From 465af4c4d4f403909208a420c21dbf7cf9cc015d Mon Sep 17 00:00:00 2001
From: Ben Wiederhake <BenWiederhake.GitHub@gmx.de>
Date: Sun, 31 Oct 2021 23:38:04 +0100
Subject: [PATCH] Applications: Fix visibility of Object-derivative
 constructors

Derivatives of Core::Object should be constructed through
ClassName::construct(), to avoid handling ref-counted objects with
refcount zero. Fixing the visibility means that misuses like this are
more difficult.
---
 Userland/Applets/Network/main.cpp             |  3 +-
 Userland/Applets/ResourceGraph/main.cpp       |  2 +-
 Userland/Applications/Assistant/main.cpp      | 40 +++++++++----------
 .../Applications/KeyboardMapper/KeyButton.h   |  4 +-
 .../KeyboardMapper/KeyboardMapperWidget.h     |  5 ++-
 .../Applications/PDFViewer/NumericInput.h     |  2 +-
 Userland/Applications/Piano/AudioPlayerLoop.h |  6 +--
 .../Applications/PixelPaint/PaletteWidget.cpp | 17 ++++----
 Userland/Applications/SoundPlayer/Common.h    |  3 +-
 .../SoundPlayer/PlaylistWidget.cpp            |  2 +
 .../Applications/SoundPlayer/PlaylistWidget.h |  7 +++-
 .../SoundPlayerWidgetAdvancedView.h           |  4 +-
 .../SoundPlayer/VisualizationWidget.h         |  1 +
 13 files changed, 53 insertions(+), 43 deletions(-)

diff --git a/Userland/Applets/Network/main.cpp b/Userland/Applets/Network/main.cpp
index dbb44cd856..fd06555704 100644
--- a/Userland/Applets/Network/main.cpp
+++ b/Userland/Applets/Network/main.cpp
@@ -20,7 +20,7 @@
 class NetworkWidget final : public GUI::ImageWidget {
     C_OBJECT(NetworkWidget);
 
-public:
+private:
     NetworkWidget(bool notifications)
     {
         m_notifications = notifications;
@@ -28,7 +28,6 @@ public:
         start_timer(5000);
     }
 
-private:
     virtual void timer_event(Core::TimerEvent&) override
     {
         update_widget();
diff --git a/Userland/Applets/ResourceGraph/main.cpp b/Userland/Applets/ResourceGraph/main.cpp
index 60287ad0a4..69300ccff4 100644
--- a/Userland/Applets/ResourceGraph/main.cpp
+++ b/Userland/Applets/ResourceGraph/main.cpp
@@ -30,6 +30,7 @@ class GraphWidget final : public GUI::Frame {
 public:
     static constexpr size_t history_size = 24;
 
+private:
     GraphWidget(GraphType graph_type, Optional<Gfx::Color> graph_color, Optional<Gfx::Color> graph_error_color)
         : m_graph_type(graph_type)
     {
@@ -39,7 +40,6 @@ public:
         start_timer(1000);
     }
 
-private:
     virtual void timer_event(Core::TimerEvent&) override
     {
         switch (m_graph_type) {
diff --git a/Userland/Applications/Assistant/main.cpp b/Userland/Applications/Assistant/main.cpp
index 426d8913ac..522e65a444 100644
--- a/Userland/Applications/Assistant/main.cpp
+++ b/Userland/Applications/Assistant/main.cpp
@@ -35,26 +35,6 @@ struct AppState {
 class ResultRow final : public GUI::Widget {
     C_OBJECT(ResultRow)
 public:
-    ResultRow()
-    {
-        auto& layout = set_layout<GUI::HorizontalBoxLayout>();
-        layout.set_spacing(12);
-        layout.set_margins(4);
-
-        m_image = add<GUI::ImageWidget>();
-
-        m_label_container = add<GUI::Widget>();
-        m_label_container->set_layout<GUI::VerticalBoxLayout>();
-        m_label_container->set_fixed_height(30);
-
-        m_title = m_label_container->add<GUI::Label>();
-        m_title->set_text_alignment(Gfx::TextAlignment::CenterLeft);
-
-        set_shrink_to_fit(true);
-        set_fill_with_background_color(true);
-        set_greedy_for_hits(true);
-    }
-
     void set_image(RefPtr<Gfx::Bitmap> bitmap)
     {
         m_image->set_bitmap(bitmap);
@@ -89,6 +69,26 @@ public:
     Function<void()> on_selected;
 
 private:
+    ResultRow()
+    {
+        auto& layout = set_layout<GUI::HorizontalBoxLayout>();
+        layout.set_spacing(12);
+        layout.set_margins(4);
+
+        m_image = add<GUI::ImageWidget>();
+
+        m_label_container = add<GUI::Widget>();
+        m_label_container->set_layout<GUI::VerticalBoxLayout>();
+        m_label_container->set_fixed_height(30);
+
+        m_title = m_label_container->add<GUI::Label>();
+        m_title->set_text_alignment(Gfx::TextAlignment::CenterLeft);
+
+        set_shrink_to_fit(true);
+        set_fill_with_background_color(true);
+        set_greedy_for_hits(true);
+    }
+
     void mousedown_event(GUI::MouseEvent&) override
     {
         set_background_role(ColorRole::MenuBase);
diff --git a/Userland/Applications/KeyboardMapper/KeyButton.h b/Userland/Applications/KeyboardMapper/KeyButton.h
index 6aed8d059a..38afde394a 100644
--- a/Userland/Applications/KeyboardMapper/KeyButton.h
+++ b/Userland/Applications/KeyboardMapper/KeyButton.h
@@ -8,7 +8,7 @@
 
 #include <LibGUI/AbstractButton.h>
 
-class KeyButton : public GUI::AbstractButton {
+class KeyButton final : public GUI::AbstractButton {
     C_OBJECT(KeyButton)
 
 public:
@@ -25,5 +25,7 @@ protected:
     virtual void paint_event(GUI::PaintEvent&) override;
 
 private:
+    KeyButton() = default;
+
     bool m_pressed { false };
 };
diff --git a/Userland/Applications/KeyboardMapper/KeyboardMapperWidget.h b/Userland/Applications/KeyboardMapper/KeyboardMapperWidget.h
index 1c11dc17ca..84534be567 100644
--- a/Userland/Applications/KeyboardMapper/KeyboardMapperWidget.h
+++ b/Userland/Applications/KeyboardMapper/KeyboardMapperWidget.h
@@ -10,11 +10,10 @@
 #include <LibGUI/Button.h>
 #include <LibKeyboard/CharacterMapData.h>
 
-class KeyboardMapperWidget : public GUI::Widget {
+class KeyboardMapperWidget final : public GUI::Widget {
     C_OBJECT(KeyboardMapperWidget)
 
 public:
-    KeyboardMapperWidget();
     virtual ~KeyboardMapperWidget() override;
 
     void create_frame();
@@ -31,6 +30,8 @@ protected:
     void update_window_title();
 
 private:
+    KeyboardMapperWidget();
+
     Vector<KeyButton*> m_keys;
     RefPtr<GUI::Widget> m_map_group;
 
diff --git a/Userland/Applications/PDFViewer/NumericInput.h b/Userland/Applications/PDFViewer/NumericInput.h
index 8f256bd62f..2e9a53540d 100644
--- a/Userland/Applications/PDFViewer/NumericInput.h
+++ b/Userland/Applications/PDFViewer/NumericInput.h
@@ -12,7 +12,6 @@
 class NumericInput final : public GUI::TextBox {
     C_OBJECT(NumericInput)
 public:
-    NumericInput();
     virtual ~NumericInput() override = default;
 
     Function<void(i32)> on_number_changed;
@@ -22,6 +21,7 @@ public:
     void set_current_number(i32 number, bool call_change_handler = true);
 
 private:
+    NumericInput();
     void on_focus_lost();
 
     bool m_needs_text_reset { false };
diff --git a/Userland/Applications/Piano/AudioPlayerLoop.h b/Userland/Applications/Piano/AudioPlayerLoop.h
index 0125215298..186b833190 100644
--- a/Userland/Applications/Piano/AudioPlayerLoop.h
+++ b/Userland/Applications/Piano/AudioPlayerLoop.h
@@ -17,17 +17,17 @@ class TrackManager;
 
 // Wrapper class accepting custom events to advance the track playing and forward audio data to the system.
 // This does not run on a separate thread, preventing IPC multithreading madness.
-class AudioPlayerLoop : public Core::Object {
+class AudioPlayerLoop final : public Core::Object {
     C_OBJECT(AudioPlayerLoop)
 public:
-    AudioPlayerLoop(TrackManager& track_manager, bool& need_to_write_wav, Audio::WavWriter& wav_writer);
-
     void enqueue_audio();
 
     void toggle_paused();
     bool is_playing() { return m_should_play_audio; }
 
 private:
+    AudioPlayerLoop(TrackManager& track_manager, bool& need_to_write_wav, Audio::WavWriter& wav_writer);
+
     TrackManager& m_track_manager;
     Array<Sample, sample_count> m_buffer;
     Optional<Audio::ResampleHelper<double>> m_resampler;
diff --git a/Userland/Applications/PixelPaint/PaletteWidget.cpp b/Userland/Applications/PixelPaint/PaletteWidget.cpp
index b6affd8ed8..bae64b426c 100644
--- a/Userland/Applications/PixelPaint/PaletteWidget.cpp
+++ b/Userland/Applications/PixelPaint/PaletteWidget.cpp
@@ -24,13 +24,6 @@ class ColorWidget : public GUI::Frame {
     C_OBJECT(ColorWidget);
 
 public:
-    explicit ColorWidget(Color color, PaletteWidget& palette_widget)
-        : m_palette_widget(palette_widget)
-        , m_color(color)
-    {
-        set_fixed_width(16);
-    }
-
     virtual ~ColorWidget() override
     {
     }
@@ -57,6 +50,13 @@ public:
     }
 
 private:
+    explicit ColorWidget(Color color, PaletteWidget& palette_widget)
+        : m_palette_widget(palette_widget)
+        , m_color(color)
+    {
+        set_fixed_width(16);
+    }
+
     PaletteWidget& m_palette_widget;
     Color m_color;
 };
@@ -87,6 +87,9 @@ public:
 
     Function<void(Color const&)> on_color_change;
     Color m_color = Color::White;
+
+private:
+    SelectedColorWidget() = default;
 };
 
 PaletteWidget::PaletteWidget()
diff --git a/Userland/Applications/SoundPlayer/Common.h b/Userland/Applications/SoundPlayer/Common.h
index 901a7d17bb..75f8aed2e5 100644
--- a/Userland/Applications/SoundPlayer/Common.h
+++ b/Userland/Applications/SoundPlayer/Common.h
@@ -21,7 +21,7 @@ public:
 
     bool mouse_is_down() const { return m_mouse_is_down; }
 
-protected:
+private:
     AutoSlider(Orientation orientation)
         : GUI::Slider(orientation)
     {
@@ -42,6 +42,5 @@ protected:
         GUI::Slider::mouseup_event(event);
     }
 
-private:
     bool m_mouse_is_down { false };
 };
diff --git a/Userland/Applications/SoundPlayer/PlaylistWidget.cpp b/Userland/Applications/SoundPlayer/PlaylistWidget.cpp
index 189ab67d32..f954c93489 100644
--- a/Userland/Applications/SoundPlayer/PlaylistWidget.cpp
+++ b/Userland/Applications/SoundPlayer/PlaylistWidget.cpp
@@ -92,6 +92,8 @@ String PlaylistModel::column_name(int column) const
     VERIFY_NOT_REACHED();
 }
 
+PlaylistTableView::PlaylistTableView() = default;
+
 void PlaylistTableView::doubleclick_event(GUI::MouseEvent& event)
 {
     AbstractView::doubleclick_event(event);
diff --git a/Userland/Applications/SoundPlayer/PlaylistWidget.h b/Userland/Applications/SoundPlayer/PlaylistWidget.h
index 5b19b6e79a..d4c10360ad 100644
--- a/Userland/Applications/SoundPlayer/PlaylistWidget.h
+++ b/Userland/Applications/SoundPlayer/PlaylistWidget.h
@@ -40,19 +40,22 @@ public:
     void doubleclick_event(GUI::MouseEvent& event) override;
 
     Function<void(const Gfx::Point<int>&)> on_doubleclick;
+
+private:
+    PlaylistTableView();
 };
 
 class PlaylistWidget : public GUI::Widget {
     C_OBJECT(PlaylistWidget)
 public:
-    PlaylistWidget();
     void set_data_model(RefPtr<PlaylistModel> model)
     {
         m_table_view->set_model(model);
         m_table_view->update();
     }
 
-protected:
 private:
+    PlaylistWidget();
+
     RefPtr<PlaylistTableView> m_table_view;
 };
diff --git a/Userland/Applications/SoundPlayer/SoundPlayerWidgetAdvancedView.h b/Userland/Applications/SoundPlayer/SoundPlayerWidgetAdvancedView.h
index f63ad7658c..e8198f7eca 100644
--- a/Userland/Applications/SoundPlayer/SoundPlayerWidgetAdvancedView.h
+++ b/Userland/Applications/SoundPlayer/SoundPlayerWidgetAdvancedView.h
@@ -21,8 +21,6 @@ class SoundPlayerWidgetAdvancedView final : public GUI::Widget
     C_OBJECT(SoundPlayerWidgetAdvancedView)
 
 public:
-    explicit SoundPlayerWidgetAdvancedView(GUI::Window&, Audio::ClientConnection&);
-
     void set_nonlinear_volume_slider(bool nonlinear);
     void set_playlist_visible(bool visible);
 
@@ -51,6 +49,8 @@ protected:
     void keydown_event(GUI::KeyEvent&) override;
 
 private:
+    SoundPlayerWidgetAdvancedView(GUI::Window&, Audio::ClientConnection&);
+
     void sync_previous_next_buttons();
 
     void drop_event(GUI::DropEvent& event) override;
diff --git a/Userland/Applications/SoundPlayer/VisualizationWidget.h b/Userland/Applications/SoundPlayer/VisualizationWidget.h
index 99a64ae711..03db2e6e46 100644
--- a/Userland/Applications/SoundPlayer/VisualizationWidget.h
+++ b/Userland/Applications/SoundPlayer/VisualizationWidget.h
@@ -17,5 +17,6 @@ public:
     virtual void set_samplerate(int) { }
 
 protected:
+    VisualizationWidget() = default;
     virtual ~VisualizationWidget() = default;
 };