cache: reimplemented auto-caching

Implemented a smarter auto-cache that's context sensitive. Caching will
automatically pause when playback begins or values are being changed and resume
when inactive.

app/task/cache/cache.cpp

@@ -50,12 +50,14 @@ bool CacheTask::Run()
 
   Render(range_to_cache, QMatrix4x4(), false);
 
+  download_threads_.waitForDone();
+
   return true;
 }
 
 QFuture<void> CacheTask::DownloadFrame(FramePtr frame, const QByteArray &hash)
 {
-  return QtConcurrent::run(FrameHashCache::SaveCacheFrame, hash, frame);
+  return QtConcurrent::run(&download_threads_, FrameHashCache::SaveCacheFrame, hash, frame);
 }
 
 void CacheTask::FrameDownloaded(const QByteArray &hash, const QLinkedList<rational> &times)

app/task/cache/cache.h

@@ -47,6 +47,8 @@ protected:
 private:
   bool in_out_only_;
 
+  QThreadPool download_threads_;
+
 };
 
 OLIVE_NAMESPACE_EXIT

app/task/render/render.cpp

@@ -92,7 +92,7 @@ void RenderTask::Render(const TimeRangeList& range_to_cache,
     QLinkedList<HashTimePair> sorted_times;
     QLinkedList<HashTimePair>::iterator sorted_iterator;
 
-    // Rendering is more efficient if we cache in order
+    // Rendering is more efficient if we cache in order, so here we sort
     QMap< QByteArray, QLinkedList<rational> >::const_iterator i;
     for (i=times_to_render.constBegin(); i!=times_to_render.constEnd(); i++) {
       const QByteArray& hash = i.key();
@@ -141,9 +141,10 @@ void RenderTask::Render(const TimeRangeList& range_to_cache,
   QLinkedList<HashDownloadFuturePair>::iterator j;
   QLinkedList<RangeSampleFuturePair>::iterator k;
 
-  while (!render_lookup_table.isEmpty()
-         || !download_futures.isEmpty()
-         || !audio_lookup_table.isEmpty()) {
+  while (!IsCancelled()
+         && (!render_lookup_table.isEmpty()
+             || !download_futures.isEmpty()
+             || !audio_lookup_table.isEmpty())) {
 
     i = render_lookup_table.begin();
 
@@ -197,4 +198,9 @@ void RenderTask::AudioDownloaded(const TimeRange &, SampleBufferPtr)
 {
 }
 
+void RenderTask::SetAnchorPoint(const rational &r)
+{
+  anchor_point_ = r;
+}
+
 OLIVE_NAMESPACE_EXIT

app/task/render/render.h

@@ -57,6 +57,8 @@ protected:
     return audio_params_;
   }
 
+  void SetAnchorPoint(const rational& r);
+
 private:
   ViewerOutput* viewer_;
 
@@ -64,6 +66,8 @@ private:
 
   AudioRenderingParams audio_params_;
 
+  rational anchor_point_;
+
 };
 
 OLIVE_NAMESPACE_EXIT

app/task/taskmanager.cpp

@@ -72,6 +72,17 @@ Task *TaskManager::GetFirstTask() const
   return tasks_.begin().value();
 }
 
+void TaskManager::CancelTaskAndWait(Task* t)
+{
+  t->Cancel();
+
+  QFutureWatcher<bool>* w = tasks_.key(t);
+
+  if (w) {
+    w->waitForFinished();
+  }
+}
+
 void TaskManager::AddTask(Task* t)
 {
   // Create a watcher for signalling
@@ -89,6 +100,17 @@ void TaskManager::AddTask(Task* t)
   emit TaskListChanged();
 }
 
+void TaskManager::CancelTask(Task *t)
+{
+  if (failed_tasks_.contains(t)) {
+    failed_tasks_.removeOne(t);
+    emit TaskRemoved(t);
+    t->deleteLater();
+  } else {
+    t->Cancel();
+  }
+}
+
 void TaskManager::TaskFinished()
 {
   QFutureWatcher<bool>* watcher = static_cast<QFutureWatcher<bool>*>(sender());

app/task/taskmanager.h

@@ -63,6 +63,8 @@ public:
 
   Task* GetFirstTask() const;
 
+  void CancelTaskAndWait(Task* t);
+
 public slots:
   /**
    * @brief Add a new Task
@@ -81,6 +83,8 @@ public slots:
    */
   void AddTask(Task *t);
 
+  void CancelTask(Task* t);
+
 signals:
   /**
    * @brief Signal emitted when a Task is added by AddTask()