kinow commented on a change in pull request #116:
URL: https://github.com/apache/commons-imaging/pull/116#discussion_r760907698
##########
File path: src/main/java/org/apache/commons/imaging/ImageParser.java
##########
@@ -898,7 +892,7 @@ public boolean canAcceptType(final ImageFormat type) {
* @param file An valid file reference.
* @return If the parser can accept the format, true; otherwise, false.
*/
- protected final boolean canAcceptExtension(final File file) {
+ public boolean canAcceptExtension(final File file) {
Review comment:
Made it public because I created methods in the new internal `Util`
class. Similar to the already public `canAcceptType(ImageFormat)` of this class.
##########
File path: src/main/java/org/apache/commons/imaging/ImageParser.java
##########
@@ -123,12 +115,18 @@
new TiffImageParser(),
new WbmpImageParser(),
new XbmImageParser(),
- new XpmImageParser(),
+ new XpmImageParser()
// new JBig2ImageParser(),
// new TgaImageParser(),
- };
+ );
}
+ /**
+ * Get a default parameters instance for this parser.
+ * @return default parameters instance
+ */
+ public abstract T getDefaultParameters();
Review comment:
Copied from @darkma773r 's PR. By moving it here from the `ImageFormat`
(i.e. responsible for defining the default parameter is the parser, not the
format) several generics warnings don't happen anymore.
##########
File path: src/main/java/org/apache/commons/imaging/internal/Util.java
##########
@@ -0,0 +1,54 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.imaging.internal;
+
+import java.util.function.Predicate;
+import java.util.function.Supplier;
+
+import org.apache.commons.imaging.ImageFormat;
+import org.apache.commons.imaging.ImageParser;
+import org.apache.commons.imaging.ImagingParameters;
+
+/**
+ * Internal utilities.
+ *
+ * @since 1.0-alpha3
+ */
+public class Util {
+
+ private Util() {}
+
+ public static <T extends ImagingParameters> ImageParser<T>
getImageParser(ImageFormat format) {
+ return getImageParser((parser) -> parser.canAcceptType(format), () ->
new RuntimeException("Unknown Format: " + format));
+ }
+
+ public static <T extends ImagingParameters> ImageParser<T>
getImageParser(String fileExtension) {
+ return getImageParser((parser) ->
parser.canAcceptExtension(fileExtension), () -> new RuntimeException("Unknown
Extension: " + fileExtension));
+ }
+
+ // This generics suppression is as good as the predicate given. If the
predicate violates a generics design,
+ // then there will be an error during runtime.
+ @SuppressWarnings("unchecked")
+ private static <T extends ImagingParameters> ImageParser<T>
getImageParser(Predicate<ImageParser<?>> pred, Supplier<? extends
RuntimeException> supl) {
+ return (ImageParser<T>) ImageParser
+ .getAllImageParsers()
+ .stream()
+ .filter((parser) -> pred.test(parser))
+ .findFirst()
Review comment:
This is the only place where we have an issue with the generics used in
this PR now. The `Predicate` given to this function should return `true` only
if the parser matches something like a file format, file extension, etc.
Assuming the predicate is correct, there should be no runtime errors for the
parameters :+1: that's the best we can achieve with Java generics IMO
##########
File path: src/main/java/org/apache/commons/imaging/Imaging.java
##########
@@ -16,9 +16,6 @@
*/
package org.apache.commons.imaging;
-import static org.apache.commons.imaging.ImagingConstants.PARAM_KEY_FILENAME;
-import static org.apache.commons.imaging.ImagingConstants.PARAM_KEY_FORMAT;
Review comment:
N.B. no generics warnings being suppressed in `Imaging` now :tada:
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