wrangled QWidgets to allow for resizable tracks with track headers

app/widget/timelinewidget/timelineandtrackview.cpp

@@ -13,7 +13,7 @@ TimelineAndTrackView::TimelineAndTrackView(const TrackType &type, Qt::Alignment
   splitter_->setChildrenCollapsible(false);
   layout->addWidget(splitter_);
 
-  track_view_ = new TrackView();
+  track_view_ = new TrackView(vertical_alignment);
   splitter_->addWidget(track_view_);
 
   view_ = new TimelineView(type, vertical_alignment);

app/widget/timelinewidget/trackview/CMakeLists.txt

@@ -18,5 +18,9 @@ set(OLIVE_SOURCES
   ${OLIVE_SOURCES}
   widget/timelinewidget/trackview/trackview.h
   widget/timelinewidget/trackview/trackview.cpp
+  widget/timelinewidget/trackview/trackviewitem.h
+  widget/timelinewidget/trackview/trackviewitem.cpp
+  widget/timelinewidget/trackview/trackviewsplitter.h
+  widget/timelinewidget/trackview/trackviewsplitter.cpp
   PARENT_SCOPE
 )

app/widget/timelinewidget/trackview/trackview.cpp

@@ -1,29 +1,52 @@
 #include "trackview.h"
 
+#include <QDebug>
+#include <QResizeEvent>
+#include <QScrollBar>
 #include <QSplitter>
 #include <QVBoxLayout>
 
-TrackView::TrackView(QWidget *parent) :
-  QWidget(parent)
+#include "trackviewitem.h"
+
+TrackView::TrackView(Qt::Alignment vertical_alignment, QWidget *parent) :
+  QScrollArea(parent),
+  alignment_(vertical_alignment)
 {
-  QVBoxLayout* layout = new QVBoxLayout(this);
-  layout->setSpacing(0);
+  QWidget* central = new QWidget();
+  setWidget(central);
+  setWidgetResizable(true);
+
+  QVBoxLayout* layout = new QVBoxLayout(central);
   layout->setMargin(0);
+  layout->setSpacing(0);
 
-  QSplitter* splitter = new QSplitter(Qt::Vertical);
-  splitter->setChildrenCollapsible(false);
-  splitter->setHandleWidth(1);
-  layout->addWidget(splitter);
+  if (alignment_ == Qt::AlignBottom) {
+    layout->addStretch();
 
-  QWidget* test1 = new QWidget();
-  test1->setStyleSheet("background: red;");
-  splitter->addWidget(test1);
+    connect(verticalScrollBar(), SIGNAL(rangeChanged(int, int)), this, SLOT(ScrollbarRangeChanged(int, int)));
+    last_scrollbar_max_ = verticalScrollBar()->maximum();
+  }
 
-  QWidget* test3 = new QWidget();
-  test3->setStyleSheet("background: yellow;");
-  splitter->addWidget(test3);
+  splitter_ = new TrackViewSplitter(alignment_);
+  splitter_->setChildrenCollapsible(false);
+  layout->addWidget(splitter_);
+}
 
-  QWidget* test2 = new QWidget();
-  test2->setStyleSheet("background: blue;");
-  splitter->addWidget(test2);
+void TrackView::resizeEvent(QResizeEvent *event)
+{
+  QScrollArea::resizeEvent(event);
+
+  //splitter_->setFixedWidth(viewport()->width());
+}
+
+void TrackView::ScrollbarRangeChanged(int, int max)
+{
+  if (max != last_scrollbar_max_) {
+    int ba_val = last_scrollbar_max_ - verticalScrollBar()->value();
+    int new_val = max - ba_val;
+
+    verticalScrollBar()->setValue(new_val);
+
+    last_scrollbar_max_ = max;
+  }
 }

app/widget/timelinewidget/trackview/trackview.h

@@ -1,14 +1,32 @@
 #ifndef TRACKVIEW_H
 #define TRACKVIEW_H
 
-#include <QWidget>
+#include <QScrollArea>
+#include <QSplitter>
 
-class TrackView : public QWidget
+#include "trackviewsplitter.h"
+
+class TrackView : public QScrollArea
 {
+  Q_OBJECT
 public:
-  TrackView(QWidget* parent = nullptr);
+  TrackView(Qt::Alignment vertical_alignment = Qt::AlignTop,
+            QWidget* parent = nullptr);
+
+protected:
+  virtual void resizeEvent(QResizeEvent* event) override;
 
 private:
+  TrackViewSplitter* splitter_;
+
+  Qt::Alignment alignment_;
+
+  int last_scrollbar_max_;
+
+  QWidget* top_spacer_;
+
+private slots:
+  void ScrollbarRangeChanged(int min, int max);
 
 };
 

app/widget/timelinewidget/trackview/trackviewitem.cpp

@@ -0,0 +1,44 @@
+#include "trackviewitem.h"
+
+#include <QDebug>
+#include <QHBoxLayout>
+#include <QMouseEvent>
+#include <QPainter>
+#include <QtMath>
+
+TrackViewItem::TrackViewItem(Qt::Alignment alignment, QWidget *parent) :
+  QWidget(parent),
+  alignment_(alignment)
+{
+  QHBoxLayout* layout = new QHBoxLayout(this);
+  layout->setSpacing(0);
+  layout->setMargin(0);
+
+  label_ = new QLabel(tr("Track"));
+  layout->addWidget(label_);
+
+  mute_button_ = CreateMSLButton(tr("M"), Qt::red);
+  layout->addWidget(mute_button_);
+
+  solo_button_ = CreateMSLButton(tr("S"), Qt::yellow);
+  layout->addWidget(solo_button_);
+
+  lock_button_ = CreateMSLButton(tr("L"), Qt::gray);
+  layout->addWidget(lock_button_);
+
+  setMinimumHeight(mute_button_->height());
+}
+
+QPushButton *TrackViewItem::CreateMSLButton(const QString& text, const QColor& checked_color) const
+{
+  QPushButton* button = new QPushButton(text);
+  button->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Expanding);
+  button->setCheckable(true);
+  button->setStyleSheet(QStringLiteral("QPushButton::checked { background: %1; }").arg(checked_color.name()));
+
+  int size = button->sizeHint().height();
+  size = qRound(size * 0.75);
+  button->setFixedSize(size, size);
+
+  return button;
+}

app/widget/timelinewidget/trackview/trackviewitem.h

@@ -0,0 +1,28 @@
+#ifndef TRACKVIEWITEM_H
+#define TRACKVIEWITEM_H
+
+#include <QLabel>
+#include <QPushButton>
+#include <QWidget>
+
+class TrackViewItem : public QWidget
+{
+  Q_OBJECT
+public:
+  TrackViewItem(Qt::Alignment alignment = Qt::AlignTop,
+                QWidget* parent = nullptr);
+
+private:
+  QPushButton* CreateMSLButton(const QString &text, const QColor &checked_color) const;
+
+  Qt::Alignment alignment_;
+
+  QLabel* label_;
+
+  QPushButton* mute_button_;
+  QPushButton* solo_button_;
+  QPushButton* lock_button_;
+
+};
+
+#endif // TRACKVIEWITEM_H

app/widget/timelinewidget/trackview/trackviewsplitter.cpp

@@ -0,0 +1,109 @@
+#include "trackviewsplitter.h"
+
+#include <QDebug>
+#include <QPainter>
+
+#include "trackviewitem.h"
+
+TrackViewSplitter::TrackViewSplitter(Qt::Alignment vertical_alignment, QWidget* parent) :
+  QSplitter(Qt::Vertical, parent),
+  alignment_(vertical_alignment)
+{
+  setHandleWidth(1);
+
+  int initial_height = 0;
+
+  if (alignment_ == Qt::AlignBottom) {
+    // Add empty spacer so we get a splitter handle after the last element
+    addWidget(new QWidget());
+  }
+
+  for (int i=0;i<3;i++) {
+    TrackViewItem* w = new TrackViewItem();
+    addWidget(w);
+
+    initial_height += w->sizeHint().height() + handleWidth();
+  }
+
+  if (alignment_ == Qt::AlignTop) {
+    // Add empty spacer so we get a splitter handle after the last element
+    addWidget(new QWidget());
+  }
+
+  setFixedHeight(initial_height);
+}
+
+void TrackViewSplitter::HandleReceiver(TrackViewSplitterHandle *h, int diff)
+{
+  int ele_id = -1;
+
+  for (int i=0;i<count();i++) {
+    if (handle(i) == h) {
+      ele_id = i;
+      break;
+    }
+  }
+
+  // The handle index is actually always one above the element index
+  if (alignment_ == Qt::AlignTop) {
+    ele_id--;
+  } else if (alignment_ == Qt::AlignBottom) {
+    diff = -diff;
+  }
+
+  QList<int> element_sizes = sizes();
+
+  int old_ele_sz = element_sizes.at(ele_id);
+
+  // Transform element size by diff
+  int new_ele_sz = old_ele_sz + diff;
+
+  // Validate it with the widget's minimum size
+  new_ele_sz = qMax(new_ele_sz, widget(ele_id)->minimumHeight());
+
+  // Correct diff
+  diff = new_ele_sz - old_ele_sz;
+
+  // Set new size on element
+  element_sizes.replace(ele_id, new_ele_sz);
+  setSizes(element_sizes);
+
+  // Increase height by the difference
+  setFixedHeight(height() + diff);
+}
+
+QSplitterHandle *TrackViewSplitter::createHandle()
+{
+  return new TrackViewSplitterHandle(orientation(), this);
+}
+
+TrackViewSplitterHandle::TrackViewSplitterHandle(Qt::Orientation orientation, QSplitter *parent) :
+  QSplitterHandle(orientation, parent),
+  dragging_(false)
+{
+}
+
+void TrackViewSplitterHandle::mousePressEvent(QMouseEvent *)
+{
+}
+
+void TrackViewSplitterHandle::mouseMoveEvent(QMouseEvent *)
+{
+  if (dragging_) {
+    static_cast<TrackViewSplitter*>(parent())->HandleReceiver(this, QCursor::pos().y() - drag_y_);
+  }
+
+  drag_y_ = QCursor::pos().y();
+  dragging_ = true;
+}
+
+void TrackViewSplitterHandle::mouseReleaseEvent(QMouseEvent *)
+{
+  dragging_ = false;
+}
+
+void TrackViewSplitterHandle::paintEvent(QPaintEvent *)
+{
+  QPainter p(this);
+  p.fillRect(rect(), palette().base());
+}

app/widget/timelinewidget/trackview/trackviewsplitter.h

@@ -0,0 +1,39 @@
+#ifndef TRACKVIEWSPLITTER_H
+#define TRACKVIEWSPLITTER_H
+
+#include <QSplitter>
+
+class TrackViewSplitterHandle : public QSplitterHandle
+{
+  Q_OBJECT
+public:
+  TrackViewSplitterHandle(Qt::Orientation orientation, QSplitter *parent);
+
+protected:
+  virtual void	mousePressEvent(QMouseEvent *e) override;
+  virtual void	mouseMoveEvent(QMouseEvent *e) override;
+  virtual void	mouseReleaseEvent(QMouseEvent *e) override;
+
+  virtual void	paintEvent(QPaintEvent *e) override;
+
+private:
+  int drag_y_;
+
+  bool dragging_;
+};
+
+class TrackViewSplitter : public QSplitter
+{
+public:
+  TrackViewSplitter(Qt::Alignment vertical_alignment, QWidget* parent = nullptr);
+
+  void HandleReceiver(TrackViewSplitterHandle* h, int diff);
+
+protected:
+  virtual QSplitterHandle *createHandle() override;
+
+private:
+  Qt::Alignment alignment_;
+};
+
+#endif // TRACKVIEWSPLITTER_H