From 18fe6441ce9bcd1aaa35f86e687fbbd5b302cbe7 Mon Sep 17 00:00:00 2001
From: Giulio Eulisse <10544+ktf@users.noreply.github.com>
Date: Wed, 24 Nov 2021 16:22:43 +0100
Subject: [PATCH] DPL GUI: drastically improve ability to debug large
 topologies

This marks in purple incoming and outgoing connections to the selected
node. Notice that the tip of the outgoing arrow is still yellow,
due to the fact it's considered to be part of the target node. Good
enough improvement for now.
---
 .../src/FrameworkGUIDevicesGraph.cxx          | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/Framework/GUISupport/src/FrameworkGUIDevicesGraph.cxx b/Framework/GUISupport/src/FrameworkGUIDevicesGraph.cxx
index 9f9ebdfec002d..608b12b9563d4 100644
--- a/Framework/GUISupport/src/FrameworkGUIDevicesGraph.cxx
+++ b/Framework/GUISupport/src/FrameworkGUIDevicesGraph.cxx
@@ -77,6 +77,7 @@ const static ImColor OUTPUT_SLOT_COLOR = {150, 150, 150, 150};
 const static ImVec4& ERROR_MESSAGE_COLOR = PaletteHelpers::RED;
 const static ImVec4& WARNING_MESSAGE_COLOR = PaletteHelpers::YELLOW;
 const static ImColor ARROW_COLOR = {200, 200, 100};
+const static ImColor ARROW_SELECTED_COLOR = {200, 0, 100};
 const static ImU32 GRID_COLOR = ImColor(200, 200, 200, 40);
 const static ImColor NODE_BORDER_COLOR = {100, 100, 100};
 const static ImColor LEGEND_COLOR = {100, 100, 100};
@@ -459,12 +460,20 @@ void showTopologyNodeGraph(WorkspaceGUIState& state,
   displayGrid(show_grid, offset, draw_list);
 
   // Display links
-  draw_list->ChannelsSetCurrent(0); // Background
   for (int link_idx = 0; link_idx < links.Size; link_idx++) {
+    draw_list->ChannelsSetCurrent(0); // Background
     NodeLink* link = &links[link_idx];
+    auto color = ARROW_COLOR;
+    auto thickness = ARROW_THICKNESS;
+    if (link->InputIdx == node_selected || link->OutputIdx == node_selected) {
+      auto foregroundLayer = (nodes.Size + 1) * 2 + 1;
+      draw_list->ChannelsSetCurrent(foregroundLayer);
+      color = ARROW_SELECTED_COLOR;
+      thickness = thickness + 2;
+    }
     ImVec2 p1 = offset + NodePos::GetOutputSlotPos(nodes, positions, link->InputIdx, link->InputSlot);
     ImVec2 p2 = ImVec2(-3 * NODE_SLOT_RADIUS, 0) + offset + NodePos::GetInputSlotPos(nodes, positions, link->OutputIdx, link->OutputSlot);
-    draw_list->AddBezierCurve(p1, p1 + ImVec2(+50, 0), p2 + ImVec2(-50, 0), p2, ARROW_COLOR, ARROW_THICKNESS);
+    draw_list->AddBezierCurve(p1, p1 + ImVec2(+50, 0), p2 + ImVec2(-50, 0), p2, color, thickness);
   }
 
   // Display nodes
@@ -567,7 +576,11 @@ void showTopologyNodeGraph(WorkspaceGUIState& state,
       auto pp1 = p1 + offset + NodePos::GetInputSlotPos(nodes, positions, node_idx, slot_idx);
       auto pp2 = p2 + offset + NodePos::GetInputSlotPos(nodes, positions, node_idx, slot_idx);
       auto pp3 = p3 + offset + NodePos::GetInputSlotPos(nodes, positions, node_idx, slot_idx);
-      draw_list->AddTriangleFilled(pp1, pp2, pp3, ARROW_COLOR);
+      auto color = ARROW_COLOR;
+      if (node_idx == node_selected) {
+        color = ARROW_SELECTED_COLOR;
+      }
+      draw_list->AddTriangleFilled(pp1, pp2, pp3, color);
       draw_list->AddCircleFilled(offset + NodePos::GetInputSlotPos(nodes, positions, node_idx, slot_idx), NODE_SLOT_RADIUS, INPUT_SLOT_COLOR);
     }
     for (int slot_idx = 0; slot_idx < node->OutputsCount; slot_idx++) {