Piano: Allow per-track controls (again)

This makes Piano exactly as usable as when I started the large refactor
some years ago, which *sounds* like I'm a terrible person but now it (1)
looks nicer and (2) has a flexible backend that can already deal with
aribtrary kinds of processors on any track.

Userland/Applications/Piano/MainWidget.cpp

@@ -18,6 +18,7 @@
 #include <LibGUI/BoxLayout.h>
 #include <LibGUI/Menu.h>
 #include <LibGUI/Slider.h>
+#include <LibGUI/StackWidget.h>
 #include <LibGUI/TabWidget.h>
 
 ErrorOr<NonnullRefPtr<MainWidget>> MainWidget::try_create(TrackManager& manager, AudioPlayerLoop& loop)
@@ -47,7 +48,7 @@ ErrorOr<void> MainWidget::initialize()
     m_roll_widget->set_fixed_height(300);
 
     (void)TRY(m_tab_widget->try_add_tab<SamplerWidget>("Sampler"_short_string, m_track_manager));
-    m_player_widget = TRY(try_add<PlayerWidget>(m_track_manager, m_audio_loop));
+    m_player_widget = TRY(try_add<PlayerWidget>(m_track_manager, *this, m_audio_loop));
 
     m_keys_and_knobs_container = TRY(try_add<GUI::Widget>());
     TRY(m_keys_and_knobs_container->try_set_layout<GUI::HorizontalBoxLayout>(GUI::Margins {}, 2));
@@ -78,7 +79,11 @@ ErrorOr<void> MainWidget::initialize()
         m_octave_value->set_text(String::number(new_octave).release_value_but_fixme_should_propagate_errors());
     };
 
-    m_knobs_widget = TRY(m_keys_and_knobs_container->try_add<TrackControlsWidget>(m_track_manager, *this));
+    m_knobs_widget = TRY(m_keys_and_knobs_container->try_add<GUI::StackWidget>());
+    for (auto track : m_track_manager.tracks())
+        TRY(m_track_controls.try_append(TRY(m_knobs_widget->try_add<TrackControlsWidget>(TRY(track->try_make_weak_ptr())))));
+
+    update_selected_track();
 
     m_roll_widget->set_keys_widget(m_keys_widget);
 
@@ -100,6 +105,20 @@ ErrorOr<void> MainWidget::add_track_actions(GUI::Menu& menu)
     return {};
 }
 
+void MainWidget::update_selected_track()
+{
+    if (static_cast<size_t>(m_track_manager.track_count()) > m_track_controls.size())
+        MUST(add_controls_for_current_track());
+    m_knobs_widget->set_active_widget(m_track_controls.at(m_track_manager.current_track_index()).ptr());
+}
+
+ErrorOr<void> MainWidget::add_controls_for_current_track()
+{
+    auto track = m_track_manager.current_track();
+    TRY(m_track_controls.try_append(TRY(m_knobs_widget->try_add<TrackControlsWidget>(TRY(track->try_make_weak_ptr())))));
+    return {};
+}
+
 // FIXME: There are some unnecessary calls to update() throughout this program,
 // which are an easy target for optimization.
 

Userland/Applications/Piano/MainWidget.h

@@ -11,6 +11,7 @@
 
 #include "Music.h"
 #include <LibDSP/Keyboard.h>
+#include <LibGUI/StackWidget.h>
 #include <LibGUI/Widget.h>
 
 class AudioPlayerLoop;
@@ -32,6 +33,8 @@ public:
 
     void change_octave_via_keys(DSP::Keyboard::Direction);
     void set_octave_via_slider(int octave);
+    void update_selected_track();
+    ErrorOr<void> add_controls_for_current_track();
 
 private:
     explicit MainWidget(TrackManager&, AudioPlayerLoop&);
@@ -57,7 +60,8 @@ private:
     RefPtr<GUI::TabWidget> m_tab_widget;
     RefPtr<GUI::Widget> m_keys_and_knobs_container;
     RefPtr<KeysWidget> m_keys_widget;
-    RefPtr<TrackControlsWidget> m_knobs_widget;
+    RefPtr<GUI::StackWidget> m_knobs_widget;
+    Vector<NonnullRefPtr<TrackControlsWidget>> m_track_controls;
     RefPtr<PlayerWidget> m_player_widget;
 
     RefPtr<GUI::Widget> m_octave_container;

Userland/Applications/Piano/PlayerWidget.cpp

@@ -8,6 +8,7 @@
 #include "PlayerWidget.h"
 
 #include "AudioPlayerLoop.h"
+#include "MainWidget.h"
 #include "Music.h"
 #include "TrackManager.h"
 #include <LibGUI/BoxLayout.h>
@@ -16,9 +17,9 @@
 #include <LibGUI/ItemListModel.h>
 #include <LibGUI/Label.h>
 
-ErrorOr<NonnullRefPtr<PlayerWidget>> PlayerWidget::create(TrackManager& manager, AudioPlayerLoop& loop)
+ErrorOr<NonnullRefPtr<PlayerWidget>> PlayerWidget::try_create(TrackManager& manager, MainWidget& main_widget, AudioPlayerLoop& loop)
 {
-    auto widget = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) PlayerWidget(manager, loop)));
+    auto widget = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) PlayerWidget(manager, main_widget, loop)));
 
     widget->m_play_icon = TRY(Gfx::Bitmap::load_from_file("/res/icons/16x16/play.png"sv));
     widget->m_pause_icon = TRY(Gfx::Bitmap::load_from_file("/res/icons/16x16/pause.png"sv));
@@ -31,8 +32,9 @@ ErrorOr<NonnullRefPtr<PlayerWidget>> PlayerWidget::create(TrackManager& manager,
     return widget;
 }
 
-PlayerWidget::PlayerWidget(TrackManager& manager, AudioPlayerLoop& loop)
+PlayerWidget::PlayerWidget(TrackManager& manager, MainWidget& main_widget, AudioPlayerLoop& loop)
     : m_track_manager(manager)
+    , m_main_widget(main_widget)
     , m_audio_loop(loop)
 {
 }
@@ -54,6 +56,7 @@ ErrorOr<void> PlayerWidget::initialize()
     m_track_dropdown->set_selected_index(0);
     m_track_dropdown->on_change = [this]([[maybe_unused]] auto name, GUI::ModelIndex model_index) {
         m_track_manager.set_current_track(static_cast<size_t>(model_index.row()));
+        m_main_widget.update_selected_track();
     };
 
     m_add_track_button = TRY(try_add<GUI::Button>());

Userland/Applications/Piano/PlayerWidget.h

@@ -11,11 +11,12 @@
 
 class AudioPlayerLoop;
 class TrackManager;
+class MainWidget;
 
 class PlayerWidget final : public GUI::Toolbar {
-    C_OBJECT(PlayerWidget)
+    C_OBJECT_ABSTRACT(PlayerWidget)
 public:
-    static ErrorOr<NonnullRefPtr<PlayerWidget>> create(TrackManager&, AudioPlayerLoop&);
+    static ErrorOr<NonnullRefPtr<PlayerWidget>> try_create(TrackManager&, MainWidget&, AudioPlayerLoop&);
     virtual ~PlayerWidget() override = default;
 
     void add_track();
@@ -23,11 +24,12 @@ public:
     void toggle_paused();
 
 private:
-    explicit PlayerWidget(TrackManager&, AudioPlayerLoop&);
+    explicit PlayerWidget(TrackManager&, MainWidget&, AudioPlayerLoop&);
 
     ErrorOr<void> initialize();
 
     TrackManager& m_track_manager;
+    MainWidget& m_main_widget;
     AudioPlayerLoop& m_audio_loop;
     Vector<DeprecatedString> m_track_number_choices;
 

Userland/Applications/Piano/RollWidget.cpp

@@ -8,6 +8,7 @@
  */
 
 #include "RollWidget.h"
+#include "LibDSP/Music.h"
 #include "TrackManager.h"
 #include <AK/IntegralMath.h>
 #include <LibGUI/Event.h>
@@ -127,7 +128,7 @@ void RollWidget::paint_event(GUI::PaintEvent& event)
             int distance_to_next_x = next_x_pos - x_pos;
             Gfx::IntRect rect(x_pos, y_pos, distance_to_next_x, note_height);
 
-            if (m_track_manager.keyboard()->is_pressed(note))
+            if (static_cast<size_t>(note) < DSP::note_frequencies.size() && m_track_manager.keyboard()->is_pressed(note))
                 painter.fill_rect(rect, note_pressed_color.with_alpha(128));
         }
     }

Userland/Applications/Piano/TrackControlsWidget.cpp

@@ -7,28 +7,46 @@
  */
 
 #include "TrackControlsWidget.h"
-#include "MainWidget.h"
 #include "ProcessorParameterWidget/ParameterWidget.h"
-#include "TrackManager.h"
-#include <LibDSP/ProcessorParameter.h>
 #include <LibGUI/BoxLayout.h>
-#include <LibGUI/Label.h>
-#include <LibGfx/Orientation.h>
+#include <LibGUI/Frame.h>
+#include <LibGUI/GroupBox.h>
+#include <LibGUI/Widget.h>
 
-TrackControlsWidget::TrackControlsWidget(TrackManager& track_manager, MainWidget& main_widget)
-    : m_track_manager(track_manager)
-    , m_main_widget(main_widget)
+TrackControlsWidget::TrackControlsWidget(WeakPtr<DSP::Track> track)
+    : m_track(move(track))
 {
-    set_layout<GUI::HorizontalBoxLayout>();
-    set_preferred_width(GUI::SpecialDimension::Grow);
-    set_fill_with_background_color(true);
-
-    for (auto& parameter : m_track_manager.current_track()->track_mastering()->parameters())
-        m_parameter_widgets.append(add<ProcessorParameterWidget>(parameter));
-
-    for (auto& parameter : m_track_manager.current_track()->synth()->parameters())
-        m_parameter_widgets.append(add<ProcessorParameterWidget>(parameter));
-
-    for (auto& parameter : m_track_manager.current_track()->delay()->parameters())
-        m_parameter_widgets.append(add<ProcessorParameterWidget>(parameter));
+}
+
+ErrorOr<NonnullRefPtr<TrackControlsWidget>> TrackControlsWidget::try_create(WeakPtr<DSP::Track> track)
+{
+    auto widget = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) TrackControlsWidget(move(track))));
+
+    TRY(widget->try_set_layout<GUI::HorizontalBoxLayout>());
+    widget->set_preferred_width(GUI::SpecialDimension::Grow);
+    widget->set_fill_with_background_color(true);
+
+    auto mastering_parameters = TRY(widget->try_add<GUI::GroupBox>());
+    TRY(mastering_parameters->try_set_layout<GUI::HorizontalBoxLayout>());
+
+    auto strong_track = widget->m_track.value();
+
+    for (auto& parameter : strong_track->track_mastering()->parameters())
+        (void)TRY(mastering_parameters->try_add<ProcessorParameterWidget>(parameter));
+
+    TRY(widget->m_processor_groups.try_append(mastering_parameters));
+
+    TRY(widget->add_spacer());
+
+    for (auto& processor : strong_track->processor_chain()) {
+        auto processor_parameters = TRY(widget->try_add<GUI::GroupBox>());
+        TRY(processor_parameters->try_set_layout<GUI::HorizontalBoxLayout>());
+
+        for (auto& parameter : processor->parameters())
+            (void)TRY(processor_parameters->try_add<ProcessorParameterWidget>(parameter));
+
+        TRY(widget->m_processor_groups.try_append(processor_parameters));
+    }
+
+    return widget;
 }

Userland/Applications/Piano/TrackControlsWidget.h

@@ -9,25 +9,21 @@
 #pragma once
 
 #include "ProcessorParameterWidget/ParameterWidget.h"
-#include <LibDSP/ProcessorParameter.h>
-#include <LibDSP/Synthesizers.h>
-#include <LibGUI/Frame.h>
-#include <LibGUI/Label.h>
-#include <LibGUI/Widget.h>
-
-class TrackManager;
-class MainWidget;
+#include <AK/Vector.h>
+#include <AK/WeakPtr.h>
+#include <LibDSP/Track.h>
+#include <LibGUI/Forward.h>
 
 class TrackControlsWidget final : public GUI::Frame {
-    C_OBJECT(TrackControlsWidget)
+    C_OBJECT_ABSTRACT(TrackControlsWidget)
 public:
     virtual ~TrackControlsWidget() override = default;
 
+    static ErrorOr<NonnullRefPtr<TrackControlsWidget>> try_create(WeakPtr<DSP::Track>);
+
 private:
-    TrackControlsWidget(TrackManager&, MainWidget&);
+    TrackControlsWidget(WeakPtr<DSP::Track>);
 
-    TrackManager& m_track_manager;
-    MainWidget& m_main_widget;
-
-    Vector<NonnullRefPtr<ProcessorParameterWidget>> m_parameter_widgets;
+    WeakPtr<DSP::Track> m_track;
+    Vector<NonnullRefPtr<GUI::GroupBox>> m_processor_groups;
 };

Userland/Applications/Piano/TrackManager.h

@@ -28,11 +28,13 @@ public:
 
     NonnullRefPtr<DSP::NoteTrack> current_track() { return *m_tracks[m_current_track]; }
     size_t track_count() { return m_tracks.size(); };
+    size_t current_track_index() const { return m_current_track; }
     void set_current_track(size_t track_index)
     {
         VERIFY(track_index < track_count());
         m_current_track = track_index;
     }
+    Span<NonnullRefPtr<DSP::NoteTrack>> tracks() { return m_tracks.span(); }
 
     NonnullRefPtr<DSP::Transport> transport() const { return m_transport; }
     NonnullRefPtr<DSP::Keyboard> keyboard() const { return m_keyboard; }

Userland/Libraries/LibDSP/Track.h

@@ -9,6 +9,7 @@
 #include <AK/DisjointChunks.h>
 #include <AK/NonnullRefPtr.h>
 #include <AK/RefCounted.h>
+#include <AK/Weakable.h>
 #include <LibDSP/Clip.h>
 #include <LibDSP/Effects.h>
 #include <LibDSP/Keyboard.h>
@@ -19,7 +20,8 @@
 namespace DSP {
 
 // A track is also known as a channel and serves as a container for the audio pipeline: clips -> processors -> mixing & output
-class Track : public RefCounted<Track> {
+class Track : public RefCounted<Track>
+    , public Weakable<Track> {
 public:
     virtual ~Track() = default;