UNIT 1- AWT(Abstract windowing toolkit) PDF

INTRODUCTION TO ABSTRACT WINDOWING TOOLKIT(AWT) 12 Marks  UNIT 1- AWT(Abstract windowing toolkit) Java AWT or Abstract Window Toolkit is an API used for developing GUI(Graphic User Interfaces) or Window-Based Applications in Java Java AWT is part of the...

INTRODUCTION TO ABSTRACT WINDOWING TOOLKIT(AWT) 12 Marks  UNIT 1- AWT(Abstract windowing toolkit) Java AWT or Abstract Window Toolkit is an API used for developing GUI(Graphic User Interfaces) or Window-Based Applications in Java Java AWT is part of the Java Foundation Classes (JFC) that provides a way to build platform-independent graphical applications. The java.awt package contains AWT API classes such as TextField, Label, TextArea, RadioButton, CheckBox, Choice, List etc. AWT is heavyweight, which means that its components consume resources from the underlying operating system (OS)  AWT is Platform Independent? The Java AWT utilizes the native platform subroutine to create API components such as TextField, CheckBox, and buttons. This results in a different visual format for these components on different platforms such as Windows, MAC OS, and Unix. The reason for this is that each platform has a distinct view of its native components Java AWT Hierarchy  Container Container is a component in AWT that contains another component like button, text field, tables etc. Container is a subclass of component class. Container class keeps track of components that are added to another component. A container is responsible for laying out (that is positioning) any components that it contains. It does this through the use of various layout managers.  Panel Panel class is a concrete subclass of Container. Panel is the super-class for Applet. When screen output is directed to an applet, it is drawn on the surface of a Panel object. Panel does not contain title bar, menu bar or border. It is container that is used for holding components. To create panel, Panel p=new panel();  Window The Window class creates a top-level window. A top -level window is not contained withinany other object; it sits directly on the desktop. Generally, we won’t create Window objects directly. Instead, we will use a subclass of Window called Frame.  Canvas Canvas is not there in the hierarchy but still it exists Canvas encapsulates a blank window upon which we can draw.  Frame Frame is a subclass of Window and have resizing canvas. It is a container that contain several different components like button, title bar, textfield, label etc. In Java, most of the AWT applications are created using Frame window. Frame class has two different constructors Frame() throws HeadlessException Frame(String title) throws HeadlessException Creating a Frame There are two ways to create a Frame. They are, By Instantiating Frame class By extending Frame class AWT Classes AWT Classes AWT Classes AWT Classes AWT Classes  Setting a Window’s Title  void setTitle(String newTitle) Closing a Frame Window setVisible(false). you must implement the windowClosing( ) method of the WindowListener interface Inside windowClosing( ), you must remove the window from the screen AWT CONTROLS  The controls are different components which allows a user to interact with our application in various wayss.  For adding contols in a window,first create an instance of the required control and then add it to a window by calling add() method.  Syntax Component add(Component compObj) Here, compObj is an instance of the control that we want to add.  For removing controls from a window,call remove() method  Syntax void remove(Component obj)  Here, obj is a reference to the control that we want to remove. We can remove all controls by calling removeAll( ).  TYPES OF CONTROLS  Passive Control This are the control which do not generate any event Ex Label  Active Control This are the control which generate certain event Ex Button,List,Scrollbar etc  AWT CONTROLS  Label  Button  Checkbox  Checkbox Group  Choice  List  Scrollbar  TextField  TextArea  LABEL  Labels are passive controls that do not support any interaction with the user.  Constructors Label( ) Label(String str) Label(String str, int how) Where as str- String to display which is left aligned. how- how the alignment. I t’s value can be set as, Label.LEFT, Label.RIGHT, Label.CENTER  Methods 1) void setText(String str) 2) String getText() 3) void setAlignment(int how) : Sets the alignment of the string within the label. 4)int getAlignment() : Allow you to set the alignment and also to get the the current alignment.  PROGRAM TO DEMONSTRATE USE OF LABEL import java.awt.*; public class LabelEx { public static void main(String[] args) { Label one=new Label("ONE", Label.LEFT); Label two=new Label("TWO"); Frame f=new Frame("Label Frame"); f.add(one); f.add(two); f.setVisible(true); f.setSize(500,300); one.setBounds(80, 80, 50, 20); two.setBounds(80,80,30,20); } }  Points to Remember: While creating a frame (either by instantiating or extending Frame class), Following two attributes are must for visibility of the frame: – setSize(int width, int height); – setVisible(true); When you create other components like Buttons, TextFields, etc. Then you need to add it to the frame by using the method - add(Component's Object); You can add the following method also for resizing the frame - setResizable(true);  setBounds() method The setBounds() method is used to set the x and y coordinates, as well as the width and height of a component. Its signature is as follows: void setBounds(int x, int y, int width, int height) x: The x-coordinate of the component's top-left corner. y: The y-coordinate of the component's top-left corner. width: The width of the component. height: The height of the component.  AWT Button In Java, AWT contains a Button Class. It is used for creating a labeled button which can perform an action. BUTTON  It is a component which has a label andit generates an event when it is pressed.  Constructors: Button( ) Button(String str)  Methods: void setLabel(String str) String getLabel()  Creating Frame window by extending Frame class import java.awt.Button; import java.awt.Frame; public class ButtonEx extends Frame { ButtonEx() { Button y=new Button("YES"); Button n=new Button("NO"); Button MN=new Button("MAY not decided"); add(y); add(n); add(MN); setSize(200,200); y.setBounds(50,80,40,30); MN.setBounds(50,100,40,30); n.setBounds(50,120,40,30); setVisible(true); } public static void main(String[] args) { ButtonEx b=new ButtonEx(); } }  TEXT FIELD  The TextField class implements a single-line text- entry area, usually called an edit control. Text fields allow the user to enter strings and to edit the text using the arrow keys, cut and paste keys, and mouse selections.  TextField is a subclass of TextComponent.  Constructors: 1) TextField() : Default text field. 2) TextField(int numChars) : specifies the number of characters it can hold. 3) TextField(String str) : It initializes the textfield with the string specified. 4) TextField(String str, int numChars) : initializes a textfield and sets it width. ▪ Events: TextListener textChanged() TextEvent  Methods: 1) String getText() : to obtain the string currently in the textfield. 2) void setText(String str) : to set the text. 3) Void select(int startindex,int endindex) : you can select portion of text under program control. 4) String getSelectedText() : to obtain the currently selected text. 5)Void setEditable(boolean edit) : allows you to control a textfield may be modified by the user. void setEditable(Boolean canEdit) 6)isEditable() : to deteremine whether it is editable or not. Boolean isEditable() 7) setEchoChar() : to set echoing of character as they are typed. void setEchoChar(char ch) 8) Char getEchoChar() : to retrieve the echochar  AWT TextField In Java, AWT contains aTextField Class. It is used for displaying single line text. import java.awt.*; class TextFieldDemo1{ public static void main(String args[]) { Frame TextF_f= new Frame("studytonight ==>TextField"); TextField text1,text2; text1=new TextField("Welcome to studytonight"); text1.setBounds(60,100, 230,40); text2=new TextField("This tutorial is of Java"); text2.setBounds(60,150, 230,40); TextF_f.add(text1); TextF_f.add(text2); TextF_f.setSize(500,500); TextF_f.setLayout(null); TextF_f.setVisible(true); } }  AWT TextArea In Java, AWT contains aTextArea Class. It is used for displaying multiple-line text.  TEXT AREA  It is a multi line editor byAWT.  Constructors: TextArea( ) TextArea(int numLines, int numChars) TextArea(String str) TextArea(String str, int numLines, int numChars) TextArea(String str, int numLines, int numChars, int sBars)  import java.awt.*; public class TextAreaDemo1 { TextAreaDemo1() { Frame textArea_f= new Frame(); TextArea area=new TextArea("Welcome to studytonight.com"); area.setBounds(30,40, 200,200); textArea_f.add(area); textArea_f.setSize(300,300); textArea_f.setLayout(null); textArea_f.setVisible(true); } public static void main(String args[]) { new TextAreaDemo1(); } }  AWT Checkbox In Java, AWT contains a Checkbox Class. It is used when we want to select only one option i.e true or false. When the checkbox is checked then its state is "on" (true) else it is "off"(false).  CHECK BOX  A check box is a control that is used to turn an option on or off. It consists of a small box that can either contain a check mark or not.  Constructors Checkbox( ) Checkbox(String str) Checkbox(String str, boolean on) Checkbox(String str, boolean on, CheckboxGroup cbGroup) Checkbox(String str, CheckboxGroup cbGroup, boolean on) Methods boolean getState( ) void setState(boolean on) String getLabel( ) void setLabel(String str)  package javacomponent; import java.awt.*; public class CheckBoxEx { public static void main(String[] args) { Checkbox Win98, winNT, solaris, mac; Frame f=new Frame("Checkbox example"); Win98=new Checkbox("Windows 98", true); winNT=new Checkbox("windows NT"); mac=new Checkbox("MAC OS"); f.add(Win98); f.add(winNT); f.add(mac); Win98.setBounds(80,100,100,80); mac.setBounds(80,200,100,80); winNT.setBounds(80, 160, 100, 80); f.setVisible(true); f.setSize(600, 600); } }  CHECKBOX GROUP  It is used to create a set of mutually exclusive check boxes in which one and only one checkbox in the group can be checked at any one time. These check boxes are often called radio buttons  Constructor CheckboxGroup(); Methods  Checkbox getSelectedCheckbox( ) void setSelectedCheckbox(Checkbox which) where as which is the check box that you want to be selected.  import java.awt.*; public class CheckboxGroupExample { CheckboxGroupExample() { Frame f= new Frame("CheckboxGroup Example"); CheckboxGroup cbg = new CheckboxGroup(); Checkbox checkBox1 = new Checkbox("Male", cbg, false); checkBox1.setBounds(100,100, 50,50); Checkbox checkBox2 = new Checkbox("Female", cbg, true); checkBox2.setBounds(100,150, 60,50); f.add(checkBox1); f.add(checkBox2); f.setSize(400,400); f.setLayout(null); f.setVisible(true); } public static void main(String args[]) { new CheckboxGroupExample(); } }  Java AWT Choice The object of Choice class is used to show popup menu of choices. Choice selected by user is shown on the top of a menu. It inherits Component class.  Constructor Choice();  Methods void add(String name) String getSelectedItem( ) int getSelectedIndex( ) int getItemCount( ) void select(int index) void select(String name) String getItem(int index)  import java.awt.*; public class ChoicegrpEx { public static void main(String[] args) { // creating a frame Frame f = new Frame(); // creating a choice component Choice c = new Choice(); // setting the bounds of choice menu c.setBounds(100, 100, 75, 75); // adding items to the choice menu c.add("DEPT"); c.add("CM"); c.add("IT"); c.add("CE"); c.add("ME"); // adding choice menu to frame f.add(c); // setting size, layout and visibility of frame f.setSize(400, 400); f.setLayout(null); f.setVisible(true); } }  Java AWT List The object of List class represents a list of text items. With the help of the List class, user can choose either one item or multiple items. It inherits the Component class. LIST  It provides a compact, multiple-choice, scrolling selection list.  Constructors List( ) List(int numRows) List(int numRows, boolean multipleSelect) Where as, numRows=number of entries in the list multipleSelect=t can be set as true or false. If true user can select two or more items at a time.  Methods 1) void add(String name) 2) void add(String name, int index) : adds item at the specified index. 3) String getSelectedItem() : returns String containing the name of the item. 4) int getSelectedIndex() : It returns the index of the item. 5) String[] getSelectedItems() : returns an array containing the name of currently selected items. 6)Int[] getSelectedIndexes() : returns an array containing the indexes of currently selected items.  import java.awt.*; // setting size, layout and visibility of frame f.setSize(400, 400); public class ListExample1 f.setLayout(null); { f.setVisible(true); // class constructor } ListExample1() { // creating the frame //main method Frame f = new Frame(); public static void main(String args[]) // creating the list of 5 rows { List l1 = new List(5); new ListExample1(); } } // setting the position of list component l1.setBounds(100, 100, 75, 75); // adding list items into the list l1.add("C"); l1.add("C++"); l1.add("JAVA"); l1.add("Python"); l1.add("DBMS"); // adding the list to frame f.add(l1);  SCROLL BARS  Scrollbars allows users to scroll the components. It can be set horizontally or vertically. The slider box can be dragged by the user to a new position.  Constructors: 1) Scrollbar() : creates vertical scroll bar 2) Scrollbar(int style) 3)Scrollbar(int style, int initialValue, int thumbsize, int min, int max )  Where as Styles:the orientation of the scroll bar. Styles can have values : Scrollbar.VERTICAL – creates vertical scrollbar Scrollbar.HORIZONTAL – creates horizontal scroll bar thumbsize’ represents number of units represented by the height of the thumb is passed. ‘min’ and ‘max’ represents minimum and maximum values for the scroll bar.  Methods 1) void setValues(int initialValue, int thumbsize, int min, int max ) : to set the parameters. 2)int getValue() : to obtain current value of the scroll bar. 3) void setValue(int newValue) : ‘newValue’ specifies new value for scroll bar. 4)int getMinimum():To retrieveminimum value. 5)int getMaximum():To retrievemaximum value.  import java.awt.Frame; import java.awt.Scrollbar; public class Scrollbarexample { public static void main(String[] args) { Frame f=new Frame("ScrollBar example"); Scrollbar s1=new Scrollbar(Scrollbar.HORIZONTAL); Scrollbar s2=new Scrollbar(Scrollbar.VERTICAL); f.add(s1); f.add(s2); f.setVisible(true); f.setSize(500,500); } }  LAYOUT MANAGER  Layout means the arrangement of components within the container.  The layout manager automatically positions all the components within the container.  The layout manager is associated with every Container object.  Each layout manager is an object of the class that implements the LayoutManager interface.  The layout manager is set by the setLayout( ) method void setLayout(LayoutManager layoutObj)  TYPES OF LAYOUTMANAGER  FlowLayout  BorderLayout  GridLayout  CardLayout  GridBagLayout  The constructors for FlowLayout are shownbelow: 1. FlowLayout( ) It creates the default layout, which centers components and leaves five pixels of space between each component. 2. FlowLayout(int how) It allows you to specify how each Line is aligned.The value of how is  FlowLayout.LEFT  FlowLayout.CENTER  FlowLayout.RIGHT 3. FlowLayout(int how, int horz, int vert) It allows specifying the horizontal and vertical space left between components  package LayoutExamples; import java.awt.*; public class FlowLayoutEx { public static void main(String[] args) { Frame f=new Frame("Flowayout Example"); Button one=new Button("1"); Button two=new Button("2"); Button three=new Button("3"); Button plus=new Button("+"); Button min=new Button("-"); f.add(one); f.add(two); f.add(three); f.add(plus); f.add(min); f.setVisible(true); f.setSize(200,200); f.setLayout(new FlowLayout()); } }  BORDERLAYOUT  The BorderLayout is used to arrange the components in five regions: north, south, east, west and center.  Each region (area) may contain one component only  The constructors defined by BorderLayout are shown below: BorderLayout( ) BorderLayout(int horz, int vert)  To add the control in the window void add(Component compObj, Object region) Here, compObj is the component to be added, and region specifies where the component will be added.  BorderLayout defines the following constants that specify the regions: BorderLayout.CENTER BorderLayout.SOUTH BorderLayout.EAST BorderLayout.WEST BorderLayout.NORTH  import java.awt.*; public class BorderLayoutEx { public static void main(String[] args) { Button R,L,N,S,C; Frame fm=new Frame(); R=new Button("EAST"); L=new Button("WEST") ; N=new Button("NORTH" ); S=new Button("SOUTH" ); C=new Button("CENTER"); fm.add(L,BorderLayout.EAST); fm.add(R,BorderLayout.WEST); fm.add(N,BorderLayout.NORTH); fm.add(S,BorderLayout.SOUTH); fm.add(C,BorderLayout.CENTER); fm.setVisible(true); fm.setSize(500,500); // TODO Auto-generated method stub } }  Grid Layout The Grid Layout class is used to arrange the components in a rectangular grid. One component is displayed in each rectangle When you instantiate a GridLayout, you define the number of rows and columns.  The constructors supported by GridLayout are shown below: GridLayout( ) It creates a single-column grid layout. GridLayout(int numRows, int numColumns ) It creates a grid layout with the specified number of rows and columns but no gaps between the component GridLayout(int numRows, int numColumns, int horz, int vert) It allows you to specify the horizontal and vertical space between components  package LayoutExamples; f.add(b1); import java.awt.*; f.add(b2); public class GridLayoutExample f.add(b3); { f.add(b1); public GridLayoutExample() f.add(b4); { f.add(b5); Frame f=new Frame(); f.add(b6); Button b1,b2,b3,b4,b5,b6,b7,b8,b9; f.add(b7); b1=new Button("1"); f.add(b8); b2=new Button("2"); f.add(b9); b3=new Button("3"); b4=new Button("4"); //f.setLayout(new GridLayout()); b5=new Button("5"); b6=new Button("6"); f.setLayout(new GridLayout(3,3));// setting gridLayout 3 rows and 3 column b7=new Button("7"); f.setVisible(true); b8=new Button("8"); f.setSize(300,300); b9=new Button("9"); // TODO Auto-generated constructor stub } public static void main(String[] args) { new GridLayoutExample(); }  Card Layout Cardlayout class manages the components in such a manner that only one component is visible at a time. The container acts as a stack of cards. The first component added to a card layout is the visible component when the container is first displayed.  Constructors CardLayout() Creates a new card layout with gaps of size zero CardLayout(int hgap, int vgap) Creates a new card layout with the specified horizontal and vertical gaps  Methods public void next(Container parent): is used to flip to the next card of the given container. public void previous(Container parent): is used to flip to the previous card of the given container. public void first(Container parent): is used to flip to the first card of the given container. public void last(Container parent): is used to flip to the last card of the given container. public void show(Container parent, String name): is used to flip to the specified card with the given name.  package LayoutExamples; @Override import java.awt.Button; public void import java.awt.CardLayout; actionPerformed(ActionEvent e) import java.awt.Container; { import java.awt.Frame; card.next(this); import java.awt.event.ActionEvent; import java.awt.event.ActionListener; public class CardLayoutEx extends Frame implements // TODO Auto-generated ActionListener method stub { } CardLayout card; Button bt1, bt2,bt3,bt4; public static void main(String[] args) { CardLayoutEx frm=new CardLayoutEx(); frm.setSize(500,500); CardLayoutEx() frm.setVisible(true); { frm.setVisible(true); card=new CardLayout(); frm.setSize(500,500); setLayout(card); bt1=new Button("CM Class"); bt2=new Button("CM 1"); } bt3=new Button("CM 2"); bt4=new Button ("CM3"); } add(bt1); add(bt2); add(bt3); add(bt4);  GridBagLayout Class  GridBagLayout places components in a grid of rows and columns,  allowing specified components to span multiple rows or columns  It doesn’t require the components of the same size  Each GridBagLayout object manages a rectangular grid of cells, dynamic with each component occupying one or more cells, called its display area. Constructor GridBagLayout()  commonly Used Methods: removeLayoutComponent(Component cmp): Removes the specified component from this layout. getLayoutAlignmentY(Container p): Returns the alignment along the y-axis. addLayoutComponent(Component cmp, Object cons): Add the specified component with the specified name to the layout. toString(): Returns a string representation of this grid bag layout’s values. getLayoutAlignmentX(Container p): Returns the alignment along the x-axis. getConstraints(Component cmp): Gets the constraints for the specified component. maximumLayoutSize(Container tar): Returns the maximum dimensions for this layout given the components in the specified target container. minimumLayoutSize(Container par): Determines the minimum size of the parent container using this grid bag layout.  The GridBagConstraints Class The appearance of a grid bag layout is controlled by sets of GridBagConstraints int gridx, gridy Controls the position of the component on the layout’s grid. int weightx, weighty Controls how additional space in the row or column is allotted to the component. int fillControls whether the component expands to fill the space allotted to it. int gridheight, gridwidth Controls the number of rows or columns the component spans. int anchor Controls the position of the component if there is extra room within the space allotted to it. int ipadx, ipady Controls padding between the component and the borders of its area. Insets insets Controls padding between the component and neighboring components.  JAVA AWT MENU HIERARCH  Menus creation involves lot of classes like MenuBar, Menu and MenuItem and one is added to the other.  MenuBar: MenuBar holds the menus. MenuBar is added to frame with setMenuBar()method. Implicitly,the menu bar is added to the north (top) of the frame.  Menu: Menu holds the menu items.  Menu is added to frame with add() method. A sub- menu can be added to Menu.  MenuItem: MenuItem displays the actual option user can select.  Menu items are added to menu with method addMenuItem().  A dull-colored line can be added in between menu items with addSeparator()method.  CheckboxMenuItem: It differs from MenuItem in that it appears along with a checkbox. The selection can be done with checkbox selected.  To Enable or Disable a menu item,setEnabled() method is true  STEPS OF CREATING JAVA AWTMENU  Create menu bar: MenuBar mbobj=new MenuBar();  Add menu bar to the frame:setMenuBar(mbobj);  Create menus:Menu mobj=new Menu(String str);  Add menus to menu bar:mbobj.add(mobj);  Create menu items:MenuItem miobj=new MenuItem(String str);  Add menu items to menus:mobj.add(miobj);  Menu fileMenu = new Menu("File"); package LayoutExamples; MenuItem openItem = new MenuItem("Open"); MenuItem saveItem = new import java.awt.Frame; MenuItem("Save"); import java.awt.Menu; fileMenu.add(openItem); import java.awt.MenuBar; fileMenu.add(saveItem); import java.awt.MenuItem; fileMenu.addSeparator(); menuBar.add(fileMenu); public class Menu1 Menu editMenu=new Menu("Edit"); { MenuItem cut=new public static void main(String[] args) { MenuItem("Cut"); Frame frame = new Frame("Menu MenuItem paste=new Example"); MenuItem("Paste"); MenuBar menuBar = new MenuBar(); editMenu.add(cut); frame.setMenuBar(menuBar); editMenu.add(paste); // Create a "File" menu menuBar.add(editMenu); frame.setSize(300, 300); frame.setVisible(true); } }  import java.awt.CheckboxMenuItem; frame.setMenuBar(menuBar); import java.awt.Frame; Menu m1 = new Menu("Insert"); import java.awt.Menu; Menu m2 = new Menu("Home"); import java.awt.MenuBar; menuBar.add(m1); menuBar.add(m2); CheckboxMenuItem i1 = new public class Checkablemenu CheckboxMenuItem("Picture",true); { CheckboxMenuItem i2 = new public static void main(String[] args) CheckboxMenuItem("Paste",false); { m1.add(i1); Frame frame = new Frame("Menu m2.add(i2); Example"); MenuBar menuBar = new MenuBar(); frame.setSize(500,300); frame.setVisible(true); }  DIALOGBOX  Dialog boxes are pop-up windows on the screen that appear for a small time to take either input or display output while a main application is running.  A top-level pop-up window with a title and a border that typically takes some form of input from the user.  It is used to display message and get specific information from the user.  It is used to obtain user Input.  TYPES OF DIALOG BOXES  Modal dialog box does not allow the user todo any activity without dismissing (closing) it; example is File Deletion Confirmation dialog box  Modeless dialog box permits the user to do any activity without closing it; example is Find and Replace dialog box of MS Word. Java supports both styles of dialog boxes. CONSTRUCTOR  Dialog(Frame parent)  Dialog(Frame parent,Boolean mode)  Dialog(Frame parent,String title)  Dialog(Frame parent,String title,Boolean mode)  package LayoutExamples; ok.addActionListener ( new ActionListener() import java.awt.Button; { import java.awt.Dialog; public void actionPerformed( ActionEvent e ) import java.awt.FlowLayout; { import java.awt.Frame; // Hide dialog import java.awt.Label; Dialogexample.d.setVisible(false); import java.awt.event.ActionEvent; } import java.awt.event.ActionListener; }); public class Dialogexample d.add( new Label ("Click OK to continue")); d.add( ok ); { private static Dialog d; // Show dialog d.pack(); d.setVisible(true); public static void main(String args[]) System.exit(0); { } Frame window = new Frame(); // Create a modal dialog d = new Dialog(window, "Alert", true); } // Use a flow layout d.setLayout( new FlowLayout() ); // Create an OK button Button ok = new Button ("OK");  FILEDIALOG  The FileDialog class displays a dialog window from which the user can select a file.  To create a file dialog box ,object of type FileDialog is instatiated,this display std file dialog box  CONSTRUCTOR  FileDialog(Frame parent)  FileDialog(Frame parent,String title) FileDialog(Frame parent,String title,int how) whereas how is 1) FileDialog.SAVE This constant value indicates that the purpose of the file dialog window is to locate a file to which to write. 2) FileDialog.LOAD This constant value indicates that the purpose of the file dialog window is to locate a file from which to read. METHODS  String getDirectory()Gets the directory of this file dialog.  String getFile() Gets the selected file of this file dialog.  int getMode()Indicates whether this file dialog box is for loading from a file or for saving to a file.  Void setDirectory(String str)Sets the directory of this file dialog window to be the specified directory.  void setFile(String str)Sets the selected file for this file dialog window to be the specified file.  void setMode(int how)Sets the mode of the file dialog.