Show only single editor when open plain BND files

Currently the manifest editor shows an error when one opens a plain bnd
file. This is because no "manifest first" parts are found and the bnd
form page is only added for pde.bnd files.

This now fixes the issue by making manifest-first files completely
optional and show a plain bnd editor instead in case of only a bnd file.

ui/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/editor/context/InputContextManager.java

@@ -201,6 +201,9 @@ public boolean isDirty() {
 	}
 
 	public void monitorFile(IFile file) {
+		if (file == null) {
+			return;
+		}
 		monitoredFiles.add(file);
 	}
 

ui/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/editor/plugin/ManifestEditor.java

@@ -33,12 +33,10 @@
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.eclipse.jface.action.Action;
 import org.eclipse.jface.action.IToolBarManager;
-import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.osgi.service.resolver.BaseDescription;
 import org.eclipse.osgi.service.resolver.BundleDescription;
-import org.eclipse.osgi.util.NLS;
 import org.eclipse.pde.core.IBaseModel;
 import org.eclipse.pde.core.IIdentifiable;
 import org.eclipse.pde.core.build.IBuild;
@@ -239,33 +237,28 @@ protected void createResourceContexts(InputContextManager manager, IFileEditorIn
 			manifestFile = container.getFile(ICoreConstants.MANIFEST_PATH);
 		} else if (name.endsWith(BndProject.INSTRUCTIONS_FILE_EXTENSION)) {
 			IProject project = file.getProject();
-			manifestFile = PDEProject.getManifest(project);
-			buildFile = PDEProject.getBuildProperties(project);
-			pluginFile = PDEProject.getPluginXml(project);
 			if (name.equalsIgnoreCase(BndProject.INSTRUCTIONS_FILE)) {
-				IEditorInput in = new FileEditorInput(file);
-				BndInputContext bndInputContext = new BndInputContext(this, in, true);
-				manager.putContext(in, bndInputContext);
-				manager.monitorFile(file);
-				manager.addInputContextListener(bndInputContext);
+				manifestFile = PDEProject.getManifest(project);
+				buildFile = PDEProject.getBuildProperties(project);
+				pluginFile = PDEProject.getPluginXml(project);
 			}
+			IEditorInput in = new FileEditorInput(file);
+			BndInputContext bndInputContext = new BndInputContext(this, in, true);
+			manager.putContext(in, bndInputContext);
+			manager.monitorFile(file);
+			manager.addInputContextListener(bndInputContext);
 		}
-		if (manifestFile == null) {
-			MessageDialog.openError(PDEPlugin.getActiveWorkbenchShell(), PDEUIMessages.OpenPluginManifestsAction_title,
-					NLS.bind(PDEUIMessages.OpenManifestsAction_cannotOpenThisFile, name));
-			return;
-		}
-		if (manifestFile.exists()) {
+		if (manifestFile != null && manifestFile.exists()) {
 			IEditorInput in = new FileEditorInput(manifestFile);
 			manager.putContext(in, new BundleInputContext(this, in, file == manifestFile));
 		}
 		manager.monitorFile(manifestFile);
-		if (pluginFile.exists()) {
+		if (pluginFile != null && pluginFile.exists()) {
 			FileEditorInput in = new FileEditorInput(pluginFile);
 			manager.putContext(in, new PluginInputContext(this, in, file == pluginFile, fragment));
 		}
 		manager.monitorFile(pluginFile);
-		if (buildFile.exists()) {
+		if (buildFile != null && buildFile.exists()) {
 			FileEditorInput in = new FileEditorInput(buildFile);
 			manager.putContext(in, new BuildInputContext(this, in, false));
 		}
@@ -401,12 +394,14 @@ public void contextRemoved(InputContext context) {
 	private void updateFirstThreePages() {
 		try {
 			int index = getActivePage();
-			removePage(0);
-			removePage(0);
-			removePage(0);
-			addPage(0, new RuntimePage(this));
-			addPage(0, new DependenciesPage(this));
-			addPage(0, new OverviewPage(this));
+			removePage(RuntimePage.PAGE_ID);
+			removePage(DependenciesPage.PAGE_ID);
+			removePage(OverviewPage.PAGE_ID);
+			if (fInputContextManager.hasContext(BundleInputContext.CONTEXT_ID)) {
+				addPage(0, new RuntimePage(this));
+				addPage(0, new DependenciesPage(this));
+				addPage(0, new OverviewPage(this));
+			}
 			setActivePage(index);
 		} catch (PartInitException e) {
 			PDEPlugin.logException(e);
@@ -527,9 +522,11 @@ protected void createJarEntryContexts(InputContextManager manager, JarEntryEdito
 	@Override
 	protected void addEditorPages() {
 		try {
-			addPage(new OverviewPage(this));
-			addPage(new DependenciesPage(this));
-			addPage(new RuntimePage(this));
+			if (fInputContextManager.hasContext(BundleInputContext.CONTEXT_ID)) {
+				addPage(new OverviewPage(this));
+				addPage(new DependenciesPage(this));
+				addPage(new RuntimePage(this));
+			}
 			if (showExtensionTabs()) {
 				addExtensionTabs();
 			}