I am troubleshooting performance issues on IE 11 with an existing HTML page which is quite big (table with a few hundred rows containing links).
I noticed with the F12 UI responsiveness tool that the lagging is caused by many "Layout" events generated as soon as I move the mouse anywhere hover the page and which basically recompute the style of all elements (including the table cells) even if the mouse is on the page's header section.
From the documentation:
•Layout: Changes were made to the DOM that required the size and/or position of all affected elements to be computed.
How can I find the cause of this issue?
I guess there is some :hover CSS style somewhere that causes this full style recomputing, but how to find out which one?
Well it seems that the performance issue was caused by the excessive number of CSS rules which was beyond the limit described here: Internet Explorer's CSS rules limits
Related
I have developed a MSFS toolbar app using tabulator.
https://github.com/daveblackuk/VSR
Users have noted that the MSFS internal browser does not render certain icons in tabulator correctly (although Chrome does). These include cell overflow indicators and menu icons. Whilst I recognise this is an MS bug it is likely to be way down on their priorities.
Missing overflow
I am therefore considering modifying the CSS or JS that renders these elements, by either removing them or replacing them with something (possibly an FA-Icon or img) - can someone point me to the right elements, as the element inspector in chrome does not distinguish them from the cell?
thanks
/DB
I have a responsive Drupal Zen subtheme that I hacked together about a year & a half ago from some CSS & HTML that a non-Drupal designer handed off to me for my website. I've known that in certain layouts, it is buggy, and needs to be fixed, but I just haven't gotten around to it. After repeatedly reaching out to a local Drupal developer (and offering to pay him), I've gotten tired of waiting, and just need to fix this thing.
My bounce rate for folks on mobile devices is awful.
The URL is http://developcents.com. The homepage looks decent on any device. Internal pages need a lot of help, though, when viewed in certain screen sizes (including mobile devices). Let's use http://developcents.com/blog as an example.
In the below scenario, my question is not how to find the CSS files themselves. Rather, my question is, how can I find the necessary CSS settings using Firebug Lite, so that I can debug the CSS through my browser, instead of having to manually update each CSS file every time I want to test a change?
I can't find the actual CSS-styled divs, blocks, etc... causing the layout to break under certain dimensions. I know how to find, and edit, the CSS within the CSS panel, but I can't track down the specific CSS in this instance.
Additionally, as a secondary question, if you want to provide pointers on what I actually need to change, then please be my guest! But if you point me in the right direction on how I can go figure it out myself, that's fine too. :)
Let's get on to the scenario (which you can easily see by testing it yourself):
When I resize my browser window down to a certain size, the links & tweets section in the left sidebar move over to the right, so that the left side of the navbar aligns with the right side of the header area, while the content spans the full width of the page, except for the left margin, which stays in place but gets wider. Basically everything below the header gets screwed up, and it's easier to see the problems than explain them (so go test it).
Using Firebug Lite in Chrome, I can't seem to find the left margin for the "main" content area (see this screenshot clearly indicating the yellow margin), nor can I find the CSS for the navbar / tweets block (which I presume is some sort of float).
To modify the CSS within Firebug or Firebug Lite just select an element inside the HTML panel or inspect it via its inspector. Inside the Style side panel you'll see all CSS rules applying to the element.
Clicking the name or the value of a CSS property opens an inline editor to allow editing it.
On the right side of each rule you'll see the name of the style sheet, which contains the rule. Hovering it displays you the full URL and clicking it allows you to inspect it within the CSS panel.
You can also edit the styles directly within the CSS panel, which lists all style sheets available on the page.
Note: The changes you do there are not permament, i.e. on the next page reload they are gone! To make permanent changes you need to edit the files on the server.
Also note that I'm referring to the panels within Firebug. The panels within Firebug Lite basically work the same, though may look and work a little bit different. Furthermore Firebug Lite is not maintained anymore, so there's no guarantee that everything is working as expected.
I just spent an hour troubleshooting an issue I had were all my paragraph elements were shifted down.
This happened after I moved the design from jsfiddle.net to my web host.
I killed an hour before I finally realized I needed to insert
p{margin:0px;}
and all was well...well still off by 1px;
Questions:
Why did this error not occur in jsfiddle.net?
Why does FF CSS Debugger not let me know that there is a margin in there or where it came from. I don't know what is was set to but it was not 0px;
I'm trying to learn from "my mistakes" so I can know what to expect next time.
Web browsers set their own default values for rendering HTML elements. This includes margins, paddings, font sizes etc. When you create a HTML document with no CSS you can see lists, paragraphs and headings are formatted in a default way.
Debuggers tend to show the values that you have applied to the document in your CSS.
To get around these sorts of inconsistencies (browsers use different defaults) some people use a 'reset' CSS file that removes this behaviour by setting as much as possible to 0.
Take a look at http://meyerweb.com/eric/tools/css/reset/
In Webkit, will a 3D CSS transform set to repeat indefinitely, continue even when it or a parent element is hidden from view by styling (CSS)?
The reason I ask is that I am seeing unexpectedly high CPU usage on a page I am developing.
If anyone knows a good way to diagnose this issue (for example visualizing where CPU cycles are going on a page, as opposed to a blanket CPU usage per tab), I would be very grateful.
Anecdotal evidence (removal of the hidden CSS animation) would suggest that the animations do run in the background. Does anyone know how to prevent this?
In chrome 16.0.912.75, at least CSS animations appear to continue even when the element is set to visibility:hidden;. Setting display:none appears to resolve the issue.
you can debug this kind of situation with the developer tools
chrome / safari right click inspect element.
Go to the timeline tab and click on record, after that you can see what the browser is doing internally.
I have been working on a little photo slider. It looks slightly different in Chrome than in FF so I thought a CSS reset would make them both look the same. I used the Yahoo! YUI CSS reset model but nothing changed. It looks good in FF but in Chrome the "Resume" button on the right side sticks up too high and a thin gray line at the bottom of the big pictures gets cut off where the main buttons are located. Here is the URL:
http://www.replayground.com/slider/02.html
You can ignore the stuff below the circles. Just testing stuff down there.
Here is what I added to my 02.html file:
<link rel="stylesheet" type="text/css" href="http://yui.yahooapis.com/2.9.0/build/reset/reset-min.css">
I'd really like advice on how to get CSS Reset working correctly. Not how to fix the specific buttons problem you see. As I add elements to the page I don't want to have to go through this each time.
A CSS reset is not designed to make all the rest of CSS cross-browser. It is designed to set all of the client default rules on all the different browsers to the same thing so that you are always working from a predictable set of CSS rules. How the browsers interpret those rules is still specific to each one.
In your case, you still need to figure out how to write CSS rules that operate the same in both Chrome and FF - the reset simply levels your starting point a little, it doesn't remove the browser rendering differences.
You may find a cross browser CSS framework (e.g. blueprintcss.org or 960.gs) to be more helpful for your current situation. They often use a reset, but also have rules that compensate for the differences in the rendering of the after-reset CSS rules.
jball is very right about the resets. They just allow you to start with a blank page, but you should still write a proper document structure and good CSS to get good and consistent results.
In your case, all elements in your page are loose in the page. This will give you trouble in the end. Some things will shift a few pixels, especially when you don't specify exact height for every item. Fonts are rendered in different heights by each browser. These may be tenths of pixes, but when they get rounded, your website is a little off between browsers.
When you use a little deeper nesting of elements, you can make better use of positioning elements (relative and absolute). If you put in a specific div for the header, and give it a fixed size, you can position each element in there very precisely, which is especially handy for headers and menu's.
I took the liberty of creating a small example, which shows just some basics of positioning. It is not perfect and uses brightly colored borders instead of images for the layout. But it's just for showing the element nesting and absolute and relative positioning, along with a negative margin trick.
http://jsfiddle.net/YwCxQ/3/