enum RendererType
{
    FocusRectangle,
    Raw,
    SolidBorder,
    SinkBorder,
    SinkSplitter,
    SolidBackground,
    GradientBackground,
    InnerShadow,
    SolidLabel,
    Polygon,
    ImageFrame,
    DocumentParagraph,
}

struct RendererCreation
{
    var id : int;
    var type : RendererType;
}

message RendererCreated                             { request: RendererCreation[]; }
message RendererDestroyed                           { request: int[]; }

union OrdinaryElementDescVariant
{
    ElementDesc_SolidBorder,
    ElementDesc_SinkBorder,
    ElementDesc_SinkSplitter,
    ElementDesc_SolidBackground,
    ElementDesc_GradientBackground,
    ElementDesc_InnerShadow,
    ElementDesc_Polygon,
    ElementDesc_SolidLabel,
    ElementDesc_ImageFrame,
}

struct ElementBeginRendering
{
    var frameId : int;
    var updatedElements : OrdinaryElementDescVariant[];
}

struct ElementRendering
{
    var id : int;
    var bounds : Rect;
    var areaClippedByParent : Rect;
}

struct ElementBoundary
{
    var id : int;
    var hitTestResult : WindowHitTestResult?;
    var cursor: WindowSystemCursorType?;
    var bounds : Rect;
    var areaClippedBySelf : Rect;
}

struct ElementMeasuring_FontHeight
{
    var fontFamily : string;
    var fontSize : int;
    var height : int;
}

struct ElementMeasuring_ElementMinSize
{
    var id : int;
    var minSize : Size;
}

struct ElementMeasuring_InlineObjectBounds
{
    var elementId : int;
    var callbackId : int;
    var bounds : Rect;
}

struct ElementMeasurings
{
    var fontHeights : ElementMeasuring_FontHeight[];
    var minSizes : ElementMeasuring_ElementMinSize[];
    var createdImages : ImageMetadata[];
    var inlineObjectBounds : ElementMeasuring_InlineObjectBounds[];
}

message RendererBeginRendering                      { request: ElementBeginRendering; }
message RendererBeginBoundary                       { request: ElementBoundary; }
message RendererRenderElement                       { request: ElementRendering; }
message RendererEndBoundary                         {}
message RendererEndRendering                        { response: ElementMeasurings; }
message RendererIdle                                {}