Piano: Rewrite application

Goals: - Switch to a more typical LibGUI arrangement - Separate GUI (MainWidget) and audio (AudioEngine) - Improve on existing features while retaining the same feature set Improvements: - Each GUI element is a separate widget - The wave (WaveWidget) scales with the window - The piano roll (RollWidget) scales horizontally and scrolls vertically - The piano (KeysWidget) fits as many notes as possible - The knobs (KnobsWidget) are now sliders - All mouse and key events are handled in constant time - The octave can be changed while playing notes - The same note can be played with the mouse, keyboard and roll at the same time, and the volume of the resulting note is scaled accordingly - Note frequency constants use the maximum precision available in a double
2025-05-31 03:58:12 +00:00 · 2020-01-31 03:02:45 +11:00 · 2020-01-31 03:02:45 +11:00 · 4a36a51618
commit 4a36a51618
parent ddefb95b21
17 changed files with 1647 additions and 762 deletions
--- a/Applications/Piano/MainWidget.cpp
+++ b/Applications/Piano/MainWidget.cpp
@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2019-2020, William McPherson <willmcpherson2@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "MainWidget.h"
+#include "AudioEngine.h"
+#include "KeysWidget.h"
+#include "KnobsWidget.h"
+#include "RollWidget.h"
+#include "WaveWidget.h"
+#include <LibGUI/GBoxLayout.h>
+
+MainWidget::MainWidget(AudioEngine& audio_engine)
+    : m_audio_engine(audio_engine)
+{
+    set_layout(make<GBoxLayout>(Orientation::Vertical));
+    layout()->set_spacing(2);
+    layout()->set_margins({ 2, 2, 2, 2 });
+    set_fill_with_background_color(true);
+
+    m_wave_widget = WaveWidget::construct(this, audio_engine);
+    m_wave_widget->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
+    m_wave_widget->set_preferred_size(0, 100);
+
+    m_roll_widget = RollWidget::construct(this, audio_engine);
+    m_roll_widget->set_size_policy(SizePolicy::Fill, SizePolicy::Fill);
+    m_roll_widget->set_preferred_size(0, 300);
+
+    m_keys_and_knobs_container = GWidget::construct(this);
+    m_keys_and_knobs_container->set_layout(make<GBoxLayout>(Orientation::Horizontal));
+    m_keys_and_knobs_container->layout()->set_spacing(2);
+    m_keys_and_knobs_container->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
+    m_keys_and_knobs_container->set_preferred_size(0, 100);
+    m_keys_and_knobs_container->set_fill_with_background_color(true);
+
+    m_keys_widget = KeysWidget::construct(m_keys_and_knobs_container, audio_engine);
+
+    m_knobs_widget = KnobsWidget::construct(m_keys_and_knobs_container, audio_engine, *this);
+    m_knobs_widget->set_size_policy(SizePolicy::Fixed, SizePolicy::Fill);
+    m_knobs_widget->set_preferred_size(200, 0);
+}
+
+MainWidget::~MainWidget()
+{
+}
+
+// FIXME: There are some unnecessary calls to update() throughout this program,
+// which are an easy target for optimization.
+
+void MainWidget::custom_event(CCustomEvent&)
+{
+    m_wave_widget->update();
+
+    if (m_audio_engine.time() == 0)
+        m_roll_widget->update_roll();
+}
+
+void MainWidget::keydown_event(GKeyEvent& event)
+{
+    // This is to stop held-down keys from creating multiple events.
+    if (m_keys_pressed[event.key()])
+        return;
+    else
+        m_keys_pressed[event.key()] = true;
+
+    note_key_action(event.key(), On);
+    special_key_action(event.key());
+    m_keys_widget->update();
+}
+
+void MainWidget::keyup_event(GKeyEvent& event)
+{
+    m_keys_pressed[event.key()] = false;
+
+    note_key_action(event.key(), Off);
+    m_keys_widget->update();
+}
+
+void MainWidget::note_key_action(int key_code, Switch switch_note)
+{
+    int key = m_keys_widget->key_code_to_key(key_code);
+    m_keys_widget->set_key(key, switch_note);
+}
+
+void MainWidget::special_key_action(int key_code)
+{
+    switch (key_code) {
+    case Key_Z:
+        set_octave_and_ensure_note_change(Down);
+        break;
+    case Key_X:
+        set_octave_and_ensure_note_change(Up);
+        break;
+    case Key_C:
+        m_audio_engine.set_wave(Up);
+        m_knobs_widget->update_knobs();
+        break;
+    }
+}
+
+void MainWidget::set_octave_and_ensure_note_change(Direction direction)
+{
+    m_keys_widget->set_key(m_keys_widget->mouse_note(), Off);
+    for (int i = 0; i < key_code_count; ++i) {
+        if (m_keys_pressed[i])
+            note_key_action(i, Off);
+    }
+
+    m_audio_engine.set_octave(direction);
+
+    m_keys_widget->set_key(m_keys_widget->mouse_note(), On);
+    for (int i = 0; i < key_code_count; ++i) {
+        if (m_keys_pressed[i])
+            note_key_action(i, On);
+    }
+
+    m_knobs_widget->update_knobs();
+    m_keys_widget->update();
+}