org.eclipse.swt.widgets

Class Dialog

java.lang.Object

org.eclipse.swt.widgets.Dialog

Direct Known Subclasses:

ColorDialog, DirectoryDialog, FileDialog, FontDialog, MessageBox, PrintDialog, PromptDialog

public abstract class Dialog
extends java.lang.Object

This class is the abstract superclass of the classes that represent the built in platform dialogs. A Dialog typically contains other widgets that are not accessible. A Dialog is not a Widget.

This class can also be used as the abstract superclass for user-designed dialogs. Such dialogs usually consist of a Shell with child widgets. The basic template for a user-defined dialog typically looks something like this:

 public class MyDialog extends Dialog {
        Object result;
                
        public MyDialog (Shell parent, int style) {
                super (parent, style);
        }
        public MyDialog (Shell parent) {
                this (parent, 0); // your default style bits go here (not the Shell's style bits)
        }
        public Object open () {
                Shell parent = getParent();
                Shell shell = new Shell(parent, SWT.DIALOG_TRIM | SWT.APPLICATION_MODAL);
                shell.setText(getText());
                // Your code goes here (widget creation, set result, etc).
                shell.open();
                Display display = parent.getDisplay();
                while (!shell.isDisposed()) {
                        if (!display.readAndDispatch()) display.sleep();
                }
                return result;
        }
 }
 

Note: The modality styles supported by this class are treated as HINTs, because not all are supported by every subclass on every platform. If a modality style is not supported, it is "upgraded" to a more restrictive modality style that is supported. For example, if PRIMARY_MODAL is not supported by a particular dialog, it would be upgraded to APPLICATION_MODAL. In addition, as is the case for shells, the window manager for the desktop on which the instance is visible has ultimate control over the appearance and behavior of the instance, including its modality.

Styles:

APPLICATION_MODAL, PRIMARY_MODAL, SYSTEM_MODAL, SHEET

Events:

(none)

Note: Only one of the styles APPLICATION_MODAL, PRIMARY_MODAL, and SYSTEM_MODAL may be specified.

See Also:

Shell, SWT Example: ControlExample, Sample code and further information

Structure Diagram

Field Summary

Fields

Modifier and Type	Field and Description
(package private) Shell	parent
(package private) int	style
(package private) java.lang.String	title

Constructor Summary

Constructors

Constructor and Description
Dialog(Shell parent) Constructs a new instance of this class given only its parent.
Dialog(Shell parent, int style) Constructs a new instance of this class given its parent and a style value describing its behavior and appearance.

Method Summary

Methods

Modifier and Type	Method and Description
(package private) void	checkParent(Shell parent) Throws an exception if the specified widget can not be used as a parent for the receiver.
(package private) static int	checkStyle(Shell parent, int style)
protected void	checkSubclass() Checks that this class can be subclassed.
(package private) void	error(int code) Does whatever dialog specific cleanup is required, and then uses the code in SWTError.error to handle the error.
Shell	getParent() Returns the receiver's parent, which must be a Shell or null.
int	getStyle() Returns the receiver's style information.
java.lang.String	getText() Returns the receiver's text, which is the string that the window manager will typically display as the receiver's title.
void	setText(java.lang.String string) Sets the receiver's text, which is the string that the window manager will typically display as the receiver's title, to the argument, which must not be null.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

style

int style

parent

Shell parent

title

java.lang.String title

Constructor Detail

Dialog

public Dialog(Shell parent)

Constructs a new instance of this class given only its parent.

Parameters:

parent - a shell which will be the parent of the new instance

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the parent is null

SWTException -

• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent

Dialog

public Dialog(Shell parent,
      int style)

Constructs a new instance of this class given its parent and a style value describing its behavior and appearance.

The style value is either one of the style constants defined in class SWT which is applicable to instances of this class, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those SWT style constants. The class description lists the style constants that are applicable to the class. Style bits are also inherited from superclasses.

Parameters:

parent - a shell which will be the parent of the new instance

style - the style of dialog to construct

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the parent is null

SWTException -

• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent

See Also:

SWT.PRIMARY_MODAL, SWT.APPLICATION_MODAL, SWT.SYSTEM_MODAL

Method Detail

checkSubclass

protected void checkSubclass()

Checks that this class can be subclassed.

IMPORTANT: See the comment in Widget.checkSubclass().

Throws:

SWTException -

• ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass

See Also:

Widget.checkSubclass()

checkParent

void checkParent(Shell parent)

Throws an exception if the specified widget can not be used as a parent for the receiver.

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the parent is null
• ERROR_INVALID_ARGUMENT - if the parent is disposed

SWTException -

• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent

checkStyle

static int checkStyle(Shell parent,
             int style)

error

void error(int code)

Does whatever dialog specific cleanup is required, and then uses the code in SWTError.error to handle the error.

Parameters:

code - the descriptive error code

See Also:

SWT.error(int)

getParent

public Shell getParent()

Returns the receiver's parent, which must be a Shell or null.

Returns:

the receiver's parent

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

getStyle

public int getStyle()

Returns the receiver's style information.

Note that, the value which is returned by this method may not match the value which was provided to the constructor when the receiver was created.

Returns:

the style bits

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

getText

public java.lang.String getText()

Returns the receiver's text, which is the string that the window manager will typically display as the receiver's title. If the text has not previously been set, returns an empty string.

Returns:

the text

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

setText

public void setText(java.lang.String string)

Sets the receiver's text, which is the string that the window manager will typically display as the receiver's title, to the argument, which must not be null.

Parameters:

string - the new text

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the text is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver