org.araneaframework.jsp.tag.basic
Class BaseKeyboardHandlerTag

java.lang.Object
  org.araneaframework.jsp.tag.BaseTag
      org.araneaframework.jsp.tag.basic.BaseKeyboardHandlerTag

All Implemented Interfaces:

ContainedTagInterface, javax.servlet.jsp.tagext.JspTag, javax.servlet.jsp.tagext.Tag, javax.servlet.jsp.tagext.TryCatchFinally

Direct Known Subclasses:

FormKeyboardHandlerHtmlTag, KeyboardHandlerHtmlTag, ServerSideKeyboardHandlerHtmlTag

public abstract class BaseKeyboardHandlerTag

extends BaseTag

implements ContainedTagInterface

The base class for a set of "keyboard handler" tags. All these tags simply emit a "uiRegisterKeyboardHandler" javascript invocation. Custom subclasses should basically use the "writeRegisterKeypressHandlerScript" static method of this class to do their job.

Author:

Konstantin Tretyakov (kt@webmedia.ee)

Field Summary

protected String	defaultKey
protected String	defaultKeyCode
protected String	intKey
protected String	intKeyCode
protected String	key
protected String	keyCode
protected String	keyCombo

Fields inherited from class org.araneaframework.jsp.tag.BaseTag

GLOBAL_CONTEXT_ENTRIES_KEY, pageContext, parent

Fields inherited from interface javax.servlet.jsp.tagext.Tag

EVAL_BODY_INCLUDE, EVAL_PAGE, SKIP_BODY, SKIP_PAGE

Constructor Summary

BaseKeyboardHandlerTag()

Method Summary

protected int	doStartTag(Writer out) Checks that either keyCode or key is specified (not both), and initializes the keyCode field.
static int	keyToKeyCode(String key) Translates a "key alias" to its key-code.
void	setKey(String key) Key to which the event must be triggered.
void	setKeyCode(String keyCode)
void	setKeyCombo(String keyCombo)
static void	writeRegisterKeycomboHandlerScript(Writer out, String scope, String keyCombo, String handler)
static void	writeRegisterKeypressHandlerScript(Writer out, String scope, String keyCode, String handler) Writes "uiRegisterKeypressHandler" javascript, surrounded by <script> tags.

Methods inherited from class org.araneaframework.jsp.tag.BaseTag

addContextEntry, doCatch, doEndTag, doEndTag, doFinally, doStartTag, evaluate, evaluateNotNull, executeEndSubtag, executeEndTagAndUnregister, executeStartSubtag, executeSubtag, getConfiguration, getContextEntry, getContextWidget, getContextWidgetFullId, getEnvironment, getLocalizationContext, getOutputData, getParent, hideGlobalContextEntries, registerAndExecuteStartTag, registerSubtag, release, requireContextEntry, restoreGlobalContextEntries, setPageContext, setParent, unregisterSubtag

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.araneaframework.jsp.tag.ContainedTagInterface

doEndTag, doFinally, doStartTag, release, setPageContext

Field Detail

defaultKeyCode

protected String defaultKeyCode

intKeyCode

protected String intKeyCode

keyCode

protected String keyCode

defaultKey

protected String defaultKey

intKey

protected String intKey

key

protected String key

keyCombo

protected String keyCombo

Constructor Detail

BaseKeyboardHandlerTag

public BaseKeyboardHandlerTag()

Method Detail

setKeyCode

public void setKeyCode(String keyCode)
                throws javax.servlet.jsp.JspException

Throws:

javax.servlet.jsp.JspException

Jsp.attribute:

type = "java.lang.String" required = "false" description = "Keycode to which the event must be triggered. 13 means enter. Either keyCode or key must be specified, but not both."

setKeyCombo

public void setKeyCombo(String keyCombo)
                 throws javax.servlet.jsp.JspException

Throws:

javax.servlet.jsp.JspException

Jsp.attribute:

type = "java.lang.String" required = "false" description = "Keycode to which the event must be triggered. 13 means enter. Either keyCode or key must be specified, but not both."

setKey

public void setKey(String key)
            throws javax.servlet.jsp.JspException

Key to which the event must be triggered. Similar to setKeyCode, but accepts key "aliases" instead of codes. For example, to react to the return key, you either specify keyCode = "13", or key = "enter" (but you can't specify both!). A list of available aliases is given in keyToKeyCode(java.lang.String).

Throws:

javax.servlet.jsp.JspException

See Also:

keyToKeyCode(java.lang.String)

Jsp.attribute:

type = "java.lang.String" required = "false" description = "Key, to which the event must be triggered. Key is specified as a certain 'alias'. The alias may be an ASCII character or a digit (this will denote the corresponding key on a US keyboard), a space (' '), or one of the following: 'return', 'escape', 'backspace', 'tab', 'shift', 'control', 'space', 'f1', 'f2', ..., 'f12'."

doStartTag

protected int doStartTag(Writer out)
                  throws Exception

Checks that either keyCode or key is specified (not both), and initializes the keyCode field. When overriding don't forget to invoke superimplementation first.

Overrides:

doStartTag in class BaseTag

Throws:

Exception

writeRegisterKeypressHandlerScript

public static final void writeRegisterKeypressHandlerScript(Writer out,
                                                            String scope,
                                                            String keyCode,
                                                            String handler)
                                                     throws javax.servlet.jsp.JspException,
                                                            IOException

Writes "uiRegisterKeypressHandler" javascript, surrounded by <script> tags. Throws exceptions if parameters are not consistent (e.g. keyCode not specified).

Throws:

javax.servlet.jsp.JspException

IOException

writeRegisterKeycomboHandlerScript

public static final void writeRegisterKeycomboHandlerScript(Writer out,
                                                            String scope,
                                                            String keyCombo,
                                                            String handler)
                                                     throws javax.servlet.jsp.JspException,
                                                            IOException

Throws:

javax.servlet.jsp.JspException

IOException

keyToKeyCode

public static final int keyToKeyCode(String key)

Translates a "key alias" to its key-code. Under key-code we mean the keyboard code reported by the javascript keyboard event, when the corresponding key is pushed on a usual US keyboard.

For example keyToKeyCode("A") returns 65. keyToKeyCode("RETURN") returns 13. Available key aliases are:

• All ASCII characters and digits
• "F1"..."F12"
• "RETURN"/"ENTER", "BACKSPACE", "ESCAPE", "TAB", "SHIFT", "CONTROL", "SPACE"
• " " (space) is space

Case does not matter. If input is invalid, zero iz returned.

Parameters:

key -

Returns:

corresponding keyCode (that is supposed