Canvas.getContext() returns a context for drawing on the canvas
This argument specifies the type of drawing you want to
do with the canvas. Pass
the string 2d to obtain a
object with which you can do two-dimensional drawing.
An object with which you can draw into the Canvas element. When
you pass the string 2d, this will be a CanvasRenderingContext2D object for 2D drawing.
There is only one CanvasRenderingContext2D object per canvas
element, so repeated calls to getContext("2d") return
the same object.
HTML5 standardizes the 2d argument to this method and defines no
other valid arguments. A separate standard, WebGL, is under development
for 3D graphics. In browsers that support it, you can pass the string
webgl to this method to obtain an object that allows 3D rendering.
Note, however, that the CanvasRenderingContext2D object is the only drawing
context documented in this book.
Gendered images underlay much anticommunist rhetoric, reinforcing the idealized social structure advocated by conservatives and providing potent language for attacking their opposition. A strong man supporting and protecting his family and the little woman contentedly caring for her children and home represented a social order most Americans found desirable. Anticommunists, however, imbued those images with political meaning. In their scenario, the happy family members symbolized perfection of the American way of life and proved the superiority of democratic, capitalistic, Christian Americans over the communistic, totalitarian, atheistic Soviets and Chinese. At the same time that they reflected all that was good about America, they also served as a bulwark protecting Americans from the evil in the world. As a result, these images not only had to be recognized as the ideal, but they had to be reinforced continually to preserve the American system. If any part of these safeguards weakened, anticommunists warned, the communists would have an opening through which to poison the rest of America.
This chapter describes the interface configurations for a Juniper
Networks router. It starts with a description of the types of interfaces,
the naming conventions, and the interface properties. It then identifies how
to configure a large variety of interface media, such as T1 interfaces,
Ethernet, and Serial interfaces. Lastly, it examines common interface
problems, concentrating on the tools available to detect these
Before you begin to design a networks routing topology, you should
ensure that all the proper physical connections are in place and are
operational. With such a large variance in interface types, this can often
be a challenging task, so it is important to understand how an interface is
organized within the Junos network operating system.
Juniper Networks routers contain two major categories of interfaces:
permanent and transient. Users
cannot remove permanent interfaces, whereas they can move, change, and
remove transient interfaces. Other technical differences exist that are
evident when you examine the applications for each interface type.
subclasses of the class it is included with. The tag should appear either before the class definition in ActionScript, or inside a tag in MXML.
Once the tag is included properly, the style may be set with setStyle(), or in inline or external CSS. Flex Builder 2 will even include custom styles in its CSS mode autocompletion.
... and Everything Else
The previous sections of this Short Cut cover the core topics of Flex 2 development, touching only on Flex's library of over 600 classes. By assaying what topics this Short Cut does not cover in full, I hope to provide you with knowledge of what exists and where to find information on it. Knowing that a facility exists will always save time over re-creating it.
You can easily swap out the default pointer for any embedded cursor image using the CursorManager class.
You can enable users to drag and drop objects in data components with some simple attributes (dragEnabled, dropEnabled) or create custom drag and drop behavior with the DragManager class.
Contrary to the opinion of C programmers everywhere, tuning is not simply a matter of eking the last bit of performance out of a program by condensing a five-line sequence of commands down to one super-dense statement. Instead, tuning is more a state of mind: good performance is a natural consequence of clean, well-designed programs. It is not an afterthought. If youve been using what youve learned from this book, particularly about packages, in your PL/SQL code, youre well on your way to developing high-performance PL/SQL programs.
Having said all that, theres still a lot you can do to improve your PL/SQL programs. Once of the most interesting aspects of PL/SQL tuning stems from the fact that PL/SQL, unlike C or COBOL, lives and executes inside the database. Consequently, you must carefully manage how your programs move in and out of memory, and how they interact with competing processes. On a less esoteric front, you must also make sure that your programs dont do unnecessary work and that they effectively use algorithms, SQL, and data structures. This chapter tests your ability to apply these concepts.