Refactor fillGradientRectangle to avoid DPIUtil.autoScaleDown()

This PR replaces the use of DPIUtil.autoScaleDown() with
DPIUtil.scaleDown() in the fillGradientRectangle method.
Additionally, it refactors the image creation logic 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

@@ -2609,35 +2609,40 @@ static void buildDitheredGradientChannel(int from, int to, int steps,
  * @param redBits the number of significant red bits, 0 for palette modes
  * @param greenBits the number of significant green bits, 0 for palette modes
  * @param blueBits the number of significant blue bits, 0 for palette modes
+ * @param zoom the zoom of gc drawer used
  */
-static void fillGradientRectangle(GC gc, Device device,
-	int x, int y, int width, int height, boolean vertical,
-	RGB fromRGB, RGB toRGB,
-	int redBits, int greenBits, int blueBits) {
+static void fillGradientRectangle(GC gc, Device device, int x, int y, int width, int height, boolean vertical,
+		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 -> {
+		float scaleFactor = imageZoom / 100.0f;
+		int scaledWidth = Math.round(width * scaleFactor);
+		int scaledHeight = Math.round(height * scaleFactor);
+		return createGradientBand(scaledWidth, scaledHeight, vertical, fromRGB, toRGB, redBits, greenBits,
+				blueBits);
+	};
+	Image image = new Image(device, imageDataProvider);
+	ImageData band = image.getImageData();
 	if ((band.width == 1) || (band.height == 1)) {
-			gc.drawImage(image, 0, 0, DPIUtil.autoScaleDown(band.width), DPIUtil.autoScaleDown(band.height),
-					DPIUtil.autoScaleDown(x), DPIUtil.autoScaleDown(y), DPIUtil.autoScaleDown(width),
-					DPIUtil.autoScaleDown(height));
+			gc.drawImage(image, 0, 0, DPIUtil.scaleDown(band.width, zoom), DPIUtil.scaleDown(band.height, zoom),
+					DPIUtil.scaleDown(x, zoom), DPIUtil.scaleDown(y, zoom), DPIUtil.scaleDown(width, zoom),
+					DPIUtil.scaleDown(height, zoom));
 		} else {
 		if (vertical) {
 			for (int dx = 0; dx < width; dx += band.width) {
 				int blitWidth = width - dx;
 				if (blitWidth > band.width) blitWidth = band.width;
-					gc.drawImage(image, 0, 0, DPIUtil.autoScaleDown(blitWidth), DPIUtil.autoScaleDown(band.height),
-							DPIUtil.autoScaleDown(dx + x), DPIUtil.autoScaleDown(y), DPIUtil.autoScaleDown(blitWidth),
-							DPIUtil.autoScaleDown(band.height));
+					gc.drawImage(image, 0, 0, DPIUtil.scaleDown(blitWidth, zoom), DPIUtil.scaleDown(band.height, zoom),
+							DPIUtil.scaleDown(dx + x, zoom), DPIUtil.scaleDown(y, zoom), DPIUtil.scaleDown(blitWidth, zoom),
+							DPIUtil.scaleDown(band.height, zoom));
 				}
 		} else {
 			for (int dy = 0; dy < height; dy += band.height) {
 				int blitHeight = height - dy;
 				if (blitHeight > band.height) blitHeight = band.height;
-					gc.drawImage(image, 0, 0, DPIUtil.autoScaleDown(band.width), DPIUtil.autoScaleDown(blitHeight),
-							DPIUtil.autoScaleDown(x), DPIUtil.autoScaleDown(dy + y), DPIUtil.autoScaleDown(band.width),
-							DPIUtil.autoScaleDown(blitHeight));
+					gc.drawImage(image, 0, 0, DPIUtil.scaleDown(band.width, zoom), DPIUtil.scaleDown(blitHeight, zoom),
+							DPIUtil.scaleDown(x, zoom), DPIUtil.scaleDown(dy + y, zoom), DPIUtil.scaleDown(band.width, zoom),
+							DPIUtil.scaleDown(blitHeight, zoom));
 				}
 		}
 	}

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/GC.java

@@ -3183,7 +3183,7 @@ private void fillGradientRectangleInPixels(int x, int y, int width, int height,
 	final int bitResolution = (depth >= 24) ? 8 : (depth >= 15) ? 5 : 0;
 	ImageData.fillGradientRectangle(this, data.device,
 		x, y, width, height, vertical, fromRGB, toRGB,
-		bitResolution, bitResolution, bitResolution);
+		bitResolution, bitResolution, bitResolution, getZoom());
 }
 
 /**