[E4] Introduce EModelService.findMatchingElements() as Xpath replacement

Author: HannesWell

bundles/org.eclipse.e4.ui.workbench/META-INF/MANIFEST.MF

@@ -1,7 +1,7 @@
 Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-SymbolicName: org.eclipse.e4.ui.workbench;singleton:=true
-Bundle-Version: 1.16.100.qualifier
+Bundle-Version: 1.17.0.qualifier
 Bundle-Name: %pluginName
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
@@ -17,7 +17,8 @@ Require-Bundle: org.eclipse.e4.ui.model.workbench;bundle-version="1.2.0",
  org.eclipse.e4.ui.di;bundle-version="0.9.0",
  org.eclipse.emf.ecore.xmi;bundle-version="2.7.0",
  org.eclipse.e4.core.di.extensions,
- org.eclipse.core.runtime;bundle-version="[3.29.0,4.0.0)"
+ org.eclipse.core.runtime;bundle-version="[3.29.0,4.0.0)",
+ org.eclipse.e4.emf.xpath;bundle-version="0.6.0"
 Bundle-ActivationPolicy: lazy
 Bundle-RequiredExecutionEnvironment: JavaSE-17
 Export-Package: org.eclipse.e4.ui.internal.workbench;

bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/ModelServiceImpl.java

@@ -27,12 +27,14 @@
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Objects;
+import java.util.stream.Stream;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.IExtensionRegistry;
 import org.eclipse.e4.core.contexts.ContextInjectionFactory;
 import org.eclipse.e4.core.contexts.IEclipseContext;
 import org.eclipse.e4.core.services.events.IEventBroker;
 import org.eclipse.e4.core.services.log.Logger;
+import org.eclipse.e4.emf.xpath.XPathContextFactory;
 import org.eclipse.e4.ui.model.application.MAddon;
 import org.eclipse.e4.ui.model.application.MApplication;
 import org.eclipse.e4.ui.model.application.MApplicationElement;
@@ -434,6 +436,11 @@ public <T> List<T> findElements(MApplicationElement searchRoot, Class<T> clazz,
 		return new ArrayList<>(elements);
 	}
 
+	@Override
+	public <T> Stream<T> findMatchingElements(MApplicationElement searchRoot, String xpath, Class<T> clazz) {
+		return XPathContextFactory.newInstance().newContext((EObject) searchRoot).stream(xpath, clazz);
+	}
+
 	private <T> Iterable<T> findPerspectiveElements(MUIElement searchRoot, String id,
 			Class<T> clazz,
 			List<String> tagsToMatch) {

bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/workbench/modeling/EModelService.java

@@ -17,6 +17,7 @@
 package org.eclipse.e4.ui.workbench.modeling;
 
 import java.util.List;
+import java.util.stream.Stream;
 import org.eclipse.e4.core.contexts.IEclipseContext;
 import org.eclipse.e4.ui.model.application.MApplicationElement;
 import org.eclipse.e4.ui.model.application.descriptor.basic.MPartDescriptor;
@@ -279,6 +280,11 @@ <T> List<T> findElements(MUIElement searchRoot, String id, Class<T> clazz,
 	<T> List<T> findElements(MApplicationElement searchRoot, Class<T> clazz,
 			int searchFlags, Selector matcher);
 
+	/**
+	 * @since 1.17
+	 */
+	<T> Stream<T> findMatchingElements(MApplicationElement contextBean, String xpath, Class<T> clazz);
+
 	/**
 	 * Returns the first element, recursively searching under the specified search
 	 * root (inclusive)