Core: Refactor argument handling

Split up getting the data from the arguments list and actually applying
the values, and move the details of theme creation and application to
better places.

This gets rid of ugly control flow details like that
CorePlugin::initialize created the action manager before calling
parseArguments, because that is needed to apply the presentation mode
argument setting, and parseArguments created the main window because
that needs to be created _after_ setting the theme (which can be
overridden by command line argument), but _before_ applying the override
color argument setting.

Change-Id: I9c99305b6efbfcc4b37cea9e5c70d816a621963b
Reviewed-by: David Schulz <david.schulz@qt.io>

src/libs/utils/theme/theme.cpp

@@ -58,6 +58,8 @@ void setCreatorTheme(Theme *theme)
         return;
     delete m_creatorTheme;
     m_creatorTheme = theme;
+    if (theme && theme->flag(Theme::ApplyThemePaletteGlobally))
+        QApplication::setPalette(theme->palette());
 }
 
 Theme::Theme(const QString &id, QObject *parent)

src/plugins/coreplugin/coreplugin.cpp

@@ -93,53 +93,29 @@ CorePlugin::~CorePlugin()
     setCreatorTheme(0);
 }
 
-void CorePlugin::parseArguments(const QStringList &arguments)
-{
-    const Id settingsThemeId = Id::fromSetting(ICore::settings()->value(
-                QLatin1String(Constants::SETTINGS_THEME), QLatin1String(Constants::DEFAULT_THEME)));
-    Id themeId = settingsThemeId;
+struct CoreArguments {
     QColor overrideColor;
+    Id themeId;
     bool presentationMode = false;
+};
 
+CoreArguments parseArguments(const QStringList &arguments)
+{
+    CoreArguments args;
     for (int i = 0; i < arguments.size(); ++i) {
         if (arguments.at(i) == QLatin1String("-color")) {
             const QString colorcode(arguments.at(i + 1));
-            overrideColor = QColor(colorcode);
+            args.overrideColor = QColor(colorcode);
             i++; // skip the argument
         }
         if (arguments.at(i) == QLatin1String("-presentationMode"))
-            presentationMode = true;
+            args.presentationMode = true;
         if (arguments.at(i) == QLatin1String("-theme")) {
-            themeId = Id::fromString(arguments.at(i + 1));
-            i++;
+            args.themeId = Id::fromString(arguments.at(i + 1));
+            i++; // skip the argument
         }
     }
-    const QList<ThemeEntry> availableThemes = ThemeEntry::availableThemes();
-    int themeIndex = Utils::indexOf(availableThemes, Utils::equal(&ThemeEntry::id, themeId));
-    if (themeIndex < 0) {
-        themeIndex = Utils::indexOf(availableThemes,
-                                    Utils::equal(&ThemeEntry::id, settingsThemeId));
-    }
-    if (themeIndex < 0)
-        themeIndex = 0;
-    if (themeIndex < availableThemes.size()) {
-        const ThemeEntry themeEntry = availableThemes.at(themeIndex);
-        QSettings themeSettings(themeEntry.filePath(), QSettings::IniFormat);
-        Theme *theme = new Theme(themeEntry.id().toString(), qApp);
-        theme->readSettings(themeSettings);
-        if (theme->flag(Theme::ApplyThemePaletteGlobally))
-            QApplication::setPalette(theme->palette());
-        setCreatorTheme(theme);
-    }
-
-    // defer creation of these widgets until here,
-    // because they need a valid theme set
-    m_mainWindow = new MainWindow;
-    ActionManager::setPresentationModeEnabled(presentationMode);
-    m_locator = new Locator;
-
-    if (overrideColor.isValid())
-        m_mainWindow->setOverrideColor(overrideColor);
+    return args;
 }
 
 bool CorePlugin::initialize(const QStringList &arguments, QString *errorMessage)
@@ -148,10 +124,18 @@ bool CorePlugin::initialize(const QStringList &arguments, QString *errorMessage)
         *errorMessage = tr("No themes found in installation.");
         return false;
     }
-    new ActionManager(this);
+    const CoreArguments args = parseArguments(arguments);
     Theme::initialPalette(); // Initialize palette before setting it
+    Theme *themeFromArg = ThemeEntry::createTheme(args.themeId);
+    setCreatorTheme(themeFromArg ? themeFromArg
+                                 : ThemeEntry::createTheme(ThemeEntry::themeSetting()));
+    new ActionManager(this);
+    ActionManager::setPresentationModeEnabled(args.presentationMode);
+    m_mainWindow = new MainWindow;
+    if (args.overrideColor.isValid())
+        m_mainWindow->setOverrideColor(args.overrideColor);
+    m_locator = new Locator;
     qsrand(QDateTime::currentDateTime().toTime_t());
-    parseArguments(arguments);
     const bool success = m_mainWindow->init(errorMessage);
     if (success) {
         m_editMode = new EditMode;

src/plugins/coreplugin/coreplugin.h

@@ -78,7 +78,6 @@ private slots:
 #endif
 
 private:
-    void parseArguments(const QStringList & arguments);
     static void addToPathChooserContextMenu(Utils::PathChooser *pathChooser, QMenu *menu);
 
     MainWindow *m_mainWindow;

src/plugins/coreplugin/themechooser.cpp

@@ -171,8 +171,7 @@ void ThemeChooser::apply()
         return;
     const QString themeId = d->m_themeListModel->themeAt(index).id().toString();
     QSettings *settings = ICore::settings();
-    const QString currentThemeId = settings->value(QLatin1String(Constants::SETTINGS_THEME),
-                                                   QLatin1String(Constants::DEFAULT_THEME)).toString();
+    const QString currentThemeId = ThemeEntry::themeSetting().toString();
     if (currentThemeId != themeId) {
         QMessageBox::information(ICore::mainWindow(), tr("Restart Required"),
                                  tr("The theme change will take effect after a restart of Qt Creator."));
@@ -215,5 +214,25 @@ QList<ThemeEntry> ThemeEntry::availableThemes()
     return themes;
 }
 
+Id ThemeEntry::themeSetting()
+{
+    return Id::fromSetting(ICore::settings()->value(QLatin1String(Constants::SETTINGS_THEME),
+                                                    QLatin1String(Constants::DEFAULT_THEME)));
+}
+
+Theme *ThemeEntry::createTheme(Id id)
+{
+    if (!id.isValid())
+        return nullptr;
+    const ThemeEntry entry = Utils::findOrDefault(availableThemes(),
+                                                  Utils::equal(&ThemeEntry::id, id));
+    if (!entry.id().isValid())
+        return nullptr;
+    QSettings themeSettings(entry.filePath(), QSettings::IniFormat);
+    Theme *theme = new Theme(entry.id().toString());
+    theme->readSettings(themeSettings);
+    return theme;
+}
+
 } // namespace Internal
 } // namespace Core

src/plugins/coreplugin/themechooser.h

@@ -31,6 +31,8 @@
 
 #include <QWidget>
 
+namespace Utils { class Theme; }
+
 namespace Core {
 namespace Internal {
 
@@ -46,6 +48,8 @@ public:
     QString displayName() const;
     QString filePath() const;
     static QList<ThemeEntry> availableThemes();
+    static Id themeSetting();
+    static Utils::Theme *createTheme(Id id);
 
 private:
     Id m_id;