How to Bind Load event for Image in jQueryMobile - iphone

I have a mobile website running jQuery Mobile 1.0a2 and I'm currently testing in Mobile Safari for Firmware 4.1 via the iPhone Simulator.
I cannot seem to bind to the load event for an image.
I have a simple gallery of thumbnails and a large image. When you click on a thumbnail it changes the src attribute of the main img
The js for that uses the live('click' method to bind and it works just fine.
$('.gallery-navigation img').live('click',function() {
// change source of main image to new
$.mobile.pageLoading(); // show jquerymobile loading message
});
My problem is that I need feedback on this click, so I wanted to show a loading message (provided by jquerymobile) and then hide it once the image loads.
Where #gallery_image_large is the actual <img> where the src is changing, I tried the following:
$("#gallery_image_large").bind("load", function () {
$.mobile.pageLoading(true); // hide jquerymobile loading message
});
This works in Safari on my desktop but does not in the iPhone Simulator mentioned above.
For reference:
jQuery Mobile Loading Message Methods
UPDATE: I am experimenting with JQuery Image load fails on MobiOne iPhone simulator, which explains how to implement the .load manually by "checking .complete".

I changed the structure of my jquery and it's seemed to have fixed it!
$('#gallery_image_large').one('load',function() {
try { // a grade
$.mobile.pageLoading(true);
} catch(err) { // low grade
}
}).attr('src',full_src);
(as you can see, I opt'd for a try { .. } catch { .. } to verify jquerymobile is available.
Although I didn't use the solution (directly) from JQuery Image load fails on MobiOne iPhone simulator, the manual firing of load via .complete is probably a good solution for anyone else out there!

Related

Take screenshot of host app using iOS share/action extensions?

I will like to know how to take a screenshot of the iOS host app with the use of a share/action extension.
My use case is as follows:
use the Safari browser to access a webpage (https such as gmail)
tap on the Share button and select the extension
the extension will take a screenshot of the current webpage
An working example for this use case is the Awesome Screenshot iOS app.
I had tried the following methods
reload the baseURI (loadRequest) on a UIWebView/WKWebkit (would not be able to access https contents such as Gmail). So not doing any reload (Awesome Screenshot is not doing a reload btw)
Used the ExtensionPreprocessingJS to obtain the DOM contents through the arguments.completionFunction function. I could not extract the document.body here although i could get the source etc. loadHTMLString with the baseURI will mess up the presentation layer.
Used html2canvas in the ExtensionPreprocessingJS to obtain an image and appended it to the host app's webpage as a child but do not know how to extract it. Also, the image got lost for some webpages such as Gmail.
Mobile Safari does not have the visibleContentsAsDataURL method.
I think a viable approach will be to use the html2canvas in the ExtensionPreprocessingJS but how do I save this image somehow?
Edit: So the below works in the Simulator but does not work on the device. I'm presently looking for a solution as well.
Here's a solution that I think the Awesome Screenshot app uses:
func captureScreen() -> UIImage
{
// Get the "screenshot" view.
let view = UIScreen.mainScreen().snapshotViewAfterScreenUpdates(false)
// Add the screenshot view as a subview of the ShareViewController's view.
self.view.addSubview(view);
// Now screenshot *this* view.
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, false, 0);
self.view.drawViewHierarchyInRect(view.bounds, afterScreenUpdates: true)
let image: UIImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// Finally, remove the subview.
view.removeFromSuperview()
return image
}

Native HTML5 Drag and Drop in Mobile Safari (iPad, iPod, iPhone)?

I've successfully implemented native HTML5 Drag and Drop for moving HTML elements inside a page (just, say, a div from one place to another, nothing related to interacting with the host OS' files whatsoever). This works fine in Chrome and Safari on a PC but I can't start a drag operation in my iPad's Safari.
I've found this so far:
Using Drag and Drop From JavaScript
Safari, Dashboard, and WebKit-based
applications include support for
customizing the behavior of drag and
drop operations within your HTML
pages.
Note: This technology is supported
only on desktop versions of Safari.
For iPhone OS, use DOM Touch,
described in Handling Events (part of
Safari Web Content Guide) and Safari
DOM Additions Reference.
Here. But it's outdated (2009-06-08).
Doe's anyone know if it is possible to use native HTML5 in Mobile Safari? (I don't want javascript-framework like solutions like jQuery UI).
Thanks!
I've just been trying to get native drag&drop working in ios safari (ipad pro with 14.0.1), and I'm updating this answer as it kept coming up as my first google result (and no other q&a seems to be up to date).
Following https://developer.apple.com/library/archive/documentation/AppleApplications/Conceptual/SafariJSProgTopics/DragAndDrop.html
I have found native html5 drag&drop now works in safari, with a few specific notes;
You MUST set some data in OnDragStart's event; (the effect settings seem to be optional) Event.dataTransfer.setData('text/plain', 'hello');
you MUST Event.preventDefault(); in OnDrop otherwise safari will load the data you added (unless that's your intention)
OnDragOver event handler needs Event.preventDefault(); otherwise drop fails (unless intended, as docuemnted)
On ios safari, if you set OnDragStart's Event.dataTransfer.dropEffect='copy' and in OnDragOver's Event.dataTransfer.dropEffect='link' the drop fails (no OnDrop()); Seems to be the only combination that fails
I thought you required
CSS -webkit-user-drag: Element; and `-webkit-user-drop: element;
or if you prefer
Element.style.setProperty('webkitUserDrag','element');
Element.style.setProperty('webkitUserDrop','element');
but it seems just the usual draggable attribute is enough
Element.setAttribute('draggable',true);
This seems to be the bare minimum to drag & drop an element
Element.setAttribute('draggable',true);
function OnDragOver(Event)
{
Element.setAttribute('DragOver',true);
Event.stopPropagation(); // let child accept and don't pass up to parent element
Event.preventDefault(); // ios to accept drop
Event.dataTransfer.dropEffect = 'copy';// move has no icon? adding copy shows +
}
function OnDragLeave(Event)
{
Element.removeAttribute('DragOver');
}
function OnDrop(Event)
{
Element.removeAttribute('DragOver');
Event.preventDefault(); // dont let page attempt to load our data
Event.stopPropagation();
}
function OnDragStart(Event)
{
Event.stopPropagation(); // let child take the drag
Event.dataTransfer.dropEffect = 'move';
Event.dataTransfer.setData('text/plain', 'hello');
}
Element.addEventListener('dragstart',OnDragStart);
Element.addEventListener('drop',OnDrop);
Element.addEventListener('dragover',OnDragOver);
Element.addEventListener('dragleave',OnDragLeave);
Touch events do work now on Safari too (including Mobile). This article has nice code snippets that you can start from:
http://www.html5rocks.com/en/mobile/touch/

Jquery img preload not working in FireFox

I recently did a small jQuery snippet that allows me to show a loading img until the real image is loaded.
The snippet seems to work in Safari, Chrome but not FireFox.
FireFox only displays a loading alt and never switches to the loaded image.
Here is the snippet
var loading = $('<img src="/media/ajax-loader.gif" alt="loading" />');
$('.thumbnail').each(function(){
var loadIMG = loading.clone();
$(this).after(loadIMG).load(function(){
$(this).fadeIn('fast');
loadIMG.hide();
}).hide();
});
Any ideas why?
You haven't said what exactly is happing on FF but below can be one of the problem. From jquery documentation
It is possible that the load event
will not be triggered if the image is
loaded from the browser cache. To
account for this possibility, we can
use a special load event that fires
immediately if the image is ready.
event.special.load is currently
available as a plugin.
Here's the link for plugin.
Edit:
Based on comments from load event, try below:
$('.thumbnail').each(function(){
var loadIMG = loading.clone();
$(this).after(loadIMG).load(function(){
$(this).fadeIn('fast');
loadIMG.hide();
}).hide();
if (this.complete) $(this).trigger("load");
});
Of course, the plug-in seems to be doing same thing along with handling some other scenarios as well as.

No response after submitting form on iPad from UIWebView

I am currently opening a webpage in UIWebView and submitting a form which performs a query on the server side and youtube video is returned (if available). I have no say/control over the server side implementation.
This webview works fine on iPhone/iPod, however, when I try to run the same app on iPad there is no response after submitting the form.
I created a dummy app, compiled on iOS 3.2 and problem is still there.
I put NSLogs in webview delegate methods which shows that after the form is submitted (UIWebViewNavigationTypeFormSubmitted) nothing happens.
I'm unable to figure out why this happens only on iPad and not on iPhone/iPod Touch.
I have created the webview in IB and setting the URL is viewDidLoad
[viewTourWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:#"http://www.realestatetour.com/mobiletours.htm"]]];
The URL for reference is http://www.realestatetour.com/mobiletours.htm
Enter the Tour ID as 10.
Thanks
The reason it wasn't working is because the form opens the result in a new page, (i.e. _blank) and apparantly all links opening in new window are ignored by uiwebview and its delegates.
I found 2 possible solutions for this:
1) Modifying the html using javascript to replace all _blank with _self for all anchor tags.
(source)
2) A more elegant solution which works for handling links which open a new window.
(source)
In my case i recreated the web page displaying form on the iphone app and changed _blank to _self.

How to require fullscreen mode in a jQTouch application?

I'm using jQTouch to develop a version of a website optimized for safari on the iphone. The jQTouch demo helpfully shows how to show an "install this" message for users not using full screen mode and hide it for those who are. When in fullscreen mode, the body should have the class "fullscreen." So you can hide the "install this" message for people who have already added your app to their home page by adding this css rule to your stylesheet:
body.fullscreen #home .info {
display: none;
}
What I'd like to do is require users to use the app in fullscreen mode only. When viewed from the regular browser, they should only see a message asking them to install the app. That message should of course be hidden otherwise.
This ought to be really, really easy, so I must just be missing something obvious.
I thought one way to do this would be to simply test for the class "fullscreen" on the body: if it's not there, use goTo to get to another div, or hide the other divs, or something like that.
Strangely, however, this doesn't work. As a test, I've still got the original "info" message, as in the jQTouch demo, and it doesn't show up when I launch in fullscreen mode. So the body must have the fullscreen class. And yet I can't find any other trace of it: when I put this alert to test things after the document has loaded, I get nothing when launching in fullscreen mode:
alert($("body").attr("class"));
I also thought I might test for fullscreen mode by checking for the value of the fullScreen boolean. But this doesn't seem to work either. What am I missing? What is the best way to do this?
Well, I couldn't figure out why the standard way wasn't working, but someone on the jQTouch Google Group suggested this, which works:
if (window.navigator.standalone) {
alert ('Thanks for launching this app your home screen')
} else {
alert('Add this app to your home screen for the best experience')
}