made node edge changes undoable

app/node/input/image/image.cpp

@@ -0,0 +1,46 @@
+#include "image.h"
+
+ImageInput::ImageInput() :
+  texture_(nullptr)
+{
+  texture_output_ = new NodeOutput();
+  texture_output_->set_data_type(NodeOutput::kTexture);
+  AddParameter(texture_output_);
+}
+
+QString ImageInput::Name()
+{
+  return tr("Image");
+}
+
+QString ImageInput::Category()
+{
+  return tr("Input");
+}
+
+QString ImageInput::Description()
+{
+  return tr("Import an image file.");
+}
+
+NodeOutput *ImageInput::texture_output()
+{
+  return texture_output_;
+}
+
+void ImageInput::Process(const rational &time)
+{
+  // FIXME: Use OIIO and OCIO here
+
+  // FIXME: Test code
+  Q_UNUSED(time)
+
+  if (texture_ == nullptr) {
+    QImage img("/home/matt/Desktop/oof.png");
+
+    texture_ = new QOpenGLTexture(img);
+  }
+
+  texture_output_->set_value(texture_->textureId());
+  // End test code
+}