Mixers: re-add show effect stack to master, improve layout with collapsed track mixers

src/audiomixer/mixermanager.cpp

@@ -41,6 +41,7 @@ MixerManager::MixerManager(QWidget *parent)
     m_channelsBox->setContentsMargins(0, 0, 0, 0);
     m_box = new QHBoxLayout;
     m_box->setSpacing(0);
+    m_box->addStretch(10);
     auto *channelsBoxContainer = new QWidget(this);
     m_channelsBox->setWidget(channelsBoxContainer);
     m_channelsBox->setWidgetResizable(true);

src/audiomixer/mixerwidget.cpp

@@ -273,6 +273,8 @@ void MixerWidget::buildUI(Mlt::Tractor *service, const QString &trackName)
     mute->setDefaultAction(m_muteAction);
     mute->setAutoRaise(true);
 
+    QToolButton *showEffects = nullptr;
+
     // Setup default width
     setFixedWidth(3 * mute->sizeHint().width());
 
@@ -320,6 +322,14 @@ void MixerWidget::buildUI(Mlt::Tractor *service, const QString &trackName)
             m_collapse->setIcon(m_collapse->isChecked() ? QIcon::fromTheme("arrow-left") : QIcon::fromTheme("arrow-right"));
             m_manager->collapseMixers();
         });
+        showEffects = new QToolButton(this);
+        showEffects->setIcon(QIcon::fromTheme("autocorrection"));
+        showEffects->setToolTip(i18n("Open Effect Stack"));
+        showEffects->setAutoRaise(true);
+        connect(showEffects, &QToolButton::clicked, this,  [&]() {
+            emit m_manager->showEffectStack(m_tid);
+        });
+
     }
 
     connect(m_volumeSlider, &QSlider::valueChanged, this, [&](int value) {
@@ -378,6 +388,9 @@ void MixerWidget::buildUI(Mlt::Tractor *service, const QString &trackName)
     if (m_monitor) {
         buttonslay->addWidget(m_monitor);
     }
+    if (showEffects) {
+        buttonslay->addWidget(showEffects);
+    }
     lay->addLayout(buttonslay);
     if (m_balanceSlider) {
         auto *balancelay = new QGridLayout;