Now, assume one also desires the ability to add borders to windows. Again, the original Window class has no support. The ScrollingWindow subclass now poses a problem, because it has effectively created a new kind of window. If one wishes to add border support to many but not all windows, one must create subclasses WindowWithBorder and ScrollingWindowWithBorder etc. This problem gets worse with every new feature or window subtype to be added. For the decorator solution, we simply create a new BorderedWindowDecorator—at runtime, we can decorate existing windows with the ScrollingWindowDecorator or the BorderedWindowDecorator or both, as we see fit. Notice that if the functionality needs to be added to all Windows, you could modify the base class and that will do. On the other hand, sometimes (e.g., using external frameworks) it is not possible, legal, or convenient to modify the base class.
The decorate() proposal was that no new syntax be implemented -- instead a magic function that used introspection to manipulate the following function. Both Jp Calderone and Philip Eby produced implementations of functions that did this. Guido was pretty firmly against this -- with no new syntax, the magicness of a function like this is extremely high:
The Crowne Plaza London Kings Cross has recently completed its exciting journey to emerge as the newest Crowne Plaza hotel in London following a multi-million pound refurbishment and re-branding from Holiday Inn. Our hotel has 429 newly designed bedrooms, the first franchised Belgo Restaurant and the Bloom Bar & Kitchen, which opened a few months ago. The hotel also has 6 state of the art Meeting & Event spaces, a Club Lounge and a Leisure Club. A new opportunity has arisen for the position of Maintenance Shift Engineer. This position would suit a multi-skilled, hands-on, motivated and hard-working individual looking to develop. A person should be adaptable, flexible and able to work both independently and with the team. Experience within the hotel industry and Maintenance/Engineering is desirable but not critically essential. Ideally the candidate will have electrical, mechanical, carpentry, plumbing and decorating/tiling skills and a reasonable working knowledge of stringent PPM of automated plant equipment and general building maintenance. A good level of English is essential. Key responsibilities -Report to the Maintenance Supervisor before your shift starts to go through your daily tasks. -Promptly and efficiently attends and inspects all maintenance requests, defects or Health & Safety matters su
Writing a class decorator is very similar to writing a function decorator. The only difference is that the decorator will receive a class and not a function as an argument. In fact, all the decorators you saw above will work as class decorators. When you are using them on a class instead of a function, their effect might not be what you want. In the following example, the @timer decorator is applied to a class:
A still life is a work of art depicting mostly inanimate subject matter, typically commonplace objects—which may be either natural (food, flowers, plants, rocks, or shells) or man-made (drinking glasses, books, vases, jewelry, coins, pipes, and so on). With origins in the Middle Ages and Ancient Greek/Roman art, still life paintings give the artist more leeway in the arrangement of design elements within a composition than do paintings of other types of subjects such as landscape or portraiture. Still life paintings, particularly before 1700, often contained religious and allegorical symbolism relating to the objects depicted. Some modern still life breaks the two-dimensional barrier and employs three-dimensional mixed media, and uses found objects, photography, computer graphics, as well as video and sound.
As an example, consider a window in a windowing system. To allow scrolling of the window's contents, one may wish to add horizontal or vertical scrollbars to it, as appropriate. Assume windows are represented by instances of the Window interface, and assume this class has no functionality for adding scrollbars. One could create a subclass ScrollingWindow that provides them, or create a ScrollingWindowDecorator that adds this functionality to existing Window objects. At this point, either solution would be fine.
The decorator pattern can be used to extend (decorate) the functionality of a certain object statically, or in some cases at run-time, independently of other instances of the same class, provided some groundwork is done at design time. This is achieved by designing a new Decorator class that wraps the original class. This wrapping could be achieved by the following sequence of steps:
Abstract painting uses a visual language of form, colour and line to create a composition that may exist with a degree of independence from visual references in the world. Abstract expressionism was an American post-World War II art movement that combined the emotional intensity and self-denial of the German Expressionists with the anti-figurative aesthetic of the European abstract schools—such as Futurism, Bauhaus and Cubism, and the image of being rebellious, anarchic, highly idiosyncratic and, some feel, nihilistic.
Speed, portability and permanence also make aerosol paint a common graffiti medium. In the late 1970s, street graffiti writers' signatures and murals became more elaborate and a unique style developed as a factor of the aerosol medium and the speed required for illicit work. Many now recognize graffiti and street art as a unique art form and specifically manufactured aerosol paints are made for the graffiti artist. A stencil protects a surface, except the specific shape to be painted. Stencils can be purchased as movable letters, ordered as professionally cut logos or hand-cut by artists.
Rhythm is important in painting as it is in music. If one defines rhythm as "a pause incorporated into a sequence", then there can be rhythm in paintings. These pauses allow creative force to intervene and add new creations—form, melody, coloration. The distribution of form, or any kind of information is of crucial importance in the given work of art, and it directly affects the aesthetic value of that work. This is because the aesthetical value is functionality dependent, i.e. the freedom (of movement) of perception is perceived as beauty. Free flow of energy, in art as well as in other forms of "techne", directly contributes to the aesthetical value.