Find/Replace Overlay: add help context to Overlay

Add the find/replace help context to the overlay which was also used for
the find/replace dialog. In particular, display help for find/replace
with regex patterns.

fixes #1994

bundles/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/findandreplace/overlay/FindReplaceOverlay.java

@@ -64,6 +64,7 @@
 import org.eclipse.ui.internal.findandreplace.SearchOptions;
 import org.eclipse.ui.internal.findandreplace.status.IFindReplaceStatus;
 
+import org.eclipse.ui.texteditor.IAbstractTextEditorHelpContextIds;
 import org.eclipse.ui.texteditor.StatusTextEditor;
 
 /**
@@ -434,6 +435,9 @@ private void bindListeners() {
 
 	@Override
 	public Control createContents(Composite parent) {
+		PlatformUI.getWorkbench().getHelpSystem().setHelp(getShell(),
+				IAbstractTextEditorHelpContextIds.FIND_REPLACE_OVERLAY);
+
 		backgroundToUse = new Color(getShell().getDisplay(), new RGBA(0, 0, 0, 0));
 		Control ret = createDialog(parent);
 

bundles/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/texteditor/IAbstractTextEditorHelpContextIds.java

@@ -291,6 +291,15 @@ public interface IAbstractTextEditorHelpContextIds {
 	 */
 	String FIND_REPLACE_DIALOG= PREFIX + "find_replace_dialog_context"; //$NON-NLS-1$
 
+	/**
+	 * Help context id for the overlay which may be shown instead of the
+	 * find/replace dialog.
+	 * <code>"org.eclipse.ui.find_replace_overlay_context"</code>
+	 *
+	 * @since 3.17
+	 */
+	String FIND_REPLACE_OVERLAY = PREFIX + "find_replace_overlay_context"; //$NON-NLS-1$
+
 	/**
 	 * Help context id for the action.
 	 * Value: <code>"org.eclipse.ui.goto_last_edit_position_action_context"</code>