Text and Formatting

Add text to slides with Podium.add_text_box/3. Text can be a plain string for simple cases or a structured list for rich formatting with multiple fonts, colors, and paragraph styles.

slide = Podium.add_text_box(slide, "Quarterly Results",
  x: {1, :inches}, y: {1, :inches},
  width: {8, :inches}, height: {1, :inches},
  font_size: 24)

Plain Text

The fastest way to add text is with a plain string. Podium wraps it in a single paragraph with a single run, and you control the defaults through text box options.

slide = Podium.add_text_box(slide, "Revenue grew 35% year-over-year",
  x: {1, :inches}, y: {1, :inches},
  width: {10, :inches}, height: {0.8, :inches},
  font_size: 18, alignment: :center)

The :font_size and :alignment options on the text box apply to every paragraph and run inside it. This is all you need for headings, labels, and single-line text.

The Text Hierarchy

Text in Podium follows a hierarchy that mirrors the OOXML specification:

• Presentation contains slides
• Slide contains text boxes (and other shapes)
• Text box contains one or more paragraphs
• Paragraph contains one or more runs
• Run is a contiguous span of text with uniform formatting

When you pass a plain string to add_text_box/3, Podium creates one paragraph with one run. When you need more control, you provide a list of paragraphs, each containing a list of runs.

Rich Text

Rich text is a list of paragraphs. Each paragraph is a list of runs. Each run is either a plain string or a {text, options} tuple.

slide = Podium.add_text_box(slide, [
  [{"Q1 Revenue Report", bold: true, font_size: 32, color: "003366"}],
  [{"Prepared by ", font_size: 14}, {"Engineering", bold: true, italic: true}]
], x: {1, :inches}, y: {1, :inches},
   width: {8, :inches}, height: {2, :inches})

The first paragraph has one bold, blue, 32pt run. The second paragraph has two runs: a plain 14pt run and a bold italic run. Each paragraph renders on its own line.

Paragraph Options

Wrap a paragraph's run list and options in a tuple to set paragraph-level formatting:

slide = Podium.add_text_box(slide, [
  {[{"Executive Summary", bold: true, font_size: 28}], alignment: :center, space_after: 12},
  {[{"Key metrics improved across all regions."}], alignment: :left, line_spacing: 1.5}
], x: {1, :inches}, y: {1, :inches},
   width: {10, :inches}, height: {3, :inches})

Run-Level Formatting

Each run can carry its own formatting options. These override any defaults set on the text box.

slide = Podium.add_text_box(slide, [
  [
    {"Normal text "},
    {"bold", bold: true},
    {" and ", font_size: 14},
    {"red italic", italic: true, color: "CC0000"}
  ]
], x: {1, :inches}, y: {1, :inches},
   width: {8, :inches}, height: {1, :inches})

Superscript and Subscript

Use :superscript and :subscript for mathematical notation, chemical formulas, and footnote references:

slide = Podium.add_text_box(slide, [
  [{"E = mc", font_size: 18}, {"2", font_size: 12, superscript: true}],
  [{"H", font_size: 18}, {"2", font_size: 12, subscript: true}, {"O", font_size: 18}]
], x: {1, :inches}, y: {1, :inches},
   width: {6, :inches}, height: {1.5, :inches})

Underline Styles

Podium supports all 18 OOXML underline styles. Pass true or :single for the standard underline, or use a specific style atom:

slide = Podium.add_text_box(slide, [
  [
    {"Single", underline: :single, font_size: 14},
    {"  Double", underline: :double, font_size: 14},
    {"  Wavy", underline: :wavy, font_size: 14}
  ]
], x: {1, :inches}, y: {1, :inches},
   width: {8, :inches}, height: {0.6, :inches})

Bullets and Numbered Lists

Add bullet points by setting :bullet on a paragraph. Use :level to create nested items.

slide = Podium.add_text_box(slide, [
  {["Revenue up 35% year-over-year"], bullet: true},
  {["North America grew fastest"], bullet: true, level: 1},
  {["APAC close behind"], bullet: true, level: 1},
  {["Customer satisfaction at all-time high"], bullet: true}
], x: {1, :inches}, y: {1, :inches},
   width: {10, :inches}, height: {3, :inches})

Numbered Lists

Pass bullet: :number for auto-numbered items:

slide = Podium.add_text_box(slide, [
  {["Review quarterly data"], bullet: :number},
  {["Identify growth opportunities"], bullet: :number},
  {["Present findings to board"], bullet: :number}
], x: {1, :inches}, y: {1, :inches},
   width: {10, :inches}, height: {2, :inches})

Custom Bullet Characters

Pass any string to :bullet to use a custom character:

{["Action item on track"], bullet: "-->"}
{["Hiring plan complete"], bullet: "-->"}

Line Breaks

There are two ways to insert a line break within a single paragraph.

Newline in a string -- Podium automatically splits the text at \n and inserts line breaks between segments:

slide = Podium.add_text_box(slide, "Line 1\nLine 2\nLine 3",
  x: {1, :inches}, y: {1, :inches},
  width: {4, :inches}, height: {2, :inches})

:line_break atom -- Insert an explicit break in a rich text run list:

slide = Podium.add_text_box(slide, [
  [
    {"First line", bold: true},
    :line_break,
    {"Second line", color: "4472C4"}
  ]
], x: {1, :inches}, y: {1, :inches},
   width: {6, :inches}, height: {1.5, :inches})

Both methods produce the same OOXML <a:br/> element. The difference is that :line_break lets you change formatting between lines within a single paragraph, while \n keeps the same run formatting on both sides.

Text Box Options

Beyond position and size, text boxes accept several formatting options that apply to the entire text frame.

slide = Podium.add_text_box(slide, "Padded and styled",
  x: {1, :inches}, y: {1, :inches},
  width: {6, :inches}, height: {2, :inches},
  fill: "E8EDF2",
  line: [color: "003366", width: {1, :pt}],
  margin_left: {0.3, :inches},
  margin_right: {0.3, :inches},
  margin_top: {0.15, :inches},
  margin_bottom: {0.15, :inches},
  alignment: :center,
  font_size: 16)

Auto-Size Modes

Control how the text box and its text interact when the content grows:

slide = Podium.add_text_box(slide, "This text shrinks to fit",
  x: {1, :inches}, y: {1, :inches},
  width: {3, :inches}, height: {0.5, :inches},
  auto_size: :text_to_fit_shape)

Putting It All Together

Here is a complete example combining plain text, rich paragraphs, bullets, spacing, and formatting:

prs = Podium.new()
slide = Podium.Slide.new()

slide =
  slide
  |> Podium.add_text_box(
    [
      {[{"Q4 2025 Summary", bold: true, font_size: 28, color: "003366"}],
       alignment: :center, space_after: 12}
    ],
    x: {0.5, :inches}, y: {0.3, :inches},
    width: {12, :inches}, height: {0.8, :inches},
    fill: {:gradient, [{0, "E8EDF2"}, {100_000, "FFFFFF"}], angle: 5_400_000})
  |> Podium.add_text_box(
    [
      {[{"Key Results", bold: true, font_size: 20}], space_after: 6},
      {["Revenue grew 35% to $18.2M"], bullet: true},
      {["North America led growth"], bullet: true, level: 1},
      {["APAC expanded 42%"], bullet: true, level: 1},
      {["Operating margin improved to 28%"], bullet: true},
      {[{"Next Steps", bold: true, font_size: 20}], space_before: 12, space_after: 6},
      {["Finalize APAC expansion plan"], bullet: :number},
      {["Launch self-service portal"], bullet: :number},
      {["Target 95% satisfaction by Q2"], bullet: :number}
    ],
    x: {0.5, :inches}, y: {1.5, :inches},
    width: {12, :inches}, height: {5, :inches})

prs = Podium.add_slide(prs, slide)
Podium.save(prs, "text_demo.pptx")

Text formatting is the foundation for every slide. Next, learn how to present structured data with Tables, or add visual elements with Shapes and Styling.