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XP

Working with Working with Cascading Style Cascading Style

SheetsSheetsCreating a Style for Online Creating a Style for Online

ScrapbooksScrapbooks

Tutorial 7

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XPIntroducing Cascading Style Introducing Cascading Style

SheetsSheets Style sheetsStyle sheets are files or forms that are files or forms that

describe the layout and appearance of describe the layout and appearance of a documenta document Separate content from display informationSeparate content from display information

Cascading Style SheetsCascading Style Sheets, or , or CSSCSS, is a , is a style sheet style sheet languagelanguage used on the Web used on the Web CSS specifications are maintained by the CSS specifications are maintained by the

World Wide Web Consortium (W3C)World Wide Web Consortium (W3C) Three versions of CSS exist: CSS1, CSS2, Three versions of CSS exist: CSS1, CSS2,

and CSS3and CSS3

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XP4 Factors4 Factors

How web document is rendered to How web document is rendered to useruser Media - computer screen, printers, etc.Media - computer screen, printers, etc. Browser/OSBrowser/OS User - most browsers allow user to User - most browsers allow user to

override default settingsoverride default settings Code - separate content from Code - separate content from

instructions how to renderinstructions how to render

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XPApplying a Style SheetApplying a Style Sheet

Three ways to apply a style to an Three ways to apply a style to an HTML or XHTML document:HTML or XHTML document: Inline Styles - applied to specific Inline Styles - applied to specific

elementelement Embedded Styles - in document Embedded Styles - in document

head - for document elementshead - for document elements External Styles - separate External Styles - separate

document - applied to a group of document - applied to a group of web pagesweb pages

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XPUsing Inline StylesUsing Inline Styles

Inline styles are easy to use and Inline styles are easy to use and interpret because they are applied interpret because they are applied directly to the elements they affect.directly to the elements they affect.

<<elementelement style style=“style1: value1; style2:=“style1: value1; style2:

value2; style3: value3;value2; style3: value3;…”>…”>

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XPUsing Embedded StylesUsing Embedded Styles

You can embed style definitions in You can embed style definitions in a document head using the a document head using the following form:following form:

<style><style>

style declarationsstyle declarations

</style></style> Style attributesStyle attributes Applying embedded styleApplying embedded style

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XPUsing an External Style SheetUsing an External Style Sheet

Because an embedded style sheet only Because an embedded style sheet only applies to the content of the start.htm applies to the content of the start.htm file, you need to place a style declaration file, you need to place a style declaration in an in an external style sheetexternal style sheet to apply to to apply to the headings in the rest of the Web site - the headings in the rest of the Web site - could do it with one filecould do it with one file

An An external style sheetexternal style sheet is a text file is a text file that contains style declarationsthat contains style declarations It can be linked to any page in the site, It can be linked to any page in the site,

allowing the same style declaration to be allowing the same style declaration to be applied to the entire siteapplied to the entire site

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XPUsing an External Style SheetUsing an External Style Sheet

You can add style comments as you You can add style comments as you develop an external style sheet - develop an external style sheet - should doshould do

Use the link element to link a Web Use the link element to link a Web page to an external style sheetpage to an external style sheet

You can import the content of one You can import the content of one style sheet into another - must come style sheet into another - must come before any other style declarations - before any other style declarations - recommended over link - supported recommended over link - supported by more browsersby more browsers

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XPUnderstanding Cascading Understanding Cascading

OrderOrder You can link a single style sheet to You can link a single style sheet to

multiple documents in your Web site multiple documents in your Web site by using the link element or the by using the link element or the @import element@import element

You can also link a single document You can also link a single document to several style sheetsto several style sheets

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XPApplying a single style sheet Applying a single style sheet

to multiple documentsto multiple documents

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XPApplying multiple sheets to a Applying multiple sheets to a

single documentsingle document

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XPStyle PrecedenceStyle Precedence

1.1. External style sheetExternal style sheet

2.2. Embedded stylesEmbedded styles

3.3. Inline stylesInline styles• If same weight - last declaration - If same weight - last declaration -

takes precedencetakes precedence• Override precedence - important Override precedence - important

propertyproperty

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XPStyle InheritanceStyle Inheritance

If a style is not specified for an If a style is not specified for an element, it inherits the style of its element, it inherits the style of its parent element; This is called parent element; This is called style style inheritance.inheritance.

Get the bigger declarationGet the bigger declaration Override - specify alternate for Override - specify alternate for

one of the descendant elementsone of the descendant elements

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XPWorking with SelectorsWorking with Selectors

CSS allows you to work with a wide CSS allows you to work with a wide variety of selectors to match variety of selectors to match different combinations of elementsdifferent combinations of elements

Use Use contextual selectors contextual selectors to apply a to apply a style based on the context in which style based on the context in which an element is usedan element is used

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XPSimple and contextual Simple and contextual

selectorsselectors

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XPAttribute SelectorsAttribute Selectors

Create an Create an attribute selectorattribute selector to to select an element based on the select an element based on the element’s attributeselement’s attributes

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XPUsing IDs and ClassesUsing IDs and Classes

Use an id to distinguish something, Use an id to distinguish something, like a paragraph, from the others in like a paragraph, from the others in a documenta document For example, to identify a paragraph For example, to identify a paragraph

as “head”, use the codeas “head”, use the code::

<p id=“head”>… </p><p id=“head”>… </p>

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XPClassesClasses

HTML and XHTML require each HTML and XHTML require each id be unique– therefore an id id be unique– therefore an id value can only be used once in a value can only be used once in a documentdocument

You can mark a group of elements You can mark a group of elements with a common identifier using with a common identifier using the class attributethe class attribute

<element class=“class”> … </element><element class=“class”> … </element>

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XPApplying a style to a classApplying a style to a class

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XPApplying a style to a class Applying a style to a class

and elementand element

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XPSizing Elements and Floating Sizing Elements and Floating

an Elementan Element Style sheets instead of tables - more Style sheets instead of tables - more

flexible, applied to multiple documents, flexible, applied to multiple documents, easier to maintain, smaller file sizes, more easier to maintain, smaller file sizes, more manageable codemanageable code

Not supported by all browsersNot supported by all browsers You can define the width of columns in a You can define the width of columns in a

columnar layout using: columnar layout using: width: width: valuevalue You can use CSS to set an element’s height You can use CSS to set an element’s height

using: using: height: height: valuevalue You can float a paragraph using: You can float a paragraph using: float: float:

positionposition

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XPWorking with the div Working with the div

ElementElement The The div elementdiv element is a generic block- is a generic block-

level element - treat several elements as level element - treat several elements as a single unita single unit

<div><div>

contentcontent

</div></div>

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XPSetting the Display StyleSetting the Display Style

Values of the display style

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XPSetting the Display StyleSetting the Display Style

Values of the display style

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XPWorking with the Box ModelWorking with the Box Model

The The box modelbox model is an element composed is an element composed of four sections:of four sections:

Margin - between element and other Margin - between element and other contentcontent

BorderBorder Padding - between element’s content and Padding - between element’s content and

borderborder contentcontent

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XPThe Box ModelThe Box Model

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XPWorking with the Box ModelWorking with the Box Model

Styles to set padding are similar to Styles to set padding are similar to styles to set margins:styles to set margins:

padding-top: padding-top: valuevalue padding-right: padding-right: valuevalue padding-bottom: padding-bottom: valuevalue padding-left: padding-left: valuevalue

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XPBorder StylesBorder Styles

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XPBorder Style TypesBorder Style Types

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XPUsing Pseudo-Classes and Using Pseudo-Classes and

Pseudo-ElementsPseudo-Elements

A A pseudo-classpseudo-class is a classification of an is a classification of an element based on its status, position, or element based on its status, position, or current use in the documentcurrent use in the document

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XPUsing Pseudo-Classes and Using Pseudo-Classes and

Pseudo-ElementsPseudo-Elements

Rollover effectsRollover effects can be created using pseudo- can be created using pseudo-classesclasses

Pseudo-elementsPseudo-elements are elements based on are elements based on information about an element’s content, use or information about an element’s content, use or positionposition

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XPPositioning Objects with CSSPositioning Objects with CSS

The different positioning styles in the original CSS1 specifications were known as CSS-Positioning or CSS-P

To place an element at a specific position on a page use:

position: type; top: value; right: value; bottom: value; left: value;

• Type - positioning type applied to element• Absolute - place at specific coordinates• Relative - in relation to its default, normal position• Fixed - does not scroll with rest of page• Inherited - inherit position style of parent element

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XPWorking with Overflow and Working with Overflow and

ClippingClipping

The overflow property syntax:overflow: type

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XPStacking ElementsStacking Elements

Specify stacking order with:z-index: value

z-index: 3

z-index: 1

z-index: 2

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XPWorking with Different Working with Different

MediaMedia

Specify output styles for particular devices in the media attribute of the link and style elements

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XPThe @media RuleThe @media Rule

You can also specify the output media within a style sheet using:

@media type {style declarations}

Where media is one of the supported media types and style declarations are the styles associated with that media type

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XPMedia GroupsMedia Groups

CSS2 uses media groups to describe basic facets of different media– and to differentiate between different types of media based on the ways they render content

Continuous or pagedVisual, aural, or tactileGrid (for character grid devices) or bitmapInteractive or static

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XPMedia GroupsMedia Groups

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XPHiding ElementsHiding Elements

• Two different styles that allow you to hide elements:• Display style - “none” - element is not rendered by output

device• Visibility style -

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XPComparing the visibility and Comparing the visibility and

display stylesdisplay styles

Visibility hidden

Object is hidden but still is part of the page flow

Display: none

Object is hidden and is removed from the page flow

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XPUsing Print StylesUsing Print Styles

• You can specify the size of a page, margins, internal padding, etc. of the page box

• Page pseudo-classes and named pages• First• Left• Right• Name

• Setting the page size• Displaying crop marks• Page breaks - relation to the elements

• Before• After

• Always, avoid, left, right, auto, inherit

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XP

•Assign #18 Case 1, pg. 424-426 - print code and finished product, black and white is acceptable. •Assign #19 Case 2, pg. 427-429 - print code and finished product, black and white is acceptable.