Restore commit c1d129ec98

src/HistoryWindow.cpp

@@ -35,6 +35,7 @@ undo memory so as to free up space.
 
 #include "AudioIO.h"
 #include "Clipboard.h"
+#include "CommonCommandFlags.h"
 #include "../images/Arrow.xpm"
 #include "../images/Empty9x16.xpm"
 #include "UndoManager.h"
@@ -316,3 +317,85 @@ void HistoryDialog::OnSize(wxSizeEvent & WXUNUSED(event))
    if (mList->GetItemCount() > 0)
       mList->EnsureVisible(mSelected);
 }
+
+// Remaining code hooks this add-on into the application
+#include "commands/CommandContext.h"
+#include "commands/CommandManager.h"
+
+namespace {
+
+// History window attached to each project is built on demand by:
+AudacityProject::AttachedWindows::RegisteredFactory sHistoryWindowKey{
+   []( AudacityProject &parent ) -> wxWeakRef< wxWindow > {
+      auto &undoManager = UndoManager::Get( parent );
+      return safenew HistoryDialog( &parent, &undoManager );
+   }
+};
+
+// Define our extra menu item that invokes that factory
+struct Handler : CommandHandlerObject {
+   void OnHistory(const CommandContext &context)
+   {
+      auto &project = context.project;
+
+      auto historyWindow = &project.AttachedWindows::Get( sHistoryWindowKey );
+      historyWindow->Show();
+      historyWindow->Raise();
+   }
+};
+
+CommandHandlerObject &findCommandHandler(AudacityProject &) {
+   // Handler is not stateful.  Doesn't need a factory registered with
+   // AudacityProject.
+   static Handler instance;
+   return instance;
+}
+
+// Register that menu item
+
+using namespace MenuTable;
+AttachedItem sAttachment{ wxT("View/Windows"),
+   // History window should be available either for UndoAvailableFlag
+   // or RedoAvailableFlag,
+   // but we can't make the AddItem flags and mask have both,
+   // because they'd both have to be true for the
+   // command to be enabled.
+   //    If user has Undone the entire stack, RedoAvailableFlag is on
+   //    but UndoAvailableFlag is off.
+   //    If user has done things but not Undone anything,
+   //    RedoAvailableFlag is off but UndoAvailableFlag is on.
+   // So in either of those cases,
+   // (AudioIONotBusyFlag | UndoAvailableFlag | RedoAvailableFlag) mask
+   // would fail.
+   // The only way to fix this in the current architecture
+   // is to hack in special cases for RedoAvailableFlag
+   // in AudacityProject::UpdateMenus() (ugly)
+   // and CommandManager::HandleCommandEntry() (*really* ugly --
+   // shouldn't know about particular command names and flags).
+   // Here's the hack that would be necessary in
+   // AudacityProject::UpdateMenus(), if somebody decides to do it:
+   //    // Because EnableUsingFlags requires all the flag bits match the
+   //    // corresponding mask bits,
+   //    // "UndoHistory" specifies only
+   //    // AudioIONotBusyFlag | UndoAvailableFlag, because that
+   //    // covers the majority of cases where it should be enabled.
+   //    // If history is not empty but we've Undone the whole stack,
+   //    // we also want to enable,
+   //    // to show the Redo's on stack.
+   //    // "UndoHistory" might already be enabled,
+   //    // but add this check for RedoAvailableFlag.
+   //    if (flags & RedoAvailableFlag)
+   //       GetCommandManager()->Enable(wxT("UndoHistory"), true);
+   // So for now, enable the command regardless of stack.
+   // It will just show empty sometimes.
+   // FOR REDESIGN,
+   // clearly there are some limitations with the flags/mask bitmaps.
+
+   /* i18n-hint: Clicking this menu item shows the various editing steps
+      that have been taken.*/
+   ( FinderScope{ findCommandHandler },
+      Command( wxT("UndoHistory"), XXO("&History..."), &Handler::OnHistory,
+         AudioIONotBusyFlag() ) )
+};
+
+}