I am using GWT 2.4, GWTP and Chrome 22.0.1229.94 for testing. I have struggled with this issue for days.
On startup I present a custom PopupDialog using a view that has extended PopupViewImpl. In an overridden onReveal() method I center the dialog. The GWTP code centers synchronously and also using scheduleDeferred.
In development mode and running complied on local server everything works as expected: the popup dialog is always rendered and centered correctly. I have also tested in IE.
However, when deploying to the live web server on the Internet I notice that when I refresh using F5, sometimes the CSS is not applied before the script tries to center the dialog. This results in the measurements being wrong and the dialog is not placed in the center. Interestingly this only seems to happen now and then, typically when the browser is not fast enough in rendering all (CSS) resources before the scheduled deferred command is invoked.
So, I have already tried the following:
Loading CSS using different techniques (reference in HTML-file, reference in GWT-module, put in CssResouce)
Center using Scheduler.get().scheduleDeferred as default code also does.
Calling RootLayoutPanel.get().onResize() in onReveal to try to trigger some layout before centering deferred.
I notice the same behaviour in Chrome and IE so it might not be a browser issue. My question is where to put my "center"-call to ensure that it is called after the all CSS has been properly applied or if there is anything else I can do to force the CSS to render?
Thanks!
Here is the onReveal code in the Presenter extending PresenterWidget:
#Override
protected void onReveal() {
super.onReveal();
// Hide loading image
fireEvent(new HideApplicationLoadingImageEvent());
// Reset message
getView().setStatusMessage(null);
// Center the popup
getView().center();
}
There is method addToPopupSlot(child, boolean center); if you send true for center argument it take care of centering the popup in GWTP Example:- addToPopupSlot(widget, true)
Related
I recently came across a fairly new cordova plugin called cordova-plugin-qrscanner (https://github.com/bitpay/cordova-plugin-qrscanner). I have been using other QR Scanners before, but those simply overlay some kind of native camera UI until the QR has been scanned and then return back to the app.
However, the approach of this plugin is a bit different. The camera is actually shown "behind" your app and you have to make everything transparent in order to see it.
This is very interesting because you can then easily add custom overlays with HTML and CSS. However, I am not quite sure what the best approach is here.
After adding the plugin and simply calling QRScanner.scan(displayContents); you can't see anything, but the scanner is already running in the background. I then recursively removed any styles (see simplest way to remove all the styles in a page) from the app and set the background-color to transparent to see if it worked. It did, but I could obviously still see the text that was displayed before.
I guess I could create and push a new page with my overlay on it, set the background-color to transparent and then navigate back once the code has been scanned. But this feels really hacky.
Does anyone have a better solution for this?
For example, is there a way to "swap" the whole visible part of the app with the overlay and restore the state after the code has been scanned?
Thanks for your help.
EDIT:
It's not the same plugin, but this article is relevant to my question.
http://www.joshmorony.com/ionic-go-create-a-pokemon-go-style-interface-in-ionic-2/
Applying the css styles works, but again, the rest of the app is not usable then.
#Andreas I had the some problem a few weeks ago. Here is how I fixed it:
1) First of all, create a class called lowOpacity on your theme/variables.scss, it has to be global, if you create it in the page's scss adding it dynamically won't work:
.lowOpacity {
opacity: 0;
}
2) When you show the qrScanner, you should apply the class to the ion-app element, and optionally register a backbutton action:
this.qrScanner.show().then(()=>{
let unregister = this.platform.registerBackButtonAction(()=>{
this.closeQrScanner();
unregister();
});
window.document.querySelector('ion-app').classList.add('lowOpacity');
});
3) Remeber to remove the class after the qrScanner scanned something ot was closed:
closeQrScanner() {
this.qrScanner.hide().then(()=>{
window.document.querySelector('ion-app').classList.remove('lowOpacity');
}); // hide camera preview
}
ngOnDestroy() {
this.closeQrScanner();
}
Hope it helps
I wouldn't make the app transparent, since I don't see the point of that.
Instead you would just show the contents of the camera in a div in your page, and layer other HTML elements on top of that using a higher z-index than the element containing the camera image.
As #vrijdenker said you should display the camera content to the right level and do not weirdly hack the CSS.
To do that you can remote debug your app to localise the camera container and apply some CSS on it to modify the z-index / display / etc.
Remote debug on Android:
https://developers.google.com/web/tools/chrome-devtools/remote-debugging/
Remote debug on iOS:
https://developer.apple.com/library/content/documentation/AppleApplications/Conceptual/Safari_Developer_Guide/GettingStarted/GettingStarted.html
You can do that on real device or on simulator
I'm displaying mathematical expressions in a webview (using jqmath library and some CSS). One requirement is that expressions should be centred, and here's what I use to achieve that:
<html><head><style type='text/css'>html,body {margin: 0;padding: 0;width: 100%;height: 100%;}html {display: table;}body {display: table-cell;vertical-align: middle;text-align: center;}</style></head><body><p>here goes the expression</p></body></html>
Since rendering math takes some time, the webview is hidden while the expression is rendering, and displayed only when it is ready (once the WebViewClient's onPageFinished has been called). This worked well until Android 4.4.
The problem with the new webview seems to be that it only applies CSS when it is visible on screen. So after revealing the hidden webview, the expression first appears in the top left corner, and only after ~0.1 seconds "jumps" to the center. This looks ugly, since I have to display many expressions in quick succession.
A related problem is described in this question: width:100% in CSS not rendering well in Android 4.4. The asker was able to solve his problem by removing the display: table; from html, but that doesn't work in my case.
So is there a way to either:
(a) force the new (Chromium-based) webview to render content while it is not visible, or
(b) display the content at the center from the beginning (without first displaying it in the top left corner).
It is not true that the KK WebView applies CSS only when visible on screen:
the WebView will not size itself if it has visibility set to GONE because the Android framework will call layout-related methods on it (like layout and onSizeChanged). This might be what you're seeing. Try setting the visibility to INVISIBLE instead.
WebViewClient.onPageFinished is not a reliable trigger for showing your WebView. What the callback really means is that the resource for the main frame had been loaded from the network. Unfortunately there never was a reliable callback that would tell you 'your content is ready to be displayed' - what you're describing probably happened to work because of particular timing. The most reliable way to not show unfinished content would be to do so in the HTML/CSS.
you might be using WebView.loadDataWithBaseUrl to load your contents into a new/blank WebView - this API is has an effect similar to re-writing the page's content (rather than issuing a 'real' navigation) and can result in weird layout. If possible use loadData or loadUrl. If neither of those are feasible try calling loadUrl("data:text/html,<body style=\"margin: 0px;\"/>"); before loading the real content (wait at least till you get an WebViewClient.onPageStarted callback for that bootstrap URL).
you might be setting height to WRAP_CONTENTS. This is very unlikely to cause the issues you're describing, but it would be good to rule out. Try setting a width of MATCH_PARENT and a height with a fixed number of pixels.
I'm confused on what makes background images that I set with css load when the image comes into view and sometimes not. That is, I have one scenario in my code (I can give examples if that would help) where I can watch my network traffic and I don't see the image get loaded over the wire until it scrolled into view. I had changed from using a standard img tag to the css background to make this happen.
Now, I have another simple example where I just have what seems to me to be the same
any guideline on when it gets loaded?
thanks
I've created a rather simple Flex application using Flex Builder 4, which connects to a webcam on the user's PC. To do so, Flash is presenting the user with the infamous privacy warning.
Now, the problem is that user can't click on the panel, as it seems unresponsive to any user interaction.
Some more details:
Firefox 3.6.12 on Mac/OSX, Snow Leopard.
Adobe Flash Plugin 10.1.85.3 / 10.1 r85
The Flex app is working fine in its own window/tab but the problem shows up as soon as the html page with the Flex app is embedded into the iframe of another page.
If I artificially put an Alert box before connecting the camera, the user is able to interact with the Flex application but as soon as the Privacy panel is shown, the Flex app stops interacting.
The app works fine under Chrome and Safari but I have not tried this under Windows.
I've read that there are problems with CSS positioning so I removed any CSS style impacting the Flex app.
Before I change my strategy and get rid of the iframe (which will cost me quite some effort) I'd be happy to know whether others have experienced the same problem and if there are workarounds.
Thanks.
I had the same issue for weeks now. I found what may be the problem. It has something to do with the css alignment. try to remove the text-align:center; from the div flash is in and it will work again. Somehow the active areas from the security panel don´t shift with the display image…
In my application, this problem is apparently caused by an element containing the flash having the css margin: 0 auto. This leads to the left edge of the flash object sometimes being reported as a decimal, e.g. $('.flash').position().left --> 450.5px. Whenever it's not a whole number, the security panel failed to react to clicks.
The fix described in https://bugs.adobe.com/jira/browse/FP-4183 and linked to by Christiano almost works. However, it failed whenever the browser was resized to be so small that the left margin disappeared.
Here's what fixed the issue for me:
function registerMozillaFlashFix() {
if ($.browser.mozilla) {
$(window).resize(function() {
$(".flash").each(function(ii, e) {
var $e = $(e);
$e.css('margin-left', $e.position().left % 1 === 0 ? '0' : '0.5px');
});
});
}
}
Then just call window.resize() once your flash has been set up.
Facebook Connect uses JS/CSS overlays/popups for user interaction. I have sites with Flash elements, and no matter how I set the z-indices, the Flash always seems to go to the top.
I have a similar and likely related problem with a div with display:fixed at the top of the screen, where it gets covered by the Flash when you start scrolling.
How can I make sure the Flash element layers properly?
If you just need your flash to fall behind other object then you should use wmode=opaque. This will correct the z-index.
wmode=transparent will also correct the z-index but it also makes your stage transparent so whenever you have nothing on the stage or gaps between objects your html will show through underneath. This in turn causes more system strain.
Ergo if you just need the z-index correcting use wmode=opaque
Generally, I've needed to set the wmode=transparent property on the Flash object and/or embed string.
http://www.communitymx.com/content/article.cfm?cid=e5141