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Window

Represents a browser window or frame. This is the top-level object for each document, Location, and History object group.

Client-side object.

Implemented in

Navigator 2.0
Navigator 3.0: added
closed, history, and opener properties; added blur, focus, and scroll methods; added onBlur, onError, and onFocus event handlers
Navigator 4.0: added innerHeight, innerWidth, locationbar, menubar, outerHeight, outerWidth, pageXOffset, pageYOffset, personalbar, scrollbars, statusbar, and toolbar properties; added back, captureEvents, clearInterval, disableExternalCapture, enableExternalCapture, find, forward, handleEvent, home, moveBy, moveTo, releaseEvents, resizeBy, resizeTo, routeEvent, scrollBy, scrollTo, setInterval, and stop methods; deprecated scroll method.

Created by

The JavaScript runtime engine creates a Window object for each BODY or FRAMESET tag. It also creates a Window object to represent each frame defined in a FRAME tag. In addition, you can create other windows by calling the Window.open method. For details on defining a window, see open.

Event handlers

In Navigator 3.0, on some platforms, placing an onBlur or onFocus event handler in a FRAMESET tag has no effect.

Description

The Window object is the top-level object in the JavaScript client hierarchy. A Window object can represent either a top-level window or a frame inside a frameset. As a matter of convenience, you can think about a Frame object as a Window object that isn't a top-level window. However, there is not really a separate Frame class; these objects really are Window objects, with a very few minor differences:

For all windows, the self and window properties of a Window object are synonyms for the current window, and you can optionally use them to refer to the current window. For example, you can close the current window by calling the close method of either window or self. You can use these properties to make your code more readable or to disambiguate the property reference self.status from a form called status. See the properties and methods listed below for more examples.

Because the existence of the current window is assumed, you do not have to refer to the name of the window when you call its methods and assign its properties. For example, status="Jump to a new location" is a valid property assignment, and close() is a valid method call.

However, when you open or close a window within an event handler, you must specify window.open() or window.close() instead of simply using open() or close(). Due to the scoping of static objects in JavaScript, a call to close() without specifying an object name is equivalent to document.close().

For the same reason, when you refer to the location object within an event handler, you must specify window.location instead of simply using location. A call to location without specifying an object name is equivalent to document.location, which is a synonym for document.URL.

You can refer to a window's Frame objects in your code by using the frames array. In a window with a FRAMESET tag, the frames array contains an entry for each frame.

A windows lacks event handlers until HTML that contains a BODY or FRAMESET tag is loaded into it.

Property Summary

closed
Specifies whether a window has been closed.

defaultStatus
Reflects the default message displayed in the window's status bar.

document
Contains information on the current document, and provides methods for displaying HTML output to the user.

frames
An array reflecting all the frames in a window.

history
Contains information on the URLs that the client has visited within a window.

innerHeight
Specifies the vertical dimension, in pixels, of the window's content area.

innerWidth
Specifies the horizontal dimension, in pixels, of the window's content area.

length
The number of frames in the window.

location
Contains information on the current URL.

locationbar
Represents the browser window's location bar.

menubar
Represents the browser window's menu bar.

name
A unique name used to refer to this window.

opener
Specifies the window name of the calling document when a window is opened using the open method

outerHeight
Specifies the vertical dimension, in pixels, of the window's outside boundary.

outerWidth
Specifies the horizontal dimension, in pixels, of the window's outside boundary.

pageXOffset
Provides the current x-position, in pixels, of a window's viewed page.

pageYOffset
Provides the current y-position, in pixels, of a window's viewed page.

parent
A synonym for a window or frame whose frameset contains the current frame.

personalbar
Represents the browser window's personal bar (also called the directories bar).

scrollbars
Represents the browser window's scroll bars.

self
A synonym for the current window.

status
Specifies a priority or transient message in the window's status bar.

statusbar
Represents the browser window's status bar.

toolbar
Represents the browser window's tool bar.

top
A synonym for the topmost browser window.

window
A synonym for the current window.

Method Summary

alert
Displays an Alert dialog box with a message and an OK button.

back
Undoes the last history step in any frame within the top-level window.

blur
Removes focus from the specified object.

captureEvents
Sets the window or document to capture all events of the specified type.

clearInterval
Cancels a timeout that was set with the setInterval method.

clearTimeout
Cancels a timeout that was set with the setTimeout method.

close
Closes the specified window.

confirm
Displays a Confirm dialog box with the specified message and OK and Cancel buttons.

disableExternalCapture
Disables external event capturing set by the enableExternalCapture method.

enableExternalCapture
Allows a window with frames to capture events in pages loaded from different locations (servers).

find
Finds the specified text string in the contents of the specified window.

focus
Gives focus to the specified object.

forward
Loads the next URL in the history list.

handleEvent
Invokes the handler for the specified event.

home
Points the browser to the URL specified in preferences as the user's home page.

moveBy
Moves the window by the specified amounts.

moveTo
Moves the top-left corner of the window to the specified screen coordinates.

open
Opens a new web browser window.

print
Prints the contents of the window or frame.

prompt
Displays a Prompt dialog box with a message and an input field.

releaseEvents
Sets the window to release captured events of the specified type, sending the event to objects further along the event hierarchy.

resizeBy
Resizes an entire window by moving the window's bottom-right corner by the specified amount.

resizeTo
Resizes an entire window to the specified outer height and width.

routeEvent
Passes a captured event along the normal event hierarchy.

scroll
Scrolls a window to a specified coordinate.

scrollBy
Scrolls the viewing area of a window by the specified amount.

scrollTo
Scrolls the viewing area of the window to the specified coordinates, such that the specified point becomes the top-left corner.

setInterval
Evaluates an expression or calls a function every time a specified number of milliseconds elapses.

setTimeout
Evaluates an expression or calls a function once after a specified number of milliseconds has elapsed.

stop
Stops the current download.

Examples

Example 1. Windows opening other windows. In the following example, the document in the top window opens a second window, window2, and defines push buttons that open a message window, write to the message window, close the message window, and close window2. The onLoad and onUnload event handlers of the document loaded into window2 display alerts when the window opens and closes.

win1.html, which defines the frames for the first window, contains the following code:

<HTML>
<HEAD>
<TITLE>Window object example: Window 1</TITLE>
</HEAD>
<BODY BGCOLOR="antiquewhite">
<SCRIPT>
window2=open("win2.html","secondWindow",
   "scrollbars=yes,width=250, height=400")
document.writeln("<B>The first window has no name: "
   + window.name + "</B>")
document.writeln("<BR><B>The second window is named: "
   + window2.name + "</B>")
</SCRIPT>
<FORM NAME="form1">
<P><INPUT TYPE="button" VALUE="Open a message window"
   onClick = "window3=window.open('','messageWindow',
   'scrollbars=yes,width=175, height=300')">
<P><INPUT TYPE="button" VALUE="Write to the message window"
   onClick="window3.document.writeln('Hey there');
   window3.document.close()">
<P><INPUT TYPE="button" VALUE="Close the message window"
   onClick="window3.close()">
<P><INPUT TYPE="button" VALUE="Close window2"
   onClick="window2.close()">
</FORM>
</BODY>
</HTML>
win2.html, which defines the content for window2, contains the following code:

<HTML>
<HEAD>
<TITLE>Window object example: Window 2</TITLE>
</HEAD>
<BODY BGCOLOR="oldlace"
   onLoad="alert('Message from ' + window.name + ': Hello, World.')"
   onUnload="alert('Message from ' + window.name + ': I\'m closing')">
<B>Some numbers</B>
<UL><LI>one
<LI>two
<LI>three
<LI>four</UL>
</BODY>
</HTML>
Example 2. Creating frames. The following example creates two windows, each with four frames. In the first window, the first frame contains push buttons that change the background colors of the frames in both windows. framset1.html, which defines the frames for the first window, contains the following code:

<HTML>
<HEAD>
<TITLE>Frames and Framesets: Window 1</TITLE>
</HEAD>
<FRAMESET ROWS="50%,50%" COLS="40%,60%"
   onLoad="alert('Hello, World.')">
<FRAME SRC=framcon1.html NAME="frame1">
<FRAME SRC=framcon2.html NAME="frame2">
<FRAME SRC=framcon2.html NAME="frame3">
<FRAME SRC=framcon2.html NAME="frame4">
</FRAMESET>
</HTML>
framset2.html, which defines the frames for the second window, contains the following code:

<HTML>
<HEAD>
<TITLE>Frames and Framesets: Window 2</TITLE>
</HEAD>
<FRAMESET ROWS="50%,50%" COLS="40%,60%">
<FRAME SRC=framcon2.html NAME="frame1">
<FRAME SRC=framcon2.html NAME="frame2">
<FRAME SRC=framcon2.html NAME="frame3">
<FRAME SRC=framcon2.html NAME="frame4">
</FRAMESET>
</HTML>
framcon1.html, which defines the content for the first frame in the first window, contains the following code:

<HTML>
<BODY>
<A NAME="frame1"><H1>Frame1</H1></A>
<P><A HREF="framcon3.htm" target=frame2>Click here</A>
   to load a different file into frame 2.
<SCRIPT>
window2=open("framset2.htm","secondFrameset")
</SCRIPT>
<FORM>
<P><INPUT TYPE="button" VALUE="Change frame2 to teal"
   onClick="parent.frame2.document.bgColor='teal'">
<P><INPUT TYPE="button" VALUE="Change frame3 to slateblue"
   onClick="parent.frames[2].document.bgColor='slateblue'">
<P><INPUT TYPE="button" VALUE="Change frame4 to darkturquoise"
   onClick="top.frames[3].document.bgColor='darkturquoise'">
<P><INPUT TYPE="button" VALUE="window2.frame2 to violet"
   onClick="window2.frame2.document.bgColor='violet'">
<P><INPUT TYPE="button" VALUE="window2.frame3 to fuchsia"
   onClick="window2.frames[2].document.bgColor='fuchsia'">
<P><INPUT TYPE="button" VALUE="window2.frame4 to deeppink"
   onClick="window2.frames[3].document.bgColor='deeppink'">
</FORM>
</BODY>
</HTML>
framcon2.html, which defines the content for the remaining frames, contains the following code:

<HTML>
<BODY>
<P>This is a frame.
</BODY>
</HTML>
framcon3.html, which is referenced in a Link object in framcon1.html, contains the following code:

<HTML>
<BODY>
<P>This is a frame. What do you think?
</BODY>
</HTML>

See also

document, Frame

Properties

closed

Specifies whether a window is closed.

Property of

Window

Read-only

Implemented in

Navigator 3.0

Description

The closed property is a boolean value that specifies whether a window has been closed. When a window closes, the window object that represents it continues to exist, and its closed property is set to true.

Use closed to determine whether a window that you opened, and to which you still hold a reference (from the return value of window.open), is still open. Once a window is closed, you should not attempt to manipulate it.

Examples

Example 1. The following code opens a window, win1, then later checks to see if that window has been closed. A function is called depending on whether win1 is closed.

win1=window.open('opener1.html','window1','width=300,height=300')
...
if (win1.closed)
   function1()
   else
   function2()
Example 2. The following code determines if the current window's opener window is still closed, and calls the appropriate function.

if (window.opener.closed)
   function1()
   else
   function2()

See also

Window.close, Window.open

defaultStatus

The default message displayed in the status bar at the bottom of the window.

Property of

Window

Implemented in

Navigator 2.0

Security

Navigator 3.0: This property is tainted by default. For information on data tainting, see "JavaScript Security".

Description

The defaultStatus message appears when nothing else is in the status bar. Do not confuse the defaultStatus property with the status property. The status property reflects a priority or transient message in the status bar, such as the message that appears when a mouseOver event occurs over an anchor.

You can set the defaultStatus property at any time. You must return true if you want to set the defaultStatus property in the onMouseOut or onMouseOver event handlers.

Examples

In the following example, the statusSetter function sets both the status and defaultStatus properties in an onMouseOver event handler:

function statusSetter() {
   window.defaultStatus = "Click the link for the Netscape home page"
   window.status = "Netscape home page"
}
<A HREF="http://home.netscape.com"
   onMouseOver = "statusSetter(); return true">Netscape</A>
In the previous example, notice that the onMouseOver event handler returns a value of true. You must return true to set status or defaultStatus in an event handler.

See also

Window.status

document

Contains information on the current document, and provides methods for displaying HTML output to the user.

Property of

Window

Implemented in

Navigator 2.0

Description

The value of this property is the window's associated document object.

frames

An array of objects corresponding to child frames (created with the FRAME tag) in source order.

Property of

Window

Read-only

Implemented in

Navigator 2.0

You can refer to the child frames of a window by using the frames array. This array contains an entry for each child frame (created with the FRAME tag) in a window containing a FRAMESET tag; the entries are in source order. For example, if a window contains three child frames whose NAME attributes are fr1, fr2, and fr3, you can refer to the objects in the images array either as:

parent.frames["fr1"]
parent.frames["fr2"]
parent.frames["fr3"]
or as:

parent.frames[0]
parent.frames[1]
parent.frames[2]
You can find out how many child frames the window has by using the length property of the Window itself or of the frames array.

The value of each element in the frames array is <object nameAttribute>, where nameAttribute is the NAME attribute of the frame.

history

Contains information on the URLs that the client has visited within a window.

Property of

Window

Implemented in

Navigator 3.0

Description

The value of this property is the window's associated History object.

innerHeight

Specifies the vertical dimension, in pixels, of the window's content area.

Property of

Window

Implemented in

Navigator 4.0

Description

To create a window smaller than 100 x 100 pixels, set this property in a signed script.

Security

To set the inner height of a window to a size smaller than 100 x 100 or larger than the screen can accommodate, you need the UniversalBrowserWrite privilege. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

See also

Window.innerWidth, Window.outerHeight, Window.outerWidth

innerWidth

Specifies the horizontal dimension, in pixels, of the window's content area.

Property of

Window

Implemented in

Navigator 4.0

Description

To create a window smaller than 100 x 100 pixels, set this property in a signed script.

Security

To set the inner width of a window to a size smaller than 100 x 100 or larger than the screen can accommodate, you need the UniversalBrowserWrite privilege. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

See also

Window.innerHeight, Window.outerHeight, Window.outerWidth

length

The number of child frames in the window.

Property of

Window

Read-only

Implemented in

Navigator 2.0

Description

This property gives you the same result as using the length property of the frames array.

location

Contains information on the current URL.

Property of

Window

Implemented in

Navigator 2.0

Description

The value of this property is the window's associated Location object.

locationbar

Represents the browser window's location bar (the region containing the bookmark and URL areas).

Property of

Window

Implemented in

Navigator 4.0

Description

The value of the locationbar property itself has one property, visible. If true, the location bar is visible; if false, it is hidden.

Security

Setting the value of the location bar's visible property requires the UniversalBrowserWrite privilege. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Examples

The following example would make the referenced window "chromeless" (chromeless windows lack toolbars, scrollbars, status areas, and so on, much like a dialog box) by hiding most of the user interface toolbars:

self.menubar.visible=false;
self.toolbar.visible=false;
self.locationbar.visible=false;
self.personalbar.visible=false;
self.scrollbars.visible=false;
self.statusbar.visible=false;

menubar

Represents the browser window's menu bar. This region contains browser's drop-down menus such as File, Edit, View, Go, Communicator, and so on.

Property of

Window

Implemented in

Navigator 4.0

Description

The value of the menubar property itself one property, visible. If true, the menu bar is visible; if false, it is hidden.

Security

Setting the value of the menu bar's visible property requires the UniversalBrowserWrite privilege. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Examples

The following example would make the referenced window "chromeless" (chromeless windows lack toolbars, scrollbars, status areas, and so on, much like a dialog box) by hiding most of the user interface toolbars:

self.menubar.visible=false;
self.toolbar.visible=false;
self.locationbar.visible=false;
self.personalbar.visible=false;
self.scrollbars.visible=false;
self.statusbar.visible=false;

name

A string specifying the window's name.

Property of

Window

Read-only (2.0); Modifiable (later versions)

Implemented in

Navigator 2.0

Security

Navigator 3.0: This property is tainted by default. For information on data tainting, see "JavaScript Security".

Description

In Navigator 2.0, NAME was a read-only property. In later versions, this property is modifiable by your code. This allows you to assign a name to a top-level window.

Examples

In the following example, the first statement creates a window called netscapeWin. The second statement displays the value "netscapeHomePage" in the Alert dialog box, because "netscapeHomePage" is the value of the windowName argument of netscapeWin.

netscapeWin=window.open("http://home.netscape.com","netscapeHomePage")
alert(netscapeWin.name)

opener

Specifies the window of the calling document when a window is opened using the open method.

Property of

Window

Implemented in

Navigator 3.0

Description

When a source document opens a destination window by calling the open method, the opener property specifies the window of the source document. Evaluate the opener property from the destination window.

This property persists across document unload in the opened window.

You can change the opener property at any time.

You may use Window.open to open a new window and then use Window.open on that window to open another window, and so on. In this way, you can end up with a chain of opened windows, each of which has an opener property pointing to the window that opened it.

Communicator allows a maximum of 100 windows to be around at once. If you open window2 from window1 and then are done with window1, be sure to set the opener property of window2 to null. This allows JavaScript to garbage collect window1. If you do not set the opener property to null, the window1 object remains, even though it's no longer really needed.

Examples

Example 1: Close the opener. The following code closes the window that opened the current window. When the opener window closes, opener is unchanged. However, window.opener.name then evaluates to undefined.

window.opener.close()
Example 2: Close the main browser window.

top.opener.close()
Example 3: Evaluate the name of the opener. A window can determine the name of its opener as follows:

document.write("<BR>opener property is " + window.opener.name)
Example 4: Change the value of opener. The following code changes the value of the opener property to null. After this code executes, you cannot close the opener window as shown in Example 1.

window.opener=null
Example 5: Change a property of the opener. The following code changes the background color of the window specified by the opener property.

window.opener.document.bgColor='bisque'

See also

Window.close, Window.open

outerHeight

Specifies the vertical dimension, in pixels, of the window's outside boundary.

Property of

Window

Implemented in

Navigator 4.0

Description

The outer boundary includes the scroll bars, the status bar, the tool bars, and other "chrome" (window border user interface elements). To create a window smaller than 100 x 100 pixels, set this property in a signed script.

See also

Window.innerWidth, Window.innerHeight, Window.outerWidth

outerWidth

Specifies the horizontal dimension, in pixels, of the window's outside boundary.

Property of

Window

Implemented in

Navigator 4.0

Description

The outer boundary includes the scroll bars, the status bar, the tool bars, and other "chrome" (window border user interface elements). To create a window smaller than 100 x 100 pixels, set this property in a signed script.

See also

Window.innerWidth, Window.innerHeight, Window.outerHeight

pageXOffset

Provides the current x-position, in pixels, of a window's viewed page.

Property of

Window

Read-only

Implemented in

Navigator 4.0

Description

The pageXOffset property provides the current x-position of a page as it relates to the upper-left corner of the window's content area. This property is useful when you need to find the current location of the scrolled page before using scrollTo or scrollBy.

Example

The following example returns the x-position of the viewed page.

x = myWindow.pageXOffset

See Also

Window.pageYOffset

pageYOffset

Provides the current y-position, in pixels, of a window's viewed page.

Property of

Window

Read-only

Implemented in

Navigator 4.0

Description

The pageYOffset property provides the current y-position of a page as it relates to the upper-left corner of the window's content area. This property is useful when you need to find the current location of the scrolled page before using scrollTo or scrollBy.

Example

The following example returns the y-position of the viewed page.

x = myWindow.pageYOffset

See also

Window.pageXOffset

parent

The parent property is the window or frame whose frameset contains the current frame.

Property of

Window

Read-only

Implemented in

Navigator 2.0

Description

This property is only meaningful for frames; that is, windows that are not top-level windows.

The parent property refers to the FRAMESET window of a frame. Child frames within a frameset refer to sibling frames by using parent in place of the window name in one of the following ways:

parent.frameName
parent.frames[index]
For example, if the fourth frame in a set has NAME="homeFrame", sibling frames can refer to that frame using parent.homeFrame or parent.frames[3].

You can use parent.parent to refer to the "grandparent" frame or window when a FRAMESET tag is nested within a child frame.

The value of the parent property is

<object nameAttribute>
where nameAttribute is the NAME attribute if the parent is a frame, or an internal reference if the parent is a window.

Examples

See examples for Frame.

personalbar

Represents the browser window's personal bar (also called the directories bar). This is the region the user can use for easy access to certain bookmarks.

Property of

Window

Implemented in

Navigator 4.0

Description

The value of the personalbar property itself one property, visible. If true, the personal bar is visible; if false, it is hidden.

Security

Setting the value of the personal bar's visible property requires the UniversalBrowserWrite privilege. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Examples

The following example would make the referenced window "chromeless" (chromeless windows lack toolbars, scrollbars, status areas, and so on, much like a dialog box) by hiding most of the user interface toolbars:

self.menubar.visible=false;
self.toolbar.visible=false;
self.locationbar.visible=false;
self.personalbar.visible=false;
self.scrollbars.visible=false;
self.statusbar.visible=false;

scrollbars

Represents the browser window's vertical and horizontal scroll bars for the document area.

Property of

Window

Implemented in

Navigator 4.0

Description

The value of the scrollbars property itself has one property, visible. If true, both scrollbars are visible; if false, they are hidden.

Security

Setting the value of the scrollbars' visible property requires the UniversalBrowserWrite privilege. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Examples

The following example would make the referenced window "chromeless" (chromeless windows lack toolbars, scrollbars, status areas, and so on, much like a dialog box) by hiding most of the user interface toolbars:

self.menubar.visible=false;
self.toolbar.visible=false;
self.locationbar.visible=false;
self.personalbar.visible=false;
self.scrollbars.visible=false;
self.statusbar.visible=false;

self

The self property is a synonym for the current window.

Property of

Window

Read-only

Implemented in

Navigator 2.0

Description

The self property refers to the current window. That is, the value of this property is a synonym for the object itself.

Use the self property to disambiguate a window property from a form or form element of the same name. You can also use the self property to make your code more readable.

The value of the self property is

<object nameAttribute>
where nameAttribute is the NAME attribute if self refers to a frame, or an internal reference if self refers to a window.

Examples

In the following example, self.status is used to set the status property of the current window. This usage disambiguates the status property of the current window from a form or form element called status within the current window.

<A HREF=""
   onClick="this.href=pickRandomURL()"
   onMouseOver="self.status='Pick a random URL' ; return true">
Go!</A>

status

Specifies a priority or transient message in the status bar at the bottom of the window, such as the message that appears when a mouseOver event occurs over an anchor.

Property of

Window

Implemented in

Navigator 2.0

Security

Navigator 3.0: This property is tainted by default. For information on data tainting, see "JavaScript Security".

Description

Do not confuse the status property with the defaultStatus property. The defaultStatus property reflects the default message displayed in the status bar.

You can set the status property at any time. You must return true if you want to set the status property in the onMouseOver event handler.

Examples

Suppose you have created a JavaScript function called pickRandomURL that lets you select a URL at random. You can use the onClick event handler of an anchor to specify a value for the HREF attribute of the anchor dynamically, and the onMouseOver event handler to specify a custom message for the window in the status property:

<A HREF=""
   onClick="this.href=pickRandomURL()"
   onMouseOver="self.status='Pick a random URL'; return true">
Go!</A>
In the preceding example, the status property of the window is assigned to the window's self property, as self.status.

See also

Window.defaultStatus

statusbar

Represents the browser window's status bar. This is the region containing the security indicator, browser status, and so on.

Property of

Window

Implemented in

Navigator 4.0

Description

The value of the statusbar property itself one property, visible. If true, the status bar is visible; if false, it is hidden.

Security

Setting the value of the status bar's visible property requires the UniversalBrowserWrite privilege. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Examples

The following example would make the referenced window "chromeless" (chromeless windows lack toolbars, scrollbars, status areas, and so on, much like a dialog box) by hiding most of the user interface toolbars:

self.menubar.visible=false;
self.toolbar.visible=false;
self.locationbar.visible=false;
self.personalbar.visible=false;
self.scrollbars.visible=false;
self.statusbar.visible=false;

toolbar

Represents the browser window's tool bar, containing the navigation buttons, such as Back, Forward, Reload, Home, and so on.

Property of

Window

Implemented in

Navigator 4.0

Description

The value of the toolbar property itself one property, visible. If true, the tool bar is visible; if false, it is hidden.

Security

Setting the value of the tool bar's visible property requires the UniversalBrowserWrite privilege. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Examples

The following example would make the referenced window "chromeless" (chromeless windows lack toolbars, scrollbars, status areas, and so on, much like a dialog box) by hiding most of the user interface toolbars:

self.menubar.visible=false;
self.toolbar.visible=false;
self.locationbar.visible=false;
self.personalbar.visible=false;
self.scrollbars.visible=false;
self.statusbar.visible=false;

top

The top property is a synonym for the topmost browser window, which is a document window or web browser window.

Property of

Window

Read-only

Implemented in

Navigator 2.0

Description

The top property refers to the topmost window that contains frames or nested framesets. Use the top property to refer to this ancestor window.

The value of the top property is

<object objectReference>
where objectReference is an internal reference.

Examples

The statement top.close() closes the topmost ancestor window.

The statement top.length specifies the number of frames contained within the topmost ancestor window. When the topmost ancestor is defined as follows, top.length returns three:

<FRAMESET COLS="30%,40%,30%">
<FRAME SRC=child1.htm NAME="childFrame1">
<FRAME SRC=child2.htm NAME="childFrame2">
<FRAME SRC=child3.htm NAME="childFrame3">
</FRAMESET>
The following example sets the background color of a frame called myFrame to red. myFrame is a child of the topmost ancestor window.

top.myFrame.document.bgColor="red"

window

The window property is a synonym for the current window or frame.

Property of

Window

Read-only

Implemented in

Navigator 2.0

Description

The window property refers to the current window or frame. That is, the value of this property is a synonym for the object itself.

Although you can use the window property as a synonym for the current frame, your code may be more readable if you use the self property. For example, window.name and self.name both specify the name of the current frame, but self.name may be easier to understand (because a frame is not displayed as a separate window).

Use the window property to disambiguate a property of the window object from a form or form element of the same name. You can also use the window property to make your code more readable.

The value of the window property is

<object nameAttribute>
where nameAttribute is the NAME attribute if window refers to a frame, or an internal reference if window refers to a window.

Examples

In the following example, window.status is used to set the status property of the current window. This usage disambiguates the status property of the current window from a form called "status" within the current window.

<A HREF=""
   onClick="this.href=pickRandomURL()"
   onMouseOver="window.status='Pick a random URL' ; return true">
Go!</A>

See also

Window.self

Methods

alert

Displays an Alert dialog box with a message and an OK button.

Method of

Window

Implemented in

Navigator 2.0

Syntax

alert("message")

Parameters

message
A string.

Description

An alert dialog box looks as follows:

Use the alert method to display a message that does not require a user decision. The message argument specifies a message that the dialog box contains.

You cannot specify a title for an alert dialog box, but you can use the open method to create your own alert dialog box. See open.

Examples

In the following example, the testValue function checks the name entered by a user in the Text object of a form to make sure that it is no more than eight characters in length. This example uses the alert method to prompt the user to enter a valid value.

function testValue(textElement) {
   if (textElement.length > 8) {
      alert("Please enter a name that is 8 characters or less")
   }
}
You can call the testValue function in the onBlur event handler of a form's Text object, as shown in the following example:

Name: <INPUT TYPE="text" NAME="userName"
   onBlur="testValue(userName.value)">

See also

Window.confirm, Window.prompt

back

Undoes the last history step in any frame within the top-level window; equivalent to the user pressing the browser's Back button.

Method of

Window

Implemented in

Navigator 4.0

Syntax

back()

Parameters

None

Description

Calling the back method is equivalent to the user pressing the browser's Back button. That is, back undoes the last step anywhere within the top-level window, whether it occurred in the same frame or in another frame in the tree of frames loaded from the top-level window. In contrast, the history object's back method backs up the current window or frame history one step.

For example, consider the following scenario. While in Frame A, you click the Forward button to change Frame A's content. You then move to Frame B and click the Forward button to change Frame B's content. If you move back to Frame A and call FrameA.back(), the content of Frame B changes (clicking the Back button behaves the same).

If you want to navigate Frame A separately, use FrameA.history.back().

Examples

The following custom buttons perform the same operation as the browser's Back button:

<P><INPUT TYPE="button" VALUE="< Go Back"
   onClick="history.back()">
<P><INPUT TYPE="button" VALUE="> Go Back"
   onClick="myWindow.back()">

See also

Window.forward, History.back

blur

Removes focus from the specified object.

Method of

Window

Implemented in

Navigator 2.0

Syntax

blur()

Parameters

None

Description

Use the blur method to remove focus from a specific window or frame. Removing focus from a window sends the window to the background in most windowing systems.

See also

Window.focus

captureEvents

Sets the window to capture all events of the specified type.

Method of

Window

Implemented in

Navigator 4.0

Syntax

captureEvents(eventType)

Parameters

eventType
The type of event to be captured. The available event types are listed with the event object.

Security

When a window with frames wants to capture events in pages loaded from different locations (servers), you need to use captureEvents in a signed script and precede it with enableExternalCapture. You must have the UniversalBrowserWrite privilege. For more information and an example, see enableExternalCapture. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

See also

captureEvents works in tandem with releaseEvents, routeEvent, and handleEvent. For more information, see "Events in Navigator 4.0".

clearInterval

Cancels a timeout that was set with the setInterval method.

Method of

Window

Implemented in

Navigator 4.0

Syntax

clearInterval(intervalID)

Parameters

intervalID
Timeout setting that was returned by a previous call to the setInterval method.

Description

See setInterval.

Examples

See setInterval.

See also

Window.setInterval

clearTimeout

Cancels a timeout that was set with the setTimeout method.

Method of

Window

Implemented in

Navigator 2.0

Syntax

clearTimeout(timeoutID)

Parameters

timeoutID
A timeout setting that was returned by a previous call to the setTimeout method.

Description

See setTimeout.

Examples

See setTimeout.

See also

Window.clearInterval, Window.setTimeout

close

Closes the specified window.

Method of

Window

Implemented in

Navigator 2.0: closes any window.
Navigator 3.0: closes only windows opened by JavaScript.
Navigator 4.0: must use signed scripts to unconditionally close a window.

Syntax

close()

Parameters

None

Security

Navigator 4.0: To unconditionally close a window, you need the UniversalBrowserWrite privilege. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Description

The close method closes the specified window. If you call close without specifying a windowReference, JavaScript closes the current window.

The close method closes only windows opened by JavaScript using the open method. If you attempt to close any other window, a confirm is generated, which lets the user choose whether the window closes. This is a security feature to prevent "mail bombs" containing self.close(). However, if the window has only one document (the current one) in its session history, the close is allowed without any confirm. This is a special case for one-off windows that need to open other windows and then dispose of themselves.

In event handlers, you must specify window.close() instead of simply using close(). Due to the scoping of static objects in JavaScript, a call to close() without specifying an object name is equivalent to document.close().

Examples

Example 1. Any of the following examples closes the current window:

window.close()
self.close()
close()
Example 2: Close the main browser window. The following code closes the main browser window.

top.opener.close()
Example 3. The following example closes the messageWin window:

messageWin.close()
This example assumes that the window was opened in a manner similar to the following:

messageWin=window.open("")

See also

Window.closed, Window.open

confirm

Displays a Confirm dialog box with the specified message and OK and Cancel buttons.

Method of

Window

Implemented in

Navigator 2.0

Syntax

confirm("message")

Parameters

message
A string.

Description

A confirm dialog box looks as follows:

Use the confirm method to ask the user to make a decision that requires either an OK or a Cancel. The message argument specifies a message that prompts the user for the decision. The confirm method returns true if the user chooses OK and false if the user chooses Cancel.

You cannot specify a title for a confirm dialog box, but you can use the open method to create your own confirm dialog. See open.

Examples

This example uses the confirm method in the confirmCleanUp function to confirm that the user of an application really wants to quit. If the user chooses OK, the custom cleanUp function closes the application.

function confirmCleanUp() {
   if (confirm("Are you sure you want to quit this application?")) {
      cleanUp()
   }
}
You can call the confirmCleanUp function in the onClick event handler of a form's push button, as shown in the following example:

<INPUT TYPE="button" VALUE="Quit" onClick="confirmCleanUp()">

See also

Window.alert, Window.prompt

disableExternalCapture

Disables external event capturing set by the enableExternalCapture method.

Method of

Window

Implemented in

Navigator 4.0

Syntax

disableExternalCapture()

Parameters

None

Description

See enableExternalCapture.

enableExternalCapture

Allows a window with frames to capture events in pages loaded from different locations (servers).

Method of

Window

Implemented in

Navigator 4.0

Syntax

enableExternalCapture()

Parameters

None

Description

Use this method in a signed script requesting UniversalBrowserWrite privileges, and use it before calling the captureEvents method.

If Communicator sees additional scripts that cause the set of principals in effect for the container to be downgraded, it disables external capture of events. Additional calls to enableExternalCapture (after acquiring the UniversalBrowserWrite privilege under the reduced set of principals) can be made to enable external capture again.

Example

In the following example, the window is able to capture all Click events that occur across its frames.

<SCRIPT ARCHIVE="myArchive.jar" ID="2">
function captureClicks() {
   netscape.security.PrivilegeManager.enablePrivilege(
      "UniversalBrowserWrite");
   enableExternalCapture();
   captureEvents(Event.CLICK);
   ...
}
</SCRIPT>

See also

Window.disableExternalCapture, Window.captureEvents

find

Finds the specified text string in the contents of the specified window.

Method of

Window

Implemented in

Navigator 4.0

Syntax

find(string, casesensitive, backward)

Parameters

string
(Optional) The text string for which to search.

casesensitive
(Optional) Boolean value. If true, specifies a case-sensitive search. If you supply this parameter, you must also supply backward.

backward
(Optional) Boolean. If true, specifies a backward search. If you supply this parameter, you must also supply casesensitive.

Returns

true if the string is found; otherwise, false.

Description

When a string is specified, the browser performs a case-insensitive, forward search. If a string is not specified, the method displays the Find dialog box, allowing the user to enter a search string.

focus

Gives focus to the specified object.

Method of

Window

Implemented in

Navigator 3.0

Syntax

focus()

Parameters

None

Description

Use the focus method to navigate to a specific window or frame, and give it focus. Giving focus to a window brings the window forward in most windowing systems.

In Navigator 3.0, on some platforms, the focus method gives focus to a frame but the focus is not visually apparent (for example, the frame's border is not darkened).

Examples

In the following example, the checkPassword function confirms that a user has entered a valid password. If the password is not valid, the focus method returns focus to the Password object and the select method highlights it so the user can reenter the password.

function checkPassword(userPass) {
   if (badPassword) {
      alert("Please enter your password again.")
      userPass.focus()
      userPass.select()
   }
}
This example assumes that the Password object is defined as

<INPUT TYPE="password" NAME="userPass">

See also

Window.blur

forward

Points the browser to the next URL in the current history list; equivalent to the user pressing the browser's Forward button

Method of

Window

Implemented in

Navigator 4.0

Syntax

history.forward()
forward()

Parameters

None

Description

This method performs the same action as a user choosing the Forward button in the browser. The forward method is the same as history.go(1).

When used with the Frame object, forward behaves as follows: While in Frame A, you click the Back button to change Frame A's content. You then move to Frame B and click the Back button to change Frame B's content. If you move back to Frame A and call FrameA.forward(), the content of Frame B changes (clicking the Forward button behaves the same). If you want to navigate Frame A separately, use FrameA.history.forward().

Examples

The following custom buttons perform the same operation as the browser's Forward button:

<P><INPUT TYPE="button" VALUE="< Go Forth"
   onClick="history.forward()">
<P><INPUT TYPE="button" VALUE="> Go Forth"
   onClick="myWindow.forward()">

See also

Window.back

handleEvent

Invokes the handler for the specified event.

Method of

Window

Implemented in

Navigator 4.0

Syntax

handleEvent(event)

Parameters

event
The name of an event for which the specified object has an event handler.

Description

handleEvent works in tandem with captureEvents, releaseEvents, and routeEvent. For more information, see "Events in Navigator 4.0".

home

Points the browser to the URL specified in preferences as the user's home page; equivalent to the user pressing the browser's Home button.

Method of

Window

Implemented in

Navigator 4.0

Syntax

home()

Parameters

None

Description

This method performs the same action as a user choosing the Home button in the browser.

moveBy

Moves the window relative to its current position, moving the specified number of pixels.

Method of

Window

Implemented in

Navigator 4.0

Syntax

moveBy(horizontal, vertical)

Parameters

horizontal
The number of pixels by which to move the window horizontally.

vertical
The number of pixels by which to move the window vertically.

Description

This method moves the window by adding or subtracting the specified number of pixels to the current location.

Security

Exceeding any of the boundaries of the screen (to hide some or all of a window) requires signed JavaScript, so a window won't move past the screen boundaries. You need the UniversalBrowserWrite privilege for this. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Examples:

To move the current window 5 pixels up towards the top of the screen (x-axis), and 10 pixels towards the right (y-axis) of the current window position, use this statement:

self.moveBy(-5,10); // relative positioning

See also

Window.moveTo

moveTo

Moves the top-left corner of the window to the specified screen coordinates.

Method of

Window

Implemented in

Navigator 4.0

Syntax

moveTo(x-coordinate, y-coordinate)

Parameters

x-coordinate 
The left edge of the window in screen coordinates.

y-coordinate
The top edge of the window in screen coordinates.

Description

This method moves the window to the absolute pixel location indicated by its parameters. The origin of the axes is at absolute position (0,0); this is the upper left-hand corner of the display.

Security

Exceeding any of the boundaries of the screen (to hide some or all of a window) requires signed JavaScript, so a window won't move past the screen boundaries. You need the UniversalBrowserWrite privilege for this. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Examples:

To move the current window to 25 pixels from the top boundary of the screen (x-axis), and 10 pixels from the left boundary of the screen (y-axis), use this statement:

self.moveTo(25,10); // absolute positioning

See also

Window.moveBy

open

Opens a new web browser window.

Method of

Window

Implemented in

Navigator 2.0
Navigator 4.0: added several new windowFeatures

Syntax

open(URL, windowName, windowFeatures)

Parameters

URL
A string specifying the URL to open in the new window. See the Location object for a description of the URL components.

windowName
A string specifying the window name to use in the TARGET attribute of a FORM or A tag. windowName can contain only alphanumeric or underscore (_) characters.

windowFeatures
(Optional) A string containing a comma-separated list determining whether or not to create various standard window features. These options are described below.

Description

In event handlers, you must specify window.open() instead of simply using open(). Due to the scoping of static objects in JavaScript, a call to open() without specifying an object name is equivalent to document.open().

The open method opens a new Web browser window on the client, similar to choosing New Navigator Window from the File menu of the browser. The URL argument specifies the URL contained by the new window. If URL is an empty string, a new, empty window is created.

You can use open on an existing window, and if you pass the empty string for the URL, you will get a reference to the existing window, but not load anything into it. You can, for example, then look for properties in the window.

windowFeatures is an optional string containing a comma-separated list of options for the new window (do not include any spaces in this list). After a window is open, you cannot use JavaScript to change the windowFeatures. The features you can specify are:

alwaysLowered
(Navigator 4.0) If yes, creates a new window that floats below other windows, whether it is active or not. This is a secure feature and must be set in signed scripts.

alwaysRaised
(Navigator 4.0) If yes, creates a new window that floats on top of other windows, whether it is active or not. This is a secure feature and must be set in signed scripts.

dependent
(Navigator 4.0) If yes, creates a new window as a child of the current window. A dependent window closes when its parent window closes. On Windows platforms, a dependent window does not show on the task bar.

directories
If yes, creates the standard browser directory buttons, such as What's New and What's Cool.

height
(Navigator 2.0 and 3.0) Specifies the height of the window in pixels.

hotkeys
(Navigator 4.0) If no (or 0), disables most hotkeys in a new window that has no menu bar. The security and quit hotkeys remain enabled.

innerHeight
(Navigator 4.0) Specifies the height, in pixels, of the window's content area. To create a window smaller than 100 x 100 pixels, set this feature in a signed script. This feature replaces height, which remains for backwards compatibility.

innerWidth
(Navigator 4.0) Specifies the width, in pixels, of the window's content area. To create a window smaller than 100 x 100 pixels, set this feature in a signed script. This feature replaces width, which remains for backwards compatibility.

location
If yes, creates a Location entry field.

menubar
If yes, creates the menu at the top of the window.

outerHeight
(Navigator 4.0) Specifies the vertical dimension, in pixels, of the outside boundary of the window. To create a window smaller than 100 x 100 pixels, set this feature in a signed script.

resizable
If yes, allows a user to resize the window.

screenX
(Navigator 4.0) Specifies the distance the new window is placed from the left side of the screen. To place a window offscreen, set this feature in a signed scripts.

screenY
(Navigator 4.0) Specifies the distance the new window is placed from the top of the screen. To place a window offscreen, set this feature in a signed scripts.

scrollbars
If yes, creates horizontal and vertical scrollbars when the Document grows larger than the window dimensions.

status
If yes, creates the status bar at the bottom of the window.

titlebar
(Navigator 4.0) If yes, creates a window with a title bar. To set the titlebar to no, set this feature in a signed script.

toolbar
If yes, creates the standard browser toolbar, with buttons such as Back and Forward.

width
(Navigator 2.0 and 3.0) Specifies the width of the window in pixels.

z-lock
(Navigator 4.0) If yes, creates a new window that does not rise above other windows when activated. This is a secure feature and must be set in signed scripts.

Many of these features (as noted above) can either be yes or no. For these features, you can use 1 instead of yes and 0 instead of no. If you want to turn a feature on, you can also simply list the feature name in the windowFeatures string.

If windowName does not specify an existing window and you do not supply the windowFeatures parameter, all of the features which have a yes/no choice are yes by default. However, if you do supply the windowFeatures parameter, then the titlebar and hotkeys are still yes by default, but the other features which have a yes/no choice are no by default.

For example, all of the following statements turn on the toolbar option and turn off all other Boolean options:

open("", "messageWindow", "toolbar")
open("", "messageWindow", "toolbar=yes")
open("", "messageWindow", "toolbar=1")
The following statement turn on the location and directories options and turns off all other Boolean options:

open("", "messageWindow", "toolbar,directories=yes")
How the alwaysLowered, alwaysRaised, and z-lock features behave depends on the windowing hierarchy of the platform. For example, on Windows, an alwaysLowered or z-locked browser window is below all windows in all open applications. On Macintosh, an alwaysLowered browser window is below all browser windows, but not necessarily below windows in other open applications. Similarly for an alwaysRaised window.

You may use open to open a new window and then use open on that window to open another window, and so on. In this way, you can end up with a chain of opened windows, each of which has an opener property pointing to the window that opened it.

Communicator allows a maximum of 100 windows to be around at once. If you open window2 from window1 and then are done with window1, be sure to set the opener property of window2 to null. This allows JavaScript to garbage collect window1. If you do not set the opener property to null, the window1 object remains, even though it's no longer really needed.

Security

To perform the following operations using the specified screen features, you need the UniversalBrowserWrite privilege:

For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Examples

Example 1. In the following example, the windowOpener function opens a window and uses write methods to display a message:

function windowOpener() {
   msgWindow=window.open("","displayWindow","menubar=yes")
   msgWindow.document.write
      ("<HEAD><TITLE>Message window</TITLE></HEAD>")
   msgWindow.document.write
      ("<CENTER><BIG><B>Hello, world!</B></BIG></CENTER>")
}
Example 2. The following is an onClick event handler that opens a new client window displaying the content specified in the file sesame.html. The window opens with the specified option settings; all other options are false because they are not specified.

<FORM NAME="myform">
<INPUT TYPE="button" NAME="Button1" VALUE="Open Sesame!"
   onClick="window.open ('sesame.html', 'newWin',
   'scrollbars=yes,status=yes,width=300,height=300')">
</FORM>

See also

Window.close

print

Prints the contents of the window.

Method of

Window

Implemented in

Navigator 4.0

Syntax

print()

Parameters

None

prompt

Displays a Prompt dialog box with a message and an input field.

Method of

Window

Implemented in

Navigator 2.0

Syntax

prompt(message, inputDefault)

Parameters

message
A string to be displayed as the message.

inputDefault
(Optional) A string or integer representing the default value of the input field.

Description

A prompt dialog box looks as follows:

Use the prompt method to display a dialog box that receives user input. If you do not specify an initial value for inputDefault, the dialog box displays <undefined>.

You cannot specify a title for a prompt dialog box, but you can use the open method to create your own prompt dialog. See open.

Examples

prompt("Enter the number of cookies you want to order:", 12)

See also

Window.alert, Window.confirm

releaseEvents

Sets the window or document to release captured events of the specified type, sending the event to objects further along the event hierarchy.

Method of

Window

Implemented in

Navigator 4.0

Note

If the original target of the event is a window, the window receives the event even if it is set to release that type of event.

Syntax

releaseEvents(eventType)

Parameters

eventType
Type of event to be captured.

Description

releaseEvents works in tandem with captureEvents, routeEvent, and handleEvent. For more information, see "Events in Navigator 4.0".

resizeBy

Resizes an entire window by moving the window's bottom-right corner by the specified amount.

Method of

Window

Implemented in

Navigator 4.0

Syntax

resizeBy(horizontal, vertical)

Parameters

horizontal
The number of pixels by which to resize the window horizontally.

vertical
The number of pixels by which to resize the window vertically.

Description

This method changes the window's dimensions by setting its outerWidth and outerHeight properties. The upper left-hand corner remains anchored and the lower right-hand corner moves. resizeBy moves the window by adding or subtracting the specified number of pixels to that corner's current location.

Security

Exceeding any of the boundaries of the screen (to hide some or all of a window) requires signed JavaScript, so a window won't move past the screen boundaries. In addition, windows have an enforced minimum size of 100 x 100 pixels; resizing a window to be smaller than this minimum requires signed JavaScript. You need the UniversalBrowserWrite privilege for this. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Examples

To make the current window 5 pixels narrower and 10 pixels taller than its current dimensions, use this statement:

self.resizeBy(-5,10); // relative positioning

See also

Window.resizeTo

resizeTo

Resizes an entire window to the specified pixel dimensions.

Method of

Window

Implemented in

Navigator 4.0

Syntax

resizeTo(outerWidth, outerHeight)

Parameters

outerWidth
An integer representing the window's width in pixels.

outerHeight
An integer representing the window's height in pixels.

Description

This method changes the window's dimensions by setting its outerWidth and outerHeight properties. The upper left-hand corner remains anchored and the lower right-hand corner moves. resizeBy moves to the specified position. The origin of the axes is at absolute position (0,0); this is the upper left-hand corner of the display.

Security

Exceeding any of the boundaries of the screen (to hide some or all of a window) requires signed JavaScript, so a window won't move past the screen boundaries. In addition, windows have an enforced minimum size of 100 x 100 pixels; resizing a window to be smaller than this minimum requires signed JavaScript. You need the UniversalBrowserWrite privilege for this. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide.

Examples

To make the window 225 pixels wide and 200 pixels tall, use this statement:

self.resizeTo(225,200); // absolute positioning

See also

Window.resizeBy

routeEvent

Passes a captured event along the normal event hierarchy.

Method of

Window

Implemented in

Navigator 4.0

Syntax

routeEvent(event)

Parameters

event
Name of the event to be routed.

Description

If a subobject (document or layer) is also capturing the event, the event is sent to that object. Otherwise, it is sent to its original target.

routeEvent works in tandem with captureEvents, releaseEvents, and handleEvent. For more information, see "Events in Navigator 4.0".

scroll

Scrolls a window to a specified coordinate.

Method of

Window

Implemented in

Navigator 3.0; deprecated in 4.0

Description

In Navigator 4.0, scroll is no longer used and has been replaced by scrollTo. scrollTo extends the capabilities of scroll. scroll remains for backward compatibility.

scrollBy

Scrolls the viewing area of a window by the specified amount.

Method of

Window

Implemented in

Navigator 4.0

Syntax

scrollBy(horizontal, vertical)

Parameters

horizontal
The number of pixels by which to scroll the viewing area horizontally.

vertical
The number of pixels by which to scroll the viewing area vertically.

Description

This method scrolls the content in the window if portions that can't be seen exist outside of the window. scrollBy scrolls the window by adding or subtracting the specified number of pixels to the current scrolled location.

For this method to have an effect the visible property of Window.scrollbars must be true.

Examples

To scroll the current window 5 pixels towards the left and 30 pixels down from the current position, use this statement:

self.scrollBy(-5,30); // relative positioning

See also

Window.scrollTo

scrollTo

Scrolls the viewing area of the window so that the specified point becomes the top-left corner.

Method of

Window

Implemented in

Navigator 4.0

Syntax

scrollTo(x-coordinate, y-coordinate)

Parameters

x-coordinate
An integer representing the x-coordinate of the viewing area in pixels.

y-coordinate
An integer representing the y-coordinate of the viewing area in pixels.

Description

scrollTo replaces scroll. scroll remains for backward compatibility.

The scrollTo method scrolls the content in the window if portions that can't be seen exist outside of the window. For this method to have an effect the visible property of Window.scrollbars must be true.

Examples

Example 1: Scroll the current viewing area. To scroll the current window to the leftmost boundary and 20 pixels down from the top of the window, use this statement:

self.scrollTo(0,20); // absolute positioning
Example 2: Scroll a different viewing area. The following code, which exists in one frame, scrolls the viewing area of a second frame. Two Text objects let the user specify the x and y coordinates. When the user clicks the Go button, the document in frame2 scrolls to the specified coordinates.

<SCRIPT>
function scrollIt(form) {
   var x = parseInt(form.x.value)
   var y = parseInt(form.y.value)
   parent.frame2.scrollTo(x, y)
}
</SCRIPT>
<BODY>
<FORM NAME="myForm">
<P><B>Specify the coordinates to scroll to:</B>
<BR>Horizontal:
<INPUT TYPE="text" NAME=x VALUE="0" SIZE=4>
<BR>Vertical:
<INPUT TYPE="text" NAME=y VALUE="0" SIZE=4>
<BR><INPUT TYPE="button" VALUE="Go"
   onClick="scrollIt(document.myForm)">
</FORM>

See also

Window.scrollBy

setInterval

Evaluates an expression or calls a function every time a specified number of milliseconds elapses, until canceled by a call to clearInterval.

Method of

Window

Implemented in

Navigator 4.0

Syntax

setInterval(expression, msec)
setInterval(function, msec, arg1, ..., argN)

Parameters

function
Any function.

expression
A string containing a JavaScript expression. The expression must be quoted; otherwise, setInterval calls it immediately. For example, setInterval("calcnum(3, 2)", 25).

msec
A numeric value or numeric string, in millisecond units.

arg1, ..., argn
(Optional) The arguments, if any, passed to function.

Description

The timeouts continue to fire until the associated window or frame is destroyed or the interval is canceled using the clearInterval method.

See also

Window.clearInterval, Window.setTimeout

setTimeout

Evaluates an expression or calls a function once after a specified number of milliseconds elapses.

Method of

Window

Implemented in

Navigator 2.0: Evaluating an expression.
Navigator 4.0: Calling a function.

Syntax

setTimeout(expression, msec)
setTimeout(function, msec, arg1, ..., argN)

Parameters

expression
A string containing a JavaScript expression. The expression must be quoted; otherwise, setTimeout calls it immediately. For example, setTimeout("calcnum(3, 2)", 25).

msec
A numeric value or numeric string, in millisecond units.

function
Any function.

arg1, ..., argN
(Optional) The arguments, if any, passed to function.

Description

The setTimeout method evaluates an expression or calls a function after a specified amount of time. It does not act repeatedly. For example, if a setTimeout method specifies five seconds, the expression is evaluated or the function is called after five seconds, not every five seconds. For repetitive timeouts, use the setInterval method.

setTimeout does not stall the script. The script continues immediately (not waiting for the timeout to expire). The call simply schedules an additional future event.

Examples

Example 1. The following example displays an alert message five seconds (5,000 milliseconds) after the user clicks a button. If the user clicks the second button before the alert message is displayed, the timeout is canceled and the alert does not display.

<SCRIPT LANGUAGE="JavaScript">
function displayAlert() {
   alert("5 seconds have elapsed since the button was clicked.")
}
</SCRIPT>
<BODY>
<FORM>
Click the button on the left for a reminder in 5 seconds;
click the button on the right to cancel the reminder before
it is displayed.
<P>
<INPUT TYPE="button" VALUE="5-second reminder"
   NAME="remind_button"
   onClick="timerID=setTimeout('displayAlert()',5000)">
<INPUT TYPE="button" VALUE="Clear the 5-second reminder"
   NAME="remind_disable_button"
   onClick="clearTimeout(timerID)">
</FORM>
</BODY>
Example 2. The following example displays the current time in a Text object. The showtime function, which is called recursively, uses the setTimeout method to update the time every second.

<HEAD>
<SCRIPT LANGUAGE="JavaScript">
<!--
var timerID = null
var timerRunning = false
function stopclock(){
   if(timerRunning)
      clearTimeout(timerID)
   timerRunning = false
}
function startclock(){
   // Make sure the clock is stopped
   stopclock()
   showtime()
}
function showtime(){
   var now = new Date()
   var hours = now.getHours()
   var minutes = now.getMinutes()
   var seconds = now.getSeconds()
   var timeValue = "" + ((hours > 12) ? hours - 12 : hours)
   timeValue += ((minutes < 10) ? ":0" : ":") + minutes
   timeValue += ((seconds < 10) ? ":0" : ":") + seconds
   timeValue += (hours >= 12) ? " P.M." : " A.M."
   document.clock.face.value = timeValue
   timerID = setTimeout("showtime()",1000)
   timerRunning = true
}
//-->
</SCRIPT>
</HEAD>
<BODY onLoad="startclock()">
<FORM NAME="clock" onSubmit="0">
   <INPUT TYPE="text" NAME="face" SIZE=12 VALUE ="">
</FORM>
</BODY>

See also

Window.clearTimeout, Window.setInterval

stop

Stops the current download.

Method of

Window

Implemented in

Navigator 4.0

Syntax

stop()

Parameters

None

Definition

This method performs the same action as a user choosing the Stop button in the browser.


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Last Updated: 10/31/97 16:29:51


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