DropTarget.cpp

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  @file DropTarget.cpp
  @brief Inject drag-and-drop importation of files
 
  Paul Licameli split from ProjectManager.cpp
 
**********************************************************************/
 
#include <wx/dataobj.h>
#include <wx/dnd.h>
 
#include "AudacityException.h"
#include "FileNames.h"
#include "Project.h"
#include "ProjectFileManager.h"
#include "Viewport.h"
#include "TrackPanel.h"
 
#if wxUSE_DRAG_AND_DROP
class FileObject final : public wxFileDataObject
{
public:
   FileObject()
   {
   }
 
   bool IsSupportedFormat(const wxDataFormat & format, Direction WXUNUSED(dir = Get)) const
      // PRL:  This function does NOT override any inherited virtual!  What does it do?
   {
      if (format.GetType() == wxDF_FILENAME) {
         return true;
      }
 
#if defined(__WXMAC__)
#if !wxCHECK_VERSION(3, 0, 0)
      if (format.GetFormatId() == kDragPromisedFlavorFindFile) {
         return true;
      }
#endif
#endif
 
      return false;
   }
};
 
class DropTarget final : public wxFileDropTarget
{
public:
   DropTarget(AudacityProject *proj)
   {
      mProject = proj;
 
      // SetDataObject takes ownership
      SetDataObject(safenew FileObject());
   }
 
   ~DropTarget()
   {
   }
 
#if defined(__WXMAC__)
#if !wxCHECK_VERSION(3, 0, 0)
   bool GetData() override
   {
      bool foundSupported = false;
      bool firstFileAdded = false;
      OSErr result;
 
      UInt16 items = 0;
      CountDragItems((DragReference)m_currentDrag, &items);
 
      for (UInt16 index = 1; index <= items; index++) {
 
         DragItemRef theItem = 0;
         GetDragItemReferenceNumber((DragReference)m_currentDrag, index, &theItem);
 
         UInt16 flavors = 0;
         CountDragItemFlavors((DragReference)m_currentDrag, theItem , &flavors ) ;
 
         for (UInt16 flavor = 1 ;flavor <= flavors; flavor++) {
 
            FlavorType theType = 0;
            result = GetFlavorType((DragReference)m_currentDrag, theItem, flavor, &theType);
            if (theType != kDragPromisedFlavorFindFile && theType != kDragFlavorTypeHFS) {
               continue;
            }
            foundSupported = true;
 
            Size dataSize = 0;
            GetFlavorDataSize((DragReference)m_currentDrag, theItem, theType, &dataSize);
 
            ArrayOf<char> theData{ dataSize };
            GetFlavorData((DragReference)m_currentDrag, theItem, theType, (void*) theData.get(), &dataSize, 0L);
 
            wxString name;
            if (theType == kDragPromisedFlavorFindFile) {
               name = wxMacFSSpec2MacFilename((FSSpec *)theData.get());
            }
            else if (theType == kDragFlavorTypeHFS) {
               name = wxMacFSSpec2MacFilename(&((HFSFlavor *)theData.get())->fileSpec);
            }
 
            if (!firstFileAdded) {
               // reset file list
               ((wxFileDataObject*)GetDataObject())->SetData(0, "");
               firstFileAdded = true;
            }
 
            ((wxFileDataObject*)GetDataObject())->AddFile(name);
 
            // We only want to process one flavor
            break;
         }
      }
      return foundSupported;
   }
#endif
 
   bool OnDrop(wxCoord x, wxCoord y) override
   {
      // bool foundSupported = false;
#if !wxCHECK_VERSION(3, 0, 0)
      bool firstFileAdded = false;
      OSErr result;
 
      UInt16 items = 0;
      CountDragItems((DragReference)m_currentDrag, &items);
 
      for (UInt16 index = 1; index <= items; index++) {
 
         DragItemRef theItem = 0;
         GetDragItemReferenceNumber((DragReference)m_currentDrag, index, &theItem);
 
         UInt16 flavors = 0;
         CountDragItemFlavors((DragReference)m_currentDrag, theItem , &flavors ) ;
 
         for (UInt16 flavor = 1 ;flavor <= flavors; flavor++) {
 
            FlavorType theType = 0;
            result = GetFlavorType((DragReference)m_currentDrag, theItem, flavor, &theType);
            if (theType != kDragPromisedFlavorFindFile && theType != kDragFlavorTypeHFS) {
               continue;
            }
            return true;
         }
      }
#endif
      return CurrentDragHasSupportedFormat();
   }
 
#endif
 
   bool OnDropFiles(wxCoord WXUNUSED(x), wxCoord WXUNUSED(y), const wxArrayString& filenames) override
   {
      // Experiment shows that this function can be reached while there is no
      // catch block above in wxWidgets.  So stop all exceptions here.
      return GuardedCall< bool > ( [&] {
         wxArrayString sortednames(filenames);
         sortednames.Sort(FileNames::CompareNoCase);
 
         auto cleanup = finally( [&] {
            Viewport::Get(*mProject).HandleResize(); // Adjust scrollers for NEW track sizes.
         } );
 
         for (const auto &name : sortednames)
            ProjectFileManager::Get( *mProject ).Import(name);
 
         auto &viewport = Viewport::Get(*mProject);
         viewport.ZoomFitHorizontallyAndShowTrack(nullptr);
 
         return true;
      } );
   }
 
private:
   AudacityProject *mProject;
};
 
// Hook the construction of projects
static const AudacityProject::AttachedObjects::RegisteredFactory key{
   [](AudacityProject &project) {
      // We can import now, so become a drag target
      //   SetDropTarget(safenew AudacityDropTarget(this));
      //   mTrackPanel->SetDropTarget(safenew AudacityDropTarget(this));
      
      TrackPanel::Get( project )
         .SetDropTarget(
            // SetDropTarget takes ownership
            safenew DropTarget( &project ) );
      return nullptr;
   }
};
#endif