MBEditor.OnGUI C# (CSharp) Method

    void OnGUI()
    {
        if (!_instance) return;

        // Check if window was open on recompile. If so, we need to reinitialize
        if (mStyleHeaderStyle == null) {
            mStyleHeaderStyle = new GUIStyle(GUI.skin.GetStyle("button"));
            mStyleHeaderStyle.fontStyle = FontStyle.Bold;

            mStyleBoldCentered = new GUIStyle(GUI.skin.GetStyle("label"));
            mStyleBoldCentered.fontStyle = FontStyle.Bold;
            mStyleBoldCentered.alignment = TextAnchor.MiddleCenter;
            mStyleBoldCentered.stretchWidth = true;

            mStyleEmptyBox = new GUIStyle(GUI.skin.GetStyle("box"));
            mStyleEmptyBox.margin = new RectOffset(0, 0, 0, 0);
            mStyleEmptyBox.padding = new RectOffset(0, 0, 0, 0);
        }

        if (!SelectedParticleSystem) return;

        mColDefault = GUI.backgroundColor;
        Event e = Event.current;
        Object[] deephierarchy=new Object[0];
        if ((e.type == EventType.MouseDown && e.button == 0) || (e.type == EventType.KeyUp && (e.keyCode == KeyCode.Tab))) {
            deephierarchy=EditorUtility.CollectDeepHierarchy(new Object[]{SelectedObject});
            Undo.SetSnapshotTarget(deephierarchy, "Magical Box value change");
            Undo.CreateSnapshot();
            Undo.ClearSnapshotTarget();
            mListeningForGUIChanges = true;
        }
        // Store mouse position for editor enabled scripts
        if (!Application.isPlaying) {
            MBEditorEnabledScript.MousePosition = new Vector3(
                e.mousePosition.x, -e.mousePosition.y+25, 0);
        }

        // Top row holds Toolbar
        EditorGUILayout.BeginHorizontal();
        DoToolbarGUI();
        EditorGUILayout.EndHorizontal();
        // Left window side shows the overview
        GUILayout.BeginArea(new Rect(0, 26, 204, position.height - 26), GUI.skin.GetStyle("Box"));
        mOverviewScroll = EditorGUILayout.BeginScrollView(mOverviewScroll);
        DoOverviewGUI();
        EditorGUILayout.EndScrollView();
        GUILayout.EndArea();

        // Right window side shows details of selection
        GUI.backgroundColor = mColDefault;
        GUILayout.BeginArea(new Rect(205, 26, position.width - 205, position.height - 26), GUI.skin.GetStyle("Box"));
        if (SelectedObject.Matches(typeof(MBEmitter), typeof(MBParameter)))
            DoEmitterGUI();
        else if (SelectedObject is MBParticleSystem)
            DoSystemGUI();
        else if (SelectedObject is MBAnchor)
            DoAnchorGUI();
        else if (SelectedObject is MBLayer)
            DoLayerGUI();

        GUILayout.EndArea();

        // Control Undo
        if (mListeningForGUIChanges && GUI.changed) {
            Undo.SetSnapshotTarget(deephierarchy, "Magical Box value change");
            Undo.RegisterSnapshot();
            Undo.ClearSnapshotTarget();
            mListeningForGUIChanges = false;
        }

        GUI.backgroundColor = mColDefault;
    }