Bug 514935 - Reset of Perspective restores not restorable views I20170906-0225I20170905-2000

- Added new NO_RESTORE Tag
- Adding this tag to PartDescriptors when parsing the 3x registrations
- Setting Placeholders as invisible after clone if they have the tag
- PartStack Renderer skips parts with NO_RESTORE tag when filling the
tabfolder

Change-Id: Ib5b13e7cba692efaf780bcfde3e7b8d095213393
Signed-off-by: Eugen Neufeld <eneufeld@eclipsesource.com>
Signed-off-by: Alexandra Buzila <abuzila@eclipsesource.com>

4 files changed, 31 insertions, 2 deletions

diff --git a/bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/LazyStackRenderer.java b/bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/LazyStackRenderer.java
index ecf17fa4ed9..9376cb40298 100644
--- a/bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/LazyStackRenderer.java
+++ b/bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/LazyStackRenderer.java
@@ -122,6 +122,8 @@ public abstract class LazyStackRenderer extends SWTPartRenderer {
 			// part is already there...see bug 378138 for details
 			if (element instanceof MPlaceholder) {
 				MPlaceholder ph = (MPlaceholder) element;
+				if (ph.getRef().getTags().contains(IPresentationEngine.NO_RESTORE))
+					continue;
 				if (ph.getRef() instanceof MPart && ph.getRef().getWidget() != null) {
 					lazy = false;
 				}
diff --git a/bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/workbench/IPresentationEngine.java b/bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/workbench/IPresentationEngine.java
index a6a2b4ad2c3..40220b7f41d 100644
--- a/bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/workbench/IPresentationEngine.java
+++ b/bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/workbench/IPresentationEngine.java
@@ -235,6 +235,12 @@ public interface IPresentationEngine {
 	public static final String ACTIVE = "active"; //$NON-NLS-1$
 
 	/**
+	 * When applied as a tag to an MPartDescriptor marks the part as not
+	 * restorable.
+	 */
+	public static final String NO_RESTORE = "NoRestore"; //$NON-NLS-1$
+
+	/**
 	 * Creates and returns the UI element for the given model element.
 	 *
 	 * @param element
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 86e3cf4d8c0..0afe794acfb 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
@@ -3951,7 +3951,24 @@ public class WorkbenchPage implements IWorkbenchPage {
 		visiblePerspective.setLabel(perspective.getLabel());
 		visiblePerspective.setTooltip(perspective.getLabel());
 		visiblePerspective.setElementId(perspective.getId());
-		modelService.cloneElement(visiblePerspective, application);
+		MUIElement clone = modelService.cloneElement(visiblePerspective, application);
+		MWindow window = WorkbenchWindow.class.cast(getActivePart().getSite().getWorkbenchWindow()).getModel();
+		ModelServiceImpl.class.cast(modelService).getNullRefPlaceHolders(clone, window);
+		List<MPlaceholder> elementsToHide = modelService.findElements(clone, null, MPlaceholder.class, null);
+		for (MPlaceholder elementToHide : elementsToHide) {
+			if (elementToHide.getRef().getTags().contains(IPresentationEngine.NO_RESTORE)) {
+				elementToHide.setToBeRendered(false);
+				MElementContainer<MUIElement> phParent = elementToHide.getParent();
+				if (phParent.getSelectedElement() == elementToHide) {
+					phParent.setSelectedElement(null);
+				}
+				int vc = modelService.countRenderableChildren(phParent);
+				if (vc == 0) {
+					if (!modelService.isLastEditorStack(phParent))
+						phParent.setToBeRendered(false);
+				}
+			}
+		}
 		if (perspective instanceof PerspectiveDescriptor) {
 			((PerspectiveDescriptor) perspective).setHasCustomDefinition(true);
 		}
diff --git a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/ViewRegistry.java b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/ViewRegistry.java
index 8dedc610cfe..880942e62c7 100644
--- a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/ViewRegistry.java
+++ b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/ViewRegistry.java
@@ -29,6 +29,7 @@ import org.eclipse.core.runtime.Platform;
 import org.eclipse.e4.core.services.log.Logger;
 import org.eclipse.e4.ui.model.application.MApplication;
 import org.eclipse.e4.ui.model.application.descriptor.basic.MPartDescriptor;
+import org.eclipse.e4.ui.workbench.IPresentationEngine;
 import org.eclipse.e4.ui.workbench.modeling.EModelService;
 import org.eclipse.ui.ISharedImages;
 import org.eclipse.ui.IWorkbench;
@@ -194,8 +195,11 @@ public class ViewRegistry implements IViewRegistry {
 			tags.add("categoryTag:" + category.getLabel()); //$NON-NLS-1$
 			descriptor.setCategory(category.getLabel());
 		}
+		String restorable = element.getAttribute(IWorkbenchRegistryConstants.ATT_RESTORABLE);
+		if (!(restorable == null ? true : Boolean.parseBoolean(restorable))) {
+			descriptor.getTags().add(IPresentationEngine.NO_RESTORE);
+		}
 		// ==> End of update descriptor
-
 		ViewDescriptor viewDescriptor = new ViewDescriptor(application, descriptor, element);
 		descriptors.put(descriptor.getElementId(), viewDescriptor);
 		if (category != null) {