Simplify and modernize ImageLoader and other graphic related tests

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_graphics_Cursor.java

@@ -137,10 +137,8 @@ public void test_ConstructorLorg_eclipse_swt_graphics_DeviceI() {
 @Test
 public void test_ConstructorLorg_eclipse_swt_graphics_DeviceLorg_eclipse_swt_graphics_ImageDataLorg_eclipse_swt_graphics_ImageDataII() {
 	// Test new Cursor(Device device, ImageData source, ImageData mask, int hotspotX, int hotspotY)
-	int numFormats = SwtTestUtil.imageFormats.length;
 	String fileName = SwtTestUtil.imageFilenames[0];
-	for (int i=0; i<numFormats; i++) {
-		String format = SwtTestUtil.imageFormats[i];
+	for (String format : SwtTestUtil.imageFormats) {
 		ImageLoader loader = new ImageLoader();
 		try (InputStream stream = SwtTestUtil.class.getResourceAsStream(fileName + "." + format)) {
 			ImageData source = loader.load(stream)[0];

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_graphics_Image.java

@@ -256,7 +256,7 @@ public void test_ConstructorLorg_eclipse_swt_graphics_DeviceLjava_io_InputStream
 
 	String firstFile = SwtTestUtil.invalidImageFilenames[0];
 	Display[] displays = { display, null };
-	for (int j = 0; j < displays.length; j++) {
+	for (Display display : displays) {
 		for (String format : SwtTestUtil.imageFormats) {
 			try (InputStream stream = SwtTestUtil.class.getResourceAsStream(firstFile + "." + format)) {
 				e = assertThrows(SWTException.class, () -> new Image(display, stream));
@@ -316,8 +316,7 @@ public void test_ConstructorLorg_eclipse_swt_graphics_DeviceLjava_lang_String()
 	// create valid images
 	for (Display display : displays) {
 		for (String fileName : SwtTestUtil.imageFilenames) {
-			for (int i = 0; i < SwtTestUtil.imageFormats.length; i++) {
-				String format = SwtTestUtil.imageFormats[i];
+			for (String format : SwtTestUtil.imageFormats) {
 				String pathName = getPath(fileName + "." + format).toString();
 				Image image = new Image(display, pathName);
 				image.dispose();
@@ -868,10 +867,8 @@ public void test_toString() {
 /** Test implementation **/
 
 void getImageData1() {
-	int numFormats = SwtTestUtil.imageFormats.length;
 	String fileName = SwtTestUtil.imageFilenames[0];
-	for (int i=0; i<numFormats; i++) {
-		String format = SwtTestUtil.imageFormats[i];
+	for (String format : SwtTestUtil.imageFormats) {
 		try (InputStream stream = SwtTestUtil.class.getResourceAsStream(fileName + "." + format)) {
 			ImageData data1 = new ImageData(stream);
 			Image image = new Image(display, data1);

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_graphics_ImageData.java

@@ -27,7 +27,6 @@
 
 import java.io.IOException;
 import java.io.InputStream;
-import java.lang.reflect.InvocationTargetException;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -60,9 +59,10 @@ public void setUp() {
 /**
  * Tests {@link ImageData#blit}:
  * creates a random image and tests over all combinations of depth,format,scale
+ * @throws Exception
  */
 @Test
-public void test_blit() throws NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
+public void test_blit() throws Exception {
 	List<BlitTestInfo> tests = new ArrayList<>();
 
 	// Compose a list of all supported formats
@@ -117,9 +117,10 @@ public void test_blit() throws NoSuchMethodException, SecurityException, Illegal
 /**
  * Tests {@link ImageData#blit}:
  * Ensures that (MSB_FIRST, LSB_FIRST) round trip produces original.
+ * @throws Exception
  */
 @Test
-public void test_blit_MsbLsb() throws NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
+public void test_blit_MsbLsb() throws Exception {
 	List<BlitTestInfo> tests = new ArrayList<>();
 	{
 		for (int depth : indexedDepths) {
@@ -218,10 +219,8 @@ public void test_ConstructorLjava_io_InputStream() throws IOException {
 			assertThrows("No exception thrown for invalid InputStream", SWTException.class, () ->new ImageData(stream1));
 		}
 
-		int numFormats = SwtTestUtil.imageFormats.length;
 		String fileName = SwtTestUtil.imageFilenames[0];
-		for (int i=0; i<numFormats; i++) {
-			String format = SwtTestUtil.imageFormats[i];
+		for (String format : SwtTestUtil.imageFormats) {
 			try (InputStream stream2 = SwtTestUtil.class.getResourceAsStream(fileName + "." + format)) {
 				new ImageData(stream2);
 			}

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_graphics_ImageLoader.java

@@ -19,12 +19,14 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Arrays;
 
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.SWTException;
@@ -49,30 +51,26 @@ public void test_Constructor() {
 }
 
 @Test
-public void test_addImageLoaderListenerLorg_eclipse_swt_graphics_ImageLoaderListener() {
+public void test_addImageLoaderListenerLorg_eclipse_swt_graphics_ImageLoaderListener() throws IOException {
 	ImageLoader loader = new ImageLoader();
 	ImageLoaderListener loaderListener = e -> loaderListenerCalled = true;
 
-	try {
-		loader.addImageLoaderListener(null);
-		fail("No exception thrown for addImageLoaderListener with null argument");
-	} catch (IllegalArgumentException e) {
-	}
-
+	assertThrows(IllegalArgumentException.class, () -> loader.addImageLoaderListener(null),
+			"No exception thrown for addImageLoaderListener with null argument");
 	assertFalse(":a:", loader.hasListeners());
 	loader.addImageLoaderListener(loaderListener);
 	assertTrue(":b:", loader.hasListeners());
 
 	loaderListenerCalled = false;
 	try (InputStream stream = SwtTestUtil.class.getResourceAsStream("interlaced_target.png")) {
 		loader.load(stream);
-	} catch (IOException e) {}
+	}
 	assertTrue(":c:", loaderListenerCalled);
 
 	loaderListenerCalled = false;
 	try (InputStream stream = SwtTestUtil.class.getResourceAsStream("target.png")) {
 		loader.load(stream);
-	} catch (IOException e) {}
+	}
 	assertFalse(":d:", loaderListenerCalled);
 
 	loaderListenerCalled = false;
@@ -84,98 +82,70 @@ public void test_addImageLoaderListenerLorg_eclipse_swt_graphics_ImageLoaderList
 }
 
 @Test
-public void test_loadLjava_io_InputStream() {
-		ImageLoader loader = new ImageLoader();
-		try (InputStream stream = null) {
-			loader.load(stream);
-			fail("No exception thrown for load inputStream == null");
-		} catch (IllegalArgumentException | IOException e) {
-		}
+public void test_loadLjava_io_InputStream() throws IOException {
+	ImageLoader loader = new ImageLoader();
+	assertThrows(IllegalArgumentException.class, () -> loader.load((InputStream) null),
+			"No exception thrown for load inputStream == null");
 
-		try (InputStream stream = SwtTestUtil.class.getResourceAsStream("empty.txt")) {
-			loader.load(stream);
-			fail("No exception thrown for load from invalid inputStream");
-		} catch (IOException|SWTException e) {
-		}
+	try (InputStream stream = SwtTestUtil.class.getResourceAsStream("empty.txt")) {
+		assertThrows(SWTException.class, () -> loader.load(stream),
+				"No exception thrown for load from invalid inputStream");
+	}
 
-		int numFormats = SwtTestUtil.imageFormats.length;
-		String fileName = SwtTestUtil.imageFilenames[0];
-		for (int i = 0; i < numFormats; i++) {
-			String format = SwtTestUtil.imageFormats[i];
-			try (InputStream stream = SwtTestUtil.class.getResourceAsStream(fileName + "." + format)) {
-				loader.load(stream);
-			} catch (IOException e) {
-			}
+	String fileName = SwtTestUtil.imageFilenames[0];
+	for (String format : SwtTestUtil.imageFormats) {
+		try (InputStream stream = SwtTestUtil.class.getResourceAsStream(fileName + "." + format)) {
+			loader.load(stream);
 		}
+	}
 }
 
 @Test
 public void test_loadLjava_lang_String() {
 	ImageLoader loader = new ImageLoader();
 	String filename = null;
-	try {
-		loader.load(filename);
-		fail("No exception thrown for load filename == null");
-	} catch (IllegalArgumentException e) {
-	}
+	assertThrows(IllegalArgumentException.class, () -> loader.load(filename),
+			"No exception thrown for load filename == null");
 }
 
 @Test
-public void test_saveLjava_io_OutputStreamI() {
+public void test_saveLjava_io_OutputStreamI() throws IOException {
 	ImageLoader loader = new ImageLoader();
-	ByteArrayOutputStream outStream = null;
-	try {
-		try {
-			loader.save(outStream, 0);
-			fail("No exception thrown for save outputStream == null");
-		} catch (IllegalArgumentException e) {
-		}
 
-		outStream = new ByteArrayOutputStream();
-		try {
-			loader.save(outStream, -1);
-			fail("No exception thrown for save to invalid outputStream format");
-		} catch (SWTException e) {
+	OutputStream outStream1 = null;
+	assertThrows(IllegalArgumentException.class, () -> loader.save(outStream1, 0),
+			"No exception thrown for save outputStream == null");
+
+	OutputStream outStream2 = new ByteArrayOutputStream();
+	assertThrows(SWTException.class, () -> loader.save(outStream2, -1),
+			"No exception thrown for save to invalid outputStream format");
+
+	boolean jpgSupported = Arrays.asList(SwtTestUtil.imageFormats).contains("jpg");
+	if (jpgSupported) {
+		String filename = SwtTestUtil.imageFilenames[0];
+		// must use jpg since save is not implemented yet in png format
+		String filetype = "jpg";
+		try (InputStream inStream = SwtTestUtil.class.getResourceAsStream(filename + "." + filetype)) {
+			loader.load(inStream);
 		}
-		boolean jpgSupported = false;
-		for (String imageFormat : SwtTestUtil.imageFormats) {
-			if (imageFormat.equals("jpg")) {
-				jpgSupported = true;
+		OutputStream outStream = new ByteArrayOutputStream();
+		int i = 0;
+		for (String format : SwtTestUtil.imageFormats) {
+			if (format.equals(filetype)) {
+				// save using the appropriate format
+				loader.save(outStream, i++);
 				break;
 			}
 		}
-		if (jpgSupported) {
-			String filename = SwtTestUtil.imageFilenames[0];
-			// must use jpg since save is not implemented yet in png format
-			String filetype = "jpg";
-			try (InputStream inStream = SwtTestUtil.class.getResourceAsStream(filename + "." + filetype)) {
-				loader.load(inStream);
-			} catch (IOException e) {}
-			for (int i = 0; i < SwtTestUtil.imageFormats.length; i++) {
-				if (SwtTestUtil.imageFormats[i].equals(filetype)) {
-					// save using the appropriate format
-					loader.save(outStream, i);
-					break;
-				}
-			}
-		}
-	} finally {
-		try {
-			outStream.close();
-		} catch (Exception e) {
-		}
 	}
 }
 
 @Test
 public void test_saveLjava_lang_StringI() {
 	ImageLoader loader = new ImageLoader();
 	String filename = null;
-	try {
-		loader.save(filename, 0);
-		fail("No exception thrown for save filename == null");
-	} catch (IllegalArgumentException e) {
-	}
+	assertThrows(IllegalArgumentException.class, () -> loader.save(filename, 0),
+			"No exception thrown for save filename == null");
 }
 
 /**

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_widgets_Decorations.java

@@ -21,6 +21,8 @@
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
 
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.graphics.Image;
@@ -123,9 +125,9 @@ public void test_setDefaultButtonLorg_eclipse_swt_widgets_Button() {
 public void test_setImageLorg_eclipse_swt_graphics_Image() {
 	assertNull(":a:", decorations.getImage());
 	loadImages();
-	decorations.setImage(images[0]);
-	assertTrue(":b:", images[0] == decorations.getImage());
-	assertTrue(":c:", images[1] != decorations.getImage());
+	decorations.setImage(images.get(0));
+	assertTrue(":b:", images.get(0) == decorations.getImage());
+	assertTrue(":c:", images.get(1) != decorations.getImage());
 	decorations.setImage(null);
 	assertNull(":d:", decorations.getImage());
 	freeImages();
@@ -189,7 +191,7 @@ public void test_setVisibleZ() {
 
 /* custom */
 Decorations decorations;
-Image[] images = new Image [SwtTestUtil.imageFormats.length*SwtTestUtil.imageFilenames.length];
+private List<Image> images = new ArrayList<>();
 
 @Override
 protected void setWidget(Widget w) {
@@ -201,15 +203,10 @@ protected void setWidget(Widget w) {
 
 // this method must be private or protected so the auto-gen tool keeps it
 private void loadImages() {
-	int numFormats = SwtTestUtil.imageFormats.length;
-	int numFiles = SwtTestUtil.imageFilenames.length;
-	for (int i=0; i<numFormats; i++) {
-		String format = SwtTestUtil.imageFormats[i];
-		int index = i*numFiles;
-		for (int j=0; j<numFiles; j++){
-			String fileName = SwtTestUtil.imageFilenames[j];
+	for (String format : SwtTestUtil.imageFormats) {
+		for (String fileName : SwtTestUtil.imageFilenames) {
 			try (InputStream  resource = this.getClass().getResourceAsStream(fileName + "." + format)) {
-				images [index+j] = new Image (shell.getDisplay(), resource);
+				images.add(new Image(shell.getDisplay(), resource));
 			} catch (IOException e) {
 				// continue;
 			}