javax.microedition.lcdui
Class AlertType

java.lang.Object
  javax.microedition.lcdui.AlertType

public class AlertType
extends java.lang.Object

The AlertType provides an indication of the nature of alerts. Alerts are used by an application to present various kinds of information to the user. An AlertType may be used to directly signal the user without changing the current Displayable. The playSound method can be used to spontaneously generate a sound to alert the user. For example, a MIDlet using a Form with a progress bar can use AlertType.CONFIRMATION.playSound(display) to indicate that an operation has completed. The predefined types are INFO, WARNING, ERROR, ALARM, and CONFIRMATION.

Since:

MIDP 1.0

See Also:

Alert

Field Summary

static AlertType	ALARM An ALARM AlertType is a hint to alert the user to an event for which the user has previously requested to be notified.
static AlertType	CONFIRMATION A CONFIRMATION AlertType is a hint to confirm user actions.
static AlertType	ERROR An ERROR AlertType is a hint to alert the user to an erroneous operation.
static AlertType	INFO An INFO AlertType typically provides non-threatening information to the user.
static AlertType	WARNING A WARNING AlertType is a hint to warn the user of a potentially dangerous operation.

Constructor Summary

protected

AlertType() Protected constructor for subclasses.

Method Summary

boolean

playSound(Display display) Alert the user by playing the sound for this AlertType.

Methods inherited from class java.lang.Object

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

Field Detail

INFO

public static final AlertType INFO

An INFO AlertType typically provides non-threatening information to the user. For example, a simple splash/information screen might be an INFO AlertType.

WARNING

public static final AlertType WARNING

A WARNING AlertType is a hint to warn the user of a potentially dangerous operation. For example, the warning message may contain the message, "Warning: this operation will erase your data."

ERROR

public static final AlertType ERROR

An ERROR AlertType is a hint to alert the user to an erroneous operation. For example, an error alert might show the message, "There is not enough room to install the application."

ALARM

public static final AlertType ALARM

An ALARM AlertType is a hint to alert the user to an event for which the user has previously requested to be notified. For example, the message might say, "Staff meeting in five minutes."

CONFIRMATION

public static final AlertType CONFIRMATION

A CONFIRMATION AlertType is a hint to confirm user actions. For example, "Saved!" might be shown to indicate that a Save operation has completed.

Constructor Detail

AlertType

protected AlertType()

Protected constructor for subclasses.

Method Detail

playSound

public boolean playSound(Display display)

Alert the user by playing the sound for this AlertType. The AlertType instance is used as a hint to the device to generate an appropriate sound. Instances other than those predefined above may be ignored. The actual sound made by the device, if any, is determined by the device. The device may ignore the request, use the same sound for several AlertTypes or use any other means suitable to alert the user. The device indication to the user may not necessarily be sound, but may instead be visual or tactile feedback based on device settings or capabilities. For example, a user may have configured a device to be silent, so the implementation may instead flash the backlight or vibrate.

Parameters:

display - to which the AlertType's sound should be played.

Returns:

true if the user was alerted, false otherwise.

Throws:

java.lang.NullPointerException - if display is null