finished prototype of nodes providing a texture to a viewer

app/node/output/viewer/viewer.cpp

@@ -1,6 +1,57 @@
 #include "viewer.h"
 
+#include "panel/panelfocusmanager.h"
+
 ViewerOutput::ViewerOutput(QObject* parent) :
-  Node(parent)
+  Node(parent),
+  attached_viewer_(nullptr)
 {
+  texture_input_ = new NodeInput(this);
+  texture_input_->add_data_input(NodeInput::kTexture);
+}
+
+QString ViewerOutput::Name()
+{
+  return tr("Viewer");
+}
+
+QString ViewerOutput::Category()
+{
+  return tr("Output");
+}
+
+QString ViewerOutput::Description()
+{
+  return tr("Interface between a Viewer panel and the node system.");
+}
+
+NodeInput *ViewerOutput::texture_input()
+{
+  return texture_input_;
+}
+
+void ViewerOutput::Process(const rational &time)
+{
+  if (attached_viewer_ != nullptr) {
+    // Get the texture from whatever Node is currently connected (usually a Renderer of some kind)
+    GLuint current_texture = texture_input_->get_value(time).value<GLuint>();
+
+    // Send the texture to the Viewer
+    attached_viewer_->SetTexture(current_texture);
+  }
+}
+
+void ViewerOutput::AttachViewer(ViewerPanel *viewer)
+{
+  // Disconnect old viewer if there's one attached
+  if (attached_viewer_ != nullptr) {
+    disconnect(attached_viewer_, SIGNAL(TimeChanged(const rational&)), this, SLOT(Process(const rational&)));
+  }
+
+  // FIXME: Currently this attaches to ViewerPanels, but should it attached to Viewers instead?
+  attached_viewer_ = viewer;
+
+  if (attached_viewer_ != nullptr) {
+    connect(attached_viewer_, SIGNAL(TimeChanged(const rational&)), this, SLOT(Process(const rational&)));
+  }
 }