Move Eclipse E4 components from Argeo Commons to Argeo SLC

[gpl/argeo-slc.git] / swt / org.argeo.cms.e4 / src / org / argeo / cms / e4 / OsgiFilterContextFunction.java

diff --git a/swt/org.argeo.cms.e4/src/org/argeo/cms/e4/OsgiFilterContextFunction.java b/swt/org.argeo.cms.e4/src/org/argeo/cms/e4/OsgiFilterContextFunction.java
new file mode 100644 (file)
index 0000000..1e3e75c
--- /dev/null
+++ b/swt/org.argeo.cms.e4/src/org/argeo/cms/e4/OsgiFilterContextFunction.java
@@ -0,0 +1,33 @@
+package org.argeo.cms.e4;
+
+import org.argeo.cms.swt.CmsException;
+import org.eclipse.e4.core.contexts.ContextFunction;
+import org.eclipse.e4.core.contexts.IEclipseContext;
+import org.eclipse.e4.core.di.IInjector;
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.FrameworkUtil;
+import org.osgi.framework.InvalidSyntaxException;
+import org.osgi.framework.ServiceReference;
+
+/** An Eclipse 4 {@link ContextFunction} based on an OSGi filter. */
+public class OsgiFilterContextFunction extends ContextFunction {
+
+       private BundleContext bc = FrameworkUtil.getBundle(OsgiFilterContextFunction.class).getBundleContext();
+
+       @Override
+       public Object compute(IEclipseContext context, String contextKey) {
+               ServiceReference<?>[] srs;
+               try {
+                       srs = bc.getServiceReferences((String) null, contextKey);
+               } catch (InvalidSyntaxException e) {
+                       throw new CmsException("Context key " + contextKey + " must be a valid osgi filter", e);
+               }
+               if (srs == null || srs.length == 0) {
+                       return IInjector.NOT_A_VALUE;
+               } else {
+                       // return the first one
+                       return bc.getService(srs[0]);
+               }
+       }
+
+}