wxFD_PREVIEW implementation for wxGTK (slightly modified patch 1520690)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@40292 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -244,6 +244,7 @@ wxGTK:
 - Support underlined fonts in wxTextCtrl.
 - Support all border styles; wxListBox honours the borders now.
 - wxWindow and wxScrolledWindow now generate line, page and thumb-release scroll events.
+- Added file preview support in file dialogs.
 
 wxMac:
 

docs/latex/wx/filedlg.tex

@@ -23,6 +23,7 @@ This class represents the file chooser dialog.
 \twocolitem{{\windowstyle wxFD\_FILE\_MUST\_EXIST}}{For open dialog only: the user may only select files that actually exist.}
 \twocolitem{{\windowstyle wxFD\_MULTIPLE}}{For open dialog only: allows selecting multiple files.}
 \twocolitem{{\windowstyle wxFD\_CHANGE\_DIR}}{Change the current working directory to the directory where the file(s) chosen by the user are.}
+\twocolitem{{\windowstyle wxFD\_PREVIEW}}{Show the preview of the selected files (currently only supported by wxGTK using GTK+ 2.4 or later).}
 \end{twocollist}
 
 {\bf NB:} Previous versions of wxWidgets used {\tt wxFD\_CHANGE\_DIR} by default

include/wx/filedlg.h

@@ -30,7 +30,8 @@ enum
     wxFD_OVERWRITE_PROMPT  = 0x0004,
     wxFD_FILE_MUST_EXIST   = 0x0010,
     wxFD_MULTIPLE          = 0x0020,
-    wxFD_CHANGE_DIR        = 0x0040
+    wxFD_CHANGE_DIR        = 0x0040,
+    wxFD_PREVIEW           = 0x0080
 };
 
 #if WXWIN_COMPATIBILITY_2_6

samples/dialogs/dialogs.cpp

@@ -729,7 +729,7 @@ void MyFrame::FileOpen2(wxCommandEvent& WXUNUSED(event) )
                                         wxFileSelectorDefaultWildcardStr,
                                         wxFileSelectorDefaultWildcardStr
                                     ),
-                                    wxFD_OPEN|wxFD_CHANGE_DIR,
+                                    wxFD_OPEN|wxFD_CHANGE_DIR|wxFD_PREVIEW,
                                     this
                                    );
 

src/gtk/filedlg.cpp

@@ -86,16 +86,16 @@ static void gtk_filedialog_ok_callback(GtkWidget *widget, wxFileDialog *dialog)
 // "clicked" for Cancel-button
 //-----------------------------------------------------------------------------
 
-extern "C" {
+extern "C"
+{
+
 static void gtk_filedialog_cancel_callback(GtkWidget *w, wxFileDialog *dialog)
 {
     wxCommandEvent event(wxEVT_COMMAND_BUTTON_CLICKED, wxID_CANCEL);
     event.SetEventObject(dialog);
     dialog->GetEventHandler()->ProcessEvent(event);
 }
-}
 
-extern "C" {
 static void gtk_filedialog_response_callback(GtkWidget *w,
                                              gint response,
                                              wxFileDialog *dialog)
@@ -107,8 +107,32 @@ static void gtk_filedialog_response_callback(GtkWidget *w,
     else    // GTK_RESPONSE_CANCEL or GTK_RESPONSE_NONE
         gtk_filedialog_cancel_callback(w, dialog);
 }
+
+static void gtk_filedialog_update_preview_callback(GtkFileChooser *chooser,
+                                                   gpointer user_data)
+{
+#if GTK_CHECK_VERSION(2,4,0)
+    GtkWidget *preview = GTK_WIDGET(user_data);
+    wxGtkString filename(gtk_file_chooser_get_preview_filename(chooser));
+    if ( !filename )
+        return;
+
+    GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file_at_size(filename, 128, 128, NULL);
+    gboolean have_preview = pixbuf != NULL;
+
+    gtk_image_set_from_pixbuf(GTK_IMAGE(preview), pixbuf);
+    if ( pixbuf )
+        g_object_unref (pixbuf);
+
+    gtk_file_chooser_set_preview_widget_active(chooser, have_preview);
+#else
+    wxUnusedVar(chooser);
+    wxUnusedVar(user_data);
+#endif // GTK+ 2.4+
 }
 
+} // extern "C"
+
 
 //-----------------------------------------------------------------------------
 // wxFileDialog
@@ -130,8 +154,13 @@ wxFileDialog::wxFileDialog(wxWindow *parent, const wxString& message,
     : wxGenericFileDialog(parent, message, defaultDir, defaultFileName,
                           wildCard, style, pos, sz, name, true )
 {
-    if (!gtk_check_version(2,4,0))
+    if (gtk_check_version(2,4,0))
     {
+        wxGenericFileDialog::Create( parent, message, defaultDir,
+                                     defaultFileName, wildCard, style, pos );
+        return;
+    }
+
     m_needParent = false;
 
     if (!PreCreation(parent, pos, wxDefaultSize) ||
@@ -206,7 +235,7 @@ wxFileDialog::wxFileDialog(wxWindow *parent, const wxString& message,
             gtk_file_chooser_set_do_overwrite_confirmation(GTK_FILE_CHOOSER(m_widget), TRUE);
 #endif
     }
-        else
+    else // wxFD_OPEN
     {
         if ( !defaultFileName.empty() )
         {
@@ -221,12 +250,24 @@ wxFileDialog::wxFileDialog(wxWindow *parent, const wxString& message,
                 wxConvFileName->cWX2MB( wxFileName(dir, defaultFileName).GetFullPath() ) );
         }
         else if ( !defaultDir.empty() )
+        {
             gtk_file_chooser_set_current_folder( GTK_FILE_CHOOSER(m_widget),
                 wxConvFileName->cWX2MB(defaultDir) );
         }
     }
-    else
-        wxGenericFileDialog::Create( parent, message, defaultDir, defaultFileName, wildCard, style, pos );
+
+#if GTK_CHECK_VERSION(2,4,0)
+    if ( style & wxFD_PREVIEW )
+    {
+        GtkWidget *previewImage = gtk_image_new();
+
+        gtk_file_chooser_set_preview_widget(GTK_FILE_CHOOSER(m_widget),
+                                            previewImage);
+        g_signal_connect(m_widget, "update-preview",
+                         G_CALLBACK(gtk_filedialog_update_preview_callback),
+                         previewImage);
+    }
+#endif // GTK+ 2.4+
 }
 
 void wxFileDialog::OnFakeOk( wxCommandEvent &event )