AssetBundleGraph.AssetBundleGraphEditorWindow.DrawGUINodeGraph C# (CSharp) Method

        private void DrawGUINodeGraph()
        {
            background.Draw(graphRegion, scrollPos);

            using(var scrollScope = new EditorGUILayout.ScrollViewScope(scrollPos) ) {
                scrollPos = scrollScope.scrollPosition;

                // draw node window x N.
                {
                    BeginWindows();

                    nodes.ForEach(node => node.DrawNode());

                    EndWindows();
                }

                // draw connection input point marks.
                foreach (var node in nodes) {
                    node.DrawConnectionInputPointMark(currentEventSource, modifyMode == ModifyMode.CONNECTING);
                }

                // draw connections.
                foreach (var con in connections) {
                    var keyEnum = s_assetStreamMap.Keys.Where(c => c.Id == con.Id);
                    if (keyEnum.Any()) {
                        var assets = s_assetStreamMap[keyEnum.First()];
                        con.DrawConnection(nodes, assets);
                    } else {
                        con.DrawConnection(nodes, new Dictionary<string, List<Asset>>());
                    }
                }

                // draw connection output point marks.
                foreach (var node in nodes) {
                    node.DrawConnectionOutputPointMark(currentEventSource, modifyMode == ModifyMode.CONNECTING, Event.current);
                }

                // draw connecting line if modifing connection.
                switch (modifyMode) {
                case ModifyMode.CONNECTING: {
                        // from start node to mouse.
                        DrawStraightLineFromCurrentEventSourcePointTo(Event.current.mousePosition, currentEventSource);
                        break;
                    }
                case ModifyMode.SELECTING: {
                        GUI.DrawTexture(new Rect(selection.x, selection.y, Event.current.mousePosition.x - selection.x, Event.current.mousePosition.y - selection.y), selectionTex);
                        break;
                    }
                }

                // handle Graph GUI events
                HandleGraphGUIEvents();

                // set rect for scroll.
                if (nodes.Any()) {
                    GUILayoutUtility.GetRect(new GUIContent(string.Empty), GUIStyle.none, GUILayout.Width(spacerRectRightBottom.x), GUILayout.Height(spacerRectRightBottom.y));
                }
            }
            if(Event.current.type == EventType.Repaint) {
                var newRgn = GUILayoutUtility.GetLastRect();
                if(newRgn != graphRegion) {
                    graphRegion = newRgn;
                    Repaint();
                }
            }
        }