com.smartgwt.client.docs

## Interface SCImgURL

-     public interface SCImgURL

  Properties that refer to images by URL, such as `Img.src` and `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.

  For 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 "skin directory", established in `load_skin.js` via `Page.setSkinDir()`, plus..
  - the setting for `skinImgDir` on 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"`.

  Some 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 refer to `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 location.

  TIPS:

  - subcomponents may not share the parent component's setting for skinImgDir. For example, the `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).
  - for a particular image, the skinImgDir setting on the component may not be convenient. The prefix "[SKINIMG]" can be used to refer to `Page.getSkinDir() + "/images"` regardless of the setting for `skinImgDir`
  Stateful image URLs

  Many image 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.