CS 511-Web Engineering
Week 4
Topic 48-50
 |
| CS 511-Week 4:Topic 48-50 |
Topic 48:
Constructing Multicolumn Layout (using Float):
When using floats to create a multi-column layout, one common approach is to float the content container that will be on the left-hand side. It's important to remember to specify the width of the floated container. However, a limitation of using floats is that the background color of the floated element stops when its content ends. If you want the background color to extend down to the footer, achieving this visual effect can be difficult, though not impossible.
Three-column layout method is often considered less brittle because the floated elements within the container are independent of elements outside the container. However, it's crucial to ensure that the floated content appears before the non-floated content in the source code. This can pose a problem when trying to maintain an SEO-optimized order for the source.
On the other hand, positioning can also be used to create a multi-column layout. This approach typically involves using a container element that establishes the positioning context. One advantage of using positioning is that it allows for a more SEO-friendly arrangement of content in the source document. For example, the main <div> can be placed first, which can be beneficial for search engine optimization.
However, there is a drawback to using absolute positioning. When an item is positioned, it is completely removed from the normal flow of the document, resulting in subsequent items having no awareness of the positioned item. To address this issue, one solution is to place the footer within the main container. This way, the footer remains within the normal flow and interacts with other elements appropriately.
In summary, while floats and positioning can both be used to construct multicolumn layouts, each approach has its advantages and limitations. It's important to carefully consider the specific requirements and constraints of your layout to determine which method will work best for your needs.
Topic 49:
Flexbox is a powerful CSS layout module that allows for the creation of multicolumn layouts with flexible and responsive behavior. It provides a set of properties for both the parent container and the child items to control their positioning, sizing, and distribution within the layout.
Flexbox Parent Properties:
- flex-start: This property aligns the items towards the start of the flex direction.
- flex-end: This property aligns the items towards the end of the flex direction.
- center: This property centers the items along the flex direction.
- space-between: This property distributes the items evenly along the flex direction. The first item will be positioned at the start of the container, and the last item will be positioned at the end of the container. The remaining items will have equal spacing between them.
- space-around: This property evenly distributes the items along the flex direction with equal space around them. The spacing between the items and the container edges will be the same.
Flexbox Child Properties:
- flex-grow: This property specifies how much the flex item should grow to fill the available space. By default, all flex items have a flex-grow value of 1, which means they will grow equally to fill the container. If one item has a flex-grow value of 2, it will take up twice as much space as the other items.
- flex-basis: It can be set to a specific length or a percentage value.
- flex-shrink: This property determines how much a flex item can shrink if the available space is limited. By default, flex items have a flex-shrink value of 1, which means they will shrink equally if necessary.
These flexbox properties allow for the creation of flexible and responsive multicolumn layouts. By adjusting the parent and child properties, you can control the alignment, distribution, and sizing of the items within the flex container. Flexbox provides a more intuitive and efficient way to create multicolumn layouts compared to traditional methods like using floats or positioning.
Topic 50:
Approaches to CSS Layout:
When it comes to CSS layout, there are different approaches to consider in order to accommodate varying screen sizes and provide a responsive design. Two commonly used approaches are fixed layout and liquid layout.
Fixed Layout: A fixed layout involves setting a specific width for the design, usually based on a predetermined ideal width for a typical monitor resolution. It is achieved by using pixel units and enclosing the content within a container element (often named "container", "main", or "wrapper") with a fixed width property. The advantage of a fixed layout is that it is relatively easy to create and provides a predictable visual result.
However, fixed layouts have some drawbacks. On larger screens, there can be excessive empty space to the left and/or right of the content, which may not utilize the available screen real estate effectively. Moreover, if the browser window is resized to a width narrower than the fixed width, horizontal scrolling will be required to view the entire content.
Liquid Layout: The alternative approach to addressing the challenge of multiple screen sizes is a liquid layout, also known as a fluid layout. In this approach, widths are specified using percentage values rather than pixels.
With a liquid layout, the content expands or contracts proportionally to the size of the browser window. This allows the design to be more flexible and responsive, accommodating various screen sizes. By using percentage-based widths for the container and its inner elements, the layout adjusts automatically to fill the available space.
However, liquid layouts can present their own challenges. The design may not always look consistent across different screen sizes, as the content expands and contracts based on the available space. It requires careful consideration of elements and their responsiveness to ensure a visually appealing and usable design across a range of devices.
Ultimately, the choice between fixed and liquid layouts depends on the specific requirements of the project, the target audience, and the design goals. It is often beneficial to combine both approaches by using responsive design techniques, such as media queries, to adapt the layout dynamically based on different screen sizes and orientations.
Assessment:
 |
| CS 511-Week 4:Topic 48-50 |
Which approach is considered less brittle for creating a three-column layout?
Which property in the flexbox controls the alignment of items along the flex-direction?
Flex-grow property determines:
Liquid layout is achieved by specifying widths using:
One drawback of a fixed layout is:
The property that determines the initial size of a flex item before space distribution is:
The main advantage of using positioning to create a multicolumn layout is:
Which property evenly distributes flex items along the flex-direction with equal space around them?
Which layout approach requires media queries to adapt the layout dynamically?
0 Comments