How to switch between image backgrounds and solid-color background

Questions
1

My template is supposed to switch between solid color backgrounds and image backgrounds.Are there any concise method?

This is my current code

page(
  background: set_background(cover-image), // 背景图片 / Background image
 // other code
)
2

page:s parameter background takes anything that is of type content Page Function – Typst Documentation . Images are content.

an image

#set page(
  background: image("image.png"),
)

To do solid color fill, I would recommend using the parameter fill Page Function – Typst Documentation :

#set page(
  fill: color
)
1 Like
3

You’d have to reset the alternating fields with none for background and auto for fill. Unless you can automate the logic of which page does what. Though I think this won’t work for page.fill, since it doesn’t allow content and there is no way to auto-change page settings from outside of the set rule. There is show pagebreak, but I don’t think it can do that either. So for that, you’d have to use background for images and colors.

4

But how can I switch between them?

5

you can switch between it at any point you desire with this:

#set page(
  background: image("image.png"),
)

#lorem(50)   //some content which has the image as background

#set page(
  fill: red
)

#lorem(50)   //some content which has the solid color red as background

But every time you call #set page a new page is created!

6

What’s the switching rule? Every other page? Based on sections? Based on just a few specific places in the document? Would be good to have some clarification of the desired result.

7

This does not switch, as I already explained.

Which is a huge problem for most documents, as you don’t know when exactly a new page will be created, therefore it’s 99% the use case for automated page.background script.

1 Like
8

Ah whoops, yes you’re correct. I did test it with only fill so yeah…

It’s probably smarter to just have a function which does the automatic switching for you (get the page number and act accordingly for example).

9

By template setting

10

The switching by removing/adding template setting on call site:

// template.typ
#let template(
  fill: auto,
  background: none,
  doc
) = {
  set page(fill: fill, background: background)
  doc
}

// main.typ
#show: template.with(
  fill: green,
  // background: image("image.png"),
)