Turn off auto-play for hidden elements

Eltaurus · June 7, 2025, 3:43pm

Will this help?

There is:

github.com/ankidroid/Anki-Android

[BUG]: Playing audio using Javascript causes the card to not finish loading

opened 06:45AM - 19 Mar 23 UTC

closed 06:45AM - 19 Mar 23 UTC

Aquafina-water-bottle

Bug Needs Triage

### Checked for duplicates? - [X] This issue is not a duplicate ### What are t…he steps to reproduce this bug? 1. Unzip the file and import the collection: [money.zip](https://github.com/ankidroid/Anki-Android/files/11010259/money.zip) 2. Preview the card with the Front side of "Money with Mathjax". 3. Reveal the backside. <details> <summary>Card Details:</summary> The card contains 4 fields: Front, Back, Audio, and AudioMoney. Front: ``` {{Front}} ``` Back: ``` {{Front}} <hr id=answer> {{Back}} {{Audio}} <span id="audiomoney">{{AudioMoney}}</span> <script> ( () => { let x = document.querySelector("#audiomoney .soundLink, #audiomoney .replaybutton"); if (x) { console.log("going to click money..."); x.click(); console.log("clicked on money"); } })(); </script> ``` </details> ### Expected behaviour The backside should show the loaded card. ### Actual behaviour The backside is not displayed. <details> <summary>Screenshot:</summary> ![image](https://user-images.githubusercontent.com/17107540/226154699-bea8b10b-7ba1-4af9-ae4a-c4911dfd533c.png) </details> ### Debug info ```text AnkiDroid Version = 2.16alpha94-debug Android Version = 13 Manufacturer = Google Model = sdk_gphone64_x86_64 Hardware = ranchu Webview User Agent = Mozilla/5.0 (Linux; Android 13; sdk_gphone64_x86_64 Build/TE1A.220922.021; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/103.0.5060.71 Mobile Safari/537.36 ACRA UUID = 2daf5ce1-b594-44bb-b526-3ccb31f1a1e6 New schema = true Scheduler = std2 Crash Reports Enabled = false DatabaseV2 Enabled = true ``` ### (Optional) Anything else you want to share? This was tested multiple ways: - My physical phone, with release 2.16alpha94 (from Github) - Built with Android Studio and ran it on an emulator to [this commit](https://github.com/ankidroid/Anki-Android/commit/b07bf4dc5f90015ede4af51705d112bd67ec2f8c) - The latest stable release version on Github (2.15.6), with the same emulator ### Background on what this code is doing in the first place (to prevent the x-y problem): The main problem I was trying to solve is **to have a play button on the front side of the card, without having the audio played automatically**. However, I want audio to be automatically played on the backside of the card. There does not seem to be a built-in approach to simply not have an audio file play on any Anki implementation without turning off audio replays on all card sides, so my current approach is to have two audio files: `silence.wav` and (some sentence audio).wav, and use javascript to immediately play the `silence.wav` file. This approach only plays silence.wav, and overrides the natural order of how the audio is played (as if the user played `silence.wav` manually), thus the sentence audio does not play. (A different approach that I believe would work is to have a very very long silence.wav file, i.e. 24 hours long. This would remove the need of using javascript to play the file in order to stop the other file from playing). Unfortunately, something weird is happening with AnkiDroid. The audio plays as expected, i.e. the card with the front side "Money" has two audio files: the first one plays "Realm of the mad god", and the second one plays "Money x7". The second audio file is correctly played, and skips the first audio file. However, adding mathjax (i.e. the card with "Money with Mathjax") visually reveals the main problem: it seems like the card never "fully loads". The webview on **both of these cards displays a persistent blue line at the top**, suggesting that some javascript is still running and never finishes. This also suggests that **Mathjax itself is not actually related to the problem**, but simply a side effect that visually reveals the problem. <details> <summary>Screenshot of blue line on card "Money"</summary> ![image](https://user-images.githubusercontent.com/17107540/226155484-a18e5da8-ade4-462b-af22-53af84a8947e.png) </details> Using Chrome's webview on the "Money with Mathjax" card, the `mathjax-needs-to-render` CSS class is forever present on the backside of the card, and is not replaced with `mathjax-rendered`, which is the reason why the card doesn't show in the first place. I believe this suggests that something in the `onPageFinished` function of `AnkiDroid/src/main/assets/scripts/card.js` doesn't properly run in the first place. --- ### Workaround While writing this bug report, I basically rubber-ducked myself into a satisfactory workaround: we can use `onShownHook` and append a function to this array to play the audio. For example: ```js (() => { async function playMoney() { let x = document.querySelector("#audiomoney .soundLink, #audiomoney .replaybutton"); if (x) { console.log("going to click money..."); x.click(); console.log("clicked on money"); } } if (onShownHook !== undefined) { onShownHook.push(playMoney); } })(); ``` Due to a) "Javascript functionality is provided without any support or warranty" according to the Anki manual, b) this is a very niche bug that most people probably won't deal with, and c) there exists a satisfactory workaround, I'll be closing this issue despite it not being technically fixed. Hopefully, if anyone comes across the same issue, this can serve as a good reference for them! ### Research - [X] I am reporting a bug specific to AnkiDroid (Android app) - [X] I have checked the [manual](https://ankidroid.org/docs/manual.html) and the [FAQ](https://github.com/ankidroid/Anki-Android/wiki/FAQ) and could not find a solution to my issue - [X] (Optional) I have confirmed the issue is not resolved in the latest alpha release ([instructions](https://docs.ankidroid.org/manual.html#betaTesting))

but it will only work for autoplaying a single audio file. There is no good way to queue several files, as far as I know.

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Turn off auto-play for hidden elements

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