Add flag for displaying hidden files in the file dialog

Add wxFD_SHOW_HIDDEN and implement support for it for all the major
ports.

Closes https://github.com/wxWidgets/wxWidgets/pull/1413

Closes #9342.

include/wx/filedlg.h

@@ -48,7 +48,8 @@ enum
     wxFD_FILE_MUST_EXIST   = 0x0010,
     wxFD_CHANGE_DIR        = 0x0080,
     wxFD_PREVIEW           = 0x0100,
-    wxFD_MULTIPLE          = 0x0200
+    wxFD_MULTIPLE          = 0x0200,
+    wxFD_SHOW_HIDDEN       = 0x0400
 };
 
 #define wxFD_DEFAULT_STYLE      wxFD_OPEN

include/wx/msw/missing.h

@@ -413,5 +413,9 @@
     #define INVALID_FILE_ATTRIBUTES ((DWORD)-1)
 #endif
 
+#ifndef OFN_FORCESHOWHIDDEN
+    #define OFN_FORCESHOWHIDDEN          0x10000000
+#endif
+
 #endif
     // _WX_MISSING_H_

interface/wx/filedlg.h

@@ -14,7 +14,8 @@ enum
     wxFD_FILE_MUST_EXIST   = 0x0010,
     wxFD_CHANGE_DIR        = 0x0080,
     wxFD_PREVIEW           = 0x0100,
-    wxFD_MULTIPLE          = 0x0200
+    wxFD_MULTIPLE          = 0x0200,
+    wxFD_SHOW_HIDDEN       = 0x0400
 };
 
 #define wxFD_DEFAULT_STYLE      wxFD_OPEN
@@ -141,6 +142,8 @@ const char wxFileSelectorDefaultWildcardStr[];
     @style{wxFD_PREVIEW}
            Show the preview of the selected files (currently only supported by
            wxGTK).
+    @style{wxFD_SHOW_HIDDEN}
+          Show hidden files. This flag was added in wxWidgets 3.1.3
     @endStyleTable
 
     @library{wxcore}

samples/dialogs/dialogs.cpp

@@ -1616,7 +1616,7 @@ void MyFrame::FileOpen2(wxCommandEvent& WXUNUSED(event) )
                                         wxFileSelectorDefaultWildcardStr,
                                         wxFileSelectorDefaultWildcardStr
                                     ),
-                                    wxFD_OPEN|wxFD_CHANGE_DIR|wxFD_PREVIEW|wxFD_NO_FOLLOW,
+                                    wxFD_OPEN|wxFD_CHANGE_DIR|wxFD_PREVIEW|wxFD_NO_FOLLOW|wxFD_SHOW_HIDDEN,
                                     this
                                    );
 

src/gtk/filedlg.cpp

@@ -151,6 +151,21 @@ static void gtk_filedialog_update_preview_callback(GtkFileChooser *chooser,
 
 } // extern "C"
 
+extern "C"
+{
+static gboolean gtk_frame_map_callback( GtkFileChooser *file_chooser,
+                        GdkEvent * WXUNUSED(event),
+                        wxFileDialog *dlg )
+{
+/*    if ( dlg->GetWindowStyle() & wxFD_SHOW_HIDDEN )
+        gtk_file_chooser_set_show_hidden( file_chooser, TRUE );
+    else
+        gtk_file_chooser_set_show_hidden( file_chooser, FALSE );*/
+    gtk_file_chooser_set_show_hidden(file_chooser, dlg->HasFlag(wxFD_SHOW_HIDDEN));
+    return FALSE;
+}
+}
+
 void wxFileDialog::AddChildGTK(wxWindowGTK* child)
 {
     // allow dialog to be resized smaller horizontally
@@ -275,6 +290,8 @@ bool wxFileDialog::Create(wxWindow *parent, const wxString& message,
     g_signal_connect (m_widget, "selection-changed",
         G_CALLBACK (gtk_filedialog_selchanged_callback), this);
 
+    g_signal_connect (m_widget, "map_event",
+                      G_CALLBACK (gtk_frame_map_callback), this);
      // deal with extensions/filters
     SetWildcard(wildCard);
 

src/msw/filedlg.cpp

@@ -443,6 +443,9 @@ int wxFileDialog::ShowModal()
 
     if ( HasFdFlag(wxFD_FILE_MUST_EXIST) )
         msw_flags |= OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;
+
+    if ( HasFlag(wxFD_SHOW_HIDDEN) )
+        msw_flags |= OFN_FORCESHOWHIDDEN;
     /*
         If the window has been moved the programmer is probably
         trying to center or position it.  Thus we set the callback

src/osx/cocoa/filedlg.mm

@@ -340,6 +340,7 @@ void wxFileDialog::ShowWindowModal()
             modalForWindow: nativeParent modalDelegate: m_sheetDelegate
             didEndSelector: @selector(sheetDidEnd:returnCode:contextInfo:)
             contextInfo: nil];
+        [sPanel setShowsHiddenFiles: HasFlag(wxFD_SHOW_HIDDEN) ? YES : NO];
     }
     else 
     {
@@ -360,6 +361,7 @@ void wxFileDialog::ShowWindowModal()
             modalDelegate: m_sheetDelegate
             didEndSelector: @selector(sheetDidEnd:returnCode:contextInfo:)
             contextInfo: nil];
+        [oPanel setShowsHiddenFiles: HasFlag(wxFD_SHOW_HIDDEN) ? YES : NO];
     }
 
     wxGCC_WARNING_RESTORE(deprecated-declarations)
@@ -576,6 +578,7 @@ int wxFileDialog::ShowModal()
         [sPanel setCanSelectHiddenExtension:YES];
         [sPanel setAllowedFileTypes:types];
         [sPanel setAllowsOtherFileTypes:NO];
+        [sPanel setShowsHiddenFiles: HasFlag(wxFD_SHOW_HIDDEN) ? YES : NO];
 
         if ( HasFlag(wxFD_OVERWRITE_PROMPT) )
         {
@@ -609,6 +612,7 @@ int wxFileDialog::ShowModal()
         [oPanel setCanChooseFiles:YES];
         [oPanel setMessage:cf.AsNSString()];
         [oPanel setAllowsMultipleSelection: (HasFlag(wxFD_MULTIPLE) ? YES : NO )];
+        [oPanel setShowsHiddenFiles: HasFlag(wxFD_SHOW_HIDDEN) ? YES : NO];
 
         // Note that the test here is intentionally different from the one
         // above, in the wxFD_SAVE case: we need to call DoOnFilterSelected()