feat: add tab width setting

This patch allows the user to set a custom width for \t. Since we use a
monospace font we can simply use a multiple of the character width. This
is done by settings the tabstopdistance of the QTextOption property of
QTextLayout.

closes: KDAB#583

src/disassemblysettingspage.ui

@@ -32,14 +32,14 @@
    <property name="bottomMargin">
     <number>0</number>
    </property>
-   <item row="2" column="0">
+   <item row="6" column="0">
     <widget class="QLabel" name="label">
      <property name="text">
       <string>Source Code Search Paths:</string>
      </property>
     </widget>
    </item>
-   <item row="2" column="1">
+   <item row="6" column="1">
     <widget class="KEditListWidget" name="sourcePaths">
      <property name="buttons">
       <set>KEditListWidget::All</set>
@@ -60,20 +60,30 @@
      </property>
     </widget>
    </item>
-   <item row="1" column="0">
+   <item row="2" column="0">
     <widget class="QLabel" name="label_3">
      <property name="text">
       <string>Show hexdump:</string>
      </property>
     </widget>
    </item>
-   <item row="1" column="1">
+   <item row="2" column="1">
     <widget class="QCheckBox" name="showHexdump">
      <property name="text">
       <string/>
      </property>
     </widget>
    </item>
+   <item row="3" column="0">
+    <widget class="QLabel" name="label_4">
+     <property name="text">
+      <string>Tab width</string>
+     </property>
+    </widget>
+   </item>
+   <item row="3" column="1">
+    <widget class="QSpinBox" name="tabWidth"/>
+   </item>
   </layout>
  </widget>
  <customwidgets>

src/models/highlightedtext.cpp

@@ -7,6 +7,7 @@
 
 #include "highlightedtext.h"
 
+#include <QFontMetrics>
 #include <QGuiApplication>
 #include <QPalette>
 #include <QTextLayout>
@@ -15,6 +16,8 @@
 
 #include <KColorScheme>
 
+#include <hotspot-config.h>
+
 #if KFSyntaxHighlighting_FOUND
 #include <KSyntaxHighlighting/AbstractHighlighter>
 #include <KSyntaxHighlighting/Definition>
@@ -250,13 +253,24 @@ class HighlightedLine
         m_layout = nullptr;
     }
 
+    void setTabWidthInPixels(int tabWidthInPixels)
+    {
+        m_tabWidthInPixels = tabWidthInPixels;
+        m_layout = nullptr;
+    }
+
 private:
     std::unique_ptr<QTextLayout> buildLayout() const
     {
         Q_ASSERT(m_index != -1);
         auto layout = std::make_unique<QTextLayout>();
 
-        layout->setFont(QFontDatabase::systemFont(QFontDatabase::FixedFont));
+        auto option = layout->textOption();
+        option.setTabStopDistance(m_tabWidthInPixels);
+        layout->setTextOption(option);
+
+        auto font = QFontDatabase::systemFont(QFontDatabase::FixedFont);
+        layout->setFont(font);
         layout->setText(m_text);
         layout->setFormats(m_highlighter->format(m_index));
 
@@ -276,6 +290,7 @@ class HighlightedLine
     HighlightingImplementation* m_highlighter = nullptr;
     QString m_text;
     int m_index = -1;
+    int m_tabWidthInPixels = -1; // qts default value
     mutable std::unique_ptr<QTextLayout> m_layout;
 };
 static_assert(std::is_nothrow_move_constructible_v<HighlightedLine>);
@@ -285,7 +300,6 @@ HighlightedText::HighlightedText(KSyntaxHighlighting::Repository* repository, QO
     : QObject(parent)
     , m_repository(repository)
 {
-    Q_UNUSED(repository);
 }
 
 HighlightedText::~HighlightedText() = default;
@@ -313,6 +327,9 @@ void HighlightedText::setText(const QStringList& text)
         return HighlightedLine {m_highlighter.get(), text, index++};
     });
 
+    // this is free since we currently have no text rendered
+    updateTabWidth(m_tabWidth);
+
     m_cleanedLines = text;
     std::for_each(m_cleanedLines.begin(), m_cleanedLines.end(), Util::removeAnsi);
 }
@@ -358,3 +375,13 @@ void HighlightedText::updateHighlighting()
     std::for_each(m_highlightedLines.begin(), m_highlightedLines.end(),
                   [](HighlightedLine& line) { line.updateHighlighting(); });
 }
+
+void HighlightedText::updateTabWidth(int tabWidth)
+{
+    m_tabWidth = tabWidth;
+    auto font = QFontDatabase::systemFont(QFontDatabase::FixedFont);
+    const auto tabWidthInPixels = tabWidth * QFontMetrics(font).horizontalAdvance(QLatin1Char(' '));
+
+    std::for_each(m_highlightedLines.begin(), m_highlightedLines.end(),
+                  [tabWidthInPixels](HighlightedLine& line) { line.setTabWidthInPixels(tabWidthInPixels); });
+}

src/models/highlightedtext.h

@@ -14,8 +14,6 @@
 class QTextLayout;
 class QTextLine;
 
-#include "hotspot-config.h"
-
 namespace KSyntaxHighlighting {
 class SyntaxHighlighter;
 class Definition;
@@ -53,6 +51,7 @@ class HighlightedText : public QObject
 
 public slots:
     void updateHighlighting();
+    void updateTabWidth(int tabWidth);
 
 private:
     KSyntaxHighlighting::Repository* m_repository;
@@ -61,4 +60,5 @@ public slots:
     QStringList m_lines;
     QStringList m_cleanedLines;
     bool m_isUsingAnsi = false;
+    int m_tabWidth = -1;
 };

src/resultsdisassemblypage.cpp

@@ -274,6 +274,14 @@ ResultsDisassemblyPage::ResultsDisassemblyPage(CostContextMenu* costContextMenu,
     connect(ui->assemblyView, &QTreeView::entered, this, updateFromDisassembly);
     connect(ui->sourceCodeView, &QTreeView::entered, this, updateFromSource);
 
+    connect(settings, &Settings::tabWidthChanged, m_sourceCodeModel->highlightedText(),
+            &HighlightedText::updateTabWidth);
+    connect(settings, &Settings::tabWidthChanged, m_disassemblyModel->highlightedText(),
+            &HighlightedText::updateTabWidth);
+
+    m_sourceCodeModel->highlightedText()->updateTabWidth(settings->tabWidth());
+    m_disassemblyModel->highlightedText()->updateTabWidth(settings->tabWidth());
+
     auto createContextMenu = [](QTreeView* view, auto* model, auto&& addEntries) {
         auto gotoMenuWidget = new QWidget(view);
         auto layout = new QHBoxLayout(gotoMenuWidget);

src/settings.cpp

@@ -253,6 +253,11 @@ void Settings::loadFromFile()
     connect(this, &Settings::showHexdumpChanged, [sharedConfig](bool showHexdump) {
         sharedConfig->group(QStringLiteral("Disassembly")).writeEntry("showHexdump", showHexdump);
     });
+
+    setTabWidth(sharedConfig->group(QStringLiteral("Disassembly")).readEntry("tabWidth", DefaultTabWidth));
+    connect(this, &Settings::tabWidthChanged, [sharedConfig](int distance) {
+        sharedConfig->group(QStringLiteral("Disassembly")).writeEntry("tabWidth", distance);
+    });
 }
 
 void Settings::setSourceCodePaths(const QString& paths)
@@ -286,3 +291,11 @@ void Settings::setShowHexdump(bool showHexdump)
         emit showHexdumpChanged(m_showHexdump);
     }
 }
+
+void Settings::setTabWidth(int distance)
+{
+    if (m_tabWidth != distance) {
+        m_tabWidth = distance;
+        emit tabWidthChanged(m_tabWidth);
+    }
+}

src/settings.h

@@ -163,6 +163,13 @@ class Settings : public QObject
         return m_showHexdump;
     }
 
+    int tabWidth() const
+    {
+        return m_tabWidth;
+    }
+
+    static constexpr int DefaultTabWidth = 4;
+
     void loadFromFile();
 
 signals:
@@ -187,6 +194,7 @@ class Settings : public QObject
     void perfPathChanged(const QString& perfPath);
     void showBranchesChanged(bool showBranches);
     void showHexdumpChanged(bool showHexdump);
+    void tabWidthChanged(int distance);
 
 public slots:
     void setPrettifySymbols(bool prettifySymbols);
@@ -212,6 +220,7 @@ public slots:
     void setPerfPath(const QString& path);
     void setShowBranches(bool showBranches);
     void setShowHexdump(bool showHexdump);
+    void setTabWidth(int distance);
 
 private:
     using QObject::QObject;
@@ -237,6 +246,7 @@ public slots:
     QString m_perfMapPath;
     bool m_showBranches = true;
     bool m_showHexdump = false;
+    int m_tabWidth = DefaultTabWidth;
 
     QString m_lastUsedEnvironment;
 

src/settingsdialog.cpp

@@ -337,10 +337,12 @@ void SettingsDialog::addSourcePathPage()
 
     disassemblyPage->showBranches->setChecked(settings->showBranches());
     disassemblyPage->showHexdump->setChecked(settings->showHexdump());
+    disassemblyPage->tabWidth->setValue(settings->tabWidth());
 
     connect(buttonBox(), &QDialogButtonBox::accepted, this, [this, colon, settings] {
         settings->setSourceCodePaths(disassemblyPage->sourcePaths->items().join(colon));
         settings->setShowBranches(disassemblyPage->showBranches->isChecked());
         settings->setShowHexdump(disassemblyPage->showHexdump->isChecked());
+        settings->setTabWidth(disassemblyPage->tabWidth->value());
     });
 }

tests/modeltests/tst_formatting.cpp

@@ -13,6 +13,8 @@
 
 #include "../testutils.h"
 
+#include <hotspot-config.h>
+
 #if KFSyntaxHighlighting_FOUND
 #include <KSyntaxHighlighting/Definition>
 #include <KSyntaxHighlighting/Repository>