From 8170501502623a0418156f1f880cf7e4f85c34c7 Mon Sep 17 00:00:00 2001
From: David Schulz <david.schulz@qt.io>
Date: Mon, 4 Jul 2022 16:16:40 +0200
Subject: [PATCH] Editor: visualize indent

Paint a horizontal line every indent size in the whitespace at the start
of each block.

Fixes: QTCREATORBUG-22756
Change-Id: I044ccb4adefa4c8c9a3a610f0e996a810487fa1e
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>
---
 share/qtcreator/styles/creator-dark.xml       |   2 +-
 share/qtcreator/styles/dark.xml               |   1 +
 .../styles/modnokai_night_shift_v2.xml        |   2 +-
 share/qtcreator/styles/solarized-dark.xml     |   2 +-
 src/plugins/texteditor/displaysettings.cpp    |   4 +
 src/plugins/texteditor/displaysettings.h      |   1 +
 .../texteditor/displaysettingspage.cpp        |   2 +
 src/plugins/texteditor/displaysettingspage.ui | 123 ++++++++++--------
 src/plugins/texteditor/texteditor.cpp         |  44 ++++++-
 9 files changed, 123 insertions(+), 58 deletions(-)

diff --git a/share/qtcreator/styles/creator-dark.xml b/share/qtcreator/styles/creator-dark.xml
index dbb18ae47c8..c0092f46aaa 100644
--- a/share/qtcreator/styles/creator-dark.xml
+++ b/share/qtcreator/styles/creator-dark.xml
@@ -38,7 +38,7 @@
   <style name="Comment" foreground="#a8abb0" italic="true"/>
   <style name="Doxygen.Comment" foreground="#65676a" bold="true" italic="true"/>
   <style name="Doxygen.Tag" foreground="#66a334"/>
-  <style name="VisualWhitespace" foreground="#bec0c2"/>
+  <style name="VisualWhitespace" foreground="#65676a"/>
   <style name="QmlLocalId" foreground="#9acfd6" italic="true"/>
   <style name="QmlExternalId" foreground="#9aa7d6" italic="true"/>
   <style name="QmlTypeId" foreground="#66a334"/>
diff --git a/share/qtcreator/styles/dark.xml b/share/qtcreator/styles/dark.xml
index 1e169a69b02..7b46c7542e0 100644
--- a/share/qtcreator/styles/dark.xml
+++ b/share/qtcreator/styles/dark.xml
@@ -11,6 +11,7 @@
   <style name="DiffFile" foreground="#55ff55"/>
   <style name="DiffLocation" foreground="#ffff55"/>
   <style name="DisabledCode" foreground="#777777" background="#222222"/>
+  <style name="VisualWhitespace" foreground="#777777"/>
   <style name="Doxygen.Comment" foreground="#55ffff"/>
   <style name="Doxygen.Tag" foreground="#00a0a0"/>
   <style name="Field"/>
diff --git a/share/qtcreator/styles/modnokai_night_shift_v2.xml b/share/qtcreator/styles/modnokai_night_shift_v2.xml
index 1b062ae7dfa..56c03c3dbfa 100644
--- a/share/qtcreator/styles/modnokai_night_shift_v2.xml
+++ b/share/qtcreator/styles/modnokai_night_shift_v2.xml
@@ -44,7 +44,7 @@
   <style name="Comment" foreground="#75715e" italic="true"/>
   <style name="Doxygen.Comment" foreground="#75715e" bold="true" italic="true"/>
   <style name="Doxygen.Tag" foreground="#80ff80"/>
-  <style name="VisualWhitespace" foreground="#c0c0c0"/>
+  <style name="VisualWhitespace" foreground="#777777"/>
   <style name="QmlLocalId" italic="true"/>
   <style name="QmlExternalId" foreground="#aaaaff" italic="true"/>
   <style name="QmlTypeId" foreground="#55ff55"/>
diff --git a/share/qtcreator/styles/solarized-dark.xml b/share/qtcreator/styles/solarized-dark.xml
index 1a6c5a53ab4..07d97ad858d 100644
--- a/share/qtcreator/styles/solarized-dark.xml
+++ b/share/qtcreator/styles/solarized-dark.xml
@@ -44,7 +44,7 @@
   <style name="Comment" foreground="#586e75" italic="true"/>
   <style name="Doxygen.Comment" foreground="#586e75" italic="true"/>
   <style name="Doxygen.Tag" foreground="#586e75"/>
-  <style name="VisualWhitespace" foreground="#268bd2"/>
+  <style name="VisualWhitespace" foreground="#586e75"/>
   <style name="QmlLocalId" foreground="#657b83" italic="true"/>
   <style name="QmlExternalId" foreground="#2aa198" italic="true"/>
   <style name="QmlTypeId" foreground="#b58900"/>
diff --git a/src/plugins/texteditor/displaysettings.cpp b/src/plugins/texteditor/displaysettings.cpp
index f092150a0e6..9060d017fc9 100644
--- a/src/plugins/texteditor/displaysettings.cpp
+++ b/src/plugins/texteditor/displaysettings.cpp
@@ -37,6 +37,7 @@
 static const char displayLineNumbersKey[] = "DisplayLineNumbers";
 static const char textWrappingKey[] = "TextWrapping";
 static const char visualizeWhitespaceKey[] = "VisualizeWhitespace";
+static const char visualizeIndentKey[] = "VisualizeIndent";
 static const char displayFoldingMarkersKey[] = "DisplayFoldingMarkers";
 static const char highlightCurrentLineKey[] = "HighlightCurrentLine2Key";
 static const char highlightBlocksKey[] = "HighlightBlocksKey";
@@ -67,6 +68,7 @@ void DisplaySettings::toSettings(const QString &category, QSettings *s) const
     s->setValue(QLatin1String(displayLineNumbersKey), m_displayLineNumbers);
     s->setValue(QLatin1String(textWrappingKey), m_textWrapping);
     s->setValue(QLatin1String(visualizeWhitespaceKey), m_visualizeWhitespace);
+    s->setValue(QLatin1String(visualizeIndentKey), m_visualizeIndent);
     s->setValue(QLatin1String(displayFoldingMarkersKey), m_displayFoldingMarkers);
     s->setValue(QLatin1String(highlightCurrentLineKey), m_highlightCurrentLine);
     s->setValue(QLatin1String(highlightBlocksKey), m_highlightBlocks);
@@ -97,6 +99,7 @@ void DisplaySettings::fromSettings(const QString &category, const QSettings *s)
     m_displayLineNumbers = s->value(group + QLatin1String(displayLineNumbersKey), m_displayLineNumbers).toBool();
     m_textWrapping = s->value(group + QLatin1String(textWrappingKey), m_textWrapping).toBool();
     m_visualizeWhitespace = s->value(group + QLatin1String(visualizeWhitespaceKey), m_visualizeWhitespace).toBool();
+    m_visualizeIndent = s->value(group + QLatin1String(visualizeIndentKey), m_visualizeIndent).toBool();
     m_displayFoldingMarkers = s->value(group + QLatin1String(displayFoldingMarkersKey), m_displayFoldingMarkers).toBool();
     m_highlightCurrentLine = s->value(group + QLatin1String(highlightCurrentLineKey), m_highlightCurrentLine).toBool();
     m_highlightBlocks = s->value(group + QLatin1String(highlightBlocksKey), m_highlightBlocks).toBool();
@@ -123,6 +126,7 @@ bool DisplaySettings::equals(const DisplaySettings &ds) const
     return m_displayLineNumbers == ds.m_displayLineNumbers
         && m_textWrapping == ds.m_textWrapping
         && m_visualizeWhitespace == ds.m_visualizeWhitespace
+        && m_visualizeIndent == ds.m_visualizeIndent
         && m_displayFoldingMarkers == ds.m_displayFoldingMarkers
         && m_highlightCurrentLine == ds.m_highlightCurrentLine
         && m_highlightBlocks == ds.m_highlightBlocks
diff --git a/src/plugins/texteditor/displaysettings.h b/src/plugins/texteditor/displaysettings.h
index 97b716a8fc7..0da209a0e04 100644
--- a/src/plugins/texteditor/displaysettings.h
+++ b/src/plugins/texteditor/displaysettings.h
@@ -58,6 +58,7 @@ public:
     bool m_displayLineNumbers = true;
     bool m_textWrapping = false;
     bool m_visualizeWhitespace = false;
+    bool m_visualizeIndent = true;
     bool m_displayFoldingMarkers = true;
     bool m_highlightCurrentLine = false;
     bool m_highlightBlocks = false;
diff --git a/src/plugins/texteditor/displaysettingspage.cpp b/src/plugins/texteditor/displaysettingspage.cpp
index f972e1735a8..c26f4a8c0f9 100644
--- a/src/plugins/texteditor/displaysettingspage.cpp
+++ b/src/plugins/texteditor/displaysettingspage.cpp
@@ -92,6 +92,7 @@ void DisplaySettingsWidget::settingsFromUI(DisplaySettings &displaySettings,
     marginSettings.m_useIndenter = m_ui.useIndenter->isChecked();
     marginSettings.m_marginColumn = m_ui.wrapColumn->value();
     displaySettings.m_visualizeWhitespace = m_ui.visualizeWhitespace->isChecked();
+    displaySettings.m_visualizeIndent = m_ui.visualizeIndent->isChecked();
     displaySettings.m_displayFoldingMarkers = m_ui.displayFoldingMarkers->isChecked();
     displaySettings.m_highlightCurrentLine = m_ui.highlightCurrentLine->isChecked();
     displaySettings.m_highlightBlocks = m_ui.highlightBlocks->isChecked();
@@ -126,6 +127,7 @@ void DisplaySettingsWidget::settingsToUI()
     m_ui.useIndenter->setChecked(marginSettings.m_useIndenter);
     m_ui.wrapColumn->setValue(marginSettings.m_marginColumn);
     m_ui.visualizeWhitespace->setChecked(displaySettings.m_visualizeWhitespace);
+    m_ui.visualizeIndent->setChecked(displaySettings.m_visualizeIndent);
     m_ui.displayFoldingMarkers->setChecked(displaySettings.m_displayFoldingMarkers);
     m_ui.highlightCurrentLine->setChecked(displaySettings.m_highlightCurrentLine);
     m_ui.highlightBlocks->setChecked(displaySettings.m_highlightBlocks);
diff --git a/src/plugins/texteditor/displaysettingspage.ui b/src/plugins/texteditor/displaysettingspage.ui
index 29dea5649a3..316639a16ca 100644
--- a/src/plugins/texteditor/displaysettingspage.ui
+++ b/src/plugins/texteditor/displaysettingspage.ui
@@ -90,20 +90,6 @@
       <string>Display</string>
      </property>
      <layout class="QGridLayout" name="gridLayout_2">
-      <item row="6" column="1">
-       <widget class="QCheckBox" name="displayFileEncoding">
-        <property name="text">
-         <string>Display file encoding</string>
-        </property>
-       </widget>
-      </item>
-      <item row="7" column="1">
-       <widget class="QCheckBox" name="displayFileLineEnding">
-        <property name="text">
-         <string>Display file line ending</string>
-        </property>
-       </widget>
-      </item>
       <item row="2" column="1">
        <widget class="QCheckBox" name="animateMatchingParentheses">
         <property name="text">
@@ -111,10 +97,10 @@
         </property>
        </widget>
       </item>
-      <item row="5" column="0">
-       <widget class="QCheckBox" name="centerOnScroll">
+      <item row="8" column="0">
+       <widget class="QCheckBox" name="scrollBarHighlights">
         <property name="text">
-         <string>Center &amp;cursor on scroll</string>
+         <string>Highlight search results on the scrollbar</string>
         </property>
        </widget>
       </item>
@@ -125,27 +111,10 @@
         </property>
        </widget>
       </item>
-      <item row="4" column="1">
-       <widget class="QCheckBox" name="highlightMatchingParentheses">
+      <item row="9" column="0">
+       <widget class="QCheckBox" name="animateNavigationWithinFile">
         <property name="text">
-         <string>&amp;Highlight matching parentheses</string>
-        </property>
-       </widget>
-      </item>
-      <item row="5" column="1">
-       <widget class="QCheckBox" name="openLinksInNextSplit">
-        <property name="text">
-         <string>Always open links in another split</string>
-        </property>
-       </widget>
-      </item>
-      <item row="4" column="0">
-       <widget class="QCheckBox" name="visualizeWhitespace">
-        <property name="toolTip">
-         <string>Shows tabs and spaces.</string>
-        </property>
-        <property name="text">
-         <string>&amp;Visualize whitespace</string>
+         <string>Animate navigation within file</string>
         </property>
        </widget>
       </item>
@@ -156,13 +125,6 @@
         </property>
        </widget>
       </item>
-      <item row="6" column="0">
-       <widget class="QCheckBox" name="autoFoldFirstComment">
-        <property name="text">
-         <string>Auto-fold first &amp;comment</string>
-        </property>
-       </widget>
-      </item>
       <item row="1" column="1">
        <widget class="QCheckBox" name="highlightBlocks">
         <property name="text">
@@ -170,6 +132,20 @@
         </property>
        </widget>
       </item>
+      <item row="2" column="0">
+       <widget class="QCheckBox" name="markTextChanges">
+        <property name="text">
+         <string>Mark &amp;text changes</string>
+        </property>
+       </widget>
+      </item>
+      <item row="7" column="0">
+       <widget class="QCheckBox" name="autoFoldFirstComment">
+        <property name="text">
+         <string>Auto-fold first &amp;comment</string>
+        </property>
+       </widget>
+      </item>
       <item row="1" column="0">
        <widget class="QCheckBox" name="displayFoldingMarkers">
         <property name="text">
@@ -177,24 +153,55 @@
         </property>
        </widget>
       </item>
-      <item row="8" column="0">
-       <widget class="QCheckBox" name="animateNavigationWithinFile">
+      <item row="6" column="0">
+       <widget class="QCheckBox" name="centerOnScroll">
         <property name="text">
-         <string>Animate navigation within file</string>
+         <string>Center &amp;cursor on scroll</string>
         </property>
        </widget>
       </item>
-      <item row="7" column="0">
-       <widget class="QCheckBox" name="scrollBarHighlights">
+      <item row="3" column="1">
+       <widget class="QCheckBox" name="visualizeIndent">
         <property name="text">
-         <string>Highlight search results on the scrollbar</string>
+         <string>Visualize indent</string>
         </property>
        </widget>
       </item>
-      <item row="2" column="0">
-       <widget class="QCheckBox" name="markTextChanges">
+      <item row="9" column="1">
+       <widget class="QCheckBox" name="displayFileLineEnding">
         <property name="text">
-         <string>Mark &amp;text changes</string>
+         <string>Display file line ending</string>
+        </property>
+       </widget>
+      </item>
+      <item row="8" column="1">
+       <widget class="QCheckBox" name="displayFileEncoding">
+        <property name="text">
+         <string>Display file encoding</string>
+        </property>
+       </widget>
+      </item>
+      <item row="7" column="1">
+       <widget class="QCheckBox" name="openLinksInNextSplit">
+        <property name="text">
+         <string>Always open links in another split</string>
+        </property>
+       </widget>
+      </item>
+      <item row="6" column="1">
+       <widget class="QCheckBox" name="highlightMatchingParentheses">
+        <property name="text">
+         <string>&amp;Highlight matching parentheses</string>
+        </property>
+       </widget>
+      </item>
+      <item row="3" column="0">
+       <widget class="QCheckBox" name="visualizeWhitespace">
+        <property name="toolTip">
+         <string>Shows tabs and spaces.</string>
+        </property>
+        <property name="text">
+         <string>&amp;Visualize whitespace</string>
         </property>
        </widget>
       </item>
@@ -250,6 +257,7 @@
   <tabstop>enableTextWrapping</tabstop>
   <tabstop>showWrapColumn</tabstop>
   <tabstop>wrapColumn</tabstop>
+  <tabstop>useIndenter</tabstop>
   <tabstop>displayLineNumbers</tabstop>
   <tabstop>displayFoldingMarkers</tabstop>
   <tabstop>markTextChanges</tabstop>
@@ -257,13 +265,20 @@
   <tabstop>centerOnScroll</tabstop>
   <tabstop>autoFoldFirstComment</tabstop>
   <tabstop>scrollBarHighlights</tabstop>
+  <tabstop>animateNavigationWithinFile</tabstop>
   <tabstop>highlightCurrentLine</tabstop>
   <tabstop>highlightBlocks</tabstop>
   <tabstop>animateMatchingParentheses</tabstop>
+  <tabstop>visualizeIndent</tabstop>
   <tabstop>highlightMatchingParentheses</tabstop>
   <tabstop>openLinksInNextSplit</tabstop>
   <tabstop>displayFileEncoding</tabstop>
-  <tabstop>animateNavigationWithinFile</tabstop>
+  <tabstop>displayFileLineEnding</tabstop>
+  <tabstop>displayAnnotations</tabstop>
+  <tabstop>leftAligned</tabstop>
+  <tabstop>atMargin</tabstop>
+  <tabstop>rightAligned</tabstop>
+  <tabstop>betweenLines</tabstop>
  </tabstops>
  <resources/>
  <connections>
diff --git a/src/plugins/texteditor/texteditor.cpp b/src/plugins/texteditor/texteditor.cpp
index 8e6e2c53875..f089b53b337 100644
--- a/src/plugins/texteditor/texteditor.cpp
+++ b/src/plugins/texteditor/texteditor.cpp
@@ -554,6 +554,7 @@ public:
     void paintCursorAsBlock(const PaintEventData &data, QPainter &painter,
                             PaintEventBlockData &blockData, int cursorPosition) const;
     void paintAdditionalVisualWhitespaces(PaintEventData &data, QPainter &painter, qreal top) const;
+    void paintIndentDepth(PaintEventData &data, QPainter &painter, const PaintEventBlockData &blockData) const;
     void paintReplacement(PaintEventData &data, QPainter &painter, qreal top) const;
     void paintWidgetBackground(const PaintEventData &data, QPainter &painter) const;
     void paintOverlays(const PaintEventData &data, QPainter &painter) const;
@@ -4343,6 +4344,47 @@ void TextEditorWidgetPrivate::paintAdditionalVisualWhitespaces(PaintEventData &d
     }
 }
 
+void TextEditorWidgetPrivate::paintIndentDepth(PaintEventData &data,
+                                               QPainter &painter,
+                                               const PaintEventBlockData &blockData) const
+{
+    if (!m_displaySettings.m_visualizeIndent)
+        return;
+
+    const QString text = data.block.text();
+    const TabSettings &tabSettings = m_document->tabSettings();
+    const int currentDepth = tabSettings.indentationColumn(text);
+
+    if (currentDepth <= tabSettings.m_indentSize || blockData.layout->lineCount() < 1)
+        return;
+
+    const qreal horizontalAdvance = QFontMetricsF(q->font()).horizontalAdvance(
+        QString(tabSettings.m_indentSize, QChar(' ')));
+
+    painter.save();
+    painter.setPen(data.visualWhitespaceFormat.foreground().color());
+
+    const QTextLine textLine = blockData.layout->lineAt(0);
+    const QRectF rect = textLine.naturalTextRect();
+    qreal x = textLine.cursorToX(0) + data.offset.x();
+    int paintColumn = tabSettings.m_indentSize;
+
+    while (paintColumn < currentDepth) {
+        x += horizontalAdvance;
+        if (x >= 0) {
+            int paintPosition = tabSettings.positionAtColumn(text, paintColumn);
+            if (blockData.layout->lineForTextPosition(paintPosition).lineNumber() != 0)
+                break;
+            const QPointF top(x, blockData.boundingRect.top());
+            const QPointF bottom(x, blockData.boundingRect.top() + rect.height());
+            const QLineF line(top, bottom);
+            painter.drawLine(line);
+        }
+        paintColumn += tabSettings.m_indentSize;
+    }
+    painter.restore();
+}
+
 void TextEditorWidgetPrivate::paintReplacement(PaintEventData &data, QPainter &painter,
                                                qreal top) const
 {
@@ -4645,7 +4687,7 @@ void TextEditorWidget::paintEvent(QPaintEvent *e)
 
             if (drawCursor && !drawCursorAsBlock)
                 d->addCursorsPosition(data, painter, blockData);
-
+            d->paintIndentDepth(data, painter, blockData);
             d->paintAdditionalVisualWhitespaces(data, painter, blockData.boundingRect.top());
             d->paintReplacement(data, painter, blockData.boundingRect.top());
             d->updateLineAnnotation(data, blockData, painter);