Create ImageCompressor amd ImageCompressorImpl

* Methods from AttachmentCreationTask have been moved into them:
  * compressImage()
  * createBitmap()
* ImageCompressor is availabe via AttachmentModule

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AbstractAttachmentCreationTaskTest.java

@@ -1,41 +0,0 @@
-package org.briarproject.briar.android.attachment;
-
-import android.content.res.AssetManager;
-
-import org.junit.Before;
-
-import java.io.IOException;
-import java.io.InputStream;
-
-import static androidx.test.InstrumentationRegistry.getContext;
-import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
-
-abstract class AbstractAttachmentCreationTaskTest {
-
-	private final ImageHelper imageHelper = new ImageHelperImpl();
-	private final ImageSizeCalculator imageSizeCalculator =
-			new ImageSizeCalculator(imageHelper);
-
-	private AttachmentCreationTask task;
-
-	@Before
-	@SuppressWarnings("ConstantConditions")  // add real objects when needed
-	public void setUp() {
-		task = new AttachmentCreationTask(null,
-				getApplicationContext().getContentResolver(), null,
-				imageSizeCalculator, null, null, true);
-	}
-
-	void testCompress(String filename, String contentType)
-			throws IOException {
-		InputStream is = getAssetManager().open(filename);
-		task.compressImage(is, contentType);
-	}
-
-	static AssetManager getAssetManager() {
-		// pm.getResourcesForApplication(packageName).getAssets() did not work
-		//noinspection deprecation
-		return getContext().getAssets();
-	}
-
-}

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AbstractImageCompressorComponent.java

@@ -0,0 +1,15 @@
+package org.briarproject.briar.android.attachment;
+
+import javax.inject.Singleton;
+
+import dagger.Component;
+
+@Singleton
+@Component(modules = {
+		AttachmentModule.class
+})
+interface AbstractImageCompressorComponent {
+
+	void inject(AbstractImageCompressorTest test);
+
+}

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AbstractImageCompressorTest.java

@@ -0,0 +1,38 @@
+package org.briarproject.briar.android.attachment;
+
+import android.content.res.AssetManager;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import javax.inject.Inject;
+
+import static androidx.test.InstrumentationRegistry.getContext;
+
+public abstract class AbstractImageCompressorTest {
+
+	@Inject
+	ImageCompressor imageCompressor;
+
+	public AbstractImageCompressorTest() {
+		AbstractImageCompressorComponent component =
+				DaggerAbstractImageCompressorComponent.builder().build();
+		component.inject(this);
+	}
+
+	protected abstract void inject(
+			AbstractImageCompressorComponent component);
+
+	void testCompress(String filename, String contentType)
+			throws IOException {
+		InputStream is = getAssetManager().open(filename);
+		imageCompressor.compressImage(is, contentType);
+	}
+
+	static AssetManager getAssetManager() {
+		// pm.getResourcesForApplication(packageName).getAssets() did not work
+		//noinspection deprecation
+		return getContext().getAssets();
+	}
+
+}

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/ImageCompressorTest.java

@@ -9,8 +9,13 @@ import static android.os.Build.VERSION.SDK_INT;
 import static org.junit.Assume.assumeTrue;
 
 @RunWith(AndroidJUnit4.class)
-public class AttachmentCreationTaskTest
-		extends AbstractAttachmentCreationTaskTest {
+public class ImageCompressorTest
+		extends AbstractImageCompressorTest {
+
+	@Override
+	protected void inject(AbstractImageCompressorComponent component) {
+		component.inject(this);
+	}
 
 	@Test
 	public void testCompressSmallPng() throws Exception {

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/PngSuiteImageCompressorTest.java

@@ -17,11 +17,16 @@ import static org.junit.Assert.fail;
 import static org.junit.Assume.assumeTrue;
 
 @RunWith(Parameterized.class)
-public class PngSuiteAttachmentCreationTaskTest
-		extends AbstractAttachmentCreationTaskTest {
+public class PngSuiteImageCompressorTest
+		extends AbstractImageCompressorTest {
 
 	private static final Logger LOG =
-			getLogger(PngSuiteAttachmentCreationTaskTest.class.getName());
+			getLogger(PngSuiteImageCompressorTest.class.getName());
+
+	@Override
+	protected void inject(AbstractImageCompressorComponent component) {
+		component.inject(this);
+	}
 
 	@Parameters
 	public static Iterable<String> data() throws IOException {
@@ -34,14 +39,14 @@ public class PngSuiteAttachmentCreationTaskTest
 
 	private final String filename;
 
-	public PngSuiteAttachmentCreationTaskTest(String filename) {
+	public PngSuiteImageCompressorTest(String filename) {
 		this.filename = filename;
 	}
 
 	@Test
 	public void testPngSuiteCompress() throws Exception {
 		assumeTrue(isOptionalTestEnabled(
-				PngSuiteAttachmentCreationTaskTest.class));
+				PngSuiteImageCompressorTest.class));
 		LOG.info("Testing " + filename);
 		if (filename.startsWith("x")) {
 			try {