@spec add_point_attrs(
  LivePanels.Item.t() | map() | String.t(),
  non_neg_integer(),
  map(),
  keyword() | map()
) :: map()

Returns attrs for an application control that adds one committed polyline point.

index is the position in the committed vector item's point list.

@spec erase_attrs(LivePanels.Item.t() | map() | String.t(), keyword() | map()) ::
  map()

Returns attrs for an application control that removes a committed vector item.

This helper emits the vector-owned removal command rather than the generic remove command, so the server verifies that the target is a vector item before removing it through the normal item lifecycle.

@spec erase_vector_item_target_attrs(
  LivePanels.Item.t() | map() | String.t(),
  keyword() | map()
) ::
  map()

Returns browser eraser-target attrs for an app-rendered vector item hit area.

The attrs do not choose hit-testing geometry. Applications place them on the SVG path, transparent button, or other rendered vector item target they want erase mode to recognize. The browser pushes remove_vector_item; the server still verifies that the target is a committed vector item before removal.

@spec flatten_attrs(
  LivePanels.Item.t()
  | map()
  | String.t()
  | [LivePanels.Item.t() | map() | String.t()],
  keyword() | map()
) :: map()

Returns attrs for an application control that flattens committed vector items into one item.

items_or_ids may be one vector item, a vector item id, or a list of vector items/ids. The browser sends a compact comma-separated id list; the server verifies that all targets are committed vector items before replacing them.

@spec remove_point_attrs(
  LivePanels.Item.t() | map() | String.t(),
  non_neg_integer(),
  keyword() | map()
) :: map()

Returns attrs for an application control that removes one committed polyline point.

@spec set_draw_style_js(String.t(), map(), keyword()) :: Phoenix.LiveView.JS.t()

Returns a JS command that updates the browser-owned drawing style without changing the current cursor mode.

If an application mirrors the selected style in LiveView assigns, pass push: "event_name" to append an application JS.push/2 with the normalized style payload.

@spec unflatten_attrs(LivePanels.Item.t() | map() | String.t(), keyword() | map()) ::
  map()

Returns attrs for an application control that restores a preserved flattened vector item into its component vector items.

@spec update_style_attrs(
  LivePanels.Item.t() | map() | String.t(),
  map(),
  keyword() | map()
) :: map()

Returns attrs for an application control that updates a committed vector item style.

style must include all style fields: :color, :width, :fill_color, :stroke_style ("solid" | "dashed" | "dotted"), :opacity (0-100), and :roundness (non-negative integer).

@spec vector_point_add_handle_attrs(
  LivePanels.Item.t() | map() | String.t(),
  non_neg_integer(),
  keyword() | map()
) :: map()

Returns protocol attrs for an app-rendered polyline midpoint add handle.

The element must live inside an SVG that shares the committed vector item's coordinate system. The browser runtime drags the handle locally and pushes add_vector_point with the resulting point coordinate on release.

@spec vector_point_handle_attrs(
  LivePanels.Item.t() | map() | String.t(),
  non_neg_integer(),
  keyword() | map()
) :: map()

Returns protocol attrs for an app-rendered drawing point handle.

The element must live inside an SVG that shares the committed vector item's coordinate system. The browser runtime drags the handle locally and pushes update_vector_point with the resulting point coordinate on release.