labels scroll with the timeline views

ui/timelinearea.cpp

@@ -1,5 +1,10 @@
 #include "timelinearea.h"
 
+#include <QScrollArea>
+
+#include "panels/timeline.h"
+#include "global/config.h"
+
 int olive::timeline::kTimelineLabelFixedWidth = 200;
 
 TimelineArea::TimelineArea(Timeline* timeline, olive::timeline::Alignment alignment) :
@@ -12,13 +17,22 @@ TimelineArea::TimelineArea(Timeline* timeline, olive::timeline::Alignment alignm
   layout->setSpacing(0);
 
   // LABELS
-  QWidget* label_container = new QWidget();
-  label_container->setFixedWidth(olive::timeline::kTimelineLabelFixedWidth);
-  label_container_layout_ = new QVBoxLayout(label_container);
+  label_container_ = new QWidget();
+  label_container_layout_ = new QVBoxLayout(label_container_);
   label_container_layout_->setMargin(0);
   label_container_layout_->setSpacing(0);
   label_container_layout_->addStretch();
-  layout->addWidget(label_container);
+
+  // LABEL SCROLLAREA
+  QScrollArea* label_area = new QScrollArea();
+  label_area->setFrameShape(QFrame::NoFrame);
+  label_area->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+  label_area->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+  label_area->verticalScrollBar()->setMaximum(INT_MAX);
+  label_area->setWidgetResizable(true);
+  label_area->setFixedWidth(olive::timeline::kTimelineLabelFixedWidth);
+  label_area->setWidget(label_container_);
+  layout->addWidget(label_area);
 
   // VIEW
   view_ = new TimelineView(timeline_);
@@ -26,10 +40,13 @@ TimelineArea::TimelineArea(Timeline* timeline, olive::timeline::Alignment alignm
   layout->addWidget(view_);
 
   // SCROLLBAR
-  QScrollBar* scrollbar = new QScrollBar(Qt::Vertical);
-  layout->addWidget(scrollbar);
+  scrollbar_ = new QScrollBar(Qt::Vertical);
+  layout->addWidget(scrollbar_);
 
-  view_->scrollBar = scrollbar;
+  connect(scrollbar_, SIGNAL(valueChanged(int)), view_, SLOT(setScroll(int)));
+  connect(scrollbar_, SIGNAL(valueChanged(int)), label_area->verticalScrollBar(), SLOT(setValue(int)));
+  connect(view_, SIGNAL(setScrollMaximum(int)), this, SLOT(setScrollMaximum(int)));
+  connect(view_, SIGNAL(requestScrollChange(int)), scrollbar_, SLOT(setValue(int)));
 }
 
 void TimelineArea::SetTrackList(Sequence *sequence, Track::Type track_list)
@@ -55,6 +72,78 @@ void TimelineArea::SetTrackList(Sequence *sequence, Track::Type track_list)
 
 }
 
+void TimelineArea::SetAlignment(olive::timeline::Alignment alignment)
+{
+  view_->SetAlignment(alignment);
+  alignment_ = alignment;
+
+  RefreshLabels();
+}
+
+void TimelineArea::wheelEvent(QWheelEvent *event)
+{
+
+  // TODO: implement pixel scrolling
+
+  bool shift = (event->modifiers() & Qt::ShiftModifier);
+  bool ctrl = (event->modifiers() & Qt::ControlModifier);
+  bool alt = (event->modifiers() & Qt::AltModifier);
+
+  // "Scroll Zooms" false + Control up  : not zooming
+  // "Scroll Zooms" false + Control down:     zooming
+  // "Scroll Zooms" true  + Control up  :     zooming
+  // "Scroll Zooms" true  + Control down: not zooming
+  bool zooming = (olive::config.scroll_zooms != ctrl);
+
+  // Allow shift for axis swap, but don't swap on zoom... Unless
+  // we need to override Qt's axis swap via Alt
+  bool swap_hv = ((shift != olive::config.invert_timeline_scroll_axes) &
+                  !zooming) | (alt & !shift & zooming);
+
+  int delta_h = swap_hv ? event->angleDelta().y() : event->angleDelta().x();
+  int delta_v = swap_hv ? event->angleDelta().x() : event->angleDelta().y();
+
+  if (zooming) {
+
+    // Zoom only uses vertical scrolling, to avoid glitches on touchpads.
+    // Don't do anything if not scrolling vertically.
+
+    if (delta_v != 0) {
+
+      // delta_v == 120 for one click of a mousewheel. Less or more for a
+      // touchpad gesture. Calculate speed to compensate.
+      // 120 = ratio of 4/3 (1.33), -120 = ratio of 3/4 (.75)
+
+      double zoom_ratio = 1.0 + (abs(delta_v) * 0.33 / 120);
+
+      if (delta_v < 0) {
+        zoom_ratio = 1.0 / zoom_ratio;
+      }
+
+      timeline_->multiply_zoom(zoom_ratio);
+    }
+
+  } else {
+
+    // Use the Timeline's main scrollbar for horizontal scrolling, and this
+    // widget's scrollbar for vertical scrolling.
+
+    QScrollBar* bar_v = scrollbar_;
+    QScrollBar* bar_h = timeline_->horizontalScrollBar;
+
+    // Match the wheel events to the size of a step as per
+    // https://doc.qt.io/qt-5/qwheelevent.html#angleDelta
+
+    int step_h = bar_h->singleStep() * delta_h / -120;
+    int step_v = bar_v->singleStep() * delta_v / -120;
+
+    // Apply to appropriate scrollbars
+
+    bar_h->setValue(bar_h->value() + step_h);
+    bar_v->setValue(bar_v->value() + step_v);
+  }
+}
+
 void TimelineArea::RefreshLabels()
 {
   if (track_list_ == nullptr) {
@@ -68,8 +157,29 @@ void TimelineArea::RefreshLabels()
       labels_[i] = std::make_shared<TimelineLabel>();
       labels_[i]->SetTrack(track_list_->TrackAt(i));
 
-      label_container_layout_->insertWidget(label_container_layout_->count()-1, labels_[i].get());
+      switch (alignment_) {
+      case olive::timeline::kAlignmentTop:
+        label_container_layout_->insertWidget(label_container_layout_->count()-1, labels_[i].get());
+        break;
+      case olive::timeline::kAlignmentBottom:
+        label_container_layout_->insertWidget(1, labels_[i].get());
+        break;
+      case olive::timeline::kAlignmentSingle:
+        break;
+      }
     }
 
   }
 }
+
+void TimelineArea::resizeEvent(QResizeEvent *)
+{
+  scrollbar_->setPageStep(view_->height());
+}
+
+void TimelineArea::setScrollMaximum(int maximum)
+{
+  scrollbar_->setMaximum(qMax(0, maximum - view_->height()));
+  label_container_->setMinimumHeight(maximum);
+//  label_container_->setFixedHeight(maximum);
+}