📖 amp-list docs: increase clarity of overflow section

[samouri]

summary

Addresses #32601

Note: I've never heard of this rule The bottom is within 15% of the height of the entire page and within 1000px of the end of the page.

[morsssss]

I'm confused about how this coexists with #32601 ...

[samouri]

Wow. I thought #32601 was an Issue and didn't realize it was actually a PR.

I've made a huge mistake

[zhangsu]

Your version seems better since it also talks about the initial height of the amp-list. so let's go with yours :) I can drop my PR.

[morsssss]

I don't understand this really... what does "within 15% of the height of the entire page" mean precisely?

I imagine that "within 1000px of the end of the page" means that it can't be >1000px above the end of the page?

[samouri]

Its freakin weird. I didn't know about this either:

amphtml/src/service/resources-impl.js

Lines 1138 to 1145 in d1b027d

	elementNearBottom_(resource, opt_layoutBox, opt_initialLayoutBox) {
	const contentHeight = this.viewport_.getContentHeight();
	const threshold = Math.max(contentHeight * 0.85, contentHeight - 1000);
	const box = opt_layoutBox || resource.getLayoutBox();
	const initialBox = opt_initialLayoutBox || resource.getInitialLayoutBox();
	return box.bottom >= threshold || initialBox.bottom >= threshold;
	}

.

Essentially, if the element "is near bottom" of the document then it is eligible for resize. And near bottom is defined as "below the top 85% OR within the last 1000px of the doc".

[samouri]

Can reword to: "The bottom of amp-list is not near the bottom of the page (defined as being in the top 85% of the document and not in the bottom 1000px)."

🙀

[samouri]

Still wordsmithing 🤔

[samouri]

giving up

[morsssss]

This is brilliant!