[calamares] Refactor debug-window handling

Move the management of the (a?) DebugWindow to a separate
class, and hang on to that manager in CalamaresWindow.
This is prep-work towards making it available from QML as well.

src/calamares/CalamaresWindow.cpp

@@ -86,7 +86,7 @@ setButtonIcon( QPushButton* button, const QString& name )
 }
 
 static QWidget*
-getWidgetSidebar( CalamaresWindow* window,
+getWidgetSidebar( Calamares::DebugWindowManager* debug,
                   Calamares::ViewManager* viewManager,
                   QWidget* parent,
                   Qt::Orientation,
@@ -128,7 +128,7 @@ getWidgetSidebar( CalamaresWindow* window,
     tv->setFocusPolicy( Qt::NoFocus );
     sideLayout->addWidget( tv );
 
-    if ( Calamares::Settings::instance()->debugMode() || ( Logger::logLevel() >= Logger::LOGVERBOSE ) )
+    if ( debug && debug->enabled() )
     {
         QPushButton* debugWindowBtn = new QPushButton;
         debugWindowBtn->setObjectName( "debugButton" );
@@ -138,8 +138,9 @@ getWidgetSidebar( CalamaresWindow* window,
         sideLayout->addWidget( debugWindowBtn );
         debugWindowBtn->setFlat( true );
         debugWindowBtn->setCheckable( true );
-        QObject::connect( debugWindowBtn, &QPushButton::clicked, window, &CalamaresWindow::showDebugWindow );
-        QObject::connect( window, &CalamaresWindow::debugWindowShown, debugWindowBtn, &QPushButton::setChecked );
+        QObject::connect( debugWindowBtn, &QPushButton::clicked, debug, &Calamares::DebugWindowManager::show );
+        QObject::connect(
+            debug, &Calamares::DebugWindowManager::visibleChanged, debugWindowBtn, &QPushButton::setChecked );
     }
 
     CalamaresUtils::unmarginLayout( sideLayout );
@@ -147,7 +148,11 @@ getWidgetSidebar( CalamaresWindow* window,
 }
 
 static QWidget*
-getWidgetNavigation( CalamaresWindow*, Calamares::ViewManager* viewManager, QWidget* parent, Qt::Orientation, int )
+getWidgetNavigation( Calamares::DebugWindowManager*,
+                     Calamares::ViewManager* viewManager,
+                     QWidget* parent,
+                     Qt::Orientation,
+                     int )
 {
     QWidget* navigation = new QWidget( parent );
     QBoxLayout* bottomLayout = new QHBoxLayout;
@@ -235,7 +240,11 @@ setDimension( QQuickWidget* w, Qt::Orientation o, int desiredWidth )
 
 
 static QWidget*
-getQmlSidebar( CalamaresWindow*, Calamares::ViewManager*, QWidget* parent, Qt::Orientation o, int desiredWidth )
+getQmlSidebar( Calamares::DebugWindowManager*,
+               Calamares::ViewManager*,
+               QWidget* parent,
+               Qt::Orientation o,
+               int desiredWidth )
 {
     CalamaresUtils::registerQmlModels();
     QQuickWidget* w = new QQuickWidget( parent );
@@ -246,7 +255,11 @@ getQmlSidebar( CalamaresWindow*, Calamares::ViewManager*, QWidget* parent, Qt::O
 }
 
 static QWidget*
-getQmlNavigation( CalamaresWindow*, Calamares::ViewManager*, QWidget* parent, Qt::Orientation o, int desiredWidth )
+getQmlNavigation( Calamares::DebugWindowManager*,
+                  Calamares::ViewManager*,
+                  QWidget* parent,
+                  Qt::Orientation o,
+                  int desiredWidth )
 {
     CalamaresUtils::registerQmlModels();
     QQuickWidget* w = new QQuickWidget( parent );
@@ -261,12 +274,20 @@ getQmlNavigation( CalamaresWindow*, Calamares::ViewManager*, QWidget* parent, Qt
 // Calls to flavoredWidget() still refer to these *names*
 // even if they are subsequently not used.
 static QWidget*
-getQmlSidebar( CalamaresWindow*, Calamares::ViewManager*, QWidget* parent, Qt::Orientation, int desiredWidth )
+getQmlSidebar( Calamares::DebugWindowManager*,
+               Calamares::ViewManager*,
+               QWidget* parent,
+               Qt::Orientation,
+               int desiredWidth )
 {
     return nullptr;
 }
 static QWidget*
-getQmlNavigation( CalamaresWindow*, Calamares::ViewManager*, QWidget* parent, Qt::Orientation, int desiredWidth )
+getQmlNavigation( Calamares::DebugWindowManager*,
+                  Calamares::ViewManager*,
+                  QWidget* parent,
+                  Qt::Orientation,
+                  int desiredWidth )
 {
     return nullptr;
 }
@@ -281,7 +302,7 @@ template < typename widgetMaker, typename... args >
 QWidget*
 flavoredWidget( Calamares::Branding::PanelFlavor flavor,
                 Qt::Orientation o,
-                CalamaresWindow* w,
+                Calamares::DebugWindowManager* w,
                 QWidget* parent,
                 widgetMaker widget,
                 widgetMaker qml,  // Only if WITH_QML is on
@@ -321,7 +342,7 @@ insertIf( QBoxLayout* layout,
 
 CalamaresWindow::CalamaresWindow( QWidget* parent )
     : QWidget( parent )
-    , m_debugWindow( nullptr )
+    , m_debugManager( new Calamares::DebugWindowManager( this ) )
     , m_viewManager( nullptr )
 {
     // If we can never cancel, don't show the window-close button
@@ -400,14 +421,14 @@ CalamaresWindow::CalamaresWindow( QWidget* parent )
     QWidget* sideBox = flavoredWidget(
         branding->sidebarFlavor(),
         ::orientation( branding->sidebarSide() ),
-        this,
+        m_debugManager,
         baseWidget,
         ::getWidgetSidebar,
         ::getQmlSidebar,
         qBound( 100, CalamaresUtils::defaultFontHeight() * 12, w < windowPreferredWidth ? 100 : 190 ) );
     QWidget* navigation = flavoredWidget( branding->navigationFlavor(),
                                           ::orientation( branding->navigationSide() ),
-                                          this,
+                                          m_debugManager,
                                           baseWidget,
                                           ::getWidgetNavigation,
                                           ::getQmlNavigation,
@@ -461,29 +482,6 @@ CalamaresWindow::ensureSize( QSize size )
     resize( w, h );
 }
 
-void
-CalamaresWindow::showDebugWindow( bool show )
-{
-    if ( show )
-    {
-        m_debugWindow = new Calamares::DebugWindow();
-        m_debugWindow->show();
-        connect( m_debugWindow.data(), &Calamares::DebugWindow::closed, this, [=]() {
-            m_debugWindow->deleteLater();
-            emit debugWindowShown( false );
-        } );
-        emit debugWindowShown( true );
-    }
-    else
-    {
-        if ( m_debugWindow )
-        {
-            m_debugWindow->deleteLater();
-        }
-        emit debugWindowShown( false );
-    }
-}
-
 void
 CalamaresWindow::closeEvent( QCloseEvent* event )
 {

src/calamares/CalamaresWindow.h

@@ -11,12 +11,13 @@
 #ifndef CALAMARESWINDOW_H
 #define CALAMARESWINDOW_H
 
-#include <QPointer>
 #include <QWidget>
 
+#include <memory>
+
 namespace Calamares
 {
-class DebugWindow;
+class DebugWindowManager;
 class ViewManager;
 }  // namespace Calamares
 
@@ -38,23 +39,12 @@ public Q_SLOTS:
      */
     void ensureSize( QSize size );
 
-    /** @brief Set visibility of debug window
-     *
-     * Shows or hides the debug window, depending on @p show.
-     * If Calamares is not in debug mode, nothing happens and the debug
-     * window remains hidden.
-     */
-    void showDebugWindow( bool show );
-
-Q_SIGNALS:
-    void debugWindowShown( bool show );
-
 protected:
     virtual void closeEvent( QCloseEvent* e ) override;
 
 private:
-    QPointer< Calamares::DebugWindow > m_debugWindow;  // Managed by self
-    Calamares::ViewManager* m_viewManager;
+    Calamares::DebugWindowManager* m_debugManager = nullptr;
+    Calamares::ViewManager* m_viewManager = nullptr;
 };
 
 #endif  // CALAMARESWINDOW_H

src/calamares/DebugWindow.cpp

@@ -11,15 +11,14 @@
 #include "DebugWindow.h"
 #include "ui_DebugWindow.h"
 
-#include "VariantModel.h"
-
 #include "Branding.h"
-#include "modulesystem/Module.h"
-#include "modulesystem/ModuleManager.h"
-
 #include "GlobalStorage.h"
 #include "Job.h"
 #include "JobQueue.h"
+#include "Settings.h"
+#include "VariantModel.h"
+#include "modulesystem/Module.h"
+#include "modulesystem/ModuleManager.h"
 #include "utils/Logger.h"
 #include "utils/Retranslator.h"
 
@@ -225,4 +224,55 @@ DebugWindow::closeEvent( QCloseEvent* e )
     emit closed();
 }
 
+
+DebugWindowManager::DebugWindowManager( QObject* parent )
+    : QObject( parent )
+{
+}
+
+
+bool
+DebugWindowManager::enabled() const
+{
+    const auto* s = Settings::instance();
+    return ( Logger::logLevel() >= Logger::LOGVERBOSE ) || ( s ? s->debugMode() : false );
+}
+
+
+void
+DebugWindowManager::show( bool visible )
+{
+    if ( !enabled() )
+    {
+        visible = false;
+    }
+    if ( m_visible == visible )
+    {
+        return;
+    }
+
+    if ( visible )
+    {
+        m_debugWindow = new Calamares::DebugWindow();
+        m_debugWindow->show();
+        connect( m_debugWindow.data(), &Calamares::DebugWindow::closed, this, [=]() {
+            m_debugWindow->deleteLater();
+            m_visible = false;
+            emit visibleChanged( false );
+        } );
+        m_visible = true;
+        emit visibleChanged( true );
+    }
+    else
+    {
+        if ( m_debugWindow )
+        {
+            m_debugWindow->deleteLater();
+        }
+        m_visible = false;
+        emit visibleChanged( false );
+    }
+}
+
+
 }  // namespace Calamares

src/calamares/DebugWindow.h

@@ -13,6 +13,7 @@
 
 #include "VariantModel.h"
 
+#include <QPointer>
 #include <QVariant>
 #include <QWidget>
 
@@ -48,6 +49,43 @@ private:
     std::unique_ptr< VariantModel > m_module_model;
 };
 
+/** @brief Manager for the (single) DebugWindow
+ *
+ * Only one DebugWindow is expected to be around. This class manages
+ * (exactly one) DebugWindow and can create and destroy it as needed.
+ * It is available to the Calamares panels as object `DebugWindow`.
+ */
+class DebugWindowManager : public QObject
+{
+    Q_OBJECT
+
+    /// @brief Proxy to Settings::debugMode() default @c false
+    Q_PROPERTY( bool enabled READ enabled CONSTANT FINAL )
+
+    /** @brief Is the debug window visible?
+     *
+     * Writing @c true to this **may** make the debug window visible to
+     * the user; only if debugMode() is on.
+     */
+    Q_PROPERTY( bool visible READ visible WRITE show NOTIFY visibleChanged )
+
+public:
+    DebugWindowManager( QObject* parent = nullptr );
+    virtual ~DebugWindowManager() override = default;
+
+public Q_SLOTS:
+    bool enabled() const;
+    bool visible() const { return m_visible; }
+    void show( bool visible );
+
+signals:
+    void visibleChanged( bool visible );
+
+private:
+    QPointer< DebugWindow > m_debugWindow;
+    bool m_visible = false;
+};
+
 
 }  // namespace Calamares
 #endif