Avoid unnecessarily storing document in actions (eclipse-cdt#607)

With the first part of the fix in eclipse-cdt#603 we recreate the document
regularly (on each context change) therefore we need to let any
consumers of the document fetch the current version of the document
from the editor (by calling getAdapter(IDocument.class)) when
it is needed, rather than caching it.

Fixes eclipse-cdt#603

dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyPart.java

@@ -109,6 +109,7 @@
 import org.eclipse.jface.resource.ResourceLocator;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.BadPositionCategoryException;
+import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IFindReplaceTarget;
 import org.eclipse.jface.text.IRegion;
 import org.eclipse.jface.text.ITextOperationTarget;
@@ -580,8 +581,9 @@ public <T> T getAdapter(Class<T> required) {
 			if (fColumnSupport == null)
 				fColumnSupport = createColumnSupport();
 			return (T) fColumnSupport;
+		} else if (IDocument.class.equals(required)) {
+			return (T) getDocument();
 		}
-
 		return super.getAdapter(required);
 	}
 

dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/actions/RulerToggleBreakpointActionDelegate.java

@@ -37,8 +37,7 @@ protected IAction createAction(IDisassemblyPart disassemblyPart, IVerticalRulerI
 		if (fDelegate != null) {
 			fDelegate.dispose();
 		}
-		return fDelegate = new ToggleBreakpointAction(disassemblyPart, disassemblyPart.getTextViewer().getDocument(),
-				rulerInfo);
+		return fDelegate = new ToggleBreakpointAction(disassemblyPart, null, rulerInfo);
 	}
 
 	/*

dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/actions/RulerToggleBreakpointHandler.java

@@ -18,7 +18,6 @@
 import org.eclipse.core.commands.ExecutionEvent;
 import org.eclipse.core.commands.ExecutionException;
 import org.eclipse.debug.ui.actions.ToggleBreakpointAction;
-import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.source.IVerticalRulerInfo;
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.ui.IWorkbenchPart;
@@ -36,11 +35,9 @@ public class RulerToggleBreakpointHandler extends AbstractHandler {
 	public Object execute(ExecutionEvent event) throws ExecutionException {
 		IWorkbenchPart part = HandlerUtil.getActivePartChecked(event);
 		if (part instanceof IDisassemblyPart) {
-			IDisassemblyPart disassemblyPart = (IDisassemblyPart) part;
-			IDocument document = disassemblyPart.getTextViewer().getDocument();
 			final IVerticalRulerInfo rulerInfo = part.getAdapter(IVerticalRulerInfo.class);
 			if (rulerInfo != null) {
-				final ToggleBreakpointAction toggleBpAction = new ToggleBreakpointAction(part, document, rulerInfo);
+				final ToggleBreakpointAction toggleBpAction = new ToggleBreakpointAction(part, null, rulerInfo);
 				try {
 					toggleBpAction.update();
 					if (toggleBpAction.isEnabled()) {