Wednesday, June 21, 2017

screen.width/screen.height not updating after screen rotation

By Hường Hana 6:30 AM , , , Leave a Comment

I'm experiencing this problem on an iPhone device (iPhone 7, iOS 10, but also other iPhones too): in javascript, if I intercept the orientationchange event, inside the handler, screen.width and screen.height remain the same (as before rotation).

Since this may depend from the viewport settings, this is how my viewport is declared in the .html file:

<meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1, maximum-scale=1, user-scalable=no" />

Everything works fine in Chrome's simulated visualization.

Thanks in advance for your help.

4 Answers

Answers 1

As far as I know screen the width/height will not change in the device after rotation. To check if the device is rotated you could read these properties

  1. window.orientation: This value change from 0 to +90/-90
  2. window.innerHeight/innerWidth: This values are swapped
  3. document.documentElement.clientHeight/clientWidth: This values are swapped

Unfortunately, this behavior is not consistent across all Android/iOS/Window devices. I think in this figure is pretty explained.

Answers 2

iOS used to return the size of the screen as if it was in portrait. They changed it on iOS 8 (on the native classes), but they might have forgotten to do it for Safari, or maybe they kept it that way for compatibility.

If you want the real size based on the orientation you can use window.innerWidth and window.innerHeight

I get the same values with or without the viewport meta tag

It works fine on Chrome simulated visualization because it return the screen size of the simulated visualization, as it should be, but it doesn't simulate the OS where it should be running based on the device, so you won't get the same values as on a real device (in this case in which the real device doesn't return good values)

Answers 3

jQuery mobile has onOrienntetionChange event that handle orientation changing event,and there is $(window).orientationchange(); function to change orientation manually.

Answers 4

CSS can't detect the orientation change.

Use JavaScript to get the orientation change.

Add the function as

window.addEventListener("orientationchange", function() {   document.body.style.width = window.innerWidth; });

This will add an event Handler to window to change the width of body when the orientation is changed.

More reference on orientationchange

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