[win32] Improve GC init for ImageGcDrawer

This commits wraps the GC initialization for the ImageGcDrawer to directly
pass the zoom from the wrapper when the GC is initialized. In all other
cases the GC will be initialized with 100 zoom.

Author: akoch-yatta

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

@@ -1719,6 +1719,10 @@ private ImageHandle init(ImageData i, int zoom) {
  */
 @Override
 public long internal_new_GC (GCData data) {
+	return configureGC(data, 100);
+}
+
+private long configureGC(GCData data, int zoom) {
 	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
 	/*
 	* Create a new GC that can draw into the image.
@@ -1743,9 +1747,9 @@ public long internal_new_GC (GCData data) {
 			data.style |= SWT.LEFT_TO_RIGHT;
 		}
 		data.device = device;
-		data.nativeZoom = initialNativeZoom;
+		data.nativeZoom = zoom;
 		data.image = this;
-		data.font = SWTFontProvider.getSystemFont(device, initialNativeZoom);
+		data.font = SWTFontProvider.getSystemFont(device, zoom);
 	}
 	return imageDC;
 }
@@ -2530,7 +2534,7 @@ protected ImageHandle newImageHandle(int zoom) {
 		} else {
 			image = new Image(device, width, height, zoom);
 		}
-		GC gc = new GC(image, gcStyle);
+		GC gc = new GC(new DrawableWrapper(image, zoom), gcStyle);
 		try {
 			gc.data.nativeZoom = zoom;
 			drawer.drawOn(gc, width, height);
@@ -2544,6 +2548,26 @@ protected ImageHandle newImageHandle(int zoom) {
 		}
 	}
 
+	private class DrawableWrapper implements Drawable {
+		private final Image image;
+		private final int zoom;
+
+		public DrawableWrapper(Image image, int zoom) {
+			this.image = image;
+			this.zoom = zoom;
+		}
+
+		@Override
+		public long internal_new_GC(GCData data) {
+			return this.image.configureGC(data, zoom);
+		}
+
+		@Override
+		public void internal_dispose_GC(long handle, GCData data) {
+			this.image.internal_dispose_GC(handle, data);
+		}
+	}
+
 	@Override
 	Object getProvider() {
 		return drawer;