How do I correctly detect orientation change using

Question

I found this orientation test code below looking for JQTouch reference material. This works correctly in the iOS simulator on mobile Safari but doesn’t get handled correctly in Phonegap. My project is running into the same issue that is killing this test page. Is there a way to sense the orientation change using JavaScript in Phonegap?

window.onorientationchange = function() {
  /*window.orientation returns a value that indicates whether iPhone is in portrait mode, landscape mode with the screen turned to the
    left, or landscape mode with the screen turned to the right. */
  var orientation = window.orientation;
  switch (orientation) {
    case 0:
      /* If in portrait mode, sets the body's class attribute to portrait. Consequently, all style definitions matching the body[class="portrait"] declaration
         in the iPhoneOrientation.css file will be selected and used to style "Handling iPhone or iPod touch Orientation Events". */
      document.body.setAttribute("class", "portrait");

      /* Add a descriptive message on "Handling iPhone or iPod touch Orientation Events"  */
      document.getElementById("currentOrientation").innerHTML = "Now in portrait orientation (Home button on the bottom).";
      break;

    case 90:
      /* If in landscape mode with the screen turned to the left, sets the body's class attribute to landscapeLeft. In this case, all style definitions matching the
         body[class="landscapeLeft"] declaration in the iPhoneOrientation.css file will be selected and used to style "Handling iPhone or iPod touch Orientation Events". */
      document.body.setAttribute("class", "landscape");

      document.getElementById("currentOrientation").innerHTML = "Now in landscape orientation and turned to the left (Home button to the right).";
      break;

    case -90:
      /* If in landscape mode with the screen turned to the right, sets the body's class attribute to landscapeRight. Here, all style definitions matching the
         body[class="landscapeRight"] declaration in the iPhoneOrientation.css file will be selected and used to style "Handling iPhone or iPod touch Orientation Events". */
      document.body.setAttribute("class", "landscape");

      document.getElementById("currentOrientation").innerHTML = "Now in landscape orientation and turned to the right (Home button to the left).";
      break;
  }
}

Answer 1

I'm pretty new to iOS and Phonegap as well, but I was able to do this by adding in an eventListener. I did the same thing (using the example you reference), and couldn't get it to work. But this seemed to do the trick:

// Event listener to determine change (horizontal/portrait)
window.addEventListener("orientationchange", updateOrientation); 

function updateOrientation(e) {
switch (e.orientation)
{   
    case 0:
        // Do your thing
        break;

    case -90:
        // Do your thing
        break;

    case 90:
        // Do your thing
        break;

    default:
        break;
    }
}

You may have some luck searching the PhoneGap Google Group for the term "orientation".

One example I read about as an example on how to detect orientation was Pie Guy: (game, js file). It's similar to the code you've posted, but like you... I couldn't get it to work.

One caveat: the eventListener worked for me, but I'm not sure if this is an overly intensive approach. So far it's been the only way that's worked for me, but I don't know if there are better, more streamlined ways.

---

UPDATE fixed the code above, it works now

Answer 2

I believe that the correct answer has already been posted and accepted, yet there is an issue that I have experienced myself and that some others have mentioned here.

On certain platforms, various properties such as window dimensions (window.innerWidth, window.innerHeight) and the window.orientation property will not be updated by the time that the event "orientationchange" has fired. Many times, the property window.orientation is undefined for a few milliseconds after the firing of "orientationchange" (at least it is in Chrome on iOS).

The best way that I found to handle this issue was:

var handleOrientationChange = (function() {
    var struct = function(){
        struct.parse();
    };
    struct.showPortraitView = function(){
        alert("Portrait Orientation: " + window.orientation);
    };
    struct.showLandscapeView = function(){
        alert("Landscape Orientation: " + window.orientation);
    };
    struct.parse = function(){
        switch(window.orientation){
            case 0:
                    //Portrait Orientation
                    this.showPortraitView();
                break;
            default:
                    //Landscape Orientation
                    if(!parseInt(window.orientation) 
                    || window.orientation === this.lastOrientation)
                        setTimeout(this, 10);
                    else
                    {
                        this.lastOrientation = window.orientation;
                        this.showLandscapeView();
                    }
                break;
        }
    };
    struct.lastOrientation = window.orientation;
    return struct;
})();
window.addEventListener("orientationchange", handleOrientationChange, false);

I am checking to see if the orientation is either undefined or if the orientation is equal to the last orientation detected. If either is true, I wait ten milliseconds and then parse the orientation again. If the orientation is a proper value, I call the showXOrientation functions. If the orientation is invalid, I continue to loop my checking function, waiting ten milliseconds each time, until it is valid.

Now, I would make a JSFiddle for this, as I usually did, but JSFiddle has not been working for me and my support bug for it was closed as no one else is reporting the same problem. If anyone else wants to turn this into a JSFiddle, please go ahead.

Thanks! I hope this helps!

Answer 3

here is what i did:

window.addEventListener('orientationchange', doOnOrientationChange);

function doOnOrientationChange()
{
      if (screen.height > screen.width) {
         console.log('portrait');
      } else {
         console.log('landscape');
      }
}

Answer 4

if (window.matchMedia("(orientation: portrait)").matches) {
   // you're in PORTRAIT mode
}

if (window.matchMedia("(orientation: landscape)").matches) {
  // you're in LANDSCAPE mode
}

Answer 5

The following worked for me:

function changeOrientation(){
switch(window.orientation) {
case 0: // portrait, home bottom
case 180: // portrait, home top
 alert("portrait H: "+$(window).height()+" W: "+$(window).width());       
 break;
          case -90: // landscape, home left
          case 90: // landscape, home right
        alert("landscape H: "+$(window).height()+" W: "+$(window).width());
            break;
        }
    }

 window.onorientationchange = function() { 
            //Need at least 800 milliseconds
            setTimeout(changeOrientation, 1000);
        }

I needed the timeout because the value of window.orientation does not update right away

Answer 6

I've found this code to detect if the device is in landscape orientation and in this case add a splash page saying "change orientation to see the site". It's working on iOS, android and windows phones. I think that this is very useful since it's quite elegant and avoid to set a landscape view for the mobile site. The code is working very well. The only thing not completely satisfying is that if someone load the page being in landscape view the splash page doesn't appears.

<script>
(function() {
    'use strict';

    var isMobile = {
        Android: function() {
            return navigator.userAgent.match(/Android/i);
        },
        BlackBerry: function() {
            return navigator.userAgent.match(/BlackBerry/i);
        },
        iOS: function() {
            return navigator.userAgent.match(/iPhone|iPad|iPod/i);
        },
        Opera: function() {
            return navigator.userAgent.match(/Opera Mini/i);
        },
        Windows: function() {
            return navigator.userAgent.match(/IEMobile/i);
        },
        any: function() {
            return (isMobile.Android() || isMobile.BlackBerry() || isMobile.iOS() || isMobile.Opera() || isMobile.Windows());
        }
    };
    if (isMobile.any()) {
        doOnOrientationChange();
        window.addEventListener('resize', doOnOrientationChange, 'false');
    }

    function doOnOrientationChange() {
        var a = document.getElementById('alert');
        var b = document.body;
        var w = b.offsetWidth;
        var h = b.offsetHeight;
        (w / h > 1) ? (a.className = 'show', b.className = 'full-body') : (a.className = 'hide', b.className = '');
    }
})();
</script>

And the HTML: <div id="alert" class="hide"> <div id="content">This site is not thought to be viewed in landscape mode, please turn your device </div> </div>