAlignment::NextToMargin
                 && data.rightMargin > lineRect.right() + offset
                 && q->viewport()->width() > data.rightMargin + minimalContentWidth) {
@@ -4007,10 +4033,10 @@ void TextEditorWidgetPrivate::updateLineAnnotation(const PaintEventData &data,
             if (boundingRect.width() > 0)
                 offset = qMax(boundingRect.width(), initialOffset);
         }
+    }
 
-    qreal x = lineRect.right();
     for (const TextMark *mark : marks) {
-        boundingRect = QRectF(x, lineRect.top(), q->viewport()->width() - x, lineRect.height());
+        boundingRect = QRectF(x, boundingRect.top(), q->viewport()->width() - x, boundingRect.height());
         if (boundingRect.isEmpty())
             break;
         if (data.eventRect.intersects(boundingRect.toRect()))
@@ -4715,7 +4741,7 @@ void TextEditorWidget::paintEvent(QPaintEvent *e)
             d->paintAdditionalVisualWhitespaces(data, painter, blockData.boundingRect.top());
             d->paintReplacement(data, painter, blockData.boundingRect.top());
         }
-        d->updateLineAnnotation(data, painter);
+        d->updateLineAnnotation(data, blockData, painter);
 
         data.offset.ry() += blockData.boundingRect.height();