public interface SCImgURL extends URL
Button.icon, are specially interpreted in Smart GWT to allow for simpler and
more uniform image URLs, and to allow applications to be restructured more easily.
the application image directory
When specifying URLs to image files via Smart GWT component properties such as
StretchImg.src, any relative path is assumed to be relative to the
"application image directory" (
appImgDir). The application image directory can be set via
Page.setAppImgDir(), and defaults to "images/", representing the typical
practice of placing images in a subdirectory relative to the URL at which the application is accessed.
applications that may be launched from multiple URLs, the
appImgDir can be set to the correct relative path
to the image directory by calling
Page.setAppImgDir() before any
Smart GWT components are created. This enables applications or components of an application to be launched from
multiple locations, or to be relocated, without changing any image URLs supplied to Smart GWT components.
the "[SKIN]" URL prefix
The special prefix "[SKIN]" can be used to refer to images within the skin folder whenever image URLs are supplied to Smart GWT components.
The value of "[SKIN]" is the combination of:
the component where you set an image URL property
skinImgDir defaults to "images/", so creating an
Img component with
Img.src set to
"[SKIN]myButton/button.gif" will expand to
Page.getSkinDir() + "/images/myButton/button.gif".
components that use a large number of images use
skinImgDir to group them together and make it possible to
relocate all the media for the component with a single setting. For example, the
TreeGrid class sets
skinImgDir to "images/TreeGrid/". This allows
TreeGrid.folderIcon to be set to just "[SKIN]folder.gif" but
Page.getSkinDir() + "/images/TreeGrid/folder.gif".
A custom subclass of TreeGrid can set
skinImgDir to a different path, such as "/images/MyTreeGrid", to source all media from a different
Window.minimizeButton has the default setting for
"skinImgDir" ("images/"), so the
src property used with this component is
set to "[SKIN]/Window/minimize.png" (in the "Smart GWT" sample skin).
+ "/images" regardless of the setting for
URLs in Smart GWT are "stateful", meaning that the actual URL used to fetch an image will vary according to the
component's state (eg, "Disabled"), generally, by adding a suffix to the image URL. See the
Skinning Overview for more information on statefulness and the
Img.src documentation for information on how stateful image URLs are formed.
If the URL represents an SVG image, you may specify
tag as a query param to control
whether it's rendered in an object or image tag, provided
Canvas.useImageForSVG isn't set. If that query param is present and has any value other than
the SVG image will be rendered in an image tag. Otherwise, it will be rendered in an object tag. For example, an
SCImgURL of "circle.svg?tag=image" will render in an image tag.