background object
[The Windows Gadget Platform/Sidebar is available for use in the operating systems specified in the Requirements section. It may be altered or unavailable in subsequent versions. ]
Declares a gadget background with content and properties.
Members
The background object has these types of members:
Methods
The background object has these methods.
| Method | Description |
|---|---|
| addGlow | Adds a glow effect to the g:background element. |
| addImageObject | Adds a g:image element to the g:background element. |
| addShadow | Adds a shadow effect to the g:background image. |
| addTextObject | Adds a g:text element to the g:background element. |
| removeObjects | Removes all g:text and g:image elements added to the gadget background using the addTextObject and addImageObject methods. |
Properties
The background object has these properties.
| Property | Access type | Description |
|---|---|---|
| blur |
Read/write |
Gets or sets the level of blur applied to the g:background element. |
| brightness |
Read/write |
Gets or sets the brightness of the g:background element. |
| opacity |
Read/write |
Gets or sets the opacity of the g:background element. |
| rotation |
Read/write |
Gets or sets the degree of rotation applied to the g:background element. |
| softEdge |
Read/write |
Gets or sets the amount of edge softening that is applied to the g:background element. |
| src |
Read/write |
Gets or sets the image file used by the g:background element. |
Remarks
The Windows Sidebar supports JPEG, bitmap (BMP), Graphics Interchange Format (GIF), and Portable Network Graphics (PNG) image types. Only PNG supports alpha channel transparency.
This element is declared in the gadget HTML file through a non-standard tag.
An image can be assigned to the g:background element from a gadget script file by using the background property or src property.
Note
The Cascading Style Sheets (CSS) backgroundImage property can also be used to assign an image to the background.
Attributes of the g:background element can be accessed from the gadget script files if the element has an id tag.
This element is a $disp element.
This element requires a closing tag.
Examples
The following example shows how to declare a g:background element in HTML.
<g:background id="imgBackground" src="images/background.png" />
The following example shows how to use the src property to assign an image to the g:background element.
\\ imgBackground is the value of the 'id' attribute for the g:background element.
imgBackground.src = "../images/bg_undocked.jpg";
The following example shows how to access attributes of the g:background element.
\\ imgBackground is the value of the 'id' attribute for the g:background element.
imgBackground.opacity = 50;
The following example shows how to use the background property to assign an image to the g:background element.
[!Caution]
When using background images with alpha channel transparency the following two methods can result in unpredictable rendering, such as transparent pixels replaced with magenta, and limitations in functionality. As such, they are presented here for information purposes only and are not recommended.
[!Important]
For Windows 7, when the new<autoscaleDPI>element of the gadget manifest is set to true (for high-DPI support) and the following methods are used, rendering issues can increase significantly.
<html>
<head>
<title>Hello World</title>
<script type="text/jscript" language="jscript">
function init()
{
System.Gadget.background = "images\\background.png";
}
</script>
</head>
<body onload="init()">
<g:background id="imgBackground">
<span id="gadgetContent">Hello World!</span>
</g:background>
</body>
</html>
The following example shows how to use CSS to assign an image to the g:background element.
[!Important]
When using background images with alpha channel transparency the following method can result in unpredictable rendering (typically with magenta replacing transparent pixels) and limitations in functionality. As such, it is presented here for information purposes only and is not recommended.
[!Warning]
For Windows 7, when the<autoscaleDPI>element is set to true and the following method is used, rendering issues increase significantly.
<html>
<head>
<title>Hello World</title>
<script type="text/jscript" language="jscript">
function init()
{
with(document.body.style)
backgroundImage = "images\\background.png";
}
</script>
</head>
<body onload="init()">
<g:background id="imgBackground">
<span id="gadgetContent">Hello World!</span>
</g:background>
</body>
</html>
Requirements
| Minimum supported client |
Windows Vista [desktop apps only] |
| Minimum supported server |
Windows Server 2008 [desktop apps only] |
| End of client support |
Windows 7 |
| End of server support |
Windows Server 2008 |
| IDL |
|
| DLL |
|