Bug 540253 - Debug inactive after switching perspectivesI20181027-1800I20181026-1800

The fix for bug 538548 introduces a regression as follows. Switch from
Java to Debug perspective, then back to Java perspective. Debug a
snippet until a breakpoint is hit. Choose yes when asked whether to
switch to the Debug perspective. Observe that debug controls are
inactive.

This is the case since LaunchView context provider no longer reacts to
debug events, after switching to the Java perspective. It misses the
breakpoint hit (which also triggers the Debug perspective switch-to
confirmation dialog).

This change removes the fix for bug 538548 and adds a local fix to
SourceLookupService. The added fix prevents an editor popping up in the
current perspective under the following conditions:

1. If the Debug View was not open in the current
perspective.
2. Preferences to switch to a debug perspective on a breakpoint hit or
on launch are set to "never".
3. Preference to activate the Debug View on a breakpoint hit is set to
"disabled".

Change-Id: Iab575ee2f9a292c23c47c95d23afadc49b8b2dff
Signed-off-by: Simeon Andreev <simeon.danailov.andreev@gmail.com>
Signed-off-by: Andrey Loskutov <loskutov@gmx.de>

2 files changed, 46 insertions, 8 deletions

diff --git a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/sourcelookup/SourceLookupService.java b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/sourcelookup/SourceLookupService.java
index 5337c5ff5..e5dcf37d0 100644
--- a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/sourcelookup/SourceLookupService.java
+++ b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/sourcelookup/SourceLookupService.java
@@ -16,12 +16,17 @@ package org.eclipse.debug.internal.ui.sourcelookup;
 
 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.core.runtime.PlatformObject;
+import org.eclipse.debug.internal.ui.DebugUIPlugin;
+import org.eclipse.debug.internal.ui.IInternalDebugUIConstants;
 import org.eclipse.debug.internal.ui.views.launch.DebugElementAdapterFactory;
 import org.eclipse.debug.ui.DebugUITools;
+import org.eclipse.debug.ui.IDebugUIConstants;
 import org.eclipse.debug.ui.contexts.DebugContextEvent;
 import org.eclipse.debug.ui.contexts.IDebugContextListener;
 import org.eclipse.debug.ui.contexts.IDebugContextService;
 import org.eclipse.debug.ui.sourcelookup.ISourceDisplay;
+import org.eclipse.jface.dialogs.MessageDialogWithToggle;
+import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.ui.IWorkbenchPage;
@@ -52,8 +57,44 @@ public class SourceLookupService implements IDebugContextListener, ISourceDispla
 	@Override
 	public synchronized void debugContextChanged(DebugContextEvent event) {
 		if ((event.getFlags() & DebugContextEvent.ACTIVATED) > 0) {
-			displaySource(event.getContext(), event.getDebugContextProvider().getPart(), false);
+			if (isDebugViewActive() || canActivateDebugView()) {
+				displaySource(event.getContext(), event.getDebugContextProvider().getPart(), false);
+			}
+		}
+	}
+
+	private boolean isDebugViewActive() {
+		if (isDisposed()) {
+			return false;
+		}
+		IWorkbenchPage activePage = fWindow.getActivePage();
+		if (activePage != null) {
+			return activePage.findView(IDebugUIConstants.ID_DEBUG_VIEW) != null;
+		}
+		return false;
+	}
+
+	private boolean canActivateDebugView() {
+		if (isDisposed()) {
+			return false;
+		}
+		IPreferenceStore preferenceStore = DebugUIPlugin.getDefault().getPreferenceStore();
+		String[] switchPreferences = {
+				IInternalDebugUIConstants.PREF_SWITCH_TO_PERSPECTIVE,
+				IInternalDebugUIConstants.PREF_SWITCH_PERSPECTIVE_ON_SUSPEND,
+		};
+		for (String switchPreference : switchPreferences) {
+			String preferenceValue = preferenceStore.getString(switchPreference);
+			if (!MessageDialogWithToggle.NEVER.equals(preferenceValue)) {
+				return true;
+			}
 		}
+		boolean canActivateDebugView = preferenceStore.getBoolean(IInternalDebugUIConstants.PREF_ACTIVATE_DEBUG_VIEW);
+		return canActivateDebugView;
+	}
+
+	private boolean isDisposed() {
+		return fWindow == null;
 	}
 
 	/**
@@ -65,7 +106,9 @@ public class SourceLookupService implements IDebugContextListener, ISourceDispla
 	 * @param force
 	 */
 	protected synchronized void displaySource(ISelection selection, IWorkbenchPart part, boolean force) {
-	    if (fWindow == null) return; // disposed
+		if (isDisposed()) {
+			return;
+		}
 
 		if (selection instanceof IStructuredSelection) {
 			IStructuredSelection structuredSelection = (IStructuredSelection)selection;
@@ -82,9 +125,6 @@ public class SourceLookupService implements IDebugContextListener, ISourceDispla
 		}
 	}
 
-	/* (non-Javadoc)
-	 * @see org.eclipse.debug.internal.ui.contexts.ISourceDisplayAdapter#displaySource(java.lang.Object, org.eclipse.ui.IWorkbenchPage, boolean)
-	 */
 	@Override
 	public void displaySource(Object context, IWorkbenchPage page, boolean forceSourceLookup) {
 		if (context instanceof IAdaptable) {
diff --git a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/views/launch/LaunchView.java b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/views/launch/LaunchView.java
index df5fe6ded..9ba292322 100644
--- a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/views/launch/LaunchView.java
+++ b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/views/launch/LaunchView.java
@@ -474,9 +474,7 @@ public class LaunchView extends AbstractDebugView
 	private ISelectionChangedListener fTreeViewerSelectionChangedListener = new ISelectionChangedListener() {
 	    @Override
 		public void selectionChanged(SelectionChangedEvent event) {
-			if (isActive()) {
-				fTreeViewerDebugContextProvider.activate(event.getSelection());
-			}
+			fTreeViewerDebugContextProvider.activate(event.getSelection());
 	    }
 	};