timeline: automate waveform resizing

Now each UndoCommand won't have to handle it (unless it can introduce
specific optimizations).

app/node/block/block.cpp

@@ -101,7 +101,11 @@ void Block::set_length_and_media_out(const rational &length)
     return;
   }
 
-  length_input_->set_standard_value(QVariant::fromValue(length));
+  rational old_length = this->length();
+
+  set_length_internal(length);
+
+  LengthChangedEvent(old_length, length, Timeline::kTrimOut);
 }
 
 void Block::set_length_and_media_in(const rational &length)
@@ -115,8 +119,12 @@ void Block::set_length_and_media_in(const rational &length)
   // Calculate media_in adjustment
   set_media_in(media_in() + (this->length() - length) * speed());
 
+  rational old_length = this->length();
+
   // Set the length without setting media out
-  set_length_and_media_out(length);
+  set_length_internal(length);
+
+  LengthChangedEvent(old_length, length, Timeline::kTrimIn);
 }
 
 Block *Block::previous()
@@ -246,6 +254,15 @@ QList<NodeInput *> Block::GetInputsToHash() const
   return inputs;
 }
 
+void Block::LengthChangedEvent(const rational &, const rational &, const Timeline::MovementMode &)
+{
+}
+
+void Block::set_length_internal(const rational &length)
+{
+  length_input_->set_standard_value(QVariant::fromValue(length));
+}
+
 void Block::LengthInputChanged()
 {
   emit LengthChanged(length());

app/node/block/block.h

@@ -22,6 +22,7 @@
 #define BLOCK_H
 
 #include "node/node.h"
+#include "timeline/timelinecommon.h"
 
 OLIVE_NAMESPACE_ENTER
 
@@ -130,10 +131,16 @@ protected:
 
   virtual QList<NodeInput*> GetInputsToHash() const override;
 
+  virtual void LengthChangedEvent(const rational& old_length,
+                                  const rational& new_length,
+                                  const Timeline::MovementMode& mode);
+
   Block* previous_;
   Block* next_;
 
 private:
+  void set_length_internal(const rational &length);
+
   NodeInput* name_input_;
   NodeInput* length_input_;
   NodeInput* media_in_input_;

app/node/block/clip/clip.cpp

@@ -59,6 +59,26 @@ NodeInput *ClipBlock::texture_input() const
   return texture_input_;
 }
 
+void ClipBlock::LengthChangedEvent(const rational &old_length, const rational &new_length, const Timeline::MovementMode &mode)
+{
+  // Positive if made longer, negative if made shorter
+  rational diff = new_length - old_length;
+
+  if (diff < rational()) {
+    if (mode == Timeline::kTrimIn) {
+      waveform().TrimIn(-diff);
+    } else {
+      waveform().TrimOut(-diff);
+    }
+  } else {
+    if (mode == Timeline::kTrimIn) {
+      waveform().PrependSilence(diff);
+    } else {
+      waveform().AppendSilence(diff);
+    }
+  }
+}
+
 void ClipBlock::InvalidateCache(const TimeRange &range, NodeInput *from, NodeInput *source)
 {
   // If signal is from texture input, transform all times from media time to sequence time

app/node/block/clip/clip.h

@@ -72,6 +72,11 @@ public:
 signals:
   void PreviewUpdated();
 
+protected:
+  virtual void LengthChangedEvent(const rational& old_length,
+                                  const rational& new_length,
+                                  const Timeline::MovementMode& mode) override;
+
 private:
   NodeInput* texture_input_;