Clarified ImageDataProvider Contract and Debugging Support for Linear Scaling

Author: arunjose696

news/4.37/platform_isv.md

@@ -36,9 +36,22 @@ Display.getDefault().asyncExec(() -> {
 });
 ```
 
-<!--
----
-## SWT Changes
--->
 
+## SWT Changes
 
+### Clarified ImageDataProvider Contract
+
+The `ImageDataProvider` API documentation has been updated to clarify that 
+implementations are expected to return **linearly scaled** `ImageData` 
+based on the zoom level. For example, if `getImageData(100)` returns 
+an image of width *w* and height *h*, then `getImageData(200)` must 
+return an image of width `2 * w` and height `2 * h`, if non-null.
+This is only makes an implicit assumption explicit, some consumers have always 
+relied on this linear scaling behavior, and lack of it may have led to unexpected behavior in the past.
+
+Additionally, strict runtime checks verifying this linear scaling behavior 
+are available as a debugging feature to assist developers in validating 
+their implementations.  
+These checks can be enabled by starting Java with the `-Dorg.eclipse.swt.internal.enableStrictChecks`, 
+but note that this system property may be subject to change in future releases without 
+prior notice.