The primary objection to this form is that it requires "peeking inside" the method body to determine the decorators. In addition, even though the code is inside the method body, it is not executed when the method is run. Guido felt that docstrings were not a good counter-example, and that it was quite possible that a 'docstring' decorator could help move the docstring to outside the function body.
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.
Digital painting is a method of creating an art object (painting) digitally and/or a technique for making digital art in the computer. As a method of creating an art object, it adapts traditional painting medium such as acrylic paint, oils, ink, watercolor, etc. and applies the pigment to traditional carriers, such as woven canvas cloth, paper, polyester etc. by means of computer software driving industrial robotic or office machinery (printers). As a technique, it refers to a computer graphics software program that uses a virtual canvas and virtual painting box of brushes, colors and other supplies. The virtual box contains many instruments that do not exist outside the computer, and which give a digital artwork a different look and feel from an artwork that is made the traditional way. Furthermore, digital painting is not 'computer-generated' art as the computer does not automatically create images on the screen using some mathematical calculations. On the other hand, the artist uses his own painting technique to create the particular piece of work on the computer.
Color, made up of hue, saturation, and value, dispersed over a surface is the essence of painting, just as pitch and rhythm are the essence of music. Color is highly subjective, but has observable psychological effects, although these can differ from one culture to the next. Black is associated with mourning in the West, but in the East, white is. Some painters, theoreticians, writers and scientists, including Goethe, Kandinsky, and Newton, have written their own color theory.