misunderstood how webkit rendering translate3d(with bug) - css

Firstly I wanna say, that I'm not looking for the solution of this 'problem', I just wanna understand how it works(or right say - does not work).
So for example I have a block:
#block {
display: block;
position: fixed;
top: 0;
left: 0;
width: 200px;
height: 200px;
background-color: #0000ff;
-webkit-transform: translateZ(0);
}
.hidden {
-webkit-transform: translate3d(-500px, 0, 0)!important;
/*display: none!important;*/
}
and random another block for handle click event with toggle class function for #block and resizing for get scrollbar on screen
And again - YES, I know, I can't use fixed position with translate3d, because coordinate system(actually I'm not fully understand how that works.. :( ), I read specification and bug report on chromium/webkit, but I just wanna understand why, I mean how browser see it and why rendering so strange...
here some observation:
change translate position(fully hidden -> -500px):
- with scrollbar on screen :
render hide/visible through time,
like(one action = one click): hide-visibility(hidden-state) -> hide(visible) -> hide(hidden) -> visible(visible) -> hide(hidden) -||-
- without scrollbar on screen :
nothing rendering; only then something redraw on screen(like scrolling or add textcontent to block(not in layer))
change translate position(visible -> +50px):
- with scrollbar on screen :
works well, changing position on each time
- without scrollbar on screen :
nothing rendering, only then something redraw on screen
change display none/block:
- with scrollbar on screen :
hide block, after nothing rendering; only then something redraw on screen
- without scrollbar on screen :
hide block, after nothing rendering; only then something redraw on screen
with 'position:absolute' changing translate(position) works fine in all cases, 'display: none' same does not render(only then redraw something)
testing only in Chrome 33.0.1726.0, so guess it's works different in another browsers

Related

iOS 13 Safari: Bug(s) in window.innerHeight

As I understand it, the window.innerHeight should return the size of the viewport without the browser chrome (address bar, navigation, tabs, etc.). But this doesn't seem to be the case in the latest version of iOS13. Instead there are two problems:
(Sometimes* too small in portrait) If you rotate from portrait mode to landscape mode with no tabs open and then back to portrait mode, the window.innerHeight value ends up being too small (by about the size of the bottom navigation bar) giving this horrible white bar at the bottom of the screen. See this discussion on macrumors for more details: https://forums.macrumors.com/threads/is-this-a-mobile-safari-bug-white-space-appears-at-bottom-after-rotating-iphone.2209551/
(Sometimes* too big in landscape) If you have a bunch of tabs open, "Show tab bar" turned on and then rotate from portrait mode into landscape mode, then window.innerHeight is too big and the bottom of the screen gets cut off.
Even after turning on every conceivable viewport tag and all permutations thereof, it doesn't seem to work. I've also looked at several "tutorials" on how to handle this problem in iOS Safari, and to date every one that I've checked is broken.
I've also tried all variations of the window.innerHeight, with more or less the same result:
The new visual viewport API returns the same results, no different than window.innerHeight. Bottom is still truncated in landscape with tab bar and portrait mode still has the white bar at the bottom.
document.documentElement.clientHeight with various permutations of CSS (using 100vh, 100%, etc.) gives the same result. Ditto for getBoundingClientRect on various divs and combinations of div elements.
window.outerHeight and screen.height give the size of the full screen without browser chrome, which is generally too big and causes an overflow.
Also tried a bunch of other random things that I've forgotten by now (should have taken notes).
You can manually fudge it on a per-device basis if you can guess the size of the top and bottom browser chrome, but this is extremely fragile. I'm looking for a solution that doesn't involve building a giant look up table of every iOS device and software configuration.
I'm trying to make a fullscreen canvas element for a web game and this issue is blocking my ability to ship. As far as I know this issue is only present in iOS13. After looking around for weeks I still haven't found a good fix.
I have had the same issue recently and I was able to solve it like this:
CSS (only relevant parts shown):
html {
height: 100%;
min-height: 100%;
max-height: 100%;
background: #99f; /* Safari for iOS and Opera for Android in fullscreen mode?!?! */
}
body {
padding: 0;
margin: 0;
color: #000;
width: 100%; /* I was desperate! This was a wild guess... And worked! */
height: 100%;
min-height: 100%;
max-height: 100%;
overflow: hidden;
background: #99f;
}
TypeScript (only relevant parts shown):
// Assume everything here is in the global scope
function detectIOSOrSafari(): boolean {
// https://stackoverflow.com/q/9038625/3569421
if ((navigator.userAgent.indexOf("Chrome") <= 0 && navigator.userAgent.indexOf("Safari") >= 0) ||
(navigator.userAgent.indexOf("Mac") >= 0 && ("ontouchend" in document)))
return true;
switch (navigator.platform) {
case "iPad Simulator":
case "iPhone Simulator":
case "iPod Simulator":
case "iPad":
case "iPhone":
case "iPod":
return true;
}
return false;
}
const isIOSOrSafari = detectIOSOrSafari();
function adjustWindowSize(): void {
let widthCss = window.innerWidth,
heightCss = window.innerHeight;
if (document.documentElement && ("clientWidth" in document.documentElement)) {
widthCss = document.documentElement.clientWidth;
heightCss = document.documentElement.clientHeight;
}
if (isIOSOrSafari) {
let bodyRect: DOMRect = null;
// Another act out of desperation...
if (document.documentElement && ("getBoundingClientRect" in document.documentElement))
bodyRect = document.documentElement.getBoundingClientRect();
else if (("getBoundingClientRect" in document.body))
bodyRect = document.body.getBoundingClientRect();
if (bodyRect) {
widthCss = bodyRect.right - bodyRect.left;
heightCss = bodyRect.bottom - bodyRect.top;
}
}
// Rest of the code, where I use widthCss and heightCss to compute my canvas' size
}
window.onresize = adjustWindowSize;
You can check out the entire source code in the project's repository: https://github.com/carlosrafaelgn/pixel

Twitter Bootstrap - Giving thumbnail caption a minimum number of lines

I have a carousel in Bootstrap that displays 4 columns of thumbnails. Here's the carousel in question. If you move to the third page, you can see that the container increases in height in order to accommodate the contents of the thumbnail captions. I've been trying many things such as setting bottom margins, min heights, etc. to get the position of the "View Details" button constant across the entire carousel.
My question is what is the best way to approach this issue? I was thinking somehow making the thumbnail caption height a minimum of 4 or so lines, but I tried that(probably the wrong way) to no avail.
When I add
.caption h4 {
min-height: 2.2em; /* 2 lines as line-height is 1.1 */
}
I get all "View details" at the same level. However, that obviously doesn't treat the problem of captions being even higher. It only works if no caption is higher in fact. (But it IS ok, if you know for sure nothing is going to be higher than your multiple.)
So, instead I apply this little bit of CSS to put a limit from the other side.
.caption h4 {
max-height: 4.4em; /* 4 lines as line-height is 1.1 */
height: 4.4em; /* making it a multiple allows usage of overflow */
overflow: hidden; /* without cutting a line in the middle */
}
If you want to set a max-height equal to the height of the highest of captions dynamically, than you would have to use a little bit of JS:
(function(d) {
var captions = d.querySelectorAll('.caption h4'),
height = 0;
for(var i = 0; i < captions.length; i++) {
height = Math.max(height, captions[i].offsetHeight); // or clientHeight depends on you box model
}
var style = d.createElement('style');
style.type = 'text/css';
style.innerHTML = '.caption h4 { max-height: '+ height +'px; height: '+ height +'px; }'; // they don't need overflow as none of them can overflow;
d.getElementsByTagName('head')[0].appendChild(style);
})(document);
You add this script at the end of body, so that the DOM is already loaded (or somehow trigger it onload).
Important: this snippet is not supported by older browsers because of the querySelectorAll.
And that does the trick when I run it on your site.

WP8 IE10 viewport issue

Did any of you noticed that when using -ms-viewport (with specific width of 320px or device-width) then web browser content can be moved outside available space? It seems like document size is wrong so i can scroll it's content to the left but there is nothing then white empty space. I can also zoom it out(but i should not) and it's size after that is not always the same. I'm aware of http://mattstow.com/responsive-design-in-ie10-on-windows-phone-8.html but it does not help. It happens after second or third navigate to the same content and disappears for example when device is rotated.
Windows Phone 8 does not properly recognize the meta viewport tag that is standard for webkit and mobile web.
Try this in your CSS
#-ms-viewport{width:device-width}
And then add this JS
if (navigator.userAgent.match(/IEMobile\/10\.0/)) {
var msViewportStyle = document.createElement("style");
msViewportStyle.appendChild(
document.createTextNode(
"#-ms-viewport{width:auto!important}"
)
);
document.getElementsByTagName("head")[0].
appendChild(msViewportStyle);
}
More here (credit)
try adding the following
#-ms-viewport {
user-zoom: fixed;
max-zoom: 1;
min-zoom: 1;
}

Native scrollbars inside absolutely positioned element

I'm having some issues with scrollbars on element with position: absolute. The behavior I'm experiencing is that chrome 21 and firefox 15 displays scrollbars inside the box, resizing it's content thus hiding some of the text, however opera 12 and internet explorer 9 displays it also on the inside, but without resizing it's content and resizing the box instead (which is in my opinion correct, since the box doesn't have width defined). Is there any solution to make this look the same in those 4 browsers?
JsFiddle: http://jsfiddle.net/Kukkimonsuta/GaMD7/2/
Edit: as Siva Charan pointed out, it works correctly when overflow-y is set to "scroll" however that shows scrollbar always which is not desired
Edit: my final solution based on answers from Siva Charan and anonymous down voting is lame
http://jsfiddle.net/Kukkimonsuta/GaMD7/15/
function updateAutoScroll(element) {
var $element = $(element);
if (element.scrollHeight > element.clientHeight)
$element.css("overflow-y", "scroll");
else
$element.css("overflow-y", "auto");
}
The only way to do this dynamically across all browsers is with JavaScript, for simplicity I used jQuery.
http://jsfiddle.net/iambriansreed/mYuQx/
$(function(){
// loops through each container
$('.container').each(function(){
if(this.scrollHeight>this.clientHeight)
$(this).children().wrapAll(
'<div style="padding-right:'+scrollbarWidth()+'px;"/>'
);
});
// gets the browsers current scrollbar width
function scrollbarWidth() {
var parent, child, width;
if(width===undefined) {
parent = $('<div style="width:50px;height:50px;overflow:auto"><div/></div>').appendTo('body');
child = parent.children();
width = child.innerWidth() -
child.height(99).innerWidth();
parent.remove();
}
return width;
};
});
Add overflow-y: scroll; to .container.two
.container.two {
top: 250px;
overflow-y: scroll;
}
Refer LIVE DEMO
UPDATE:
If you are comfortable, you can use text-overflow: ellipsis; and replace to actual space
This is more of a workaround than an actual solution, but it might be good enough. Basically, first wrap the contents of container two in another div, and add some right padding to it. Make sure you also set width: 100% in .item.
Here's a modified version of your demo: little link.
This isn't perfect, but I hope it helped!

fixed vertical positioning of css within an iframe

I am trying to get my bottom header to stick to the bottom of the screen inside of my iframe application and have it always appear in view for the user even when the page is scrolling. I have no control over the outer iframe as it is on a different domain. The header itself must be inside of the iframe as I have no control outside the iframe. The iframe always expands to the height of its contents so that it has no scrollbars, but the bar still has to be visible in the viewport at all times.
Another thing to note: The iframe height should be the same height as its contents so their is no need for scroll bars
Chrome has a bug that doesn't fix elements with position:fixed if:
a) you use CSS3 transform in any element, and/or
b) you have a child element positioned outside the box of it's parent element
Oddly enough, the bug was reported back in 2009 and it's still open: https://code.google.com/p/chromium/issues/detail?id=20574
You might want to play around with position: fixed;
#element {
position: fixed;
z-index: 1000;
bottom: 0;
}
EDIT:
I'm sorry, I think I miss understood your post. If I'm reading it correctly you want to create a header bar similar to blogger but to keep it always in view of the user when he/she scrolls.
What you can do is create a container div, and then you can nest both your header and iframe inside that container. You can then play around with the positioning, although I'm not sure if the exact behavior that you're looking for is possible without some javascript.
EDIT 2:
After playing around a bit, I got something that I think might help (if I understand your problem correctly).
http://digitaldreamer.net/media/examples/iframe-site.html
http://digitaldreamer.net/media/examples/iframe.html
I had to look for a long time for a possible solution, and I think I have found one that is using the Intersection Observer API to detect the scrolled position of the iframe within the parent document without needing to access the parent document DOM.
I'm creating a bunch of hidden 100px high elements in the iframe. These are positioned absolutely underneath each other so that together they fill the height of the whole iframe document. An intersection observer then observes the intersection between the (top-level document) viewport and each of the hidden elements and calculates the scroll position of the iframe based on the values it returns. A ResizeObserver creates additional hidden elements if the height of the body increases.
This approach assumes that your iframe is always minimum 100px high. If you expect a smaller height, you need to adjust the hidden container height. The reason is that once a hidden container is 100% visible, the intersection observer does not emit the callback while the parent document is being scrolled (since the intersection ratio stays at 1). This is also the reason why I need a lot of small containers rather than observing the intersection with the iframe body itself.
const CONTAINER_HEIGHT = 100;
const threshold = [...Array(CONTAINER_HEIGHT + 1).keys()].map((i) => i / CONTAINER_HEIGHT);
/**
* Registers an intersection handler that detects the scrolled position of the current
* iframe within the browser viewport and calls a handler when it is first invoked and
* whenever the scrolled position changes. This allows to position elements within the
* iframe in a way that their position stays sticky in relation to the browser window.
* #param handler Is invoked when the function is first called and whenever the scroll
* position changes (for example due to the user scrolling the parent document). The
* "top" parameter is the number of pixels from the top of the browser viewport to the
* top of the iframe (if the top of the iframe is above the top of the browser viewport)
* or 0 (if the top of the iframe is below the top of the browser viewport). Positioning
* an element absolutely at this top position inside the iframe will simulate a sticky
* positioning at the top edge of the browser viewport.
* #returns Returns a callback that unregisters the handler.
*/
function registerScrollPositionHandler(handler: (top: number) => void): () => void {
const elementContainer = document.createElement('div');
Object.assign(elementContainer.style, {
position: 'absolute',
top: '0',
bottom: '0',
width: '1px',
pointerEvents: 'none',
overflow: 'hidden'
});
document.body.appendChild(elementContainer);
const elements: HTMLDivElement[] = [];
let intersectionObserver: IntersectionObserver | undefined = undefined;
const resizeObserver = new ResizeObserver(() => {
intersectionObserver = new IntersectionObserver((entries) => {
for (const entry of entries) {
if (entry.intersectionRatio > 0 && (entry.intersectionRect.top > entry.boundingClientRect.top || entry.target === elements[0])) {
handler(entry.intersectionRect.top);
}
}
}, { threshold });
const count = Math.ceil(document.documentElement.offsetHeight / CONTAINER_HEIGHT);
for (let i = 0; i < count; i++) {
if (!elements[i]) {
elements[i] = document.createElement('div');
Object.assign(elements[i].style, {
position: 'absolute',
top: `${i * CONTAINER_HEIGHT}px`,
height: `${CONTAINER_HEIGHT}px`,
width: '100%'
});
elementContainer.appendChild(elements[i]);
intersectionObserver.observe(elements[i]);
}
}
});
resizeObserver.observe(document.documentElement);
return () => {
resizeObserver.disconnect();
intersectionObserver?.disconnect();
elementContainer.remove();
};
}
This example code should create a toolbar that is sticky at the top of the browser viewport:
<div style="position: absolute; top: 0; left: 0; bottom: 0; right: 0; overflow: hidden; pointer-events: none; z-index: 90">
<div id="toolbar" style="position: absolute; top: 0; left: 0; right: 0; pointer-events: auto; transition: top 0.3s">
Line 1<br/>Line 2<br/>Line 3<br/>Line 4<br/>Line 5<br/>Line 6<br/>Line 7<br/>Line 8<br/>Line 9<br/>Line 10
</div>
</div>
<script>
registerScrollPositionHandler((top) => {
document.querySelector('#toolbar').style.top = `${top}px`;
});
</script>
Note that other than what you asked for, this will position the toolbar at the top of the viewport rather than at the bottom. Positioning at the bottom should also be possible, but is slightly more complex. If anyone requires a solution for this, please let me know in the comments and I will invest the time to adjust my answer.

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