| LayerCorresponds to a layer in an HTML page and provides a means for manipulating that layer.
Client-side object | | Implemented in | Navigator 4.0 |
Created byThe HTML LAYER 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 Communicator1.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
above
| The layer 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. | bgColor
| The color to use as a solid background color for the layer's canvas. | below
| The layer object below this one in z-order, among all layers in the document or null if this layer is at the bottom. | clip.bottom
| The bottom edge of the clipping rectangle (the part of the layer that is visible.) | clip.height
| The height of the clipping rectangle (the part of the layer that is visible.) | clip.left
| The left edge of the clipping rectangle (the part of the layer that is visible.) | clip.right
| The right edge of the clipping rectangle (the part of the layer that is visible.) | clip.top
| The top edge of the clipping rectangle (the part of the layer that is visible.) | clip.width
| The width of the clipping rectangle (the part of the layer that is visible.) | document
| The layer's associated document. | left
| The horizontal position of the layer's left edge, in pixels, relative to the origin of its parent layer. | name
| A string specifying the name assigned to the layer through the ID attribute in the LAYER tag. | pageX
| The horizontal position of the layer, in pixels, relative to the page. | page y | The vertical position of the layer, in pixels, relative to the page. | parentLayer
| The layer object that contains this layer, or the enclosing window object if this layer is not nested in another layer. | 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
| The layer 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 string specifying the URL of the layer's content. | top
| The vertical position of the layer's top edge, in pixels, relative to the origin of its parent layer. | visibility
| Whether or not the layer is visible. | zIndex
| The relative z-order of this layer with respect to its siblings. |
Method Summary
captureEvents
| Sets the window or document to capture all events of the specified type. | handleEvent
| Invokes the handler for the specified event. | 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 will be wrapped. | moveAbove
| Stacks this layer above the layer specified in the argument, without changing either layer's horizontal or vertical position. | moveBelow
| Stacks this layer below the specified layer, without changing either layer's horizontal or vertical position. | moveBy
| Changes the layer position by applying the specified deltas, measured in pixels. | moveTo
| Moves the top-left corner of the window to the specified screen coordinates. | moveToAbsolute
| Changes the layer position to the specified pixel coordinates within the page (instead of the containing layer.) | releaseEvents
| Sets the layer to release captured events of the specified type, sending the event to objects further along the event hierarchy. | resizeBy
| Resizes the layer by the specified height and width values (in pixels). | resizeTo
| Resizes the layer to have the specified height and width values (in pixels). | routeEvent
| Passes a captured event along the normal event hierarchy. |
NoteJust as in the case of a document, if you want to define mouse click response for a layer, you must capture onMouseDown and onMouseUp events at the level of the layer and process them as you want. See "Events in Navigator 4.0" for more details about capturing events.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. PropertiesaboveThe layer object above this one in z-order, among all layers in the document or the enclosing window object if this layer is topmost.
Property of | Layer | Read-only | | Implemented in | Navigator 4.0 |
backgroundThe image to use as the background for the layer's canvas (which is the part of the layer within the clip rectangle).
Property of | Layer | Implemented in | Navigator 4.0 |
DescriptionEach layer has a background property, whose value is an image object, whose src 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"; bgColorA 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).
Property of | Layer | Implemented in | Navigator 4.0 | DescriptionThe bgColor property is expressed as a hexadecimal RGB triplet or as one of the string literals listed in the 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" . ExamplesThe following example sets the background color of the myLayer 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 alsoLayer.bgColor belowThe layer object below this one in z-order, among all layers in the document or null if this layer is at the bottom.
Property of | Layer | Read-only | | Implemented in | Navigator 4.0 |
clip.bottomThe 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.
Property of | Layer | Implemented in | Navigator 4.0 |
clip.heightThe 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.
Property of | Layer | Implemented in | Navigator 4.0 |
clip.leftThe 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.
Property of | Layer | Implemented in | Navigator 4.0 |
clip.rightThe 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.
Property of | Layer | Implemented in | Navigator 4.0 |
clip.topThe 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.
Property of | Layer | Implemented in | Navigator 4.0 |
clip.widthThe 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.
Property of | Layer | Implemented in | Navigator 4.0 |
documentThe layer's associated document.
Property of | Layer | Read-only | | Implemented in | Navigator 4.0 |
DescriptionEach layer 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.leftThe horizontal position of the layer's left edge, in pixels, relative to the origin of its parent layer.
Property of | Layer | Implemented in | Navigator 4.0 |
nameA string specifying the name assigned to the layer through the ID attribute in the LAYER tag.
Property of | Layer | Read-only | | Implemented in | Navigator 4.0 |
pageXThe horizontal position of the layer, in pixels, relative to the page.
Property of | Layer | Implemented in | Navigator 4.0 |
pageYThe vertical position of the layer, in pixels, relative to the page.
Property of | Layer | Implemented in | Navigator 4.0 |
parentLayerThe layer object that contains this layer, or the enclosing window object if this layer is not nested in another layer.
Property of | Layer | Read-only | | Implemented in | Navigator 4.0 |
siblingAboveThe 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.
Property of | Layer | Read-only | | Implemented in | Navigator 4.0 |
siblingBelowThe layer object below this one in z-order, among all layers that share the same parent layer or null if layer is at the bottom.
Property of | Layer | Read-only | | Implemented in | Navigator 4.0 |
srcA URL string specifying the source of the layer's content. Corresponds to the SRC attribute.
Property of | Layer | Implemented in | Navigator 4.0 |
topThe top property is a synonym for the topmost Navigator window, which is a document window or web browser window.
Property of | Layer | Read-only | | Implemented in | Navigator 4.0 |
DescriptionThe 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. ExamplesThe 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> visibilityWhether or not the layer is visible.
Property of | Layer | Implemented in | Navigator 4.0 |
DescriptionA value of show means show the layer; hide means hide the layer; inherit means inherit the visibility of the parent layer.zIndexThe relative z-order of this layer with respect to its siblings.
Method of | Layer | Implemented in | Navigator 4.0 |
DescriptionSibling layers with lower numbered z-indexes are stacked underneath this layer. The value of zIndex must be 0 or a positive integer. MethodscaptureEventsSets the window or document to capture all events of the specified type.
Method of | Layer | Implemented in | Navigator 4.0 |
SyntaxcaptureEvents(eventType) Parameters
eventType | Type of event to be captured. Available event types are listed with event . |
DescriptionWhen 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 . For more information and an example, see enableExternalCapture . captureEvents works in tandem with releaseEvents , routeEvent , and handleEvent . For more information, see "Events in Navigator 4.0". handleEventInvokes the handler for the specified event.
Method of | Layer | Implemented in | Navigator 4.0 |
SyntaxhandleEvent(event) Parameters
event | Name of an event for which the specified object has an event handler. |
DescriptionhandleEvent works in tandem with captureEvents , releaseEvents , and routeEvent . For more information, see "Events in Navigator 4.0". loadChanges 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.
Method of | Layer | Implemented in | Navigator 4.0 |
Syntaxload(sourcestring, width) Parameters
sourcestring | A string indicating the external file name. | width | The width of the layer as a pixel value. |
moveAboveStacks 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.
Method of | Layer | Implemented in | Navigator 4.0 |
SyntaxmoveAbove(aLayer) Parameters
aLayer | The layer above which to move the current layer. |
moveBelowStacks 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.
Method of | Layer | Implemented in | Navigator 4.0 |
SyntaxmoveBelow(aLayer) Parameters
aLayer | The layer below which to move the current layer. |
moveByChanges the layer position by applying the specified deltas, measured in pixels.
Method of | Layer | Implemented in | Navigator 4.0 |
SyntaxmoveBy(horizontal, vertical) Parameters
horizontal | The number of pixels by which to move the layer horizontally. | vertical | The number of pixels by which to move the layer vertically. |
moveToMoves the top-left corner of the window to the specified screen coordinates.
Method of | Layer | Implemented in | Navigator 4.0 |
SyntaxmoveTo(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. |
SecurityTo move a window offscreen, call the moveTo method in a signed script. For information on security in Navigator 4.0, see Chapter 7, "JavaScript Security," in the JavaScript Guide. DescriptionChanges 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 alsoLayer.moveBy moveToAbsoluteChanges the layer position to the specified pixel coordinates within the page (instead of the containing layer.)
Method of | Layer | Implemented in | Navigator 4.0 |
SyntaxmoveToAbsolute(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. |
DescriptionThis method is equivalent to setting both the pageX and pageY properties of the layer object.releaseEventsSets the window or document to release captured events of the specified type, sending the event to objects further along the event hierarchy.
Method of | Layer | Implemented in | Navigator 4.0 |
SyntaxreleaseEvents(eventType) Parameters
eventType | Type of event to be captured. |
DescriptionIf 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 "Events in Navigator 4.0". resizeByResizes the layer by the specified height and width values (in pixels).
Method of | Layer | Implemented in | Navigator 4.0 |
SyntaxresizeBy(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. |
DescriptionThis 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 adding width and height to clip.width and clip.height .resizeToResizes the layer to have the specified height and width values (in pixels).
Method of | Layer | Implemented in | Navigator 4.0 |
DescriptionThis does not layout any HTML contained in the layer again. Instead, the layer contents may be clipped by the new boundaries of the layer. SyntaxresizeBy(width, height) Parameters
width | An integer representing the layer's width in pixels. | height | An integer representing the layer's height in pixels. |
DescriptionThis method has the same effect setting clip.width and clip.height .routeEventPasses a captured event along the normal event hierarchy.
Method of | Layer | Implemented in | Navigator 4.0 |
SyntaxrouteEvent(event) Parameters
DescriptionIf 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". |
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