Fix for 223250: Macro expansion hover only displays _very_ briefly

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/AbstractCompareViewerInformationControl.java

@@ -93,7 +93,7 @@ public abstract class AbstractCompareViewerInformationControl extends PopupDialo
 	 * @param persistBounds  flag indicating whether control size and location should be persisted
 	 */
 	public AbstractCompareViewerInformationControl(Shell parent, int shellStyle, int textStyle, boolean takeFocus, boolean showViewMenu, boolean persistBounds) {
-		super(parent, shellStyle, takeFocus, persistBounds, showViewMenu, false, null, null);
+		super(parent, shellStyle | SWT.ON_TOP, takeFocus, persistBounds, showViewMenu, false, null, null);
 		fStyle= textStyle & ~(SWT.V_SCROLL | SWT.H_SCROLL);
 		// Title and status text must be set to get the title label created, so force empty values here. 
 		if (hasHeader())
@@ -393,7 +393,7 @@ public abstract class AbstractCompareViewerInformationControl extends PopupDialo
 	 * {@inheritDoc}
 	 */
 	public boolean isFocusControl() {
-		return fCompareViewerControl.isFocusControl();
+		return fCompareViewerControl != null;
 	}
 
 	/**

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/c/hover/CMacroExpansionControl.java

@@ -11,6 +11,7 @@
 
 package org.eclipse.cdt.internal.ui.text.c.hover;
 
+import org.eclipse.jface.dialogs.PopupDialog;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.widgets.Shell;
 
@@ -30,7 +31,7 @@ public class CMacroExpansionControl extends AbstractSourceViewerInformationContr
 	 * @param statusFieldText  text to be displayed in the status field, may be <code>null</code>
 	 */
 	public CMacroExpansionControl(Shell parent, String statusFieldText) {
-		super(parent, SWT.NO_TRIM | SWT.TOOL, SWT.NONE, false, false, false);
+		super(parent, PopupDialog.HOVER_SHELLSTYLE, SWT.NONE, false, false, false);
 		if (statusFieldText != null) {
 			setInfoText(statusFieldText);
 		}

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/c/hover/CMacroExpansionExplorationControl.java

@@ -42,6 +42,8 @@ import org.eclipse.swt.graphics.Font;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Event;
+import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.text.edits.ReplaceEdit;
 import org.eclipse.ui.IEditorPart;
@@ -50,6 +52,7 @@ import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.contexts.IContextActivation;
 import org.eclipse.ui.contexts.IContextService;
+import org.eclipse.ui.handlers.IHandlerActivation;
 import org.eclipse.ui.handlers.IHandlerService;
 import org.eclipse.ui.keys.IBindingService;
 import org.eclipse.ui.menus.CommandContributionItem;
@@ -100,7 +103,7 @@ public class CMacroExpansionExplorationControl extends AbstractCompareViewerInfo
 	}
 
 	private IHandlerService fHandlerService;
-	private Collection fHandlerActivations;
+	private Collection<IHandlerActivation> fHandlerActivations;
 	private IContextService fContextService;
 	private IContextActivation fContextActivation;
 	private int fIndex;
@@ -186,13 +189,34 @@ public class CMacroExpansionExplorationControl extends AbstractCompareViewerInfo
 		return sourceViewer;
 	}
 
-	/*
-	 * @see org.eclipse.jface.dialogs.PopupDialog#open()
-	 */
-	public int open() {
-		int result= super.open();
 
-		if (fInput != null) {
+	@Override
+	public int open() {
+		getShell().addListener(SWT.Activate, new Listener() {
+			public void handleEvent(Event arg0) {
+				registerCommandHandlers();
+			}});
+		getShell().addListener(SWT.Deactivate, new Listener() {
+			public void handleEvent(Event arg0) {
+				unregisterCommandHandlers();
+			}});
+
+		return super.open();
+	}
+
+	protected void unregisterCommandHandlers() {
+		if (fHandlerService != null) {
+			fHandlerService.deactivateHandlers(fHandlerActivations);
+			fHandlerActivations.clear();
+			fHandlerService= null;
+		}
+		if (fContextActivation != null) {
+			fContextService.deactivateContext(fContextActivation);
+			fContextActivation= null;
+		}
+	}
+
+	protected void registerCommandHandlers() {
         IHandler backwardHandler= new AbstractHandler() {
             public Object execute(ExecutionEvent event) throws ExecutionException {
                 backward();
@@ -212,12 +236,11 @@ public class CMacroExpansionExplorationControl extends AbstractCompareViewerInfo
             }
         };
 
-	
         IWorkbench workbench= PlatformUI.getWorkbench();
         fHandlerService= (IHandlerService) workbench.getService(IHandlerService.class);
         fContextService= (IContextService) workbench.getService(IContextService.class);
         fContextActivation= fContextService.activateContext(CONTEXT_ID_MACRO_EXPANSION_HOVER);
-	        fHandlerActivations= new ArrayList();
+        fHandlerActivations= new ArrayList<IHandlerActivation>();
         fHandlerActivations.add(fHandlerService.activateHandler(COMMAND_ID_EXPANSION_BACK, backwardHandler));
         fHandlerActivations.add(fHandlerService.activateHandler(COMMAND_ID_EXPANSION_FORWARD, forwardHandler));
         fHandlerActivations.add(fHandlerService.activateHandler(ICEditorActionDefinitionIds.OPEN_DECL, gotoDefinitionHandler));
@@ -228,9 +251,6 @@ public class CMacroExpansionExplorationControl extends AbstractCompareViewerInfo
         }
 	}
 
-        return result;
-	}
-
 	/*
 	 * @see org.eclipse.cdt.internal.ui.text.AbstractCompareViewerInformationControl#fillViewMenu(org.eclipse.jface.action.IMenuManager)
 	 */
@@ -302,14 +322,7 @@ public class CMacroExpansionExplorationControl extends AbstractCompareViewerInfo
 	 * @see org.eclipse.jface.dialogs.PopupDialog#close()
 	 */
 	public boolean close() {
-		if (fHandlerService != null) {
+		unregisterCommandHandlers();
-			fHandlerService.deactivateHandlers(fHandlerActivations);
-			fHandlerActivations.clear();
-			fHandlerService= null;
-		}
-		if (fContextActivation != null) {
-			fContextService.deactivateContext(fContextActivation);
-		}
 		return super.close();
 	}
 
@@ -444,5 +457,4 @@ public class CMacroExpansionExplorationControl extends AbstractCompareViewerInfo
 		return text;
 	}
 
-
 }