timeline: copy waveform when copying

app/audio/audiovisualwaveform.cpp

@@ -164,7 +164,7 @@ void AudioVisualWaveform::OverwriteSums(const AudioVisualWaveform &sums, const r
            copy_len * sizeof(SamplePerChannel));
   }
 
-  length_ = qMax(length_, dest + length);
+  length_ = qMax(length_, dest + ((length.isNull()) ? sums.length() - offset : length));
 }
 
 void AudioVisualWaveform::OverwriteSilence(const rational &start, const rational &length)
@@ -233,7 +233,7 @@ void AudioVisualWaveform::Shift(const rational &from, const rational &to)
     }
   }
 
-  length_ += (to-from);
+  length_ = qMax(rational(0), length_ + (to-from));
 }
 
 void AudioVisualWaveform::TrimIn(const rational &length)
@@ -256,7 +256,16 @@ void AudioVisualWaveform::TrimIn(const rational &length)
     }
   }
 
-  length_ -= length;
+  length_ = qMax(rational(0), length_ - length);
+}
+
+AudioVisualWaveform AudioVisualWaveform::Mid(const rational &offset) const
+{
+  AudioVisualWaveform mid  = *this;
+
+  mid.TrimIn(offset);
+
+  return mid;
 }
 
 AudioVisualWaveform::Sample AudioVisualWaveform::GetSummaryFromTime(const rational &start, const rational &length) const

app/audio/audiovisualwaveform.h

@@ -94,6 +94,8 @@ public:
 
   void TrimIn(const rational &length);
 
+  AudioVisualWaveform Mid(const rational &offset) const;
+
   Sample GetSummaryFromTime(const rational& start, const rational& length) const;
 
   static Sample SumSamples(const float* samples, int nb_samples, int nb_channels);

app/widget/timelinewidget/tool/pointer.cpp

@@ -605,6 +605,9 @@ void PointerTool::FinishDrag(TimelineViewMouseEvent *event)
         // Duplicate rather than move
         // Place the copy instead of the original block
         block = static_cast<Block*>(Node::CopyNodeInGraph(block, command));
+        if (ClipBlock *new_clip = dynamic_cast<ClipBlock*>(block)) {
+          new_clip->waveform() = static_cast<ClipBlock*>(p.block)->waveform();
+        }
       }
 
       const Track::Reference& track_ref = p.ghost->GetAdjustedTrack();

app/widget/timelinewidget/undo/timelineundosplit.cpp

@@ -20,6 +20,7 @@
 
 #include "timelineundosplit.h"
 
+#include "node/block/clip/clip.h"
 #include "node/block/transition/transition.h"
 #include "widget/nodeview/nodeviewundo.h"
 
@@ -37,6 +38,10 @@ void BlockSplitCommand::redo()
   if (!reconnect_tree_command_) {
     reconnect_tree_command_ = new MultiUndoCommand();
     new_block_ = static_cast<Block*>(Node::CopyNodeInGraph(block_, reconnect_tree_command_));
+    if (ClipBlock *new_clip = dynamic_cast<ClipBlock*>(new_block_)) {
+      ClipBlock *old_clip = static_cast<ClipBlock*>(block_);
+      new_clip->waveform() = old_clip->waveform();
+    }
   }
 
   reconnect_tree_command_->redo_now();