How to programmatically control the guides (rules of third)?

Question

Is there any way to control guides (rules of third) in a Google Slides presentation. As far as I have read the Google Apps Script documentation, there is no method to control the guides.

I already tried lines that would behave like guides (rules of third), but these are not "real" guides. The user can delete these lines, and these lines are limited to the slide page area.

See the picture to get the difference between lines and guides (rules of third):

To enable the guides (rules of third) go here:

Oleg Valter is with Ukraine · Accepted Answer · 2020-08-28T19:42:32.400

A feature request to allow guides to be controlled via SlidesApp or Slides API is submitted to the issue tracker. Please star it if you find that the feature would be useful.

Short answer

As already mentioned, unfortunately, this is not currently possible either via the SlidesApp service or the Slides API.

Workaround

It is actually possible to make lines stretch outside of the slide bounds by passing a negative integer as an argument of insertLine. As for being able to delete the lines, guides can also be "deleted" by user if they drag the guide out of the slide boundaries.

The only property of the guides that I could not emulate is hiding them when presenting (as real guides are hidden).

Below is a workaround similar to your approach (creating a grid of Lines):

Guides

/**
 * @summary emulates adding guides to the Slide
 * 
 * @param {{
 *  rows : (number|1),
 *  deleteOld : (boolean|true),
 *  cols : (number|1),
 *  color : string
 * }} 
 */
const showGuides = ({ deleteOld = true, rows = 1, cols = 1, color = "#d3d3d3" } = {}) => {

    const presentation = SlidesApp.getActivePresentation();
    const currPage = presentation.getSelection().getCurrentPage();

    const prop = "guides";

    const store = PropertiesService.getUserProperties();

    /** @type {string[]} */
    let guideRefs = JSON.parse(store.getProperty(prop) || "[]");

    const lines = currPage.getLines();

    const oldLines = lines.filter((line) => guideRefs.includes(line.getObjectId()));

    if (deleteOld) {
        oldLines.forEach(line => line.remove());

        guideRefs = removeElements(guideRefs, oldLines.map(l => l.getObjectId()));
    }

    const currWidth = presentation.getPageWidth();
    const currHeight = presentation.getPageHeight();

    const xStep = Math.floor(currWidth / cols);
    const yStep = Math.floor(currHeight / rows);

    const newGuides = [];

    const maxScreen = 4096;

    for (let x = 0; x <= cols; x++) {
        const line = currPage.insertLine(
            SlidesApp.LineCategory.STRAIGHT,
            xStep * x, -maxScreen, xStep * x, currHeight + maxScreen
        );

        const fill = line.getLineFill();
        fill.setSolidFill(color);

        const oid = line.getObjectId();
        guideRefs.push(oid);
        newGuides.push(line);
    }

    for (let y = 0; y <= rows; y++) {
        const line = currPage.insertLine(
            SlidesApp.LineCategory.STRAIGHT,
            -maxScreen, yStep * y, currWidth + maxScreen, yStep * y
        );

        const fill = line.getLineFill();
        fill.setSolidFill(color);

        const oid = line.getObjectId();
        guideRefs.push(oid);
        newGuides.push(line);
    }

    store.setProperty(prop, JSON.stringify(guideRefs));
};

Utilities

/**
 * @summary removes elements from an array
 * @param {any[]} arr 
 * @param {...any} elems
 * @returns {any[]}
 */
const removeElements = (arr, ...elems) => arr.filter((elem) => !elems.includes(elem));

Demo

Interesting. Seems a perfect solution. How you are calculating the screens size. What about if it's a small screen , will you suggest to get the screen using javascript ? — Naresh, Aug 27 '20 at 03:52
@PuzzledBoy - you actually have a great idea here - yes! Window size can be used to determine the negative offset, I haven't thought of that, just used an arbitrarily large value (does not really matter how long these lines are - they should be shown correctly on all screen sizes) — Oleg Valter is with Ukraine, Aug 27 '20 at 04:08
I know this is pretty old now but I am very new to apps script and thought this was really interesting! I was wondering if this would have changed since it was first posted or if this is still the approach you'd use? — user2191889, Mar 20 '23 at 10:04
@user2191889 as to my knowledge, this is, unfortunately, still the case, nothing changed in the meantime. The only currently known workaround is to use lines as if they were grid lines. Not ideal, but oh well... — Oleg Valter is with Ukraine, Mar 20 '23 at 12:33

score 2 · Answer 2 · answered Aug 26 '20 at 09:08

Slides guides cannot currently be managed programmatically.

Guides are a fairly recent addition to Slides (since April '18), and they haven't been implemented on Slides API yet, let alone on Apps Script. The only way to manage them for now is manually, through the Slides editor.

File a Feature Request:

I'd suggest you to file a Feature Request on this Issue Tracker component regarding the implementation of this functionality on Slides API. I did some research on that component and it seems like no one has requested this yet.

Once that's done, you could manage this from Apps Script via Advanced Slides Service, at least until Apps Script built-in classes and methods were implemented.

How to programmatically control the guides (rules of third)?

2 Answers2

Slides guides cannot currently be managed programmatically.

File a Feature Request: