You can use a package member's simple name if the code you are writing is in the same package as that member or if that member has been imported. Examine it, compile and run it. Parameters: x - the x coordinate. Components do not stand alone, but rather are found within containers. Returns: a Shape object representing the current clipping area, or null if no clip is set.
The top and bottom edges are at y and y + height - 1. The resulting rectangle covers an area width pixels wide by height pixels tall. String, int Gets the specified Color property of the color value. Note: Another, less common form of import allows you to import the public nested classes of an enclosing class. Returns: a new graphics context. Newcomers, however, often find that its power is veiled.
That must wait until a future article. The edges of the rectangle are highlighted so that they appear to be beveled and lit from the upper left corner. Window A top-level display surface a window. A single component can be placed in each of these five zones. Each container class has a default layout manager. Creating a container Before adding the components that make up a user interface, the programmer must create a container. That is to say, the point 0, 0 in the new graphics context is the same as x, y in the original graphics context.
The action method responds to the action events that are generated, for example, by the selection of an item from a pop-up list. What is a user interface The user interface is that part of a program that interacts with the user of the program. Parameters: img - the specified image to be drawn. The code in Listing 1 creates an empty frame. Some components fire events when a user interacts with the components. Parameters: x - the x coordinate of the rectangle to clear.
All rendering operations modify only pixels which lie within the area bounded by the current clip, which is specified by a in user space and is controlled by the program using the Graphics object. Scaling of the image from source to destination is performed such that the first coordinate of the source rectangle is mapped to the first coordinate of the destination rectangle, and the second source coordinate is mapped to the second destination coordinate. When a name is used repetitively, however, typing the name repeatedly becomes tedious and the code becomes difficult to read. A con tainer can also have a layout manager that controls the visual placement of components in the container. The coordinates in the rectangle are relative to the coordinate system origin of this graphics context. This article covers only the two layout manager classes used by the examples herein: the FlowLayout class and the BorderLayout class.
Use of this method is not recommended as each byte is interpreted as a Unicode code point in the range 0 to 255, and so can only be used to draw Latin characters in that range. The method to use depends on the container's layout manager see the section titled Component layout. A frame with an empty applet You need a Java-enabled browser to view this applet. Panel A generic container for holding components. It is, of course, very important that a user interface take action as a result of user input. All subsequent rendering operations will overwrite the destination with the current color.
Rendering operations have no effect outside of the clipping area. However, if you are trying to use a member from a different package and that package has not been imported, you must use the member's fully qualified name, which includes the package name. The definition of a class is presented later. This method may use an algorithm that calculates a result quickly but which sometimes might return true even if the specified rectangular area does not intersect the clipping area. Parameters: x - the x coordinate of the rectangle to test against the clip y - the y coordinate of the rectangle to test against the clip width - the width of the rectangle to test against the clip height - the height of the rectangle to test against the clip Returns: true if the specified rectangle intersects the bounds of the current clip; false otherwise.
Coordinates are infinitely thin and lie between the pixels of the output device. This nesting of components including containers into containers creates a tree of elements, starting with the container at the root of the tree and expanding out to the leaves, which are components such as buttons. Parameters: str - the string to be drawn. Returns: false if the image pixels are still changing; true otherwise. For convenience, the Java compiler automatically imports two entire packages for each source file: 1 the java. It is otherwise very much like an instance of the Window class. The BorderLayout class has five zones as depicted in Figure 7.
This operation is equivalent to filling a rectangle of the width and height of the specified image with the given color and then drawing the image on top of it, but possibly more efficient. If the current output representation is not yet complete, then drawImage returns false. The types that comprise a package are known as the package members. Parameters: x - the x coordinate of the rectangle to be filled. The left and right edges of the rectangle are at x and x + width, respectively.