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Diffstat (limited to 'src/DragAndDropHandler.vala')
| -rw-r--r-- | src/DragAndDropHandler.vala | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/src/DragAndDropHandler.vala b/src/DragAndDropHandler.vala new file mode 100644 index 0000000..ece6d9d --- /dev/null +++ b/src/DragAndDropHandler.vala @@ -0,0 +1,182 @@ +/* Copyright 2016 Software Freedom Conservancy Inc. + * + * This software is licensed under the GNU LGPL (version 2.1 or later). + * See the COPYING file in this distribution. + */ + +// +// DragAndDropHandler attaches signals to a Page to properly handle drag-and-drop requests for the +// Page as a DnD Source. (DnD Destination handling is handled by the appropriate AppWindow, i.e. +// LibraryWindow and DirectWindow). Assumes the Page's ViewCollection holds MediaSources. +// +public class DragAndDropHandler { + private enum TargetType { + XDS, + MEDIA_LIST + } + + private const Gtk.TargetEntry[] SOURCE_TARGET_ENTRIES = { + { "XdndDirectSave0", Gtk.TargetFlags.OTHER_APP, TargetType.XDS }, + { "shotwell/media-id-atom", Gtk.TargetFlags.SAME_APP, TargetType.MEDIA_LIST } + }; + + private static Gdk.Atom? XDS_ATOM = null; + private static Gdk.Atom? TEXT_ATOM = null; + private static uint8[]? XDS_FAKE_TARGET = null; + + private weak Page page; + private Gtk.Widget event_source; + private File? drag_destination = null; + private ExporterUI exporter = null; + + public DragAndDropHandler(Page page) { + this.page = page; + this.event_source = page.get_event_source(); + assert(event_source != null); + assert(event_source.get_has_window()); + + // Need to do this because static member variables are not properly handled + if (XDS_ATOM == null) + XDS_ATOM = Gdk.Atom.intern_static_string("XdndDirectSave0"); + + if (TEXT_ATOM == null) + TEXT_ATOM = Gdk.Atom.intern_static_string("text/plain"); + + if (XDS_FAKE_TARGET == null) + XDS_FAKE_TARGET = string_to_uchar_array("shotwell.txt"); + + // register what's available on this DnD Source + Gtk.drag_source_set(event_source, Gdk.ModifierType.BUTTON1_MASK, SOURCE_TARGET_ENTRIES, + Gdk.DragAction.COPY); + + // attach to the event source's DnD signals, not the Page's, which is a NO_WINDOW widget + // and does not emit them + event_source.drag_begin.connect(on_drag_begin); + event_source.drag_data_get.connect(on_drag_data_get); + event_source.drag_end.connect(on_drag_end); + event_source.drag_failed.connect(on_drag_failed); + } + + ~DragAndDropHandler() { + if (event_source != null) { + event_source.drag_begin.disconnect(on_drag_begin); + event_source.drag_data_get.disconnect(on_drag_data_get); + event_source.drag_end.disconnect(on_drag_end); + event_source.drag_failed.disconnect(on_drag_failed); + } + + page = null; + event_source = null; + } + + private void on_drag_begin(Gdk.DragContext context) { + debug("on_drag_begin (%s)", page.get_page_name()); + + if (page == null || page.get_view().get_selected_count() == 0 || exporter != null) + return; + + drag_destination = null; + + // use the first media item as the icon + ThumbnailSource thumb = (ThumbnailSource) page.get_view().get_selected_at(0).get_source(); + + try { + Gdk.Pixbuf icon = thumb.get_thumbnail(AppWindow.DND_ICON_SCALE); + Gtk.drag_source_set_icon_pixbuf(event_source, icon); + } catch (Error err) { + warning("Unable to fetch icon for drag-and-drop from %s: %s", thumb.to_string(), + err.message); + } + + // set the XDS property to indicate an XDS save is available + Gdk.property_change(context.get_source_window(), XDS_ATOM, TEXT_ATOM, 8, Gdk.PropMode.REPLACE, + XDS_FAKE_TARGET, 1); + } + + private void on_drag_data_get(Gdk.DragContext context, Gtk.SelectionData selection_data, + uint target_type, uint time) { + debug("on_drag_data_get (%s)", page.get_page_name()); + + if (page == null || page.get_view().get_selected_count() == 0) + return; + + switch (target_type) { + case TargetType.XDS: + // Fetch the XDS property that has been set with the destination path + uchar[] data = new uchar[4096]; + Gdk.Atom actual_type; + int actual_format = 0; + bool fetched = Gdk.property_get(context.get_source_window(), XDS_ATOM, TEXT_ATOM, + 0, data.length, 0, out actual_type, out actual_format, out data); + + // the destination path is actually for our XDS_FAKE_TARGET, use its parent + // to determine where the file(s) should go + if (fetched && data != null && data.length > 0) + drag_destination = File.new_for_uri(uchar_array_to_string(data)).get_parent(); + + debug("on_drag_data_get (%s): %s", page.get_page_name(), + (drag_destination != null) ? drag_destination.get_path() : "(no path)"); + + // Set the property to "S" for Success or "E" for Error + selection_data.set(XDS_ATOM, 8, + string_to_uchar_array((drag_destination != null) ? "S" : "E")); + break; + + case TargetType.MEDIA_LIST: + Gee.Collection<MediaSource> sources = + (Gee.Collection<MediaSource>) page.get_view().get_selected_sources(); + + // convert the selected media sources to Gdk.Atom-encoded sourceID strings for + // internal drag-and-drop + selection_data.set(Gdk.Atom.intern_static_string("SourceIDAtom"), (int) sizeof(Gdk.Atom), + serialize_media_sources(sources)); + break; + + default: + warning("on_drag_data_get (%s): unknown target type %u", page.get_page_name(), + target_type); + break; + } + } + + private void on_drag_end() { + debug("on_drag_end (%s)", page.get_page_name()); + + if (page == null || page.get_view().get_selected_count() == 0 || drag_destination == null + || exporter != null) { + return; + } + + debug("Exporting to %s", drag_destination.get_path()); + + // drag-and-drop export doesn't pop up an export dialog, so use what are likely the + // most common export settings (the current -- or "working" -- file format, with + // all transformations applied, at the image's original size). + if (drag_destination.get_path() != null) { + exporter = new ExporterUI(new Exporter( + (Gee.Collection<Photo>) page.get_view().get_selected_sources(), + drag_destination, Scaling.for_original(), ExportFormatParameters.current())); + exporter.export(on_export_completed); + } else { + AppWindow.error_message(_("Photos cannot be exported to this directory.")); + } + + drag_destination = null; + } + + private bool on_drag_failed(Gdk.DragContext context, Gtk.DragResult drag_result) { + debug("on_drag_failed (%s): %d", page.get_page_name(), (int) drag_result); + + if (page == null) + return false; + + drag_destination = null; + + return false; + } + + private void on_export_completed() { + exporter = null; + } + +} |