work towards dropping clips into the timeline

app/widget/timelineview/timelineview.cpp

@@ -20,13 +20,19 @@
 
 #include "timelineview.h"
 
+#include <QDebug>
+#include <QMimeData>
 #include <QMouseEvent>
 #include <QtMath>
 #include <QPen>
 
+#include "node/input/media/media.h"
+#include "project/item/footage/footage.h"
+
 TimelineView::TimelineView(QWidget *parent) :
   QGraphicsView(parent),
-  playhead_(0)
+  playhead_(0),
+  dragging_(false)
 {
   setScene(&scene_);
   setAlignment(Qt::AlignLeft | Qt::AlignTop);
@@ -72,6 +78,7 @@ void TimelineView::SetScale(const double &scale)
 void TimelineView::SetTimebase(const rational &timebase)
 {
   timebase_ = timebase;
+  timebase_dbl_ = timebase_.toDouble();
 
   playhead_line_->SetTimebase(timebase_);
 }
@@ -96,38 +103,55 @@ void TimelineView::SetTime(const int64_t time)
 void TimelineView::mousePressEvent(QMouseEvent *event)
 {
   QGraphicsView::mousePressEvent(event);
-
-  if (itemAt(event->pos()) != nullptr) {
-    QList<QGraphicsItem*> selected_items = scene_.selectedItems();
-
-    foreach (QGraphicsItem* item, selected_items) {
-      TimelineViewGhostItem* ghost = new TimelineViewGhostItem();
-      TimelineViewClipItem* clip_item = static_cast<TimelineViewClipItem*>(item);
-
-      ClipBlock* clip = clip_item->clip();
-
-      ghost->SetIn(clip->in());
-      ghost->SetOut(clip->out());
-      ghost->SetScale(scale_);
-
-      ghost->setPos(clip_item->pos());
-
-      ghost_items_.append(ghost);
-
-      scene_.addItem(ghost);
-    }
-  }
 }
 
 void TimelineView::mouseMoveEvent(QMouseEvent *event)
 {
   QGraphicsView::mouseMoveEvent(event);
 
-  if (!ghost_items_.isEmpty()) {
-    foreach (TimelineViewGhostItem* ghost, ghost_items_) {
-      QPointF scene_pos = mapToScene(event->pos());
+  if (!dragging_) {
+    // Let's see if there's anything selected to drag
+    if (itemAt(event->pos()) != nullptr) {
+      QList<QGraphicsItem*> selected_items = scene_.selectedItems();
 
-      ghost->setX(qMax(0.0, scene_pos.x()));
+      foreach (QGraphicsItem* item, selected_items) {
+        TimelineViewGhostItem* ghost = new TimelineViewGhostItem();
+        TimelineViewClipItem* clip_item = static_cast<TimelineViewClipItem*>(item);
+
+        ClipBlock* clip = clip_item->clip();
+
+        ghost->SetIn(clip->in());
+        ghost->SetOut(clip->out());
+        ghost->SetScale(scale_);
+
+        ghost->setPos(clip_item->pos());
+
+        ghost_items_.append(ghost);
+
+        scene_.addItem(ghost);
+      }
+
+      drag_start_ = event->pos();
+    }
+
+    dragging_ = true;
+  } else if (!ghost_items_.isEmpty()) {
+    QPoint movement = event->pos() - drag_start_;
+
+    rational time_movement = ScreenToTime(movement.x());
+
+    // Validate movement
+    foreach (TimelineViewGhostItem* ghost, ghost_items_) {
+      rational validator = ghost->In() + time_movement;
+      if (validator < 0) {
+        time_movement = rational(0) - ghost->In();
+      }
+    }
+
+    // Perform movement
+    foreach (TimelineViewGhostItem* ghost, ghost_items_) {
+      ghost->SetInAdjustment(time_movement);
+      ghost->SetOutAdjustment(time_movement);
     }
   }
 }
@@ -136,6 +160,107 @@ void TimelineView::mouseReleaseEvent(QMouseEvent *event)
 {
   QGraphicsView::mouseReleaseEvent(event);
 
+  ClearGhosts();
+
+  dragging_ = false;
+}
+
+void TimelineView::dragEnterEvent(QDragEnterEvent *event)
+{
+  QStringList mime_formats = event->mimeData()->formats();
+
+  // Listen for MIME data from a ProjectViewModel
+  if (mime_formats.contains("application/x-oliveprojectitemdata")) {
+    // FIXME: Implement audio insertion
+
+    // Data is drag/drop data from a ProjectViewModel
+    QByteArray model_data = event->mimeData()->data("application/x-oliveprojectitemdata");
+
+    // Use QDataStream to deserialize the data
+    QDataStream stream(&model_data, QIODevice::ReadOnly);
+
+    // Variables to deserialize into
+    quintptr item_ptr;
+    int r;
+
+    while (!stream.atEnd()) {
+      stream >> r >> item_ptr;
+
+      // Get Item object
+      Item* item = reinterpret_cast<Item*>(item_ptr);
+
+      // Check if Item is Footage
+      if (item->type() == Item::kFootage) {
+        // If the Item is Footage, we can create a Ghost from it
+        Footage* footage = static_cast<Footage*>(item);
+
+        StreamPtr stream = footage->stream(0);
+
+        TimelineViewGhostItem* ghost = new TimelineViewGhostItem();
+
+        rational footage_duration(stream->timebase().numerator() * stream->duration(),
+                                  stream->timebase().denominator());
+
+        ghost->SetIn(0);
+        ghost->SetOut(footage_duration);
+        ghost->SetScale(scale_);
+        ghost->SetStream(stream);
+
+        ghost_items_.append(ghost);
+
+        scene_.addItem(ghost);
+      }
+    }
+
+    event->accept();
+  } else {
+    // FIXME: Implement dropping from file
+    event->ignore();
+  }
+}
+
+void TimelineView::dragMoveEvent(QDragMoveEvent *event)
+{
+  if (ghost_items_.isEmpty()) {
+    event->ignore();
+  } else {
+    event->accept();
+  }
+}
+
+void TimelineView::dragLeaveEvent(QDragLeaveEvent *event)
+{
+  if (ghost_items_.isEmpty()) {
+    event->ignore();
+  } else {
+    ClearGhosts();
+
+    event->accept();
+  }
+}
+
+void TimelineView::dropEvent(QDropEvent *event)
+{
+  if (ghost_items_.isEmpty()) {
+    event->ignore();
+  } else {
+    ClearGhosts();
+
+    event->accept();
+  }
+}
+
+rational TimelineView::ScreenToTime(const int &x)
+{
+  // Adjust screen point by scale and timebase
+  int scaled_x_mvmt = qRound(x / scale_ / timebase_dbl_);
+
+  // Return a time in the timebase
+  return rational(scaled_x_mvmt * timebase_.numerator(), timebase_.denominator());
+}
+
+void TimelineView::ClearGhosts()
+{
   if (!ghost_items_.isEmpty()) {
     foreach (TimelineViewGhostItem* ghost, ghost_items_) {
       delete ghost;