Java 2D Chapter 13 Flashcards

Questions and Answers

In the Java coordinate system, the point (0, 0) is ________.

the upper-left corner of the screen.

The fact that class Graphics is abstract contributes to Java's portability because ________.

drawing is performed differently on every platform that supports Java. A subclass of Graphics must be created that uses the drawing capabilities of the current platform.

Which of the following statements about the Graphics object is true?

The Graphics class is abstract. (correct)

The Graphics object manages a graphics context. (correct)

The Graphics object is the argument to a lightweight GUI component's paintComponent method. (correct)

The Graphics object is instantiated by the user.

The Graphics object is an argument to class Component's repaint method.

Which of the following are valid Java statements?

Color c = new Color(0.0f, 1.0f, 0.0f); Signup and view all the answers

The JColorChooser dialog allows colors to be chosen by all but which of the following?

Gradient, cycle, brightness. Signup and view all the answers

Which of the following properly creates and initializes a Font object?

Font f = new Font("Serif", Font.Bold + Font.Italic, 19); Signup and view all the answers

Method getFont of class Graphics returns ________.

a Font object representing the current font. Signup and view all the answers

Which of the following is correct for font metrics?

height = descent + ascent + leading. Signup and view all the answers

Class FontMetrics declares methods that can be used to obtain the following font metrics ________.

ascent, descent and height. Signup and view all the answers

The Java statement: g.fillOval(290, 100, 90, 55);

Draws a filled oval bounded by a rectangle with its upper-left corner at coordinates x=290, y=100, with width=90 and height=55. Signup and view all the answers

The Java statement: g.draw3DRect(290, 100, 90, 55, true);

draws a rectangle that appears to be raised (the bottom and right edges of the rectangle are slightly darker than the rectangle). Signup and view all the answers

Study Notes

Java Coordinate System

In the Java coordinate system, (0, 0) is located at the upper-left corner of the screen.

Class Graphics and Portability

Class Graphics is abstract to ensure methods are implemented to fit the drawing capabilities of the current platform, enhancing Java's portability.

Graphics Object Characteristics

The Graphics object is crucial for rendering in Java; it is passed to methods like paintComponent in lightweight GUI components and is abstract.

Valid Java Statements for Color

The valid statements for creating a Color object in Java include:
- Color c = new Color(0, 255, 0);
- Color c = new Color(0.0f, 1.0f, 0.0f);

JColorChooser Dialog

The JColorChooser dialog allows color selection through swatches, hue/saturation/brightness, and red/green/blue options, excluding gradient and cycle settings.

Creating Font Objects

A proper way to create and initialize a Font object is using:
- Font f = new Font("Serif", Font.Bold + Font.Italic, 19);

Font Object Return from Graphics

The getFont method of class Graphics returns a Font object representing the current font settings.

Font Metrics

Font metrics are defined as:
- height = descent + ascent + leading

Class FontMetrics Methods

Class FontMetrics includes methods to obtain various font metrics: ascent, descent, height, and leading.

Drawing with fillOval

The method g.fillOval(290, 100, 90, 55) draws a filled oval within a rectangle specified by its upper-left corner at (290, 100) with a width of 90 and height of 55.

Drawing 3D Rectangles

The method g.draw3DRect(290, 100, 90, 55, true) creates a simulated raised rectangle, with darker edges on the bottom and right.

Description

Test your knowledge on Java 2D graphics concepts with these flashcards. This quiz covers key terms and principles related to the Java coordinate system and the Graphics class. Ideal for students studying graphics in Java.