We're developing a mobile application using GWT and are facing the following problem:
iPhone offer a long touch function to do copy&paste for all kinds of stuff. But when we're using the HTML widget or another widget that has explicit ClickHandlers, those events are not forwarded. This even occurs, when there is no clickhandler defined.
How can we monitor long touches (since there is no click/touchup, the onclick method is not being triggered) and how can we prevent the prevention of such events?
There seems to be no method for removing all events on a widget.
We found many more problems with GWT on mobile platforms - basically performance issues with long tables or large contents which made us sit down, think about it and finally throw the stuff away.
We've now developed a native client for Android and iOS - which took in turn about the same time for development as an optimized pseudo-single-html-all-in-all-solution.
Related
I know there are lots of javascript plugins and libraries to allow users to pick emojis for text inputs, but windows and mac already have native emoji pickers (⊞ Win. or CTRL⌘Space), Is there a way for me to open these native emoji pickers when a user clicks in a text field instead of installing plugins in my website?
I already tried emulate button key press, but it didn't work at all.
Short answer is no.
In order to access any OS feature from javascript, you need a corresponding browser API to support.
AFAIK, there isn't an API for that. There's a discussion here which suggests adding <input emoji /> to standard but seems no traction gained.
Edit: Below is my original answer, revised. Comments pointed out I was focusing on the wrong aspect of the question, I totally agree.
However, the OP obviously has some wrong idea about what you can do in javascript to leverage browser ability. So I think it's still worth clarification.
You can't send arbitrary emulated keyboard event from js and hoping the OS will respond. Were it possible, it'd be a severe security issue on browser's part. Imagine open a website and it fires a series of keyboard event to your OS and wipes out your desktop (totally feasible through shortcuts).
You need to understand the runtime env inside the browser is basically isolated from the one of native OS. Whatever OS feature that's accessible to your javascript is totally up for browser vendors to decide. For security reason, they are super careful in making these decisions.
Also, make a distinction on "what browser can do", and "what browser allows you to do in js". Seeing Chrome has an "Emoji & Symbols" context menu item, doesn't necessarily mean it decides to grant you the same ability in js.
To further clarify why the emulated keyboard event is fundamentally different from the native one, I include a graph here. The blue arrow is how emulated keyboard event flows. The farthest place it can reach is the browser's internal event bus. It never got a chance to reach the OS event bus, so no way to notify native emoji picker.
We have a phonegap/ionic application targeting iOS. We have been testing with the ipad air simulator (xcode) and ipad air (10.3.3), ipad Pro (11.0.3).
The app is an ionic (v1) app that downloads and loads stand alone html files (the files contain css, html, js in one doc). The documents are typically long forms. In all test environments we are getting odd behavior with selects/drop downs.
When you click/tap on a select the options will appear correctly.
Then when you click/tap somewhere else, blank space or another input field you will usually get the select options bubble again but it will be empty.
In the above image I made my selection from the options and then clicked into the next field.
This was intermittent at first and now it seems to happen all the time. It seems like it has something to do with losing focus but I am unable to see why this is popping back up. I haven't found anything very useful from searching online in regards to this problem.
UPDATE 11/7/17
After more thorough searching this seems to be due to building the app with xcode 9 and/or the use of UIWebView vs WKWebview. I also looked through the code more to see we were already using WKWebView not UIWebView and the problem is still present. As someone mentioned in this thread.
Good thing is Cordova has support for WKWebView too. You have to install the plugin: cordova-plugin-wkwebview-engine
I need to display four realtime smooth graphs representing user's biodata in my android application. I tried every free android library but they were not as smooth as their javascript counterparts. So I decided to use the highcharts js in webview.
Four graphs in the same screen works smoothly. But webview is not recognising touch events quickly. I tried playing with H/w accelartion, touch events etc. but it did not help.
Whenever I touch a button on the webview logcat says :-
"12-13 16:13:37.436: V/WebViewInputDispatcher(9308): blockWebkitDraw"
"12-13 16:13:37.441: V/WebViewInputDispatcher(9308): blockWebkitDraw lockedfalse"
After touching buttons multiple times it says :-
"12-13 16:13:37.806: V/WebViewInputDispatcher(9308): blockWebkitDraw lockedtrue"
So basically any touch on highcharts graph or the buttons does not work quickly. I am loading html/js/css from assets folder.
What fixes I need to perform in webview to resolve this? I don't think there is any problem with my html/js/css code because it runs perfectly fine on Chrome mobile.
Having your app an important delay is a possible indicator that probably you're doing some hard work in the UIThread that you should probably sepparate in a Thread or an AsyncTask.
You don't mention what is supposed to happen when you touch a chart, but some code would probably clarify that.
I strongly recommend installing Eclipse Memory Analyzer Tool (assuming you use Eclipse, otherwise you should find a similar tool for the environment you use) and combine it's usage with DDMS. This will give you some clues of where the bottleneck might be.
This is a good tutorial on how to use them: http://therockncoder.blogspot.com.es/2012/09/fixing-android-memory-leak.html
This one's very clarifying too: http://eclipsesource.com/blogs/2013/01/21/10-tips-for-using-the-eclipse-memory-analyzer/
A few questions here:
Is there anyway to keep iOS from freezing javascript on the page while scrolling?
Does iOS freeze javascript when your in another tab or if you switch apps?
Are there any other major javascript limitations on iOS?
iOS 6.x suspends all event timers in response to touch events like scrolling and has a tendency not to start up all the timers again once the event is done. It's a well known iOS 6 bug that is super-annoying. It pretty much breaks parallax and stuff. Some people have resorted to building their own scroll functionality.
Here's another StackOverflow on the same topic:
iOS 6 safari, setInterval doesn't get fired
and another:
setInterval pauses in iphone/ipad (mobile Safari) during scrolling
and here is the closest thing you'll get to a bug report on it (Apple doesn't make bug reports public to maintain the illusion of perfection, so developers made their own bug site): http://openradar.appspot.com/12756410
This bit of code will unfreeze timers that are broken / lost / destroyed by iOS during a page scroll: https://gist.github.com/ronkorving/3755461
This is another attempt to fix the freeze: iOS 6 js events function not called if has setTimeout in it
Unfortunately, there is nothing you can do to fire events WHILE page scrolling. Like fade out a back-to-top link when scrolling up the page. When it comes to scrolling, iOS6 is incapable of rubbing it's tummy and patting it's head. (iOS5 works fine, btw. This is a regression)
To answer the third question, a decent-sized limitation is that sometimes innerHTML just plain doesn't work. From the accepted answer:
It happens when the CPU of the phone is very busy (say 100%). Then the rendering engine sometimes forget about innerHTML settings.
The solution included in my unify project is to test if there is an element in childNodes, otherwise apply it again.
I have a site that uses javascript to launch a css overlay of a google map (see [link deleted because I can only have one at a time] and click the 'Enlarge' button under the map).
This doesn't work on the ipad. I believe it has something to do with this not being a link, but using the jquery live('click',.. approach. I need to fix this but I'm new to using the ipad and I don't even know how to step through the javascript to see what the problem is.
What kind of development tools are available for testing on the ipad?
Edit: My mistake. The link above works fine in the iPad - no problem bringing up the larger map. However the sister site http://lowes-realty.com/Stateline-Plaza_Enfield_CT-11.aspx is not working. What I need is a development system that will let me look at them both on the ipad (I really want to avoid emulating or spoofing).
Have you tried firebug lite?
http://getfirebug.com/firebuglite#Install
Have you tested this in google chrome? As google chrome is a webkit browser, you may be able to do the majority of your debugging in chrome, and iron out smaller issues on the iPad itself.
Edit:
Removed unnecessary comment about iPad.
The problem ended up being that I had a javascript error that aborted the script before I ever got to the jQuery code. Once I fixed that, I was able to use jQuery without making any special modifications for the ipad - awesome! I did not have to do anything with the swipe or tap events (sweet!).
However I was not able to get any kind of javascript debugger; I had to work this one out for myself. As of Nov '09 firebug lite crashed the ipad for me and there don't seem to be any developer tools build for testing the ipad. I tried several sites that claimed to perform the same way the ipad does in your browser and not one of them held water.
I have no reason to believe that there is a good option for debugging a site on an ipad (yet).
Edit A Year Later... I'm still looking for a good way to develop on an iPad. I just got Adobe Shadow up and running - it's not actually a useful tool, but there is potential (http://tv.adobe.com/watch/adobe-technology-sneaks-2012/adobe-shadow). Right now (3-29-12) the code inspector is essentially non-functional (cannot view inherited styles, can't view elements without expanding the DOM from the body element, no javascript debugging, and much more).
I know that sounds hopeless, but it has one thing going for it that nothing else I'm aware of does: Shadow works with all existing mobile devices and its code inspector is independent of device and browser. So although the inspector sucks spectacularly right now, once they build some functionality into it Shadow could be a good solution. From their site:
Shadow will be updated regularly to stay ahead of web standards, web
browser updates and support for new mobile devices entering the
market, while incorporating user feedback to provide the best
functionality and experience possible.
~ http://labs.adobe.com/technologies/shadow/
I think the problem is that on the iPhone / iPad there are no clicks events generated but instead touch events (swipe, tap).
You can use something like jQTouch (you can start reading here Getting started and then proceed to callback events hint: tap==click).
If you have more to adapt you can also look at (and wait for a stable release) of jQuery Mobile
weinre lets you remotely attach a WebKit inspector (the built-in Dev Tools you use on desktop browsers) to a page running on your mobile device (iPad/iPhone/iPod/Android/BlackBerry 6/webOS) over WiFi.
http://phonegap.github.com/weinre/images/weinre-demo.jpg
JavaScript debugging is limited to console.logs, but it's better than nothing.
If you have an ICS device, Chrome Mobile lets you remotely attach a full-featured Inspector (with full JS debugging/breakpoints) over USB. I've been thoroughly thrilled using this tool with my Galaxy Nexus.
(source: google.com)