Slide Editor | Bullets & Numbering

The same two toggle buttons as the document editor, over PowerPoint’s own mechanism. Everything is on the shared SlideEditorController and already wired into SlideEditorView’s toolbar on both hosts.

var c = editor.Controller!;

c.ToggleBulletList();
c.ToggleNumberedList();
c.SetListStyle(ListStyle.None);   // explicit — see below

c.ShiftLevel(1);                  // nest; -1 un-nests
c.HandleTab(shift: false);

c.CaretFormat.List;               // ListStyle.None / Bullet / Numbered
c.CaretFormat.Level;              // 0-8

The mark lives in the paragraph, not in a shared part

Unlike Word, a DrawingML paragraph carries its own bullet: a:buChar for a glyph, a:buAutoNum for a number, a:buNone for neither. There is no numbering part to create, so nothing has to be added to the package to turn a paragraph into a list item.

ListStyle.None writes a:buNone rather than removing the element, and that is the part to get right. A body placeholder inherits its bullet from the master’s list style, so leaving the properties alone puts the inherited bullet straight back — and the button looks like it did nothing at all.

a:pPr’s children are a sequence, not a set: the bullet slot sits between a:buFont and a:tabLst. A a:buChar appended after a a:defRPr that was already there saves without complaint and produces a file PowerPoint reports as corrupt and refuses to repair, which is why this goes through the editor rather than being built by hand.

Auto-numbered paragraphs show a real number

The number is a function of the paragraph’s position at its own outline level within the shape, counted per text body — two bulleted placeholders on one slide each start at 1 — and returning to an outer level restarts everything nested inside it.

It renders in whatever scheme the file asks for: arabic, alphabetic or roman, with a period, a trailing paren or both. A scheme this does not model falls back to a plain number rather than to nothing.

ShapeParagraph.Bullet is the mark to draw, already resolved. ShapeParagraph.List is the kind, which Bullet cannot tell you — "1." is a perfectly good literal bullet glyph.

Tab always changes level

Unlike the document editor there is no “not in a list” case: every paragraph in a shape carries an outline level whether or not it draws a mark, and a slide has no tab stops to speak of. So Tab nests, Shift+Tab un-nests, and that is all it does.

A selection spanning two levels moves each paragraph relative to its own. Nine levels, 0 to 8, and no more — a tenth is a file PowerPoint will not open, so the level is clamped rather than written.

Typing - or 1. starts a list

The same detector as the Word side, deliberately shared so the two file types cannot drift: -, *, + or • then a space gives a bullet, a run of digits closed by . or ) gives a number, the marker and the space both go, and a paragraph that already carries a mark is left alone.

c.IsAutoFormatListEnabled = false;

Not implemented

• Choosing the glyph, the number scheme or a start value — the toggles write Arial • and arabic-with-a-period. A deck that already carries its own is read in full and only ever overridden where a button is pressed.
• Picture bullets (a:buBlip) — read as no bullet.