Fixing contracts

Author: ShahzaibIbrahim

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

@@ -514,19 +514,23 @@ private static interface CursorHandleProvider {
 }
 
 private static class StyleCursorHandleProvider implements CursorHandleProvider {
-	private final int style;
+	private final long lpCursorName;
 
 	public StyleCursorHandleProvider(int style) {
-		this.style = style;
+		this.lpCursorName = setupCursorFromStyle(style);
 	}
 
 	@Override
 	public CursorHandle createHandle(Device device, int zoom) {
 		// zoom ignored, LoadCursor handles scaling internally
-		return setupCursorFromStyle(this.style);
+		long handle = OS.LoadCursor(0, lpCursorName);
+		if (handle == 0) {
+			SWT.error(SWT.ERROR_NO_HANDLES);
+		}
+		return new CustomCursorHandle(handle);
 	}
 
-	private static final CursorHandle setupCursorFromStyle(int style) {
+	private static final long setupCursorFromStyle(int style) {
 		long lpCursorName = 0;
 		switch (style) {
 		case SWT.CURSOR_HAND:
@@ -598,11 +602,7 @@ private static final CursorHandle setupCursorFromStyle(int style) {
 		default:
 			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
 		}
-		long handle = OS.LoadCursor(0, lpCursorName);
-		if (handle == 0) {
-			SWT.error(SWT.ERROR_NO_HANDLES);
-		}
-		return new CustomCursorHandle(handle);
+		return lpCursorName;
 	}
 }
 
@@ -629,6 +629,13 @@ private static class ImageDataProviderCursorHandleProvider extends HotspotAwareC
 
 	public ImageDataProviderCursorHandleProvider(ImageDataProvider provider, int hotspotX, int hotspotY) {
 		super(hotspotX, hotspotY);
+		ImageData source = provider.getImageData(DEFAULT_ZOOM);
+		if (source == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+		/* Check the hotspots */
+		if (hotspotX >= source.width || hotspotX < 0 ||
+			hotspotY >= source.height || hotspotY < 0) {
+			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
+		}
 		this.provider = provider;
 	}
 
@@ -651,6 +658,12 @@ private static class ImageDataCursorHandleProvider extends HotspotAwareCursorHan
 
 	public ImageDataCursorHandleProvider(ImageData source, int hotspotX, int hotspotY) {
 		super(hotspotX, hotspotY);
+		if (source == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+		/* Check the hotspots */
+		if (hotspotX >= source.width || hotspotX < 0 ||
+			hotspotY >= source.height || hotspotY < 0) {
+			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
+		}
 		this.source = source;
 	}
 
@@ -667,6 +680,16 @@ private static class ImageDataWithMaskCursorHandleProvider extends ImageDataCurs
 
 	public ImageDataWithMaskCursorHandleProvider(ImageData source, ImageData mask, int hotspotX, int hotspotY) {
 		super(source, hotspotX, hotspotY);
+		if (mask == null) {
+			if (source.getTransparencyType() != SWT.TRANSPARENCY_MASK) {
+				SWT.error(SWT.ERROR_NULL_ARGUMENT);
+			}
+			mask = source.getTransparencyMask();
+		}
+		/* Check the bounds. Mask must be the same size as source */
+		if (mask.width != source.width || mask.height != source.height) {
+			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
+		}
 		this.mask = mask;
 	}