Support opening collections of files

Implement a process-local VFS to enable grouping together arbitrary
URIs passed via program arguments, DnD, or the file open dialog.

This VFS contains FivCollectionFile objects, which act as "simple"
proxies over arbitrary GFiles.  Their true URIs may be retrieved
through the "standard::target-uri" attribute, in a similar way to
GVfs's "recent" and "trash" backends.

(The main reason we proxy rather than just hackishly return foreign
GFiles from the VFS is that loading them would switch the current
directory, and break iteration as a result.

We could also keep the collection outside of GVfs, but that would
result in considerable special-casing, and the author wouldn't gain
intimate knowledge of GIO.)

There is no perceived need to keep old collections when opening
new ones, so we simply change and reload the contents when needed.

Similarly, there is no intention to make the VFS writeable.

The process-locality of this and other URI schemes has proven to be
rather annoying when passing files to other applications,
however most of the resulting complexity appears to be essential
rather than accidental.

Note that the GTK+ file chooser widget is retarded, and doesn't
recognize URIs that lack the authority part in the location bar.

1 files changed, 29 insertions, 11 deletions

diff --git a/fiv-browser.c b/fiv-browser.c
index 3edcf4a..c4475a7 100644
--- a/fiv-browser.c
+++ b/fiv-browser.c
@@ -29,6 +29,7 @@
 #endif  // GDK_WINDOWING_QUARTZ
 
 #include "fiv-browser.h"
+#include "fiv-collection.h"
 #include "fiv-context-menu.h"
 #include "fiv-io.h"
 #include "fiv-thumbnail.h"
@@ -102,6 +103,7 @@ static cairo_user_data_key_t fiv_browser_key_mtime_msec;
 
 struct entry {
 	gchar *uri;                         ///< GIO URI
+	gchar *target_uri;                  ///< GIO URI for any target
 	gint64 mtime_msec;                  ///< Modification time in milliseconds
 	cairo_surface_t *thumbnail;         ///< Prescaled thumbnail
 	GIcon *icon;                        ///< If no thumbnail, use this icon
@@ -111,6 +113,7 @@ static void
 entry_free(Entry *self)
 {
 	g_free(self->uri);
+	g_free(self->target_uri);
 	g_clear_pointer(&self->thumbnail, cairo_surface_destroy);
 	g_clear_object(&self->icon);
 }
@@ -437,6 +440,17 @@ rescale_thumbnail(cairo_surface_t *thumbnail, double row_height)
 	return scaled;
 }
 
+static char *
+entry_system_wide_uri(const Entry *self)
+{
+	// "recent" and "trash", e.g., also have "standard::target-uri" set,
+	// but we'd like to avoid saving their thumbnails.
+	if (self->target_uri && fiv_collection_uri_matches(self->uri))
+		return self->target_uri;
+
+	return self->uri;
+}
+
 static void
 entry_add_thumbnail(gpointer data, gpointer user_data)
 {
@@ -456,7 +470,7 @@ entry_add_thumbnail(gpointer data, gpointer user_data)
 		// unnecessarily; we might also shift the concern there).
 	} else {
 		cairo_surface_t *found = fiv_thumbnail_lookup(
-			self->uri, self->mtime_msec, browser->item_size);
+			entry_system_wide_uri(self), self->mtime_msec, browser->item_size);
 		self->thumbnail = rescale_thumbnail(found, browser->item_height);
 	}
 
@@ -589,7 +603,8 @@ thumbnailer_reprocess_entry(FivBrowser *self, GBytes *output, Entry *entry)
 			g_list_append(self->thumbnailers_queue, entry);
 	}
 
-	// This choice of mtime favours unnecessary thumbnail reloading.
+	// This choice of mtime favours unnecessary thumbnail reloading
+	// over retaining stale data.
 	cairo_surface_set_user_data(entry->thumbnail,
 		&fiv_browser_key_mtime_msec, (void *) (intptr_t) entry->mtime_msec,
 		NULL);
@@ -663,12 +678,13 @@ thumbnailer_next(Thumbnailer *t)
 	//  - We've found one, but we're not quite happy with it:
 	//    always run the full process for a high-quality wide thumbnail.
 	//  - We can't end up here in any other cases.
+	const char *uri = entry_system_wide_uri(t->target);
 	const char *argv_faster[] = {PROJECT_NAME, "--extract-thumbnail",
 		"--thumbnail", fiv_thumbnail_sizes[self->item_size].thumbnail_spec_name,
-		"--", t->target->uri, NULL};
+		"--", uri, NULL};
 	const char *argv_slower[] = {PROJECT_NAME,
 		"--thumbnail", fiv_thumbnail_sizes[self->item_size].thumbnail_spec_name,
-		"--", t->target->uri, NULL};
+		"--", uri, NULL};
 
 	GError *error = NULL;
 	t->minion = g_subprocess_newv(t->target->icon ? argv_faster : argv_slower,
@@ -1259,7 +1275,7 @@ fiv_browser_drag_data_get(GtkWidget *widget,
 	FivBrowser *self = FIV_BROWSER(widget);
 	if (self->selected) {
 		(void) gtk_selection_data_set_uris(
-			data, (gchar *[]){self->selected->uri, NULL});
+			data, (gchar *[]) {entry_system_wide_uri(self->selected), NULL});
 	}
 }
 
@@ -1466,10 +1482,9 @@ fiv_browser_query_tooltip(GtkWidget *widget, gint x, gint y,
 		return FALSE;
 
 	GFile *file = g_file_new_for_uri(entry->uri);
-	GFileInfo *info = g_file_query_info(file,
-		G_FILE_ATTRIBUTE_STANDARD_NAME
-		"," G_FILE_ATTRIBUTE_STANDARD_DISPLAY_NAME,
-		G_FILE_QUERY_INFO_NONE, NULL, NULL);
+	GFileInfo *info =
+		g_file_query_info(file, G_FILE_ATTRIBUTE_STANDARD_DISPLAY_NAME,
+			G_FILE_QUERY_INFO_NONE, NULL, NULL);
 	g_object_unref(file);
 	if (!info)
 		return FALSE;
@@ -1740,8 +1755,11 @@ on_model_files_changed(FivIoModel *model, FivBrowser *self)
 	gsize len = 0;
 	const FivIoModelEntry *files = fiv_io_model_get_files(self->model, &len);
 	for (gsize i = 0; i < len; i++) {
-		g_array_append_val(self->entries, ((Entry) {.thumbnail = NULL,
-			.uri = g_strdup(files[i].uri), .mtime_msec = files[i].mtime_msec}));
+		Entry e = {.thumbnail = NULL,
+			.uri = g_strdup(files[i].uri),
+			.target_uri = g_strdup(files[i].target_uri),
+			.mtime_msec = files[i].mtime_msec};
+		g_array_append_val(self->entries, e);
 	}
 
 	fiv_browser_select(self, selected_uri);