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https://issues.apache.org/jira/browse/GROOVY-12376?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18112159#comment-18112159
]
ASF GitHub Bot commented on GROOVY-12376:
-----------------------------------------
utafrali commented on code in PR #2899:
URL: https://github.com/apache/groovy/pull/2899#discussion_r3946924263
##########
subprojects/groovy-swing/src/test/groovy/groovy/swing/LookAndFeelHelperThemeTest.groovy:
##########
@@ -0,0 +1,65 @@
+/*
+ * 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 groovy.swing
+
+import org.junit.jupiter.api.Test
+
+import javax.swing.plaf.metal.DefaultMetalTheme
+import javax.swing.plaf.metal.MetalLookAndFeel
+
+import static groovy.test.GroovyAssert.shouldFail
+
+class LookAndFeelHelperThemeTest {
+
+ // the Metal 'theme' attribute handler; invoked directly so the test does
not
+ // touch UIManager and therefore runs headless
+ private static metalThemeHandler() {
+
LookAndFeelHelper.instance.@extendedAttributes['javax.swing.plaf.metal.MetalLookAndFeel'].theme
+ }
+
+ @Test
+ void rejectsNonMetalThemeClassWithoutConstructingIt() {
+ ThemeProbeFlag.constructed = false
+ def handler = metalThemeHandler()
+ shouldFail(IllegalArgumentException) {
+ handler(null, 'groovy.swing.NonMetalThemeProbe')
+ }
+ assert !ThemeProbeFlag.constructed: 'a non-MetalTheme class must not
be constructed'
+ }
+
+ @Test
+ void acceptsMetalThemeSubclass() {
+ def handler = metalThemeHandler()
+ handler(null, 'groovy.swing.CustomMetalThemeProbe')
+ assert MetalLookAndFeel.currentTheme instanceof CustomMetalThemeProbe
Review Comment:
`handler(null, ...)` sets `MetalLookAndFeel.currentTheme` as a side effect
and the test leaves it modified after completion. If other tests in the suite
read `currentTheme`, this could introduce ordering-dependent failures. Consider
saving and restoring:
```groovy
def previousTheme = MetalLookAndFeel.currentTheme
try {
handler(null, 'groovy.swing.CustomMetalThemeProbe')
assert MetalLookAndFeel.currentTheme instanceof CustomMetalThemeProbe
} finally {
MetalLookAndFeel.currentTheme = previousTheme
}
```
##########
subprojects/groovy-swing/src/main/groovy/groovy/swing/LookAndFeelHelper.groovy:
##########
@@ -94,7 +94,16 @@ class LookAndFeelHelper {
} else if (theme == 'steel') {
theme = new DefaultMetalTheme();
} else {
- theme = Class.forName(theme as
String).getConstructor().newInstance()
+ // resolve without initializing, confirm it is a
MetalTheme before
+ // constructing it, and prefer the context classloader
so application
+ // and @Grab-supplied theme classes resolve; the
context loader may be
+ // null, so fall back to this class's loader (the
pre-existing behaviour)
+ def loader = Thread.currentThread().contextClassLoader
?: LookAndFeelHelper.classLoader
+ def themeClass = Class.forName(theme as String, false,
loader)
+ if (!MetalTheme.isAssignableFrom(themeClass)) {
+ throw new IllegalArgumentException("Metal theme
class ${themeClass.name} is not a ${MetalTheme.name}")
Review Comment:
If `themeClass` is an abstract `MetalTheme` subtype, `isAssignableFrom`
passes but `getConstructor().newInstance()` will throw `InstantiationException`
with a confusing message. The fix already provides a clear
`IllegalArgumentException` for wrong types; it should do the same for abstract
classes. Consider adding before the `getConstructor()` call:
```groovy
if (java.lang.reflect.Modifier.isAbstract(themeClass.modifiers)) {
throw new IllegalArgumentException("Metal theme class ${themeClass.name}
is abstract and cannot be instantiated")
}
```
> LookAndFeelHelper: detect non-metal classes rather than fail with an obscure
> error
> ----------------------------------------------------------------------------------
>
> Key: GROOVY-12376
> URL: https://issues.apache.org/jira/browse/GROOVY-12376
> Project: Groovy
> Issue Type: Improvement
> Reporter: Paul King
> Priority: Major
>
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