cpp/functions/gfx/dag_panel.cpp

@@ -95,6 +95,8 @@ bool dag_panel(std::vector<DagStep>& pipeline) {
     int delete_idx = -1;
     int move_up_idx = -1;
     int move_down_idx = -1;
+    int drop_src_idx = -1;
+    int drop_target_idx = -1;
 
     ImGui::BeginChild("dag_pipeline_scroll", ImVec2(0, 0), false);
 
@@ -115,6 +117,19 @@ bool dag_panel(std::vector<DagStep>& pipeline) {
 
         ImGui::PopStyleColor(3);
 
+        if (ImGui::BeginDragDropSource(ImGuiDragDropFlags_SourceAllowNullID)) {
+            ImGui::SetDragDropPayload("DAG_STEP", &i, sizeof(int));
+            ImGui::Text("Move %s", def->label.c_str());
+            ImGui::EndDragDropSource();
+        }
+        if (ImGui::BeginDragDropTarget()) {
+            if (const ImGuiPayload* pl = ImGui::AcceptDragDropPayload("DAG_STEP")) {
+                drop_src_idx = *static_cast<const int*>(pl->Data);
+                drop_target_idx = i;
+            }
+            ImGui::EndDragDropTarget();
+        }
+
         if (open) {
             ImGui::Indent(8.0f);
 
@@ -221,6 +236,16 @@ bool dag_panel(std::vector<DagStep>& pipeline) {
         std::swap(pipeline[static_cast<size_t>(move_down_idx)], pipeline[static_cast<size_t>(move_down_idx + 1)]);
         changed = true;
     }
+    if (drop_src_idx >= 0 && drop_target_idx >= 0 && drop_src_idx != drop_target_idx &&
+        drop_src_idx < static_cast<int>(pipeline.size()) &&
+        drop_target_idx < static_cast<int>(pipeline.size())) {
+        DagStep moved = pipeline[static_cast<size_t>(drop_src_idx)];
+        pipeline.erase(pipeline.begin() + drop_src_idx);
+        int target = drop_target_idx;
+        if (drop_src_idx < drop_target_idx) target--;
+        pipeline.insert(pipeline.begin() + target, moved);
+        changed = true;
+    }
 
     return changed;
 }