I have QSting object:
QString someString = "<a href='link'>some text</a>"
and QLabel object:
QLabel someLabel.
with this text:
someLabel.setText(someString);
I set property for QLabel:
someLabel.setProperty("class","someID"),
and in CSS document set style for this label like this :
#someID
{
// some style
}
But style from CSS not appled to Label's text. It set default blue underlined style from css.
Question: How set style from CSS?
You could try to set the style sheet through the setStyleSheet() method.
Examples can be found here.
The important distinction to make is that there are two completely separate styling systems that affect what a QLabel does:
CSS stylesheets set on a widget via setStyleSheet() method.
In these stylesheets, # selects on the id of the object - its name. So, you should be setting the object's name, not the class property:
someLabel.setObjectName("someId");
Then the #someId selector will apply to someLabel.
CSS styling attributes applied to the rich text contents displayed by the label. These can be provided via in-line style attribute, for example <span style="font-size: 20px">FOO</span>. The <style> element in the <html> is also supported, but the external stylesheets are not supported - so the stylesheet must be within the <html>. All CSS 2.1 selectors are supported. For example,
<html><style type="text/css">em {color: red}</style>
<body><em>URGENT!</em></body>
</html>
Related
Instead of creating a whole other id and ruleset, why can’t I just put multiple values (ex. font-family: cursive; color: blue) in a single ruleset? I tried it and it works and seems like a quicker way to do it. For example, if I want to change the font, color, and uppercase/lowercase of a title, can't I just put all those values into one ruleset?
The preferred way to do this is using Cascading Style Sheet (CSS). This allows you to edit the visual aspects of the site without having to deal much with the HTML code itself.
Explanation :
<[tag] style="[css]"> Content </[tag]>
Where [tag] can be anything. For example "p" (paragraph), "span", "div", "ul", "li".. etc.
and where [css] is any valid CSS. For example "color:red; font-size:15px; font-weight:bold"
The recommended way to add style to a html element is by assigning it a "class" (a identifier that can be repeated on the document) or a "id" a unique identifier that shall not be repeated in the document.
For example:
<[tag] id="element1" class="red"> Content </[tag]>
<[tag] id="element2" class="red"> Content </[tag]>
Where tag is any html valid tag. id is a unique arbitrary name and class is an arbitrary name that can be repeated.
Then in the CSS (inside the tags of your document):
<style type="text/css">
.red {
color:red;
}
#element1 {
background-color:black;
}
</style>
For this example and to keep it simple to new users I named the class "red". However class="red" isn't the best example of how to name . Better to name CSS classes after their semantic meaning, rather than the style(s) they implement. So class="error" or class="highlight" might be more appropriate. ( Thanks to Grant Wagner for pointing that out )
For a complete guide to CSS you can visit this link: http://www.w3schools.com/css/
Remember:
Keep your HTML Code clean and use CSS to modify ANY visual style that's needed. CSS is really powerful and it'll save you a lot of time.
Yes you can and it’s okay to do that.
Actually this is the right way!
so you create a ruleset with a specific selector, then you write all the properties that you wish and element to have (if the selector applies to the element)
I have an ionic/angular app which autogenerates a custom tag element with a different _ngcontent attribute each time e.g.:
<tag _ngcontent-hgr-c2>...</tag> (1st refresh)
<tag _ngcontent-agj-c7>...</tag> (2nd refresh)
<tag _ngcontent-cfx-c5>...</tag> (3rd refresh)
Is there a way to use regex to target the custom tag attribute?
This didn't work:
tag[^=_ngcontent-] {
color: red !important;
}
Nor did just targetting the tag app e.g.:
tag {
color: red !important;
}
According to this answer, there is kind of regex in CSS, but it can be only applied to attribute's value, not to attribute itself. The W3C documentation says the same, so because Angular creates custom attributes, I'm afraid that it can be hard to achieve by regex.
If you want to style your tag like in the second example you can do it by defining its styles in global styles.scss. This is not the best solution, but should work.
This angular-blog article recently helped me understand the idea behind the style ecapsulation.
Unfortunately, there is no wildcarding support in CSS for attribute names.
If you have access to the application code which generates the custom tags, you should add classes to these elements (if the app supports it).
See also this question.
I'd like to my own HTML tags but I don't want new tags that might use the same name to cause them to break in the future.
Is this a good idea? Could I use a namespace to avoid conflicts?
Example:
HTML :
<b:HGroup>
<span>item 1</span><span>item 2</span><span>item 3</span>
</b:HGroup>
CSS:
#namespace b "library://ns.example.com/framework/1";
b|HGroup {
display:inline-block;
vertical-align: middle;
}
I read a related question and it suggests DTD. I'd rather not create a DTD but if it's necessary, then I'd like to define it inline. Also, I'd like it to be run as HTML5, not XHTML.
Note:
I do NOT want to use div plus a class.
As far as I understand it, it looks like custom elements I've written will not be overwritten by future elements of the same name if I explicitly register my custom element. Here is a quote from the W3:
Because element registration can occur at any time, a non-custom
element could be created that might in the future become a custom
element after an appropriate definition is registered. Such elements
are called undefined potentially-custom elements. If such a definition
is ever registered, the element will be upgraded, becoming a custom
element.
I've included a full page prototype based on the answers and I can't get it to attach any CSS to any element with a namespace. I've included some JS I found on one of the links but commented out part of it that was giving me errors. My main concern is getting elements with namespaces to be styled by the CSS with namespaces. From how I understand it that should work without JS.
<!DOCTYPE html>
<html xmlns:xhtml="http://www.w3.org/1999/xhtml"
xmlns:s="http://www.w3.org/2002/spark"
xmlns:space="http://www.w3.org/2002/space"
xmlns:spaced="http://www.w3.org/2002/spaced">
<head>
<script>
"use strict";
const inDocument = document.querySelector("example-element");
const outOfDocument = document.createElement("example-element");
// Before the element definition, both are HTMLElement:
//console.assert(inDocument instanceof HTMLElement);
//console.assert(outOfDocument instanceof HTMLElement);
//class ExampleElement extends HTMLElement {};
//customElements.define("example-element", HTMLElement);
//class ExampleElement3 extends HTMLElement {}
//customElements.define("element3", ExampleElement3);
//document.body.appendChild(outOfDocument);
</script>
<style>
#namespace s url(http://www.w3.org/2000/spark);
#namespace space url(http://www.example.com/2000/spark-space);
#namespace spaced "http://www.example.com/2002/spark-spaced";
example-element {
color: red;
display:block;
}
element2 {
color:green;
font-weight:bold;
}
s|element3 {
color:yellow;
}
space-element {
color:yellow;
}
space|space-element {
display:block;
color:yellow;
}
spaced|spaced-element {
display:block;
color:yellow;
}
</style>
</head>
<body>
<example-element>example-element</example-element>
<element2>element 2</element2>
<space-element>space element</space-element>
<s:element3>s namespace element 3</s:element3>
<space:space-element>space namespace el</space:space-element>
<spaced:spaced-element>spaced namespace el</spaced:spaced-element>
</body>
</html>
Custom HTML elements are supported by HTML5, but according to the specs they should contain a - character :
The name must contain a dash (-). So for example, <x-tags>,
<my-element>, and <my-awesome-app> are all valid names, while <tabs>
and <foo_bar> are not. This restriction allows the parser to
distinguish custom elements from regular elements but also ensures
forward compatibility when new tags are added to HTML.
See this article for a good introduction.
Applying CSS to custom HTML elements works the same way as applying CSS to standard HTML elements :
custom-element {
font-weight: bold;
background-color: #ff0;
}
<custom-element>
This is a custom HTML element
</custom-element>
You have a well researched question here. In doing so, you've eliminated all of the "valid" solutions.
You can definitely do what you have proposed, which (harmlessly*) breaks the standards. To be future proof, all HTML standards allow for unknown elements, instructing browsers to ignore them (essentially, they all become <span> elements) since there's no indication of what to do with them, though CSS can indeed affect them. This will work in ALL browsers, even Mosaic and the original IE (though CSS won't work in such ancient browsers).
As you already noted, the "proper" way to do this would be to define your own Document Type Definition (DTD) that can then be included at the top of your ~HTML document with the <!DOCTYPE> tag. This is probably overkill, but it is technically the right approach.
Another solution (that you've also eliminated) would be to use <span class="HGroup"> for inline elements and <div class="HGroup"> for block elements since these elements don't actually do anything by default.
A variant of that solution is to override the action of some otherwise useless tag and disable its standard properties in CSS, <s> for example:
s {
text-decoration: none; /* remove line-through */
display: inline-block;
vertical-align: middle;
}
(* The "harm" you can run into with custom element names is that if you don't specify a DTD (your own or else an existing one with an exact version), a future version of the HTML standard could theoretically define some undesired property for your custom element.)
Essentially I'm trying to create a mini-clone of JSFiddle.
That is, I want to allow my users to type some HTML and CSS and see the rendered result in another area of the screen. I'm also looking to use AngularJS.
Does anyone have any advice or experience on how to go about this?
I'm not sure how much Javascript you know/want to use, but you could create 3 frames, for the HTML, CSS and output. In the HTML and CSS frames, put an input text area. Then on the "run" button click, change the inner HTML of the output to the content of the html (within HTML tags) and the css (within Style tags).
(I drafted this before you made the Angular edit, but you can use jQuery with Angular.)
You can do this within a single page, if you're somewhat careful:
You can have only one body tag on a page. So any body styles should apply to the container only, not to the document body. The code below handles this by changing a body tag style to a .body class style, which applies to a div within the container with class body.
Any other styles should also apply to the container's children only. The code below handles this by first appending the "style sheet" textarea to the container, then iterating through the style rules and prepending the container's ID to each selector. (The original rules are deleted and the new rules are inserted.)
The code below works in IE9+ and modern browsers. Working Fiddle.
<div>
<textarea placeholder="Enter HTML here"></textarea>
<textarea placeholder="Enter CSS here"> </textarea>
</div>
<div id="Render"></div>
$('div').first()
.keyup(function() {
$('#Render').html(
'<style>'+$('div:first textarea:not(:first)').val()+'</style>'+
'<div class="body">'+$('div:first textarea:first').val()+'</div>'
);
var ss= document.styleSheets[document.styleSheets.length-1],
rules= ss.cssRules;
for(var i = 0 ; i < rules.length ; i++) {
var rule= '#Render '+rules[i].selectorText
.replace('body','.body')
.split(',').join(', #Render')+
'{'+rules[i].cssText.split('{')[1];
ss.deleteRule(i);
ss.insertRule(rule, i);
}
})
.keyup();
You could create a temporary file with the CSS and HTML provided and then use a Frame to view that file in another section of the page
<span name="tumme"><img ...
is not valid because "name" is not valid in "span".
But I need to use name="tumme" and I need to be able to use text and img inside the tag.
So what tag can I use together with "name" and on the same time follow w3c?
To answer the question directly, as per the spec the name attribute is allowed on the following HTML elements (very few of these will be useful to you):
BUTTON
TEXTAREA
SELECT
FORM
FRAME
IFRAME
IMG
A
INPUT
OBJECT
MAP
PARAM
META
Is there a reason you must use a "name" attribute rather than a class or an id? Since both class and id are valid for span elements, and since span appears to be the most appropriate element to use,I'd set one of those to "tumme" rather than bending another element into shape.
You could use the <a> tag with no href attribute.
As I said in response to your earlier question — use classes.
Basically, the only valid reason that I can think of where you would want to use the name attribute, is to have DOM access via document.getElementsByName()
or to use it as a FORM OUTPUT.
As a result, what you should be doing is using the HTML5 OUTPUT tag
and add the following in your HEAD tag for legacy browsers:
// Create a fake OUTPUT element, so IE can style it.
<script type="text/javascript> document.createElement("output");</script>
// Implement default style, so that it acts like a SPAN in other browsers:
<style type="text/css"> output { display:inline; border:0; outline:0; margin:0;padding:0; } </style>
http://html5doctor.com/the-output-element/
<output name="tumme"><img src="..." /></output>
If it is only for styling purposes or simple DOM query purposes
then you should use this as proposed earlier:
<span class="tumme"><img src="..." /></span>
or
<span id="tumme"><img src="..." /></span>
name is only valid in the <a> tag IIRC (and form elements as was pointed out by David in the comments) but I'm pretty sure that is not what you're after:
<a name="whatever"></a> would create an "anchor" on a page that could be linked to with Link text.
Why do you need to use the name attribute? Why couldn't you simply use id instead?