Can I disable vaadin flow theeming and apply ordinary css - css

Vaadin flow theming and styles confuse me. Is there a way to disable it and apply natural css. I know how to reference a css file inside vaadin, and use setClassName but I would prefer to use ordinary css style for components.
Thank you

You can override the default lumo styling by providing yours. For instance, to remove the background color from a ComboBox, I can target the input as follows in a CSS file named vaadin-combo-box.css:
[part="input-field"] {
background-color: var(--lumo-base-color);
max-width: fit-content;
}
To set the colors for a disabled button, you can target it as follows:
filename: vaadin-button.css
code:
:host([theme~='primary'][disabled]) {
background-color: red;
}
And you get the following:
To change the primary color or any other global styling, explore your styles.css file.
For a better understanding, take a look at this video https://vaadin.com/learn/training/v14-theming

Like with all other styling you need to check the states / attributes of the component while the specific state is active and check the DOM - only caveat would be that you need to add those style in the specific files like vaadin-button.css to be applied inside the shadow DOM.

Related

Angular - How To Organize CSS Overrides Across Components For The App

I'm relatively new to angular. In the process of converting a React app to Angular just for learning purposes. I have a parent component that has a button (Custom Button Component). This button when loaded in the parent should be hidden and on hover should show the button. So you probably get an idea that I have some CSS selectors related to the parent component that override the child CSS. First should be display: none and then on hover I change it to display: flex
So the first problem I encountered was that I could not override the child CSS from the parent CSS. After reading all kinds of posts I moved the CSS overrides from the parent CSS to the global stylesheet and also added encapsulation: ViewEncapsulation.None to the child component.
Next thing I noticed is that the align-items: center was not working on the child. First thought I had that guess I have to add that part to the global styles also? but what I really need to know is that is this the norm in Angular? If yes, then some things don't make sense to me. These styles are really not global. They are only related to the parent component then it seems kind of weird to add those to the global stylesheet.
In regards to the align-items not aligning the child (custom-button), I believe that happens because of the extra div being added around the button. So how do you handle such situations?
Appreciate any advice/tips.
Thank you!
You can overwrite children CSS classes from the parent componet. this is the way:
Assuming your child component have this CSS
.child-class {
background-color: blue;
}
When you use this component the background color will be blue. But if you want to change that color to RED. In the parent component where you want the change you need to do this:
In your parent component
:host {
::ng-deep{
.child-class {
background-color: red;
}
}
}
:host this refers to the component's HTML tag (that is created by Angular, in your case the tag of the component that contains the app-custom-button). Also you can apply css to the component tag.
for example:
:host{
width: 100vw;
height: 100vh
}
And with ::ng-deep you can overwrite ALL styles inside your compoent. Does not matter if is a style from your child compoenent, grandchild, great-great-grandson, etc... even if its a component from an external library.
So... For example you can have the "custom background color as blue" then in one component you can keep that color but in other component you can change the color to red and in other component you can change the color to green....
Angular have the concept of ViewEncapsulation. By default, the value is set to ViewEncapsulation.Emulated and the css you put in the component is specific to the component and only to this component. The CSS will not be applied to the child components.
You can switch to ViewEncapsulation.None and you will disable this behavior and all the css rules in your css file will be applied to all your components in the application, and maybe you don't want this behavior. That's why I advice you to leave this option.
The other option you got is to put your specific css rule in src/style.css (if you didn't modify the default path). All css rules put in this file will be applied for all the application and you can keep the ViewEncapsulation of your component.
For align-items, i think you are right : the app-custom-button is wrapping your button, so you need to set a width: 100% to your button, then eventualy resize your app-custom-button

How to remove the particular scss if the component get destroyed?

I am using PrimeNG for my project I used p-dropdown with appendTo body only for particular components files, and I changed the css in only one file as follow, for example
geneFinder.component.scss
.ui-dropdown-panel {
z-index: 999 !important;
}
and component file is
<p-dropdown [options]="geneoptions" formControlName="gene" appendTo="body"></p-dropdown>
But this css is affecting in all other files also. If I removed the !important it is not affecting in other pages and this is not working with particular component itself. How to fix this issue.?
you can try this
<p-dropdown [options]="geneoptions" formControlName="gene" appendTo="body" [style]={'z-index':'999 !important'}></p-dropdown>
You can also customize the z-index with the p-dropdown attribute baseZIndex. This way, you don't need to set it in css, and it affects only the dropdown where the attribute is set.
Angular is a single page application framework hence all the CSS would be combined and CSS styles will be created inside style tag of the single html page. If we are having a CSS class with name that is common to other component's elements it does affects it.
In case of component specific CSS, create a custom class name something like,
.mycomponent-ui-dropdown-panel {
z-index: 999 !important;
}
and add the class to the element of the component's html where we need this change to be applied. This will make sure that other elements of other components are not affected by the CSS style.
I fixed the issue by adding the panelStyleClass in my component,
<p-dropdown [options]="geneoptions" formControlName="gene" appendTo="body" panelStyleClass="overlay-zindex"></p-dropdown>
.overlay-zindex{
z-index: 999 !important;
}

GWT - Changing CSS hover property

I'm a new user of GWT and I'm looking for some advice concerning "theme management".
I have to make a website that can handle theme changes. What I mean is that a user can make is own theme by filling a form, then the website will automatically and dynamically changes its color to display the new ones.
I thought using a CSS sheet for all the static properties and using some GWT lines (e.g. label.getElement.getStyle.setColor(...)) to change color. But I have many "hover" properties and I think creating many MouseOverHandler is not a good idea ...
Is there a way to edit CSS sheet dynamically or a magic trick to do that ?
Thanks.
You have many options - the most straight forward (to me) is to make use of the existing CSS classes that GWT introduces. If you look at javadocs for any of the widgets GWT provides, you'll notice the CSS Style Rules section. For example, Button:
.gwt-Button
the outer element
That means that every Button you add to the page has a .gwt-Button style applied to it. If you inject a CSS stylesheet with a rule that overrides this style:
.gwtButton {
background: red;
}
All your buttons will turn red. You can inject stylesheets using StyleInjector. Creating the stylesheet's content dynamically is up to you - but it's just text, it shouldn't be hard (but make sure the generated CSS rules are valid!).
To get you started, try hooking up this code to some button and see if clicking it triggers changing all the Buttons on the page red:
StyleInjector.inject(".gwt-Button { background: red; }");
If you have custom widgets that you want styled differently, just add an individual class to them (.customWidgetWhatever, like Button has .gwt-Button, etc.) that you will include in your custom stylesheet.
Make sure you understand how CSS works and what it can do for you. For example, if you want to style each button the same, you don't have to change each button's style individually, just use:
button {
background: green;
}
And all the <button>s will turn green.
The easiest way to change themes without reloading the whole application is to assign a theme class to the body element.
You'd want to prepend each CSS class in your app with a particular theme, e.g.:
.theme1 .myClass {
color: red;
}
.theme2 .myClass {
color: blue;
}
Then you'll apply a particular theme to the body element:
<body class="theme1">
When you want to change themes, you'll have to change the body class so it will become:
<body class="theme2">
this way, each element that has class myClass will have its color changed from red to blue.
You cannot edit a CSS file dynamically, but you can inject CSS style either as a new CSS file, or directly into your document.
For example, you can define all key CSS rules in your "main.css" file, and add your user-defined rules directly into the host HTML page with a style tag.

Overwrite existing style with new style

Is there a way or operator in CSS to assign a new style to specific element? I don't want to change original style because it belongs to a plugin and changing it will change it on all my pages. However I want to change the position of the element on a specific web page.
I also can't call those styles in my html because that CSS file is used solely in jquery plugin, you only put class="slideshow" in html div and thats that. I can change that CSS file to suit my preferences, however I don't know how to change it for specific instances?
In order to make a specific styling on a specific instance of your plugin, you should assign a specific class or id to a parent container of that plugin for the instance you need customization.
Example : you can give the id="special" to a parent of the plugin in the page you want customization.
Then you can use that selector to style it independently from other instances of that same plugin.
example CSS:
#special .slideshow /*other selectors */ {
/*your specific style */
}
In your scenario CSS specificity Rule will be helpful for you.
For example in your plugin you are using RED Font Color in class slideshow. Then in your another CSS file you can create a more specific Rule.
Check the Demo what I've posted above on comments section. Here is the direct link.
div.slider .slideshow {color:green;}
You can refer to the element by name:
#htmlitemname{
color: green;
}
CSS is cascading, i.e. it will apply it top down - general, class and then the id.
You can add !important to your css if you wish it to override any inline styles. So long as you make a style sheet specifically for that page, this should work for what you need. Hope this helps :)

jQuery UI button: How do I override the classes used for a single button?

I am using the jQuery UI library out of the box, based on a theme.
Having links rendered as buttons is great, however I need to override some buttons with different colours.
How do I specify an specific class for a particular button to use?
I recommend looking at the CSS for the jQuery UI buttons and duplicating the structure of the CSS which specifies the buttons, but with your own class instead of the jQuery UI classes. Make the overrides that you need in this CSS and include it after the jQuery UI CSS. CSS uses a combination of the most specific selector and ordering to determine which values to apply. By doing this you will make sure that you have the same specificity for each of the CSS selectors used by jQuery so that your CSS takes precedence based on order.
Smashing Magazine has an article that probably has more information than you care to know about the specificity issue.
You can also:
Use Developer Tools in the browser (Chrome has great ones).
See what class from jQuery UI defines the button color.
Override it in your CSS file with the "!important" attribute.
For example, when I needed to override jQuery UI spinner control and remove the borders, I found the class that defines the borders using Chrome Dev Tools. Then in CSS: I added something like that:
.<jquery-ui-class-that-i-found> { border: 0px !important; }
Works great!
I would say, give the particular button or buttons an id, and:
$("#buttonId").removeClass().addClass("myClass");
If you want to apply it to multiple buttons each with its own id:
$("#buttonId, #anotherButton").removeClass().addClass("myClass");
I think the button API should include a configuration like this where you can change color etc. by passing parameters
$("button").button({background:"FFFFFF",hover:"FFFFF"});
this is just an idea where you can change some of its visual attributes.
I found this worked for me:
$(".btnSave").removeClass("ui-state-default").addClass("SaveButtonStyling");
Basically needed to remove the ui-state-default class and then add my own for the background colour etc.
Thsi meant that the rounded corner class etc stayed put and I was able to amend the background colour etc.
If you simply wish to have some additional/different for particular buttons, simply give the buttons some classes like class="mybuttonclass otherbuttonclass" - multiple classes are allowed. Then, just add css rules for your class(es)
.mybuttonclass
{
background-color: red;
}
.otherbuttonclass
{
color:white;
}
thus the background is red with white text - or whatever combination you wish, which would override items in the cascade (CSS) above it. (assumption is that your .CSS file is linked in AFTER the jquery UI css file, or is in-line on the page, both of which would override the jQuery UI css.

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