CODEWITHSUNDEEP
javascriptandroidhtmliphoneinput
Scott Boring
Scott Boring

Reputation: 2781

How to prevent mobile keyboard from covering html input

I have a simple web app with a few text inputs and the inputs toward the bottom of the page get covered up by the iPhone keyboard. This is a terrible user experience making it difficult for the user to see what text they are entering as well as selecting other elements on the page after they are done entering text.

Apple documents the behavior here: https://developer.apple.com/library/archive/documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/KeyboardManagement/KeyboardManagement.html

I've seen several posts about this problem and there are multiple solutions for iOS app development but no real solutions for web apps.

I don't have the resources to test on multiple devices and I don't have an android device so I don't know if this problem even occurs there.

Is there a cross platform solution for detecting when a keyboard is covering the UI, how much of the UI is being covered, and an approach to ensure the input is visible?

Upvotes: 9

Views: 25632

Answers (5)

babytazer
babytazer

Reputation: 1

For www.lokilist.com I needed a solution that worked without javascript for the text input used to enter a Session ID.

On the server, I used the "isMobileDevice()" PHP function found here:

https://stackoverflow.com/a/23874239/20094562

Then attached a css class with onfocus css only if the requesting browser was "mobile" (that function considers tablets as mobile, which is all the better for this purpose since we actually care about touch screens).

To summarize:

  1. Detect touch screens based on user agent with isMobileDevice()

  2. In your css, include a placeholder class like ".mobileTextInput".

  3. Also include in your css the onfocus property of that class like ".mobileTextInput:focus". This is what will reposition your text input when selected.

  4. If the user agent is a mobile device, add the mobileTextInput class to the text elements you want to move above the virtual keyboard.

Upvotes: 0

seekingtheoptimal
seekingtheoptimal

Reputation: 719

What I did is to scroll the elements into view when focused by touch.

There is no exact api or anything to know if the keyboard is open at all, or how much the keyboard covers (in chrome actually the keyboard reduces the viewport, not overlays on top), but looking at average mobiles, it covers roughly half of it.

As for the implementation, I use a kind of simple heuristic. You can go all-in if the device is a touch device see mobile device detection section here, but this doesn't necessarily cover laptops with touch screens. (and doing it based on resolution is a bad idea also)

I took this "touch device" approach one step forward, and listen on the touchstart event on form elements and set a variable something like hasTouchKeyboard, and then scroll element to top of page (or at least first half that is likely not covered) when focused if this variable is true.

The idea behind it is that the touchstart usually fires before the focused event, plus the real differentiator is that if the user touched the input field, then it is 100% that it is using a touch device AND actually used touch on it (that will likely trigger the keyboard), and not just focused it with mouse on a hybrid device.

It is definitely not bulletproof, but fairly simple and works well without any user agent magic or other crazy stuff.

Upvotes: 0

Bru
Bru

Reputation: 1

Here's an answer that might help you: Scroll textfield up when keyboard popsup

In summary, you can make use of the visual viewport api and update the next render accordingly.

Upvotes: 0

Scott Boring
Scott Boring

Reputation: 2781

This answer is a hack; but it's the best solution I have come up with.

Adding a padding to the bottom of the page that is large enough for the keyboard enables content to be displayed as desired when the keyboard is visible.

Using some javascript listeners and a CSS class, this padding can be added only when the keyboard is displayed.

body.keyboard {
    height: calc(100% + 500px); /* add padding for keyboard */
}

The following javascript will add and remove the CSS class when an input has focus, which is the closest I can get to figuring out when the keyboard is displayed.

// focus events don't bubble, must use capture phase
document.body.addEventListener("focus", event => {
    const target = event.target;
    switch (target.tagName) {
        case "INPUT":
        case "TEXTAREA":
        case "SELECT":
            document.body.classList.add("keyboard");
    }
}, true); 
document.body.addEventListener("blur", () => {
    document.body.classList.remove("keyboard");
}, true);

It's also worth noting that iOS performs an annoying zoom if the input font size is less that 16px so this is also important.

input {
    font-size: 16px !important;
}

Please let me know if you have a better solution.

Upvotes: 5

Sagar Balyan
Sagar Balyan

Reputation: 658

What you can do is hide the keyboard on any click event. So, figure out when you don't want to display a keyboard and when do you really want to show it.

So once figured, you can hide the keyboard like:

InputMethodManager manager = getSystemService(INPUT_METHOD_SERVICE);
manager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(),InputMethodManager.HIDE_NOT_ALWAYS);

Upvotes: 0

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