Not sure if this is a problem due to using transparent backgrounds, but I am using a webview to show a webpage to the user, however if the user loads another url from a link or javascript is used to dynamically insert new content into the page the rendering seems to glitch.
By glitch I mean that the page remains in the background whilst the new content / page is loaded in the foreground. They end up overlapping and making everything very unreadable.
I have hardwareacceleration turned off on my webview to enable transparent background, could that be causing the problem?
It's similar to this question Android Webview Content Overlapping While Using Transparent Background.
Many thanks.
This was due to the fact I had transparent background on, I removed this and it was okay. Not the best solution but one that is preferred over having glitchy graphics. I mimiced the transparent background by matching the CSS background properties to that of where my WebView was positioned.
Had the same problem on Google TV boxes and managed to fix this by forcing WebKit to redraw the DOM from jQuery as in:
$('<style></style>').appendTo($(document.body)).remove();
or (if you don't like jQuery):
document.body.style.display='none';
document.body.offsetHeight;
document.body.style.display='block';
You can inject either of the code fragments dynamically from Android as in webView.loadUrl("javascript:(function(){ /* put the force-redraw-code here */ })()") or do it directly from JavaScript after you altered the DOM.
More related fixes at How can I force WebKit to redraw/repaint to propagate style changes?
Related
Built a Jekyll website based on a 3-party theme (MASSIVELY).
Code of website available here: https://git.ikrypto.club/FNB_Japan/FNBJapan
When you visit the deployed website, the background image does not remain constant as expected (You can kind of see the expected behavior on the theme demo, https://iwiedenm.github.io/jekyll-theme-massively/ (Edit: This is actually a better example, https://massively.ghost.io/ ). Basically, the background image is expected to remain constant, and the foreground should scroll with the user.).
You can witness the difference in behavior if you go on our website, https://fnb-japan.info .
However, when the code is ran locally and built with
bundle exec jekyll serve
The background image does not move (as expected). What's happening and how can I remedy it?
Note: It appears that this problem only appears on FF Nightly, and not Chrome
Edit: This appears to be a problem with Firefox Nightly, as opposed to the website. This question is technically resolved.
Edit 2: It appears that the problem persists, and is due to a bad implementation of parallax scrolling causing parallax to flicker.
Edit 3: This problem only occurs once the window is of a certain width, and the difference isn'ta ctually between local/deployed but rather different window sizes.
The background div (#bg)
is being transformed by
this code in the bundled parallax plugin (as evident from setting a "break on attribute modification" on the bg element in the Chrome inspector), which in kind seems to be activated by this invocation:
// Background.
$wrapper._parallax(0.925);
Removing those lines should get rid of the parallax effect too.
I'm building an app using Vue 2. There's a page that contains a simple image gallery that contains about 20 images and one large page background image.
The background image of the page itself is actually contained in a fixed div element that is position: fixed;, has 100% width and height and uses background-size: cover; to display the image.
All of the ~20 items in the gallery as well are using div elements with background-size: cover; displayed in a 3-column grid and the images are displayed using the dynamically generated background-url CSS property using a Vue computed property. The image paths are never being changed so they aren't being recomputed constantly AFAIK.
The performance of this page in Chrome is abysmal, loading takes forever (those are some high resolution images, though, 4K in width) and once the images are loaded I can somewhat interact with the page but everything is extremely laggy and sometimes the page stops responding completely.
On the other hand, in Firefox and Edge everything is basically buttery smooth, both during the loading of the images and during the scrolling/rendering. The interaction with the app is never blocked.
What I remember trying to fix this is replacing the div elements with regular img tags and loading up images using those. Also, I've tried caching the images, I've tried using static image URLs for testing purposes - the same thing happens every time - other browsers handle it well, Chrome is choking on it.
Here's a screenshot of the performance summary in ~30 seconds, from the moment I click the page URL to the moment that basically everything is loaded and the browser is still struggling to render anything and process any interaction with the page. Obviously the painting phase is an issue here:
Any advice? Thanks!
This question is hard to answer as it is a very specific problem.
You can analyze what is causing this behaviour in chrome by using the developer tools:
Open the developer tools in chrome by pressing "Ctrl+Shift+I".
Go to the tab "Performance".
Hit the record button and do the action which has low performance.
Hit stop and you get a breakdown what happened in the background.
If you don't find the issue with above suggestion, you can post a detailed screenshot of the performance breakdown here, I might be able to help you with it.
I am working on a PhoneGap web app for iOS.
I have an implemented an infinite list, where as you scroll down the page, new elements are loaded from the server and added to the bottom of the page.
Each element added to the page includes images that are loaded asyncronously.
However, the images do not actually appear until after scrolling stops. This makes things appear sluggish, even though they are not - ie until I remove my finger from the device.
Does anyone know of a workaround for this problem?
This funky work around for safari will do the trick for you:
*:not(html) {
-webkit-transform: translate3d(0, 0, 0);
}
This will add the translate property to all elements causing the IOS browser to render your off screen elements and give you a silky smooth native like feel. Remember to check your functionality as it can mess with positioning of some elements. If if does add them to the 'not' list e.g:
*not(html, button, img...
This cannot be avoided. Image rendering on webkit-gradient IOS is executed in a dedicated US thread with real time priority.
https://news.ycombinator.com/item?id=3316383
I've noticed the same problem while building my application. The UI consists of many images and it only appears to render what's currently on the screen and when you go to scroll, everything else won't render until it's finished scrolling.
A solution that worked for me was adding an overflow: auto; property to the containers in your layout. When I add it, everything renders and there are no problems when you scroll.
I want to create a custom video control, I mean over the video itself, with issues like double click on some x and y coordinates of the video to zoom In, but I can't get this result because the real player plugin API is not that flexible, then I Tried to create a transparent layer to handle those events and I can't achieve that the transparent layer sits on top of the video, I tried this list:
1.- Put a flash transparent movie over the real player plugin- not working the player breaks the z-Index and the video goes to the top.
2.- Put an Iframe transparent over the real player plugin- not working it puts on top, but when I make the Iframe transparent, the movie goes agains to the top.
3.- I tried to use the map html tag, also is not working.
4.-I tried to put and div absolute positioned, but z-index is not working.
I need some help with this topic.
thanks guys
There is no reliable way to force a browser to layer content on top of a plugin, because plugins like Flash just talk to the video/audio system rather directly and just paint in the bounding box the browser tells them to.
Obviously it's still experimental, and there's no IE support (without ChromeFrame), but was designed to solve exactly this problem.
If this was Flash you could use wmode=opaque or wmode=transparent as an alternative to the default wmode=windowed, which is much faster but causes problems with overlays like you describe. I've found no sign of an equivalent option for real player.
http://javafx.com/ would be my recommendation
I would avoid trying to mash several different technologies together to get what you want, It will make for a maintenance nightmare between different browsers and browser upgrades.
I think this is what you search for:
http://www.dynamicdrive.com/forums/showpost.php?s=4cc8a233f39321ad1ee9e01ec57a3bef&p=200817&postcount=10
You need the wmode = opaque to get the layer over the flash.
a place where you can find this working is, www.dtele.de .
If you open the navigation, you´ll see, tha it lays over the flash movie.
I need to make my dropdown menu apprear over the top of a flash movie, how is this done cross browser?
It can be done, IBM do it: http://www.ibm.com/us/ so do GE: http://www.ge.com/
Setting the the WMODE to transparent doesn't work for Firefox
Putting it into an Iframe doesnt work below IE7
Any one know the best way to achieve this?
Set the wmode to transparent and if necessary, use z-index as you would on any other element, that really should work for Firefox too.
here is an example with all three modes: opaque, transparent and no wmode at all
http://www.communitymx.com/content/source/E5141/wmodeopaque.htm
use transparent if you have something under the flash movie that you want visible,
opaque if you don't want to show what's underneath
and set a higher z-index for menu than the flash movie has
Firefox for linux shows flash on top of everything. Regardles of wmode or z-index.
EDIT:
I just found out that the Linux issue described above can be "fixed".
You need to add an iframe with a z-index between the swf and the layer you want to put on top of it. The iframe needs to have style="display:none" initially and you must use javascript to set display:block on it after the flash plugin has initialized. The Iframe will hide all swfs that are below it on linux.