Layer
Corresponds to a layer in an HTML page and provides a means for manipulating that layer.Created by
The HTMLLAYER or ILAYER tag, or using cascading style sheet syntax. The JavaScript runtime engine creates a Layer object corresponding to each layer in your document. It puts these objects in an array in the document.layers property. You access a Layer object by indexing this array.
To define a layer, use standard HTML syntax. If you specify the ID attribute, you can use the value of that attribute to index into the layers array.
For a complete description of layers, see Dynamic HTML in Netscape Communicator.
Some layer properties can be directly modified by assignment; for example, "mylayer.visibility = hide". A layer object also has methods that can affect these properties.
Event handlers
Property Summary
Method Summary
watch and unwatch methods from Object.
NOTE: Just as in the case of a document, if you want to define mouse click response for a layer, you must captureFor details about capturing events, see the Client-Side JavaScript Guide. If an event occurs in a point where multiple layers overlap, the topmost layer gets the event, even if it is transparent. However, if a layer is hidden, it does not get events.onMouseDownandonMouseUpevents at the level of the layer and process them as you want.
above
Thelayer object above this one in z-order, among all layers in the document or the enclosing window object if this layer is topmost. background
The image to use as the background for the layer's canvas (which is the part of the layer within the clip rectangle).Description
Each layer has a background property, whose value is an image object, whosesrc attribute is a URL that indicates the image to use to provide a tiled backdrop. The value is null if the layer has no backdrop. For example:
layer.background.src = "fishbg.gif";
below
Thelayer object below this one in z-order, among all layers in the document or null if this layer is at the bottom. bgColor
A string specifying the color to use as a solid background color for the layer's canvas (the part of the layer within the clip rectangle).Description
ThebgColor property is expressed as a hexadecimal RGB triplet or as a string literal (see the Client-Side JavaScript Guide). This property is the JavaScript reflection of the BGCOLOR attribute of the BODY tag.
You can set the bgColor property at any time.
If you express the color as a hexadecimal RGB triplet, you must use the format rrggbb. For example, the hexadecimal RGB values for salmon are red=FA, green=80, and blue=72, so the RGB triplet for salmon is "FA8072".
Examples
The following example sets the background color of themyLayer layer's canvas to aqua using a string literal:
myLayer.bgColor="aqua"The following example sets the background color of the
myLayer layer's canvas to aqua using a hexadecimal triplet:
myLayer.bgColor="00FFFF"
See also
Layer.bgColor
captureEvents
Sets the window or document to capture all events of the specified type.Syntax
captureEvents(eventType)
Parameters
eventType | Type of event to be captured. Available event types are listed in the Client-Side JavaScript Guide. |
Description
When a window with frames wants to capture events in pages loaded from different locations (servers), you need to usecaptureEvents in a signed script and precede it with enableExternalCapture. For more information and an example, see enableExternalCapture.
captureEvents works in tandem with releaseEvents, routeEvent, and handleEvent. For information on handling events, see the Client-Side JavaScript Guide.
clip.bottom
The bottom edge of the clipping rectangle (the part of the layer that is visible.) Any part of a layer that is outside the clipping rectangle is not displayed.clip.height
The height of the clipping rectangle (the part of the layer that is visible.) Any part of a layer that is outside the clipping rectangle is not displayed.clip.left
The left edge of the clipping rectangle (the part of the layer that is visible.) Any part of a layer that is outside the clipping rectangle is not displayed.clip.right
The right edge of the clipping rectangle (the part of the layer that is visible.) Any part of a layer that is outside the clipping rectangle is not displayed.clip.top
The top edge of the clipping rectangle (the part of the layer that is visible.) Any part of a layer that is outside the clipping rectangle is not displayed.clip.width
The width of the clipping rectangle (the part of the layer that is visible.) Any part of a layer that is outside the clipping rectangle is not displayed.document
The layer's associated document.Description
Eachlayer object contains its own document object. This object can be used to access the images, applets, embeds, links, anchors and layers that are contained within the layer. Methods of the document object can also be invoked to change the contents of the layer.
handleEvent
Invokes the handler for the specified event.Syntax
handleEvent(event)
Parameters
event | Name of an event for which the specified object has an event handler. |
Description
handleEvent works in tandem with captureEvents, releaseEvents, and routeEvent. For information on handling events, see the Client-Side JavaScript Guide.
left
The horizontal position of the layer's left edge, in pixels, relative to the origin of its parent layer.Layer.x property is a convenience synonym for the left property.
See also
Layer.top
load
Changes the source of a layer to the contents of the specified file and simultaneously changes the width at which the layer's HTML contents are wrapped.Syntax
load(sourcestring, width)
Parameters
sourcestring | |
width |
moveAbove
Stacks this layer above the layer specified in the argument, without changing either layer's horizontal or vertical position. After re-stacking, both layers will share the same parent layer.Syntax
moveAbove(aLayer)
Parameters
aLayer |
moveBelow
Stacks this layer below the specified layer, without changing either layer's horizontal or vertical position. After re-stacking, both layers will share the same parent layer.Syntax
moveBelow(aLayer)
Parameters
aLayer |
moveBy
Changes the layer position by applying the specified deltas, measured in pixels.Syntax
moveBy(horizontal, vertical)
Parameters
horizontal | The number of pixels by which to move the layer horizontally. |
vertical |
moveTo
Moves the top-left corner of the window to the specified screen coordinates.Syntax
moveTo(x-coordinate, y-coordinate)
Parameters
x-coordinate | An integer representing the top edge of the window in screen coordinates. |
y-coordinate | An integer representing the left edge of the window in screen coordinates. |
Security
To move a window offscreen, call themoveTo method in a signed script. For information on security, see the Client-Side JavaScript Guide.
Description
Changes the layer position to the specified pixel coordinates within the containing layer. For ILayers, moves the layer relative to the natural inflow position of the layer.See also
Layer.moveBy
moveToAbsolute
Changes the layer position to the specified pixel coordinates within the page (instead of the containing layer.)Syntax
moveToAbsolute(x, y)
Parameters
x | An integer representing the top edge of the window in pixel coordinates. |
y | An integer representing the left edge of the window in pixel coordinates. |
Description
This method is equivalent to setting both thepageX and pageY properties of the layer object.
name
A string specifying the name assigned to the layer through theID attribute in the LAYER tag. pageX
The horizontal position of the layer, in pixels, relative to the page.pageY
The vertical position of the layer, in pixels, relative to the page.parentLayer
Thelayer object that contains this layer, or the enclosing window object if this layer is not nested in another layer. releaseEvents
Sets the window or document to release captured events of the specified type, sending the event to objects further along the event hierarchy.Syntax
releaseEvents(eventType)
Parameters
eventType |
Description
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.releaseEvents works in tandem with captureEvents, routeEvent, and handleEvent. For more information, see the Client-Side JavaScript Guide.
resizeBy
Resizes the layer by the specified height and width values (in pixels).Syntax
resizeBy(width, height)
Parameters
width | The number of pixels by which to resize the layer horizontally. |
height | The number of pixels by which to resize the layer vertically. |
Description
This does not layout any HTML contained in the layer again. Instead, the layer contents may be clipped by the new boundaries of the layer. This method has the same effect as addingwidth and height to clip.width and clip.height.
resizeTo
Resizes the layer to have the specified height and width values (in pixels).Description
This does not layout any HTML contained in the layer again. Instead, the layer contents may be clipped by the new boundaries of the layer.Syntax
resizeTo(width, height)
Parameters
width | |
height |
Description
This method has the same effect settingclip.width and clip.height.
routeEvent
Passes a captured event along the normal event hierarchy.Syntax
routeEvent(event)
Parameters
event |
Description
If a sub-object (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 the Client-Side JavaScript Guide.
siblingAbove
The layer object above this one in z-order, among all layers that share the same parent layer or null if the layer has no sibling above.siblingBelow
Thelayer object below this one in z-order, among all layers that share the same parent layer or null if layer is at the bottom.src
A URL string specifying the source of the layer's content. Corresponds to theSRC attribute.top
The vertical position of the layer's left edge, in pixels, relative to the origin of its parent layer.Layer.y property is a convenience synonym for the top property.
See also
Layer.left
visibility
Whether or not the layer is visible.Description
A value ofshow means show the layer; hide means hide the layer; inherit means inherit the visibility of the parent layer.
window
Thewindow or Frame object that contains the layer, regardless of whether the layer is nested within another layer.x
The horizontal position of the layer's left edge, in pixels, relative to the origin of its parent layer.x property is a convenience synonym for the Layer.left property.
See also
Layer.y
y
The vertical position of the layer's left edge, in pixels, relative to the origin of its parent layer.y property is a convenience synonym for the Layer.top property.
See also
Layer.x
zIndex
The relative z-order of this layer with respect to its siblings.Description
Sibling layers with lower numbered z-indexes are stacked underneath this layer. The value ofzIndex must be 0 or a positive integer.
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Last Updated: 05/28/99 11:59:42
