create Image with ImageDataProvider instead of ImageData in

fillGradientRectangle()

This PR  refactors the image creation logic in fillGradientRectangle() by using an
ImageDataProvider instead of directly creating ImageData. There is no
visual impact for the changes the behavior should remain as before.

Author: arunjose696

bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/ImageData.java

@@ -2616,9 +2616,14 @@ static void fillGradientRectangle(GC gc, Device device,
 	RGB fromRGB, RGB toRGB,
 	int redBits, int greenBits, int blueBits, int zoom) {
 	/* Create the bitmap and tile it */
-	ImageData band = createGradientBand(width, height, vertical,
-		fromRGB, toRGB, redBits, greenBits, blueBits);
-	Image image = new Image(device, band);
+	ImageDataProvider imageDataProvider = imageZoom -> {
+		int scaledWidth = DPIUtil.pointToPixel(width, imageZoom);
+		int scaledHeight = DPIUtil.pointToPixel(height, imageZoom);
+		return createGradientBand(scaledWidth, scaledHeight, vertical, fromRGB, toRGB, redBits, greenBits,
+				blueBits);
+	};
+	Image image = new Image(device, imageDataProvider);
+	ImageData band = image.getImageData(zoom);
 	if ((band.width == 1) || (band.height == 1)) {
 			gc.drawImage(image, 0, 0, DPIUtil.pixelToPoint(band.width, zoom), DPIUtil.pixelToPoint(band.height, zoom),
 					DPIUtil.pixelToPoint(x, zoom), DPIUtil.pixelToPoint(y, zoom), DPIUtil.pixelToPoint(width, zoom),