| 1 | """Shape tree walker. |
| 2 | |
| 3 | Reads <p:spTree> from a slide / layout / master and emits a normalized |
| 4 | ShapeNode tree that downstream converters can dispatch on. |
| 5 | |
| 6 | Handles: |
| 7 | - <p:sp> -> SHAPE |
| 8 | - <p:pic> -> PICTURE |
| 9 | - <p:cxnSp> -> CONNECTOR |
| 10 | - <p:grpSp> -> GROUP (recurses; resolves a:chOff/a:chExt frame) |
| 11 | - <p:graphicFrame> -> GRAPHIC (table / chart / SmartArt — emitted as opaque |
| 12 | placeholder for v1 so callers can decide a fallback) |
| 13 | - <mc:AlternateContent> -> supported Choice shape with the baked Fallback |
| 14 | preview retained for graphic frames |
| 15 | """ |
| 16 | |
| 17 | from __future__ import annotations |
| 18 | |
| 19 | from dataclasses import dataclass, field |
| 20 | from xml.etree import ElementTree as ET |
| 21 | |
| 22 | from .emu_units import NS, Xfrm, ooxml_bool, parse_xfrm |
| 23 | |
| 24 | |
| 25 | # --------------------------------------------------------------------------- |
| 26 | # ShapeNode |
| 27 | # --------------------------------------------------------------------------- |
| 28 | |
| 29 | SHAPE = "sp" |
| 30 | PICTURE = "pic" |
| 31 | CONNECTOR = "cxnSp" |
| 32 | GROUP = "grpSp" |
| 33 | GRAPHIC = "graphicFrame" |
| 34 | |
| 35 | _TITLE_PLACEHOLDER_TYPES = {"title", "ctrTitle"} |
| 36 | _BODY_PLACEHOLDER_TYPES = { |
| 37 | "body", |
| 38 | "chart", |
| 39 | "clipArt", |
| 40 | "dgm", |
| 41 | "media", |
| 42 | "obj", |
| 43 | "pic", |
| 44 | "subTitle", |
| 45 | "tbl", |
| 46 | } |
| 47 | _DEFAULT_PLACEHOLDER_TYPE = "obj" |
| 48 | _DEFAULT_PLACEHOLDER_INDEX = "0" |
| 49 | _TX_STYLE_TITLE_KEY = ("__txStyleTitle", None) |
| 50 | _TX_STYLE_BODY_KEY = ("__txStyleBody", None) |
| 51 | _TX_STYLE_OTHER_KEY = ("__txStyleOther", None) |
| 52 | |
| 53 | |
| 54 | @dataclass |
| 55 | class PlaceholderInfo: |
| 56 | """Resolved <p:ph> attributes for a shape if any.""" |
| 57 | |
| 58 | type: str | None = None # title / body / ctrTitle / subTitle / ftr / dt / ... |
| 59 | idx: str | None = None |
| 60 | sz: str | None = None # full / half / quarter |
| 61 | orient: str | None = None |
| 62 | |
| 63 | |
| 64 | @dataclass |
| 65 | class ShapeNode: |
| 66 | """Normalized shape entry produced by the walker.""" |
| 67 | |
| 68 | kind: str # one of SHAPE / PICTURE / CONNECTOR / GROUP / GRAPHIC |
| 69 | xml: ET.Element # original element |
| 70 | xfrm: Xfrm # resolved geometry in absolute slide pixel space |
| 71 | name: str = "" |
| 72 | spid: str = "" |
| 73 | hidden: bool = False |
| 74 | placeholder: PlaceholderInfo | None = None |
| 75 | inherited_lst_styles: tuple[ET.Element, ...] = () |
| 76 | inherited_body_properties: tuple[ET.Element, ...] = () |
| 77 | # Local plus ancestor group rotation; used for effect-fidelity decisions |
| 78 | # without applying the group transform twice to the rendered geometry. |
| 79 | effective_rotation: float = 0.0 |
| 80 | # GROUP only: children, in z-order |
| 81 | children: list["ShapeNode"] = field(default_factory=list) |
| 82 | |
| 83 | |
| 84 | # --------------------------------------------------------------------------- |
| 85 | # Walker |
| 86 | # --------------------------------------------------------------------------- |
| 87 | |
| 88 | def _read_nv_sp_pr(parent: ET.Element, nv_tag: str) -> tuple[str, str, bool, PlaceholderInfo | None]: |
| 89 | """Extract name/id/hidden/placeholder from an nvXXXPr container. |
| 90 | |
| 91 | nv_tag is one of nvSpPr / nvPicPr / nvCxnSpPr / nvGrpSpPr / nvGraphicFramePr. |
| 92 | """ |
| 93 | container = parent.find(f"p:{nv_tag}", NS) |
| 94 | name = "" |
| 95 | spid = "" |
| 96 | hidden = False |
| 97 | ph: PlaceholderInfo | None = None |
| 98 | if container is None: |
| 99 | return name, spid, hidden, ph |
| 100 | |
| 101 | cnv = container.find("p:cNvPr", NS) |
| 102 | if cnv is not None: |
| 103 | name = cnv.attrib.get("name", "") |
| 104 | spid = cnv.attrib.get("id", "") |
| 105 | if ooxml_bool(cnv.attrib.get("hidden")): |
| 106 | hidden = True |
| 107 | |
| 108 | nv_pr = container.find("p:nvPr", NS) |
| 109 | if nv_pr is not None: |
| 110 | ph_elem = nv_pr.find("p:ph", NS) |
| 111 | if ph_elem is not None: |
| 112 | ph = PlaceholderInfo( |
| 113 | type=ph_elem.attrib.get("type"), |
| 114 | idx=ph_elem.attrib.get("idx"), |
| 115 | sz=ph_elem.attrib.get("sz"), |
| 116 | orient=ph_elem.attrib.get("orient"), |
| 117 | ) |
| 118 | |
| 119 | return name, spid, hidden, ph |
| 120 | |
| 121 | |
| 122 | def _resolve_xfrm(shape: ET.Element, kind: str) -> ET.Element | None: |
| 123 | """Find the <a:xfrm> element under the right spPr / grpSpPr container.""" |
| 124 | if kind == GROUP: |
| 125 | sp_pr = shape.find("p:grpSpPr", NS) |
| 126 | elif kind == GRAPHIC: |
| 127 | # graphicFrame uses p:xfrm directly (no a: namespace) |
| 128 | return shape.find("p:xfrm", NS) |
| 129 | else: |
| 130 | sp_pr = shape.find("p:spPr", NS) |
| 131 | if sp_pr is None: |
| 132 | return None |
| 133 | return sp_pr.find("a:xfrm", NS) |
| 134 | |
| 135 | |
| 136 | def _adjust_for_group(child_xfrm: Xfrm, group_xfrm: Xfrm) -> Xfrm: |
| 137 | """Map a child shape's xfrm from group's child coordinate space into the |
| 138 | parent (group) coordinate space. |
| 139 | |
| 140 | DrawingML group rule: a child's a:off/a:ext is in the group's chOff/chExt |
| 141 | coordinate system. We map to the group's actual off/ext on the slide. |
| 142 | |
| 143 | If the group has no chOff/chExt, fall back to identity translation. |
| 144 | """ |
| 145 | if (group_xfrm.ch_w is None or group_xfrm.ch_h is None |
| 146 | or group_xfrm.ch_w == 0 or group_xfrm.ch_h == 0): |
| 147 | # No child frame — children already in slide space; just translate. |
| 148 | return child_xfrm |
| 149 | |
| 150 | # Linear map: child-frame -> group's (off..off+ext) |
| 151 | sx = group_xfrm.w / group_xfrm.ch_w if group_xfrm.ch_w else 1.0 |
| 152 | sy = group_xfrm.h / group_xfrm.ch_h if group_xfrm.ch_h else 1.0 |
| 153 | ch_x = group_xfrm.ch_x or 0.0 |
| 154 | ch_y = group_xfrm.ch_y or 0.0 |
| 155 | |
| 156 | new_x = group_xfrm.x + (child_xfrm.x - ch_x) * sx |
| 157 | new_y = group_xfrm.y + (child_xfrm.y - ch_y) * sy |
| 158 | new_w = child_xfrm.w * sx |
| 159 | new_h = child_xfrm.h * sy |
| 160 | |
| 161 | return Xfrm( |
| 162 | x=new_x, y=new_y, w=new_w, h=new_h, |
| 163 | rot=child_xfrm.rot, |
| 164 | flip_h=child_xfrm.flip_h, |
| 165 | flip_v=child_xfrm.flip_v, |
| 166 | ch_x=child_xfrm.ch_x, ch_y=child_xfrm.ch_y, |
| 167 | ch_w=child_xfrm.ch_w, ch_h=child_xfrm.ch_h, |
| 168 | ) |
| 169 | |
| 170 | |
| 171 | # Mapping from element tag -> kind / nv tag. |
| 172 | _KIND_MAP = { |
| 173 | "sp": (SHAPE, "nvSpPr"), |
| 174 | "pic": (PICTURE, "nvPicPr"), |
| 175 | "cxnSp": (CONNECTOR, "nvCxnSpPr"), |
| 176 | "grpSp": (GROUP, "nvGrpSpPr"), |
| 177 | "graphicFrame": (GRAPHIC, "nvGraphicFramePr"), |
| 178 | } |
| 179 | |
| 180 | |
| 181 | def _first_shape_child(container: ET.Element | None) -> ET.Element | None: |
| 182 | if container is None: |
| 183 | return None |
| 184 | for child in list(container): |
| 185 | if not isinstance(child.tag, str): |
| 186 | continue |
| 187 | if child.tag.split("}", 1)[-1] in _KIND_MAP: |
| 188 | return child |
| 189 | return None |
| 190 | |
| 191 | |
| 192 | def _resolve_alternate_content(wrapper: ET.Element) -> ET.Element | None: |
| 193 | """Select an AlternateContent shape while retaining its baked preview.""" |
| 194 | choice = wrapper.find("mc:Choice", NS) |
| 195 | fallback = wrapper.find("mc:Fallback", NS) |
| 196 | selected = _first_shape_child(choice) |
| 197 | selected_from_choice = selected is not None |
| 198 | if selected is None: |
| 199 | selected = _first_shape_child(fallback) |
| 200 | if selected is None: |
| 201 | return None |
| 202 | |
| 203 | clone = ET.fromstring(ET.tostring(selected, encoding="utf-8")) |
| 204 | if ( |
| 205 | selected_from_choice |
| 206 | and clone.tag.split("}", 1)[-1] == "graphicFrame" |
| 207 | and fallback is not None |
| 208 | ): |
| 209 | graphic_data = clone.find("a:graphic/a:graphicData", NS) |
| 210 | if graphic_data is not None: |
| 211 | preview = ET.Element(f"{{{NS['mc']}}}AlternateContent") |
| 212 | preview.append( |
| 213 | ET.fromstring(ET.tostring(fallback, encoding="utf-8")) |
| 214 | ) |
| 215 | graphic_data.append(preview) |
| 216 | return clone |
| 217 | |
| 218 | |
| 219 | def _walk_container( |
| 220 | container: ET.Element, |
| 221 | parent_group_xfrm: Xfrm | None, |
| 222 | ancestor_rotation: float = 0.0, |
| 223 | placeholder_xfrms: dict[tuple[str | None, str | None], Xfrm] | None = None, |
| 224 | placeholder_lst_styles: dict[ |
| 225 | tuple[str | None, str | None], |
| 226 | list[ET.Element], |
| 227 | ] | None = None, |
| 228 | placeholder_body_properties: dict[ |
| 229 | tuple[str | None, str | None], |
| 230 | list[ET.Element], |
| 231 | ] | None = None, |
| 232 | ) -> list[ShapeNode]: |
| 233 | """Walk a p:spTree or p:grpSp subtree. Children kept in document (z) order. |
| 234 | """ |
| 235 | nodes: list[ShapeNode] = [] |
| 236 | for child in list(container): |
| 237 | if not isinstance(child.tag, str): |
| 238 | continue |
| 239 | local = child.tag.split("}", 1)[-1] |
| 240 | if local == "AlternateContent": |
| 241 | resolved = _resolve_alternate_content(child) |
| 242 | if resolved is None: |
| 243 | continue |
| 244 | child = resolved |
| 245 | local = child.tag.split("}", 1)[-1] |
| 246 | kind_info = _KIND_MAP.get(local) |
| 247 | if kind_info is None: |
| 248 | continue |
| 249 | kind, nv_tag = kind_info |
| 250 | |
| 251 | name, spid, hidden, ph = _read_nv_sp_pr(child, nv_tag) |
| 252 | xfrm = parse_xfrm(_resolve_xfrm(child, kind)) |
| 253 | effective_rotation = (ancestor_rotation + xfrm.rot) % 360.0 |
| 254 | |
| 255 | # Placeholders without their own xfrm inherit geometry from a matching |
| 256 | # placeholder in the layout, then the master. This is what PowerPoint |
| 257 | # itself does when rendering the slide. Without this fallback such |
| 258 | # shapes get a 0×0 box and convert_txbody wraps every glyph onto its |
| 259 | # own line — visually a vertical strip of single characters. |
| 260 | if (ph is not None and placeholder_xfrms |
| 261 | and (xfrm.w == 0 and xfrm.h == 0)): |
| 262 | inherited = _lookup_placeholder_xfrm(ph, placeholder_xfrms) |
| 263 | if inherited is not None: |
| 264 | xfrm = Xfrm( |
| 265 | x=inherited.x, y=inherited.y, |
| 266 | w=inherited.w, h=inherited.h, |
| 267 | rot=xfrm.rot, flip_h=xfrm.flip_h, flip_v=xfrm.flip_v, |
| 268 | ch_x=xfrm.ch_x, ch_y=xfrm.ch_y, |
| 269 | ch_w=xfrm.ch_w, ch_h=xfrm.ch_h, |
| 270 | ) |
| 271 | |
| 272 | # If we're inside a group, remap to slide-absolute coordinates |
| 273 | if parent_group_xfrm is not None: |
| 274 | xfrm = _adjust_for_group(xfrm, parent_group_xfrm) |
| 275 | |
| 276 | inherited_lst_styles: tuple[ET.Element, ...] = () |
| 277 | if ph is not None and placeholder_lst_styles: |
| 278 | inherited_lst_styles = _lookup_placeholder_lst_styles( |
| 279 | ph, placeholder_lst_styles, |
| 280 | ) |
| 281 | inherited_body_properties: tuple[ET.Element, ...] = () |
| 282 | if ph is not None and placeholder_body_properties: |
| 283 | inherited_body_properties = _lookup_placeholder_body_properties( |
| 284 | ph, |
| 285 | placeholder_body_properties, |
| 286 | ) |
| 287 | |
| 288 | node = ShapeNode( |
| 289 | kind=kind, xml=child, xfrm=xfrm, |
| 290 | name=name, spid=spid, hidden=hidden, placeholder=ph, |
| 291 | inherited_lst_styles=inherited_lst_styles, |
| 292 | inherited_body_properties=inherited_body_properties, |
| 293 | effective_rotation=effective_rotation, |
| 294 | ) |
| 295 | |
| 296 | if kind == GROUP: |
| 297 | node.children = _walk_container( |
| 298 | child, xfrm, effective_rotation, |
| 299 | placeholder_xfrms=placeholder_xfrms, |
| 300 | placeholder_lst_styles=placeholder_lst_styles, |
| 301 | placeholder_body_properties=placeholder_body_properties, |
| 302 | ) |
| 303 | |
| 304 | nodes.append(node) |
| 305 | return nodes |
| 306 | |
| 307 | |
| 308 | def _lookup_placeholder_xfrm( |
| 309 | ph: PlaceholderInfo, |
| 310 | table: dict[tuple[str | None, str | None], Xfrm], |
| 311 | ) -> Xfrm | None: |
| 312 | """Find inherited geometry after applying the OOXML placeholder defaults.""" |
| 313 | ph_type, ph_idx = _placeholder_identity(ph.type, ph.idx) |
| 314 | for key in ( |
| 315 | (ph_type, ph_idx), |
| 316 | (ph_type, None), |
| 317 | (None, ph_idx), |
| 318 | ): |
| 319 | hit = table.get(key) |
| 320 | if hit is not None and (hit.w > 0 or hit.h > 0): |
| 321 | return hit |
| 322 | return None |
| 323 | |
| 324 | |
| 325 | def _lookup_placeholder_lst_styles( |
| 326 | ph: PlaceholderInfo, |
| 327 | table: dict[tuple[str | None, str | None], list[ET.Element]], |
| 328 | ) -> tuple[ET.Element, ...]: |
| 329 | """Find inherited txBody/lstStyle elements for a placeholder.""" |
| 330 | ph_type, ph_idx = _placeholder_identity(ph.type, ph.idx) |
| 331 | styles: list[ET.Element] = [] |
| 332 | seen: set[int] = set() |
| 333 | for key in ( |
| 334 | (ph_type, ph_idx), |
| 335 | (ph_type, None), |
| 336 | (None, ph_idx), |
| 337 | _placeholder_tx_style_key(ph), |
| 338 | ): |
| 339 | for style in table.get(key, []): |
| 340 | marker = id(style) |
| 341 | if marker in seen: |
| 342 | continue |
| 343 | styles.append(style) |
| 344 | seen.add(marker) |
| 345 | return tuple(styles) |
| 346 | |
| 347 | |
| 348 | def _lookup_placeholder_body_properties( |
| 349 | ph: PlaceholderInfo, |
| 350 | table: dict[tuple[str | None, str | None], list[ET.Element]], |
| 351 | ) -> tuple[ET.Element, ...]: |
| 352 | """Find inherited txBody/bodyPr elements for a placeholder.""" |
| 353 | ph_type, ph_idx = _placeholder_identity(ph.type, ph.idx) |
| 354 | exact = table.get((ph_type, ph_idx), []) |
| 355 | if exact: |
| 356 | return tuple(exact) |
| 357 | for key in ((ph_type, None), (None, ph_idx)): |
| 358 | candidates = table.get(key, []) |
| 359 | if candidates: |
| 360 | return (candidates[0],) |
| 361 | return () |
| 362 | |
| 363 | |
| 364 | def _placeholder_tx_style_key( |
| 365 | ph: PlaceholderInfo, |
| 366 | ) -> tuple[str | None, str | None]: |
| 367 | ph_type, _ph_idx = _placeholder_identity(ph.type, ph.idx) |
| 368 | if ph_type in _TITLE_PLACEHOLDER_TYPES: |
| 369 | return _TX_STYLE_TITLE_KEY |
| 370 | if ph_type in _BODY_PLACEHOLDER_TYPES: |
| 371 | return _TX_STYLE_BODY_KEY |
| 372 | return _TX_STYLE_OTHER_KEY |
| 373 | |
| 374 | |
| 375 | def _placeholder_identity( |
| 376 | ph_type: str | None, |
| 377 | ph_idx: str | None, |
| 378 | ) -> tuple[str, str]: |
| 379 | """Resolve the schema defaults used for placeholder inheritance keys.""" |
| 380 | return ( |
| 381 | _DEFAULT_PLACEHOLDER_TYPE if ph_type is None else ph_type, |
| 382 | _DEFAULT_PLACEHOLDER_INDEX if ph_idx is None else ph_idx, |
| 383 | ) |
| 384 | |
| 385 | |
| 386 | def _build_placeholder_xfrm_table( |
| 387 | *parts: ET.Element | None, |
| 388 | ) -> dict[tuple[str | None, str | None], Xfrm]: |
| 389 | """Index placeholders that *do* have explicit geometry, in priority order. |
| 390 | |
| 391 | Pass parts most-specific to least-specific (layout first, master second); |
| 392 | the first writer for a given key wins so layout overrides master, which is |
| 393 | what PowerPoint's inheritance chain expects. |
| 394 | """ |
| 395 | table: dict[tuple[str | None, str | None], Xfrm] = {} |
| 396 | for part_xml in parts: |
| 397 | if part_xml is None: |
| 398 | continue |
| 399 | sp_tree = part_xml.find("p:cSld/p:spTree", NS) |
| 400 | if sp_tree is None: |
| 401 | continue |
| 402 | for sp in sp_tree.iter(): |
| 403 | if not isinstance(sp.tag, str) or sp.tag.split("}", 1)[-1] != "sp": |
| 404 | continue |
| 405 | ph_elem = sp.find("p:nvSpPr/p:nvPr/p:ph", NS) |
| 406 | if ph_elem is None: |
| 407 | continue |
| 408 | xfrm_elem = sp.find("p:spPr/a:xfrm", NS) |
| 409 | if xfrm_elem is None: |
| 410 | continue |
| 411 | xfrm = parse_xfrm(xfrm_elem) |
| 412 | if xfrm.w <= 0 and xfrm.h <= 0: |
| 413 | continue |
| 414 | ph_type, ph_idx = _placeholder_identity( |
| 415 | ph_elem.attrib.get("type"), |
| 416 | ph_elem.attrib.get("idx"), |
| 417 | ) |
| 418 | for key in ((ph_type, ph_idx), |
| 419 | (ph_type, None), |
| 420 | (None, ph_idx)): |
| 421 | table.setdefault(key, xfrm) |
| 422 | return table |
| 423 | |
| 424 | |
| 425 | def _build_placeholder_lst_style_table( |
| 426 | *parts: ET.Element | None, |
| 427 | ) -> dict[tuple[str | None, str | None], list[ET.Element]]: |
| 428 | """Index placeholder txBody/lstStyle elements in priority order.""" |
| 429 | table: dict[tuple[str | None, str | None], list[ET.Element]] = {} |
| 430 | for part_xml in parts: |
| 431 | if part_xml is None: |
| 432 | continue |
| 433 | sp_tree = part_xml.find("p:cSld/p:spTree", NS) |
| 434 | if sp_tree is None: |
| 435 | continue |
| 436 | for sp in sp_tree.iter(): |
| 437 | if not isinstance(sp.tag, str) or sp.tag.split("}", 1)[-1] != "sp": |
| 438 | continue |
| 439 | ph_elem = sp.find("p:nvSpPr/p:nvPr/p:ph", NS) |
| 440 | if ph_elem is None: |
| 441 | continue |
| 442 | lst_style = sp.find("p:txBody/a:lstStyle", NS) |
| 443 | if lst_style is None: |
| 444 | continue |
| 445 | ph_type, ph_idx = _placeholder_identity( |
| 446 | ph_elem.attrib.get("type"), |
| 447 | ph_elem.attrib.get("idx"), |
| 448 | ) |
| 449 | for key in ((ph_type, ph_idx), |
| 450 | (ph_type, None), |
| 451 | (None, ph_idx)): |
| 452 | table.setdefault(key, []).append(lst_style) |
| 453 | _append_master_tx_styles(table, part_xml) |
| 454 | return table |
| 455 | |
| 456 | |
| 457 | def _build_placeholder_body_property_table( |
| 458 | *parts: ET.Element | None, |
| 459 | ) -> dict[tuple[str | None, str | None], list[ET.Element]]: |
| 460 | """Index placeholder txBody/bodyPr elements in priority order.""" |
| 461 | table: dict[tuple[str | None, str | None], list[ET.Element]] = {} |
| 462 | for part_xml in parts: |
| 463 | if part_xml is None: |
| 464 | continue |
| 465 | sp_tree = part_xml.find("p:cSld/p:spTree", NS) |
| 466 | if sp_tree is None: |
| 467 | continue |
| 468 | for sp in sp_tree.iter(): |
| 469 | if not isinstance(sp.tag, str) or sp.tag.split("}", 1)[-1] != "sp": |
| 470 | continue |
| 471 | ph_elem = sp.find("p:nvSpPr/p:nvPr/p:ph", NS) |
| 472 | body_pr = sp.find("p:txBody/a:bodyPr", NS) |
| 473 | if ph_elem is None or body_pr is None: |
| 474 | continue |
| 475 | ph_type, ph_idx = _placeholder_identity( |
| 476 | ph_elem.attrib.get("type"), |
| 477 | ph_elem.attrib.get("idx"), |
| 478 | ) |
| 479 | for key in ( |
| 480 | (ph_type, ph_idx), |
| 481 | (ph_type, None), |
| 482 | (None, ph_idx), |
| 483 | ): |
| 484 | table.setdefault(key, []).append(body_pr) |
| 485 | return table |
| 486 | |
| 487 | |
| 488 | def _append_master_tx_styles( |
| 489 | table: dict[tuple[str | None, str | None], list[ET.Element]], |
| 490 | part_xml: ET.Element, |
| 491 | ) -> None: |
| 492 | for key, path in ( |
| 493 | (_TX_STYLE_TITLE_KEY, "p:txStyles/p:titleStyle"), |
| 494 | (_TX_STYLE_BODY_KEY, "p:txStyles/p:bodyStyle"), |
| 495 | (_TX_STYLE_OTHER_KEY, "p:txStyles/p:otherStyle"), |
| 496 | ): |
| 497 | style = part_xml.find(path, NS) |
| 498 | if style is not None: |
| 499 | table.setdefault(key, []).append(style) |
| 500 | |
| 501 | |
| 502 | def walk_sp_tree( |
| 503 | slide_xml: ET.Element, |
| 504 | *, |
| 505 | layout_xml: ET.Element | None = None, |
| 506 | master_xml: ET.Element | None = None, |
| 507 | ) -> list[ShapeNode]: |
| 508 | """Top-level entry: return shape nodes for a slide / layout / master XML. |
| 509 | |
| 510 | When ``slide_xml`` is a regular slide, pass its ``layout_xml`` and |
| 511 | ``master_xml`` so placeholders can inherit geometry, text list styles, and |
| 512 | body properties from the layout/master. Layout and master walks pass |
| 513 | neither — their own placeholders are the source of truth. |
| 514 | """ |
| 515 | sp_tree = slide_xml.find("p:cSld/p:spTree", NS) |
| 516 | if sp_tree is None: |
| 517 | return [] |
| 518 | placeholder_xfrms = _build_placeholder_xfrm_table(layout_xml, master_xml) |
| 519 | placeholder_lst_styles = _build_placeholder_lst_style_table( |
| 520 | layout_xml, master_xml, |
| 521 | ) |
| 522 | placeholder_body_properties = _build_placeholder_body_property_table( |
| 523 | layout_xml, |
| 524 | master_xml, |
| 525 | ) |
| 526 | return _walk_container( |
| 527 | sp_tree, parent_group_xfrm=None, |
| 528 | placeholder_xfrms=placeholder_xfrms or None, |
| 529 | placeholder_lst_styles=placeholder_lst_styles or None, |
| 530 | placeholder_body_properties=placeholder_body_properties or None, |
| 531 | ) |
| 532 | |
| 533 | |
| 534 | def get_background(slide_xml: ET.Element) -> ET.Element | None: |
| 535 | """Return the <p:bg> element if the slide defines its own background.""" |
| 536 | return slide_xml.find("p:cSld/p:bg", NS) |
| 537 |