net.sf.mmm.util.gwt.api

Class JavaScriptUtil

java.lang.Object

net.sf.mmm.util.gwt.api.JavaScriptUtil

public class JavaScriptUtil
extends Object

This class holds a collection of utility functions for GWT (Google Web Toolkit) using JSNI (JavaScript Native Interface).

Since:

1.0.0

Author:

Joerg Hohwiller (hohwille at users.sourceforge.net)

See Also:

getInstance()

Field Summary

Fields

Modifier and Type	Field and Description
private String[]	fonts
private static JavaScriptUtil	INSTANCE

Constructor Summary

Constructors

Constructor and Description
JavaScriptUtil() The constructor.

Method Summary

Modifier and Type	Method and Description
Object	clone(Object template) This method creates a clone of the given template.
com.google.gwt.dom.client.InputElement	createInputElement(String type) Creates an InputElement of a custom type.
List<String>	getAvailableFonts()
String	getBlobUrl(JsBlob blob) This method creates the URL pointing to a JsBlob.
int	getBrowserHeight() This method gets the height of the browser window in pixel (vertical size).
int	getBrowserPositionX() This method gets the pixel position of the browser window's left border on the x-axis (horizontal).
int	getBrowserPositionY() This method gets the pixel position of the browser window's top border on the y-axis (vertical).
int	getBrowserWidth() This method gets the width of the browser window in pixel (horizontal size).
JsCssStyleDeclaration	getComputedStyle(com.google.gwt.dom.client.Element element) This method gets the computed style of the given Element.
JsFileList	getFileList(com.google.gwt.user.client.Event event) This method gets the JsFileList for a given Event.
com.google.gwt.dom.client.Element	getFocusable(com.google.gwt.dom.client.Element element, boolean tabable, boolean last) Get the first/last focusable or tab-able (child) Element.
com.google.gwt.dom.client.Element	getFocusedElement()
private com.google.gwt.core.client.JsArrayString	getFonts()
com.google.gwt.dom.client.Document	getFrameDocument(com.google.gwt.dom.client.Element iframe) This method gets the Document of a given <iframe> Element.
static JavaScriptUtil	getInstance()
JsBlob	getResponseAsBlob(com.google.gwt.xhr.client.XMLHttpRequest xhr) This method gets the response of the given XMLHttpRequest as JsBlob.
int	getScreenHeight() This method gets the height of the current screen/display also called the vertical resolution.
int	getScreenWidth() This method gets the width of the current screen/display also called the horizontal resolution.
JsSelection	getSelection() This method gets the JsSelection of the browser Window.
JsSelection	getSelection(com.google.gwt.dom.client.Element iframe) This method gets the JsSelection of the given <iframe> Element.
boolean	isFocusable(com.google.gwt.dom.client.Element element, boolean tabable) Determines if the given Element is focusable or tab-able.
Object	newInstance(Object template) This method creates a new instance of the given template.
void	onLoadFrame(com.google.gwt.dom.client.Element iframe, Runnable callback) This method executes the given callback when the given iframe is loaded.
void	openBlob(JsBlob blob) This method opens a given JsBlob.
boolean	setCustomValidity(com.google.gwt.dom.client.Element inputElement, String message) This method sets the custom validation message of the given input Element.
private void	setInputElementType(com.google.gwt.dom.client.InputElement inputElement, String type) This method sets the type of an InputElement.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

private static final JavaScriptUtil INSTANCE

fonts

private String[] fonts

Constructor Detail

JavaScriptUtil

public JavaScriptUtil()

The constructor.

Method Detail

getInstance

public static JavaScriptUtil getInstance()

Returns:

the singleton instance of JavaScriptUtil.

See Also:

Cdi.GET_INSTANCE

getAvailableFonts

public List<String> getAvailableFonts()

Returns:

the List of fonts available in the browser.

getScreenWidth

public int getScreenWidth()

This method gets the width of the current screen/display also called the horizontal resolution.

Returns:

the screen width in pixels.

getScreenHeight

public int getScreenHeight()

This method gets the height of the current screen/display also called the vertical resolution.

Returns:

the screen height in pixels.

getBrowserPositionX

public int getBrowserPositionX()

This method gets the pixel position of the browser window's left border on the x-axis (horizontal).

Returns:

the browsers X position.

getBrowserPositionY

public int getBrowserPositionY()

This method gets the pixel position of the browser window's top border on the y-axis (vertical).

Returns:

the browsers Y position.

getBrowserWidth

public int getBrowserWidth()

This method gets the width of the browser window in pixel (horizontal size).

Returns:

the browsers width.

getBrowserHeight

public int getBrowserHeight()

This method gets the height of the browser window in pixel (vertical size).

Returns:

the browsers height.

setCustomValidity

public boolean setCustomValidity(com.google.gwt.dom.client.Element inputElement,
                                 String message)

This method sets the custom validation message of the given input Element. The Browser needs to support HTML5 for this feature.

Parameters:

inputElement - is the input Element that has been validated.

message - - the empty string to mark as valid, the validation failure message otherwise.

Returns:

true if the browser supports custom validity and it has been set, false otherwise.

createInputElement

public com.google.gwt.dom.client.InputElement createInputElement(String type)

Creates an InputElement of a custom type. Only used while GWT does NOT directly provide a way to create HTML5 input elements.

Parameters:

type - is the requested type (e.g. "range", "date", etc.).

Returns:

the requested InputElement of the given type.

setInputElementType

private void setInputElementType(com.google.gwt.dom.client.InputElement inputElement,
                                 String type)

This method sets the type of an InputElement.

Parameters:

inputElement - is the input InputElement.

type - is the new type to set.

clone

public Object clone(Object template)

This method creates a clone of the given template.

Parameters:

template - is the object to clone.

Returns:

the cloned object.

newInstance

public Object newInstance(Object template)

This method creates a new instance of the given template.

Parameters:

template - is the object create a new instance of.

Returns:

the new instance.

getResponseAsBlob

public JsBlob getResponseAsBlob(com.google.gwt.xhr.client.XMLHttpRequest xhr)

This method gets the response of the given XMLHttpRequest as JsBlob.

Parameters:

xhr - is the XMLHttpRequest that has already been loaded.

Returns:

the response as a JsBlob.

getFileList

public JsFileList getFileList(com.google.gwt.user.client.Event event)

This method gets the JsFileList for a given Event. E.g. if files are dragged onto some element in the browser or in case of an Event (e.g. of ) of a file input you can receive the JsFileList here.

Parameters:

event - is the Event.

Returns:

the JsFileList or null if no files are available.

getBlobUrl

public String getBlobUrl(JsBlob blob)

This method creates the URL pointing to a JsBlob. Such URL is starting with the "blob:" scheme and is only valid within the current JS context.

Parameters:

blob - is the JsBlob.

Returns:

the new instance.

openBlob

public void openBlob(JsBlob blob)

This method opens a given JsBlob. The browser will show a regular popup to open the file or save it to the local disc. Depending on its mimetype the browser might already open the file immediately in a new window.

Parameters:

blob - is the JsBlob.

getComputedStyle

public JsCssStyleDeclaration getComputedStyle(com.google.gwt.dom.client.Element element)

This method gets the computed style of the given Element.
ATTENTION:
Do not get confused by the name of this method. It will only "calculate" the CSS rules but return these properties unmodified. So if you are looking for a way to get the actual calculated width or height of an Element in pixels (rather than something like "50%") just use Element.getOffsetWidth() or Element.getOffsetHeight() instead.

Parameters:

element - is the Element to compute the style of.

Returns:

the computed style.

getSelection

public JsSelection getSelection()

This method gets the JsSelection of the browser Window.

Returns:

the corresponding JsSelection.

getSelection

public JsSelection getSelection(com.google.gwt.dom.client.Element iframe)

This method gets the JsSelection of the given <iframe> Element. The given iframe needs to be loaded when calling this method. Use onLoadFrame(Element, Runnable) to ensure.

Parameters:

iframe - is the <iframe> Element.

Returns:

the corresponding JsSelection.

isFocusable

public boolean isFocusable(com.google.gwt.dom.client.Element element,
                           boolean tabable)

Determines if the given Element is focusable or tab-able.

Parameters:

element - is the Element to check.

tabable - - true if the check should only consider tab-able Elements (so if tabindex is negative, the result is false), false otherwise.

Returns:

true if focusable/tab-able, false otherwise.

getFocusedElement

public com.google.gwt.dom.client.Element getFocusedElement()

Returns:

the Element that is currently focused or null if focus is outside the current document.

getFocusable

public com.google.gwt.dom.client.Element getFocusable(com.google.gwt.dom.client.Element element,
                                                      boolean tabable,
                                                      boolean last)

Get the first/last focusable or tab-able (child) Element.

Parameters:

element - is the Element to scan recursively.

tabable - - true if the check should only consider tab-able Elements (so if tabindex is negative, the result is false), false otherwise.

last - - true if the last focusable/tab-able element shall be returned, false for the last focusable/tab-able element.

Returns:

the first/last focusable or tab-able Element or null if none exists.

getFrameDocument

public com.google.gwt.dom.client.Document getFrameDocument(com.google.gwt.dom.client.Element iframe)

This method gets the Document of a given <iframe> Element. The given iframe needs to be loaded when calling this method. Use onLoadFrame(Element, Runnable) to ensure.

Parameters:

iframe - is the <iframe> Element.

Returns:

the corresponding Document.

onLoadFrame

public void onLoadFrame(com.google.gwt.dom.client.Element iframe,
                        Runnable callback)

This method executes the given callback when the given iframe is loaded.

Parameters:

iframe - is the <iframe> Element.

callback - is the callback to execute.

getFonts

private com.google.gwt.core.client.JsArrayString getFonts()

Returns:

an array with the sorted names of the fonts installed.