Bug 575453 - defaultShowIn improvements

* Rename attribute to something more explicit
* Introduce proper API to retrieve attribute value
* Simplify calling code
* Make ShowIn menu also leverage the setting by showing the default view
as 1st item

Change-Id: Ibeeccebeac6b96d134df9cb86091bcc8c630030f
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.ui/+/186894
Tested-by: Mickael Istria <mistria@redhat.com>
Reviewed-by: Mickael Istria <mistria@redhat.com>

9 files changed, 55 insertions, 50 deletions

diff --git a/bundles/org.eclipse.ui.ide.application/plugin.xml b/bundles/org.eclipse.ui.ide.application/plugin.xml
index 65e7f269f96..b15185ae254 100644
--- a/bundles/org.eclipse.ui.ide.application/plugin.xml
+++ b/bundles/org.eclipse.ui.ide.application/plugin.xml
@@ -43,7 +43,7 @@
             name="%Perspective.resourcePerspective"
             icon="$nl$/icons/full/eview16/resource_persp.png"
             class="org.eclipse.ui.internal.ide.application.ResourcePerspective"
-            showInId="org.eclipse.ui.navigator.ProjectExplorer"
+            defaultShowIn="org.eclipse.ui.navigator.ProjectExplorer"
             id="org.eclipse.ui.resourcePerspective">
          <description>
             %Perspective.resourceDescription
diff --git a/bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java b/bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
index 8e231104242..65a55183d58 100644
--- a/bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
+++ b/bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
@@ -1607,21 +1607,15 @@ public class ExtendedMarkersView extends ViewPart {
 			}
 		}
 
-		String showInId = ((WorkbenchPage) page).getShowInId();
-		if (showIn(marker, page, showInId)) {
-			return;
-		}
+		showIn(marker, page, page.getPerspective().getDefaultShowIn());
 	}
 
 	private static boolean showIn(IMarker marker, IWorkbenchPage page, String targetPartId) {
+		if (targetPartId == null || WorkbenchPlugin.getDefault().getViewRegistry().find(targetPartId) == null) {
+			return false;
+		}
+		ISelection selection = new StructuredSelection(marker.getResource());
 		try {
-			if (targetPartId == null) {
-				return false;
-			}
-			if (WorkbenchPlugin.getDefault().getViewRegistry().find(targetPartId) == null) {
-				return false;
-			}
-			ISelection selection = new StructuredSelection(marker.getResource());
 			IViewPart view = page.showView(targetPartId);
 			if (view == null) {
 				return false;
diff --git a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/IPerspectiveDescriptor.java b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/IPerspectiveDescriptor.java
index e304c8f5b55..86d62f670ac 100644
--- a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/IPerspectiveDescriptor.java
+++ b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/IPerspectiveDescriptor.java
@@ -80,4 +80,17 @@ public interface IPerspectiveDescriptor {
 	 * @return the label
 	 */
 	String getLabel();
+
+	/**
+	 * Returns this perspective's preferred view to show resources when no better
+	 * editor or view can be deduced from context.
+	 * <p>
+	 * For perspectives declared via an extension, this is the value of its
+	 * <code>defaultShowIn</code> attribute.
+	 * </p>
+	 *
+	 * @return the preferred view id, or <code>null</code>.
+	 * @since 3.124
+	 */
+	String getDefaultShowIn();
 }
diff --git a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchPage.java b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchPage.java
index 1c44a3f91bc..5a5e17df273 100644
--- a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchPage.java
+++ b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchPage.java
@@ -57,12 +57,9 @@ import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.core.runtime.IConfigurationElement;
-import org.eclipse.core.runtime.IExtension;
-import org.eclipse.core.runtime.IExtensionPoint;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.ListenerList;
-import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.SafeRunner;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.dynamichelpers.IExtensionTracker;
@@ -2453,39 +2450,18 @@ public class WorkbenchPage implements IWorkbenchPage {
 	 *         prompt
 	 */
 	public List<String> getShowInPartIds() {
-		MPerspective perspective = getPerspectiveStack().getSelectedElement();
-		return ModeledPageLayout.getIds(perspective, ModeledPageLayout.SHOW_IN_PART_TAG);
-	}
-
-	/** @return showInId configured by perspective or null if not configured **/
-	public String getShowInId() {
-		String perspectiveId = getPerspective().getId();
-		String showInIdFromRegistry = getShowInIdFromRegistry(perspectiveId);
-		return showInIdFromRegistry;
-	}
-
-	public static String getShowInIdFromRegistry(String perspectiveId) {
-		IExtensionPoint point = Platform.getExtensionRegistry().getExtensionPoint(PlatformUI.PLUGIN_ID,
-				IWorkbenchRegistryConstants.PL_PERSPECTIVES);
-		if (point == null) {
-			return null;
-		}
-		IExtension[] extensions = point.getExtensions();
-		if (extensions == null) {
-			return null;
-		}
-		for (IExtension extension : extensions) {
-			IConfigurationElement[] configElements = extension.getConfigurationElements();
-			for (IConfigurationElement configElement : configElements) {
-				String id = configElement.getAttribute("id"); //$NON-NLS-1$
-				if (Objects.equals(perspectiveId, id)) {
-					String showInId = configElement.getAttribute("showInId"); //$NON-NLS-1$
-					return showInId;
-				}
+		MPerspective mPerspective = getPerspectiveStack().getSelectedElement();
+		List<String> ids = ModeledPageLayout.getIds(mPerspective, ModeledPageLayout.SHOW_IN_PART_TAG);
+		IPerspectiveDescriptor perspective = getPerspective();
+		if (perspective != null && perspective.getDefaultShowIn() != null) {
+			ids = new ArrayList<>(ids);
+			if (ids.remove(perspective.getDefaultShowIn())) {
+				ids.add(0, perspective.getDefaultShowIn());
 			}
 		}
-		return null;
+		return ids;
 	}
+
 	/**
 	 * The user successfully performed a Show In... action on the specified part.
 	 * Update the list of Show In items accordingly.
diff --git a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/IWorkbenchRegistryConstants.java b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/IWorkbenchRegistryConstants.java
index 00d796af99b..de8a266a528 100644
--- a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/IWorkbenchRegistryConstants.java
+++ b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/IWorkbenchRegistryConstants.java
@@ -1358,4 +1358,11 @@ public interface IWorkbenchRegistryConstants {
 	String ATT_COLOR_AND_FONT_ID = "colorAndFontId"; //$NON-NLS-1$
 
 	String ATT_OS_VERSION = "os_version"; //$NON-NLS-1$
+
+	/**
+	 * See {@link PerspectiveDescriptor#getDefaultShowIn()}
+	 *
+	 * @since 3.123
+	 */
+	String ATT_DEFAULT_SHOW_IN = "defaultShowIn"; //$NON-NLS-1$
 }
diff --git a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/PerspectiveDescriptor.java b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/PerspectiveDescriptor.java
index 82f0058617a..030b51f1744 100644
--- a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/PerspectiveDescriptor.java
+++ b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/PerspectiveDescriptor.java
@@ -51,6 +51,7 @@ public class PerspectiveDescriptor implements IPerspectiveDescriptor, IPluginCon
 	private String pluginId;
 	private String originalId; // ID of ancestor that was based on a config
 								// element
+	private String defaultShowIn;
 
 	public PerspectiveDescriptor(String id, String label, PerspectiveDescriptor originalDescriptor) {
 		this.id = id;
@@ -60,6 +61,7 @@ public class PerspectiveDescriptor implements IPerspectiveDescriptor, IPluginCon
 			this.image = originalDescriptor.getImageDescriptor();
 			this.pluginId = originalDescriptor.getPluginId();
 			this.hasCustomDefinition = true;
+			this.defaultShowIn = originalDescriptor.getDefaultShowIn();
 		}
 	}
 
@@ -180,4 +182,11 @@ public class PerspectiveDescriptor implements IPerspectiveDescriptor, IPluginCon
 	public String toString() {
 		return this.getClass().getName() + " {id=" + getId() + "}"; //$NON-NLS-1$//$NON-NLS-2$
 	}
+
+	@Override
+	public String getDefaultShowIn() {
+		return defaultShowIn == null && configElement != null
+				? configElement.getAttribute(IWorkbenchRegistryConstants.ATT_DEFAULT_SHOW_IN)
+				: defaultShowIn;
+	}
 }
diff --git a/bundles/org.eclipse.ui.workbench/META-INF/MANIFEST.MF b/bundles/org.eclipse.ui.workbench/META-INF/MANIFEST.MF
index 23c1176c7ef..a4735b4cca1 100644
--- a/bundles/org.eclipse.ui.workbench/META-INF/MANIFEST.MF
+++ b/bundles/org.eclipse.ui.workbench/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.ui.workbench; singleton:=true
-Bundle-Version: 3.123.100.qualifier
+Bundle-Version: 3.124.0.qualifier
 Bundle-ClassPath: .
 Bundle-Activator: org.eclipse.ui.internal.WorkbenchPlugin
 Bundle-ActivationPolicy: lazy
diff --git a/bundles/org.eclipse.ui.workbench/pom.xml b/bundles/org.eclipse.ui.workbench/pom.xml
index 5601737cb6d..631faf68187 100644
--- a/bundles/org.eclipse.ui.workbench/pom.xml
+++ b/bundles/org.eclipse.ui.workbench/pom.xml
@@ -20,7 +20,7 @@
   </parent>
   <groupId>org.eclipse.ui</groupId>
   <artifactId>org.eclipse.ui.workbench</artifactId>
-  <version>3.123.100-SNAPSHOT</version>
+  <version>3.124.0-SNAPSHOT</version>
   <packaging>eclipse-plugin</packaging>
 
   <properties>
diff --git a/bundles/org.eclipse.ui/schema/perspectives.exsd b/bundles/org.eclipse.ui/schema/perspectives.exsd
index c369e0b4129..ba712615b46 100644
--- a/bundles/org.eclipse.ui/schema/perspectives.exsd
+++ b/bundles/org.eclipse.ui/schema/perspectives.exsd
@@ -1,6 +1,6 @@
 <?xml version='1.0' encoding='UTF-8'?>
 <!-- Schema file written by PDE -->
-<schema targetNamespace="org.eclipse.ui">
+<schema targetNamespace="org.eclipse.ui" xmlns="http://www.w3.org/2001/XMLSchema">
 <annotation>
       <appInfo>
          <meta.schema plugin="org.eclipse.ui" id="perspective" name="Perspectives"/>
@@ -11,6 +11,11 @@
    </annotation>
 
    <element name="extension">
+      <annotation>
+         <appInfo>
+            <meta.element />
+         </appInfo>
+      </annotation>
       <complexType>
          <sequence>
             <element ref="perspective" minOccurs="0" maxOccurs="unbounded"/>
@@ -98,10 +103,10 @@ with this perspective.
                </documentation>
             </annotation>
          </attribute>
-         <attribute name="showInId" type="string">
+         <attribute name="defaultShowIn" type="string">
             <annotation>
                <documentation>
-                  the identifier of the view which will be shown by doubleclicking on a (problem) marker without file resource. The view needs to implement ISetSelectionTarget.
+                  the identifier of a preferred view which will be shown when trying to open a resource and no better view or editor can be deduced by the context. This can be for example doubleclicking on a (problem) marker without file resource, or to prioritize this view in the Show In context-menu. The view needs to implement &lt;code&gt;org.eclipse.ui.part.ISetSelectionTarget&lt;/code&gt;.
                </documentation>
                <appInfo>
                   <meta.attribute kind="identifier" basedOn="org.eclipse.ui.views/view/@id,org.eclipse.ui.views/e4view/@id"/>
@@ -122,6 +127,7 @@ with this perspective.
       </annotation>
    </element>
 
+
    <annotation>
       <appInfo>
          <meta.section type="examples"/>