pptx/image-on-slide

Metadata

XPath assertions

Render assertions

Generator source

scripts/gen_image_on_slide.py

#!/usr/bin/env python3
"""Generate ``fixtures/pptx/image-on-slide.pptx``.

A one-slide presentation carrying a tiny 1x1 PNG added via
``shapes.add_picture``. The emitted slide XML carries a <p:pic>
whose <p:blipFill>/<a:blip> references an image part through the
slide's rels. Designed to satisfy the assertions in
``features/pptx/image-on-slide.json``.

The PNG is embedded inline as a hex literal — a pre-decoded 1x1
RGBA image — so the generator has no filesystem dependency beyond
the python-pptx package itself.
"""

from __future__ import annotations

import io
from pathlib import Path

from pptx import Presentation
from pptx.util import Inches

import datetime as _dt
_REPRODUCIBLE_DT = _dt.datetime(2000, 1, 1, 0, 0, 0)

_REPO_ROOT = Path(__file__).resolve().parent.parent
_OUT = _REPO_ROOT / "fixtures" / "pptx" / "image-on-slide.pptx"

# Minimal valid 1x1 RGBA PNG. Decoded from
#   magic(8) + IHDR(13 data, 1x1 RGBA) + IDAT(13 zlib-deflated) + IEND(0)
_PNG_BYTES = bytes.fromhex(
    "89504E470D0A1A0A"
    "0000000D49484452000000010000000108060000001F15C489"
    "0000000D49444154789C63000100000500010D0A2DB4"
    "0000000049454E44AE426082"
)


def main() -> int:
    prs = Presentation()
    # slide_layouts[5] is the "title only" layout; the only picture we embed
    # is the one added below via shapes.add_picture.
    slide = prs.slides.add_slide(prs.slide_layouts[5])
    slide.shapes.add_picture(
        io.BytesIO(_PNG_BYTES), Inches(1), Inches(1), Inches(2), Inches(2)
    )

    _OUT.parent.mkdir(parents=True, exist_ok=True)
    prs.save(_OUT, zip_date_time=_REPRODUCIBLE_DT)
    print(_OUT)
    return 0


if __name__ == "__main__":
    raise SystemExit(main())

Manifest (expanded)

{
  "$schema": "../manifest.schema.json",
  "id": "pptx/image-on-slide",
  "title": "Raster image on slide",
  "format": "pptx",
  "category": "images",
  "summary": "A PNG picture placed on a slide via shapes.add_picture is emitted as a <p:pic> whose <p:blipFill>/<a:blip> carries a relationship-embedded reference to the image part.",
  "spec": {
    "source": "ecma-376-5-part-1",
    "clause": "20.2.2.3",
    "element": "p:pic",
    "rnc_reference": "spec/ecma-376-5/part-1/rnc/PresentationML.rnc",
    "xsd_reference": "spec/ecma-376-5/part-1/xsd/pml.xsd",
    "notes": "python-pptx emits shapes.add_picture() as a <p:pic> (not a <p:sp>) on the slide's <p:spTree>. The <p:blipFill>/<a:blip> carries r:embed='rIdN' pointing to the image part via the slide's rels. The embedded image part itself lives under ppt/media/ (e.g. ppt/media/image1.png)."
  },
  "fixtures": {
    "machine": "pptx/image-on-slide",
    "office": "pptx/image-on-slide"
  },
  "generator": {
    "python": "scripts/gen_image_on_slide.py"
  },
  "assertions": [
    {
      "id": "image-pic-element-present",
      "part": "ppt/slides/slide1.xml",
      "namespaces": {
        "p": "http://schemas.openxmlformats.org/presentationml/2006/main",
        "a": "http://schemas.openxmlformats.org/drawingml/2006/main",
        "r": "http://schemas.openxmlformats.org/officeDocument/2006/relationships"
      },
      "xpath": "//p:pic",
      "must": "exist",
      "description": "The slide must contain at least one <p:pic> element — the picture shape emitted by add_picture()."
    },
    {
      "id": "image-blip-has-embed-reference",
      "part": "ppt/slides/slide1.xml",
      "namespaces": {
        "p": "http://schemas.openxmlformats.org/presentationml/2006/main",
        "a": "http://schemas.openxmlformats.org/drawingml/2006/main",
        "r": "http://schemas.openxmlformats.org/officeDocument/2006/relationships"
      },
      "xpath": "//p:pic/p:blipFill/a:blip/@r:embed",
      "must": "match",
      "value": "^rId\\d+$",
      "description": "The picture's <a:blip> must carry an r:embed attribute whose value is a relationship id (rIdN)."
    }
  ],
  "render_assertions": [
    {
      "id": "image-on-slide-img-rendered",
      "kind": "css_selector",
      "selector": "img[src^='data:image/'], img[src^='http'], img[src^='blob:'], img[src^='/'], [data-kind='pic'] img, .pptx-picture img, picture img",
      "must": "exist",
      "description": "The renderer must emit an <img> (or picture-wrapped img) with a resolvable src — either a data URL, a remote URL, a blob URL, a root-relative path, or nested under a picture-shape container."
    },
    {
      "id": "slide-count",
      "kind": "css_selector",
      "selector": "section.pptx-slide, .pptx-slide, section[data-slide], .slide, [data-slide]",
      "must": "equal-count",
      "count": 1,
      "description": "Exactly one slide container must be rendered. Catches renderers that emit zero slides (hard failure) or duplicate the slide."
    },
    {
      "id": "image-on-slide-has-a11y-hook",
      "kind": "css_selector",
      "selector": "img[alt], img[aria-hidden='true'], img[aria-label], img[aria-labelledby], figure img, [role='img']",
      "must": "exist",
      "description": "Accessibility: the slide image must carry some screen-reader-visible signal — an alt attribute (even alt=''), aria-hidden='true' to mark decorative, aria-label/aria-labelledby to supply a name, a <figure> wrapper, or an explicit role='img'. Accepts any of these conventions; a renderer that emits a bare <img> with no a11y attributes or container fails this assertion."
    }
  ]
}