🗊Презентация Understanding CSS. Essentials: layouts, managing text flow, managing the graphical interface

Understanding CSS Essentials: Layouts, Managing Text Flow, Managing the Graphical Interface Vyacheslav Koldovskyy Last update: 01/07/2015

Agenda UI design Traditional CSS Box model Block-level and inline element Parent/child relationships Vendor prefixes CSS Flexbox Box model CSS Grid Layout model

Vendor Prefixes CSS3 specification is still in draft format and undergoing modifications Need to use vendor prefixes with several CSS3 constructs Internet Explorer uses the -ms- prefix. Firefox supports the -moz- prefix. Chrome and Safari support the -webkit- prefix. Opera supports the -o- prefix.

Two CSS box models

Box model sample http://jsfiddle.net/koldovsky/e1984en9/1/

Inherited Properties A parent box can contain one or more child boxes. A child can inherit CSS styles from a parent. Sample inherited property: p { color: green } <p>This paragraph has <em>emphasized text</em> in it.</p> Sample non-inherited property: p { border: medium solid } <p>This paragraph has <em>emphasized text</em> in it.</p> Using inherit property: /* make second-level headers green */ h2 { color: green; } /* ...but leave those in the sidebar alone so they use their parent's color */ #sidebar h2 { color: inherit; }

Browser Default Styles Web browsers have default CSS styles for HTML elements, consider sample: http://plnkr.co/edit/QgapgI8yuc328XV888Q8?p=preview Also these styles are different for different browsers, so same markup may look different To ensure same markup looks the same it is recommended to use "reset" or "normalize" stylesheets (second is preferred): Reset CSS: http://meyerweb.com/eric/tools/css/reset/ Normalize CSS: http://necolas.github.io/normalize.css/

Media Queries A media query consists of a media type and at least one expression that limits the style sheets' scope by using media features, such as width, height, and color.  Media queries allow to create responsive websites Details: https://developer.mozilla.org/en-US/docs/Web/CSS/Media_Queries/Using_media_queries <!-- CSS media query on a link element --> <link rel="stylesheet" media="(max-width: 800px)" href="example.css" /> <!-- CSS media query within a stylesheet --> <style> @media (max-width: 600px) { .facet_sidebar { display: none; } } </style> Sample: http://plnkr.co/edit/xYTDjomz5JNAvpQjt6LZ?p=preview Some issues with media queries: it's not so simple to reorder blocks

UI Challenges Developers have used float property for relative positioning of UI elements for years CSS3 Provides two new options: CSS3 Flexbox Box model ideal for items that should resize or reposition themselves CSS3 Grid Layout model good for complex layouts

CSS Flexbox Box Model Good for controls, toolbars, menus, and forms that resize and reposition automatically when the user changes the size of the browser window Browser takes the available space into account and calculates the dimensions for the user Enables relative sizes and positioning Good tutorial: https://css-tricks.com/snippets/css/a-guide-to-flexbox/

CSS Flexbox Model Reordering Sample http://jsfiddle.net/koldovsky/jb5h57jw/

CSS3 Grid Layout Model Gives developers greater control over complex layouts than the flexbox model Lets you control the design of sections or entire HTML-based documents using CSS3 Grid layouts use columns, rows, and cells, but you can move blocks of content from one part of page or application to another by moving code lines in CSS

Multi-column Layout Create columns by dividing text across multiple columns Specify the amount of space that appears between columns (the gap) Make vertical lines (rules) appear between columns Define where columns break

Multi-column Layout Main CSS properties for creating multiple columns in an HTML document: column-count: Sets the number of columns Alternative: Use columns property with column-count and column-width properties column-gap: Specifies the gap between the columns, known as the gutter or alley column-rule: Creates a vertical line in the gap between columns and sets the width, style (single or double line, solid, dashed, 3D, etc.) and color of the rule

Multi-column Layout Example

Practice Task:

Hyphenation The process of connecting two words with a hyphen mark (-) or breaking words between syllables at the end of a line. CSS3 hyphens property controls hyphenation Values: auto: Enables automatic hyphenation of words based on line-break opportunities within words or by a “language-appropriate hyphenation resource” manual: Enables hyphenation of words based only on line-break opportunities within words none: Prevents hyphenation

Language Declaration W3C requires a language declaration for correct automatic hyphenation to occur: <!doctype html> <html lang="en-us"> or <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">

border-radius Property Creates rounded corners around layout elements, like headers, footers, sidebars, graphics boxes, and outlines around images border-radius is a length, which is usually expressed in pixels or ems but can be a percentage

border-radius Example

border-radius Example

box-shadow Property Creates drop shadows around layout elements CSS syntax for creating a shadow: box-shadow: h-shadow v-shadow blur spread color inset; Required: h-shadow and v-shadow attributes set the horizontal and vertical position of the shadow in relation to the box Optional: blur, spread, color, and inset

box-shadow Example

Opacity and Transparency An opaque item does not let light pass through, whereas you can see through a transparent item. Syntax for applying a transparency to an image or other element: opacity: value Value is a floating-point value between 0.0 (100% transparent) and 1.0 (100% opaque)

Transparency Example

CSS Gradients Gradient is a smooth change of colors, within the same hue or starting with one color and ending with a different color Used for subtle shading within backgrounds, button embellishments, and more Created as methods to the CSS background property

Gradient Examples

2D and 3D Transformations A transform is an effect that lets you change the size, shape, and position of an element. Transformations use the transform property. Methods: matrix, perspective, rotate, scale, skew, translate To see the “action” of a transformation requires JavaScript; using only CSS shows the before and after effects of properties and their values.

Transformations Sample http://jsfiddle.net/koldovsky/2m2Zb/36/

CSS Transition A transition is a change from one thing to another; in CSS, a transition is the change in an element from one style to another. In CSS3, the action of a transition renders onscreen—no JavaScript is needed! The transition property requires the CSS property to be acted upon during the transition.

Transition Sample http://jsfiddle.net/koldovsky/PkJaD/357/

CSS Animation CSS animations animates transitions between CSS styles to another. Consist of two components: a style describing the CSS animation and a set of keyframes that indicate the start and end states of the animation's style, as well as possible waypoints. There are three key advantages to CSS animations over traditional script-driven animation: Easy to use for simple animations. The animations run well, even under moderate system load. The rendering engine can use frame-skipping and other techniques to keep the performance as smooth as possible. Letting the browser control the animation sequence lets the browser optimize performance and efficiency by, for example, reducing the update frequency of animations running in tabs that aren't currently visible. Some cool samples: http://webdesign.tutsplus.com/articles/15-inspiring-examples-of-css-animation-on-codepen--cms-23937 Details: https://css-tricks.com/almanac/properties/a/animation/

Simple Animation Example http://jsfiddle.net/koldovsky/e2tt2mao/56/

Timing Functions https://jsfiddle.net/koldovsky/HDsw2/11/ Details: https://www.smashingmagazine.com/2014/04/understanding-css-timing-functions/

SVG Filters Support Small file sizes that compress well Scales to any size without losing clarity (except very tiny) Looks great on high-res displays An SVG filter is a set of operations that use CSS to style or otherwise modify an SVG graphic The enhanced graphic is displayed in a browser while the original graphic is left alone. Sample: http://codepen.io/chriscoyier/pen/evcBu

Styling forms http://webdesign.tutsplus.com/tutorials/bring-your-forms-up-to-date-with-css3-and-html5-validation--webdesign-4738

Styling Tables http://www.w3schools.com/css/css_table.asp

Practice Task

Advanced Topics

CSS Regions Feature allows developers to dynamically flow content across multiple boxes, or containers, in HTML documents with fluid layouts Content adjusts and displays properly whether viewed on large or small

Content Flow with CSS Regions

CSS Exclusions Formerly referred to as positioned floats Enables positioning of images, text, and boxes anywhere in an HTML document and wrapping of text completely around these elements Can control the position of a float precisely, at a specified distance from the top, bottom, left, or right sides of a container

CSS Exclusions Example 1

CSS Exclusions Properties wrap-flow:both displays content on all sides of the exclusion wrap-flow:clear displays content above and below the exclusion but leaves the sides blank shape-inside and shape-outside define the content and the general shape of an exclusion, respectively -ms- vendor prefix required for Internet Explorer 10; Exclusions not supported in Internet Explorer 9

CSS Exclusions Example 2

CSS Exclusions Step-by-step

border-radius Property, Single Corners Rounding a single corner of a box: border-top-left-radius border-top-right-radius border-bottom-right-radius border-bottom-left-radius

CSS Gradient Methods CSS3 gradient methods: linear-gradient: Creates a gradient from top to bottom or vice versa, or from corner to corner radial-gradient: Creates a gradient that radiates out from a central point repeating-linear-gradient: Creates a repeating linear gradient, which results in straight bands of gradient color repeating-radial-gradient: Creates a repeating radial gradient, which results in circular bands of gradient color

Gradient Color Interpolation and Color Stops CSS gradients support color interpolation in the alpha color space Part of the red blue green alpha (RGBA) color model Can specify multiple color stops, with an RGBA color and position for each one Example of the use of rgba colors: linear-gradient(to right, rgba(255,255,255,0)

2D Translation To translate an element means to move it without rotating, skewing, or otherwise turning the image. Use the translate() method in CSS and provide x- and y-axis values to position the element relative to its original or default position. x-axis value specifies the left position of the element y-axis value specifies the top position.

2D Translation Example

2D Translation Example

2D Scaling To scale an element is to increase or decrease its size. Use the scale() method in CSS and provide x-axis (width) and y-axis (height) values. The example on the following two slides increases the width of the element two times its original size, and increases the height four times its original size: transform: scale(2,4);

2D Scaling Example

2D Scaling Example

2D Rotation To rotate an element turns it clockwise by a specified number of degrees. Use the rotate() method in CSS and specify the degrees of rotation. The example on the following two slides rotates an element by 30 degrees in the 2D plane: transform: rotate(30deg);

2D Rotation Example

2D Example

3D Rotation 3D rotation uses the rotateX() and rotateY() methods. rotateX(): Element rotates around its x-axis rotateY(): Element rotates around its y- axis

2D Skewing To skew an element is to stretch it in one or more directions. Use the skew() method and provide x-axis and y-axis values, in degrees, to create an angular shape. The example on the following two slides turns an element 20 degrees around the x-axis and 30 degrees around the y-axis: transform: skew(20deg,30deg);

2D Skewing Example

2D Skewing Example

3D Skewing 3D skewing uses the skewX() and skewY() methods to skew an element around its x-axis and y-axis, respectively. As an example, the following code skews an element 45 degrees: transform: skewX(45deg);

3D Perspective The CSS3 3D perspective property defines how a browser renders the depth of a 3D transformed element. The property takes on a number value: lower values (in the range of 1 to 1000) create a more pronounced effect than higher values.

Transition Example

Transition Example

Animation (Continued) Specify a CSS style within the @keyframes rule An example of a rule for a fadeout: @keyframes fadeout { from { opacity: 1; } to { opacity: 0; } }

Animation (Continued) Code snippet that configures animation properties for a fadeout: div { animation-duration: 3s; animation-delay: 0s; animation-timing-function: ease; } div:hover { animation-name: fadeout; }

SVG Filters An SVG filter is a set of operations that use CSS to style or otherwise modify an SVG graphic. The enhanced graphic is displayed in a browser while the original graphic is left alone.

SVG Filters feBlend feColorMatrix feComponentTransfer feComposite feConvolveMatrix feDiffuseLighting feDisplacementMap feFlood feGaussianBlur feImage feMerge feMorphology feOffset feTile feTurbulence feDistantLight fePointLight feSpecularLighting feSpotLight

SVG Filters Gaussian Blur Example

SVG Filters Offset Example

Canvas Use canvas to draw pixel-based shapes. The canvas element accepts only two attributes—height and width. You can use most CSS properties to style the canvas element, adding color, gradients, pattern fills, transformation, animation, and much more.

Canvas Example 1

Canvas Example 2 context.rotate(20*Math. PI/180);

Canvas Example 3

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