PLEASE NOTE: This is not a "use two fingers to scroll" problem. Whether it is one finger, or two, or three, or the whole hand, for some reason our iframe does not scroll on an iPad. :)
Here is the scenario:
In our web application, which is built using EXT-GWT, we have a few windows that open as (maximized) pop-ups and present some forms to the users. These forms, which are most of the times external, are rendered in an iFrame and some of the forms have their content collapsed at the initial load - the user can choose to expand any section of the form, fill it in and submit. Now everything works fine except the scrolling in iPad. After the iframe's content is loaded and collapsed (collapsing is done using JS on the client side, basically, the content loads as expanded by default and then is collapsed by JS) iPad just fails to provide scolling to the iframe. Even after the content of the iframe is expanded the iframe does not get any scrolling.
As of now, we have solved this problem by increasing the height (using JavaScript) of the EXT-GWT window to the size of the expanded iframe body content. This makes the whole window scrollable, instead of just the iframe within the window. While it works, the window becomes way to big, so I was wondering if there is any better way for us to provide scrolling to the iframe.
Thanks for the help,
Nitin
For iOS devices you need set overflow: auto; or the scrolling won't work. For my web apps I used fancybox to display iframes modally and once I change the overflow setting in the css file the two finger scroll worked perfectly on the iPad.
After trying (almost) everything, I have come to the conclusion that increasing the GWT window height to the iframe.body.height is the only solution for getting the window/iframe to scroll on iPad. Hopefully, this will help someone in future.
I´m pretty new to GWT, but for me it worked like this:
The parent-div of the iframe has a class in my case, x-component.
I made an entry to my css file like this:
.x-component{-webkit-overflow-scrolling: touch; overflow:auto;}
It works as well if I set these entries not to the class, but to the div-element itself.
Hope that helps
Related
I am currently developing a hybrid app in iOS that loads a website and has some other features (contacts, sharing, notifications...) using cordova plugins. I do have access to the content of the site that is being displayed by the iframe.
The normal way this is done is to load the website in an iframe. I have already done this in android and it works very well. In iOS however:
Safari messes up the size of the frame. I fixed this by setting the min-width css style to 100% for the frame.
Scrolling on the iframe is always set to "no" even if you specify "yes. I "fixed" this (so I thought) by using the only solution I could find which is to wrap the iframe in a div and scroll the div. This made the header (position:fixed) scroll with the page when it should be fixed to the top of the page and broke other things on the page that rely on scroll position to trigger an action. I also tried modifying the body of the content to contain css styles mentioned here but this didn't work either. I was back to square one.
I have spent a total of a week researching how to fix this with no avail. Recently I have discovered that loading my website in iOS's UIWebView or WKWebView works well to display the site exactly how I would expect.
That brings me to two possible solutions (and my question):
Maybe I missed something with the css style on the content of the site. I read that it is possible to get scrolling to work this way but I am sceptical because safari does not allow scrolling on an iframe.
(The likely solution but the one I cannot figure out) Make my cordova app use a one of iOS's webviews. This is what I am having problems with. I cannot figure out how to do this. Is a webview an iframe? How do I use one of these webviews in my app? What does the index.html (cordova specific file) look like when I use a webview instead of an iframe (because currently this is where my iframe is).
I solved this. Since I have access to the contents of the page, I added:
position:absolute
top: 0
right:0
bottom:0
left: 0
overflow-y: auto
overflow-x: hidden
-webkit-overflow-scrolling: touch
To the scrolling body of the page. This fixed my problem
I'm building an iOS wrapper application for a web page, which was built using Bootstrap, at the top of my web app is a .navbar div, not fixed or anything and displays perfectly on first load.
The problem starts when I touch an input, type and then hide the keyboard. Once the keyboard has hidden the page has been moved back down, but the navbar is nowhere to be seen.
It turns out this was caused by a bug in the CSS code which gave a margin to the body. The simplest way to fix this was to change the CSS. Although I'm still none-the-wiser as to how control the UIWebView in such situations.
My upcoming mobile web project requires viewing dynamically chosen pdf files inside the webpage. I am using iFrame to display the pdf file and the file can be scrolled using two-finger scrolling. But the problems I am facing are:
The first page of the file is not displayed completely on the iPad and gets cut off along the width unlike when I view it on the desktop browsers where the first page of the pdf is always entirely displayed although zoomed out to fit in the iFrame area.
There is no visual indication for the users that the pdf document can be scrolled, i.e., there is no scroll bar on the pdf document.
The controls (page navigation, zoom etc.) for the pdf viewer (Adobe reader) don't appear on the document unlike when I see it on the desktop browsers.
What is the best way to achieve what I am trying to do? Do any of you experts know any solutions/workarounds to the problems I am facing? An entirely different approach using anything other than iFrame can also be considered.
The reason why the pdf should be inside the html page is that, the list of pdf files will be on a menu bar on the left side of the page and the user can click on any of them to view on the same page. Ideally, they will have the capability to toggle between full screen view and that view.
Any help is appreciated.
I created a tiny JavaScript module that helps you to show a PDF inline and be able to scroll it. But I also couldn't figure out a way to make it fit the total width of the parent container.
Check it out: https://github.com/williamrjribeiro/ipdf-scroll
Cheers.
I came across this Recommended way to embed PDF in HTML? while researching on the web to find an answer.
The mentioned link discusses about some options that I can use and the google document viewer works for me though don't know if there is anything (like data limit) I need to be aware of before using it on the website. Also I have no idea if it is a good solution (though the full screen mode is not available, but zoom-in/zoom-out and next/prev page buttons are there are show up in the mobile safari on the iPad) to use for an web app that will be run on the iPad.
Anyway, I will keep researching for a better solution and if i don't find any, I'll stick to the google document viewer.
The issue appears to be a bug with Safari on the IPad.
I didn't find a solution for embedding the pdf in html but I did find this:
If you return FileStreamResult from your controller action instead of a view, the pdf will open in a new tab, it's not embedded html but at least your user is not having to download files and open them manually.
I had the same problem of the pdf not being displayed completely. The only thing I found to fix this was the change the size of the div containing the pdf.
For example if the element containing the pdf is a div then I change its width to any value and the rollback to the value it had before. Changing Width or height any one works.
Sometimes I had to wait a little using a setTimeout before calling my resizable method
I am developing a Phonegap app for the major os platforms and am currently testing it on an iPad with iOS 5. Im using jquery mobile. So for large screens i've used the splitview jquery mobile plugin. http://asyraf9.github.com/jquery-mobile/
I've put a
$scrollArea.css('overflow-y','auto');
$scrollArea.css('-webkit-overflow-scrolling','touch');
to make the page scroll instead of using iscroll like the plugin was using. Now whats happening, is that the page isn't loading/repainting as the user scrolls. I have a list of 100 items and i scroll through them. The scrolling itself isn't slow, but it takes almost a full second for the new list view rows to pop into view after it has been scrolled. Before that it's a blank area.
On observing, i can see that the the list items don't pop into view until the scrolling has come to a halt. (momentum scroll)
A similar issue is here http://forum.jquery.com/topic/help-with-slow-list-view-scrolling-on-ipad-when-scrolling-in-an-overflow-auto-div
What can i do to make this work normally?? The same thing works fine on android tabs. pls help.
EDIT: If i use only
$scrollArea.css('overflow-y','auto');
then i dont face this issue of momentary blank areas after scrolling, but then the scrolling is painfully slow.
Please don't suggest using iScroll. Already tried that. its much much slower that what i get with -webkit-overflow-scrolling, and i cant use it.
My Approach
So, I tried a lot and I read even more about this problem. I ended up with a solution which is "OK" to me (because it works), but which is definitely not near to "perfect".
When using this CSS:
.container {
overflow: scroll;
-webkit-overflow-scrolling: touch;
}
you run into a lot of problems when having a complex design (in my case a fullscreen background image), and it gets even worse, when using absolute positioned elements and iframes. (Which is - of course - both the case I needed).
So, what did the trick? Basicly this CSS:
.container > * {
-webkit-transform: translate3d(0,0,0);
}
With this rule the content was almost all the time rendered right away without getting those blank areas. Only when scrolling down the first time very fast it's a little flickering.
But be careful with the rule -webkit-transform: translate3d(0,0,0);. Using this rule heavily on many child elements forced Safari to: sometimes slow down but almost all the time to crash. The best thing is to wrap all content elements into a single div, works fine.
Done? Not really. There is still the iframe-issue: ("argh")
iframe
When the iframe is not fully in the visible part of the container at the start it gets cropped or is not even displayed at all. This could sometimes also occur when scrolling around. So, I tried to force Safari to re-render this part anytime scrolling is completed and came up with this:
//using jQuery
var container = $('#container');
var iframe = $('#iframe');
container.scroll( function (event) {
iframe.css( 'marginLeft', 1 );
setTimeout( function() {
iframe.css ( 'marginLeft', 0 );
}, 1 );
});
The thing with the scroll event on a touch device is, that it's only triggered when the scrolling has come to an end, so this function is not fired at anytime but when the momentum has come to an end. The short movement is actually not visible.
So, maybe this is helpful for somebody.
Further information
Here a few more links on this issue:
On how the scroll event is fired in iOS:
javascript scroll event for iPhone/iPad?
Bug report of this problem to Apple:
https://stackoverflow.com/a/7893031/1456376
iframe example with the same problem:
https://stackoverflow.com/a/8275972/1456376
We have used the plugin below in our project, did you try this one out?
https://github.com/jquery/jquery-mobile/tree/master/experiments/scrollview
On iOS it uses hardware acceleration to render the scrolling. It is rather easy to use, all you have to do is to assign an additional class to your div.
We did have some issues on Android 2 with this plugin, to overcome those issues we changed the scrollMethod property in jquery.mobile.scrollview.js.
I hope it helps you solve your scrolling problem
As we all know, iPad do not support the <frame> element, but both Gmail and Ymail could do something similar by creating a 2pane style , and the navi pane (left one) could scroll (in ipad style). May I ask if anyone do have the idea how it created?
Thank you very much.
I don't actually know for sure how they've done it (I can't seem to reach mobile gmail in a desktop browser, and I can't find a view-source feature on my iPad) but I suspect that it's not as complicated as it looks.
Keep in mind that in a regular browser, when there is too much content we get a scrollbar. That's not how the iPad renders long pages. On the iPad, if there is too much content we never get a scrollbar, scrolling is achieved by sliding the content up and down. So what we should imagine is that this is two panes with scrollbars, because that's how it would show up in a normal browser.
From there, it's a much simpler problem. It's probably just two divs floated in a standard two-column layout, each with their overflow set to scroll. Something super-basic, like:
<div>
{the nav list of emails goes here}
</div>
<div>
{the currently-open email goes here}
</div>
<style>
div {
float: left;
width: 50%;
overflow-y: scroll;
}
</style>
There's probably something fancy in there to make each div consume 100% of the available height (it's probably not as simple as height: 100%) but already if either div contains enough content, we'll get individual vertical scrollbars which the iPad will hide, giving us that neat sliding-scroll gesture instead.
I've tested a few of my own apps which were build back in time with Frames. They all worked "normally" are you sure you didnt use the wrong Doctype for your HTML?
Individual block elements with overflow-y:scroll are only scrollable with two fingers on the iPad. That's just the way it is.
So how does Gmail do it differently? Manually, with JavaScript, reacting to various touch events.
Your best bet at the moment is to use iScroll. This used to be a bit un-smooth (compared to Gmail and others' implementations), but the latest version is really good. Try their demo.
It works on iPad/iPhone, Android, and you can even use it in a normal browser using your mouse. It has the nice elastic effect when you reach the top/bottom of a scrollable area, and it has the iOS-style scroll indicator thing that appears on the right during a scroll. It's almost as smooth as scrolling on a native app.
By the way, if you want to examine an iPad-specific website's source, the easiest way is using Safari (I've tried this on 5.0.3 for Mac, but probably works on other platforms too). Turn on the Develop menu (Safari>Preferences>Advanced), then you can set your User Agent to iPad.
You can do the same thing in Firefox, posing as an iPad, but I often find the websites look completely broken. I think this is because many iPad/Android-specific websites rely on Webkit features that aren't present in Gecko. In fact, Apple's iPad guide site, which also uses a two-pane scrolling technique, simply rejects you if you're not (a) sending an iOS User Agent string and (b) using Webkit. And Chrome doesn't have an easy way to change your User Agent string. So Safari is the easiest way to examine these kind of sites.