Swipe on mobile sometimes moves serveral pages

[balki]

Thank you for maintaining this! It is simple and perfect for my needs.

In mobile, when I swipe to move to next page, sometimes it moves several pages. For now I use the scrolled mode as workaround. I tried different books and on both chrome and firefox. Let me know if you have any questions.

[intity]

@balki this is a known issue. Can you open this issue in the intity/epub-js/issues repository? This repository is a fork from futurepress/epub.js and in the future I will integrate this library into epubreader-js.

To test the swipe feature, use the example page: paginated-continuous

Thank you

[balki]

I have not used the javascript library directly yet. May be sometime I will try to reproduce and create a issue there. Thanks!

[StructSeeker]

@intity
I think i find the cause of the bug: In Reader.Init

epubreader-js/src/reader.js

Lines 130 to 166 in 04518ce

	this.on("prev", () => {
	if (this.book.package.metadata.direction === "rtl") {
	this.rendition.next();
	} else {
	this.rendition.prev();
	}
	});
	this.on("next", () => {
	if (this.book.package.metadata.direction === "rtl") {
	this.rendition.prev();
	} else {
	this.rendition.next();
	}
	});
	this.on("languagechanged", (value) => {
	this.settings.language = value;
	});
	this.on("flowchanged", (value) => {
	this.settings.flow = value;
	this.rendition.flow(value);
	});
	this.on("spreadchanged", (value) => {
	const mod = value.mod || this.settings.spread.mod;
	const min = value.min || this.settings.spread.min;
	this.settings.spread.mod = mod;
	this.settings.spread.min = min;
	this.rendition.spread(mod, min);
	});
	this.on("styleschanged", (value) => {
	const fontSize = value.fontSize;
	this.settings.styles.fontSize = fontSize;
	this.rendition.themes.fontSize(fontSize + "%");

When a new book is open, reader.on('next', ...), on("flowchanged", ...), on("spreadchanged", ...) is invoked again depsite having already been invoked for previous book. Causing multiple instance of 'next' event trigger callback, and thus move several pages.

[intity]

@StructSeeker
Thanks for pointing this out. In fact, the current implementation of epubreader-js requires migration to the updated version of the intity/epub-js 4.x library. Note that this is also a fork of futurepress/epub.js. At the moment, the library is undergoing testing.

[chintankamani]

Hi @intity ,

First off, thank you for maintaining this project and for the previous detailed responses.

I had cloned this repository and have been building some custom features on top of it. While testing on mobile, I noticed the same issue that others reported earlier — swiping sometimes causes multiple pages to turn at once.

After going through the thread and seeing @StructSeeker comment, I understand this may be due to multiple reader.on() handlers being attached each time a new book is opened — leading to multiple next triggers firing.

Since I’m still working off this version and haven’t migrated to intity/epub-js 4.x yet, I’d really appreciate your guidance on how to apply a temporary fix or patch within this current setup.

Is there a quick way I can clean up or avoid re-binding those event listeners? Any help would be greatly appreciated.

Thanks again!

[intity]

Hi, @chintankamani

Double page flipping is related to the removal of the previous element from the views-container.

In epub-js 4.x version, this problem is fixed by eliminating the operation of removing the previous element from the views-container.

It is not yet clear how this will affect weak devices.

[chintankamani]

Hi @intity thanks for the reply could you as well put link of the exact branch and repo here. Not able to find the version you are mentioning.

[intity]

@chintankamani

To test the swipe feature, use the example page: paginated-continuous