UI_CUSTOM_DRAW_CALLBACK(BuildNavViewDrawCallback)
{
    scene_view *SceneView = (scene_view *)Data;
    SV_DrawBackground(SceneView, Box, Group);
}

static scene_nav_item_node *W_SceneNavItemNodeAlloc(arena *Arena, workspace_view_nav_editor *Editor)
{
    scene_nav_item_node *Result = Editor->FirstFree;
    if(Result)
    {
        DLLRemove(Editor->FirstFree, Editor->LastFree, Result);
        *Result = {};
    }
    else
    {
        Result = PushStruct(Arena, scene_nav_item_node);
    }
    
    DLLInsertLast(Editor->Items.First, Editor->Items.Last, Result);
    Editor->Items.Count += 1;
    return(Result);
}

static void W_SceneNavItemNodeRelease(workspace_view_nav_editor *Editor, scene_nav_item_node *Node)
{
    DLLInsertLast(Editor->FirstFree, Editor->LastFree, Node);
    Editor->Items.Count -= 1;
}

static void W_SetupNavEditor(workspace_view *View, string FileContents)
{
    //- sixten(TODO): deserialize data
}

static void W_BuildNavEditor(workspace_view *View)
{
    workspace_view_nav_editor *Editor = (workspace_view_nav_editor *)View->Data;
    scene_view *SceneView = SV_GetState();
    
    UI_BackgroundColor(V4(0.25, 0.25, 0.25, 1))
        UI_BorderColor(V4(0.45, 0.45, 0.45, 1))
        UI_WidthFill UI_Height(UI_Em(2.0f, 1.0f))
        UI_Parent(UI_MakeBoxF(UI_BoxFlag_DrawBackground|UI_BoxFlag_DrawBorder, "Workspace Nav Editor Toolbar"))
    {
        UI_Width(UI_TextContent(10, 1.0f)) UI_Font(Font_Icons) if(UI_ButtonF("%U", FontIcon_UserPlus).Clicked)
        {
            scene_nav_item_node *NewNode = W_SceneNavItemNodeAlloc(View->Arena, Editor);
            NewNode->Item = G_DefaultSceneNavItem;
        }
    }
    
    UI_Row()
    {
        //- sixten: build inspector panel
        UI_Width(UI_Percent(0.2f, 1.0f)) UI_HeightFill
            UI_Parent(UI_MakeBox(UI_BoxFlag_DrawBorder, StrLit("Workspace Nav Editor Inspector")))
        {
            scene_nav_item_node *SelectedItem = Editor->SelectedItem;
            if(SelectedItem)
            {
            }
            else UI_WidthFill
            {
                UI_LabelF("No item selected.");
            }
        }
        
        //- sixten: build nav view
        UI_Row()
        {
            //- sixten: calculate nav view size
            r32 VerticalPad = 0;
            r32 HorizontalPad = 0;
            {
                ui_box *ParentBox = UI_TopParent();
                v2_r32 ParentDim = DimOfRange(ParentBox->Rect);
                
                r32 WidthOverHeight = ParentDim.x / ParentDim.y;
                r32 TargetRatio = 16.0f / 9.0f;
                if(WidthOverHeight > TargetRatio)
                {
                    VerticalPad = ParentDim.x - ParentDim.y*TargetRatio;
                }
                else
                {
                    HorizontalPad = ParentDim.y - ParentDim.x/TargetRatio;
                }
            }
            //- sixten: do the building of the nav view
            UI_Padding(UI_Pixels(VerticalPad/2, 1))
            {
                UI_Column() UI_Padding(UI_Pixels(HorizontalPad/2, 1))
                {
                    UI_SetNextWidth(UI_Percent(1, 0));
                    UI_SetNextHeight(UI_Percent(1, 0));
                    UI_SetNextLayoutAxis(Axis2_Y);
                    
                    ui_box *Box = UI_MakeBox(UI_BoxFlag_Clip, StrLit("Nav View"));
                    UI_EquipBoxCustomDrawCallback(Box, BuildNavViewDrawCallback, SceneView);
                    
                    v2_r32 BoxDim = UI_CalculateBoxDim(Box);
                    r32 GlobalScale = CalculateGlobalScaleFromDim(BoxDim);
                    
                    //- sixten: build all nav items
                    s32 ItemIndex = 0;
                    for(scene_nav_item_node *Node = Editor->Items.First; Node != 0; Node = Node->Next, ItemIndex += 1)
                    {
                        scene_nav_item *Item = &Node->Item;
                        
                        //- sixten: calculate item position
                        r32 AppliedScale = GlobalScale*Item->Scale;
                        render_handle Texture = TextureFromAssetID(Item->TextureID);
                        v2_r32 TextureDim = ConvertV2ToR32(DimFromTexture(Texture));
                        v2_r32 TextureOrigin = Hadamard(TextureDim, Item->Origin);
                        v2_r32 Dim = TextureDim*AppliedScale;
                        v2_r32 OriginP = TextureOrigin*AppliedScale;
                        
                        //- sixten: build the item
                        scene_nav_item_info *Data = PushStruct(UI_FrameArena(), scene_nav_item_info);
                        Data->Item = Item;
                        
                        UI_SetNextHoverCursor(PlatformCursor_Hand);
                        UI_SetNextSize(UI_Pixels(Dim.x, 1), UI_Pixels(Dim.y, 1));
                        ui_box *ItemBox = UI_MakeBoxF(UI_BoxFlag_Clickable|UI_BoxFlag_FloatingX|UI_BoxFlag_FloatingY,
                                                      "View Item Box %i", ItemIndex);
                        UI_EquipBoxCustomDrawCallback(ItemBox, BuildNavItemDrawCallback, Data);
                        
                        //- sixten: handle signals
                        {
                            ui_signal Signal = UI_SignalFromBox(ItemBox);
                            Data->Signal = Signal;
                            
                            //- sixten: inspect pressed item
                            if(Signal.Pressed)
                            {
                                Editor->SelectedItem = Node;
                            }
                            
                            //- sixten: handle dragging
                            if(Signal.Dragging)
                            {
                                if(Signal.Pressed)
                                {
                                    UI_StoreDragV2(Item->P);
                                }
                                
                                Item->P = UI_GetDragV2() + Signal.DragDelta/BoxDim*2;
                            }
                        }
                        
                        //- sixten: apply the calculated position
                        v2_r32 OffsetP = BoxDim*(V2R32(1, 1) + Item->P)*0.5f;
                        ItemBox->FixedP = (OffsetP-OriginP);
                    }
                }
            }
        }
    }
}