Enable opening images from the browser

Also, make it possible to go back, in a roughly implemented manner.

fastiv-browser.c

@@ -200,26 +200,52 @@ draw_item_border(FastivBrowser *self, cairo_t *cr, int width, int height)
 	cairo_pattern_destroy(mask);
 }
 
+static GdkRectangle
+item_extents(const Item *item, const Row *row)
+{
+	int width = cairo_image_surface_get_width(item->entry->thumbnail);
+	int height = cairo_image_surface_get_height(item->entry->thumbnail);
+	return (GdkRectangle) {
+		.x = row->x_offset + item->x_offset,
+		.y = row->y_offset + g_row_height - height,
+		.width = width,
+		.height = height,
+	};
+}
+
+static const Entry *
+entry_at(FastivBrowser *self, int x, int y)
+{
+	for (guint i = 0; i < self->layouted_rows->len; i++) {
+		const Row *row = &g_array_index(self->layouted_rows, Row, i);
+		for (Item *item = row->items; item->entry; item++) {
+			GdkRectangle extents = item_extents(item, row);
+			if (x >= extents.x &&
+				y >= extents.y &&
+				x <= extents.x + extents.width &&
+				y <= extents.y + extents.height)
+				return item->entry;
+		}
+	}
+	return NULL;
+}
+
 static void
 draw_row(FastivBrowser *self, cairo_t *cr, const Row *row)
 {
 	for (Item *item = row->items; item->entry; item++) {
-		cairo_surface_t *thumbnail = item->entry->thumbnail;
+		GdkRectangle extents = item_extents(item, row);
-		int width = cairo_image_surface_get_width(thumbnail);
-		int height = cairo_image_surface_get_height(thumbnail);
-		int x = row->x_offset + item->x_offset;
-		int y = row->y_offset + g_row_height - height;
 
 		cairo_save(cr);
-		cairo_translate(cr, x, y);
+		cairo_translate(cr, extents.x, extents.y);
-		draw_item_border(self, cr, width, height);
+		draw_item_border(self, cr, extents.width, extents.height);
 
 		// TODO(p): See if a mild checkerboard pattern would not look nice.
-		cairo_rectangle(cr, 0, 0, width, height);
+		cairo_rectangle(cr, 0, 0, extents.width, extents.height);
 		cairo_set_source_rgb(cr, .25, .25, .25);
 		cairo_fill(cr);
 
-		cairo_set_source_surface(cr, thumbnail, 0, 0);
+		cairo_set_source_surface(cr, item->entry->thumbnail, 0, 0);
 		cairo_paint(cr);
 		cairo_restore(cr);
 	}
@@ -345,6 +371,22 @@ fastiv_browser_draw(GtkWidget *widget, cairo_t *cr)
 	return TRUE;
 }
 
+static gboolean
+fastiv_browser_button_press_event(GtkWidget *widget, GdkEventButton *event)
+{
+	FastivBrowser *self = FASTIV_BROWSER(widget);
+	if (event->type != GDK_BUTTON_PRESS || event->button != 1 ||
+		event->state != 0)
+		return FALSE;
+
+	const Entry *entry = entry_at(self, event->x, event->y);
+	if (!entry)
+		return FALSE;
+
+	g_signal_emit(widget, browser_signals[ITEM_ACTIVATED], 0, entry->filename);
+	return TRUE;
+}
+
 static void
 fastiv_browser_class_init(FastivBrowserClass *klass)
 {
@@ -359,10 +401,11 @@ fastiv_browser_class_init(FastivBrowserClass *klass)
 	widget_class->realize = fastiv_browser_realize;
 	widget_class->draw = fastiv_browser_draw;
 	widget_class->size_allocate = fastiv_browser_size_allocate;
+	widget_class->button_press_event = fastiv_browser_button_press_event;
 
-	// TODO(p): Connect to this and emit it.
+	browser_signals[ITEM_ACTIVATED] =
-	browser_signals[ITEM_ACTIVATED] = g_signal_new("item-activated",
+		g_signal_new("item-activated", G_TYPE_FROM_CLASS(klass), 0, 0,
-		G_TYPE_FROM_CLASS(klass), 0, 0, NULL, NULL, NULL, G_TYPE_NONE, 0);
+			NULL, NULL, NULL, G_TYPE_NONE, 1, G_TYPE_STRING);
 
 	// TODO(p): Later override "screen_changed", recreate Pango layouts there,
 	// if we get to have any, or otherwise reflect DPI changes.

fastiv-view.c

@@ -131,6 +131,11 @@ fastiv_view_draw(GtkWidget *widget, cairo_t *cr)
 	if (h < allocation.height)
 		y = round((allocation.height - h) / 2.);
 
+	// XXX: The rounding together with padding may result in up to
+	// a pixel's worth of made-up picture data.
+	cairo_rectangle(cr, x, y, w, h);
+	cairo_clip(cr);
+
 	cairo_scale(cr, self->scale, self->scale);
 	cairo_set_source_surface(
 		cr, self->surface, x / self->scale, y / self->scale);

fastiv.c

@@ -61,6 +61,7 @@ struct {
 	gchar *basename;
 
 	GtkWidget *window;
+	GtkWidget *stack;
 	GtkWidget *view;
 	GtkWidget *browser;
 	GtkWidget *browser_scroller;
@@ -148,6 +149,7 @@ open(const gchar *path)
 	}
 
 	gtk_window_set_title(GTK_WINDOW(g.window), path);
+	gtk_stack_set_visible_child(GTK_STACK(g.stack), g.view);
 
 	gchar *basename = g_path_get_basename(path);
 	g_free(g.basename);
@@ -222,6 +224,13 @@ on_next(void)
 	}
 }
 
+static void
+on_item_activated(G_GNUC_UNUSED FastivBrowser *browser, const char *path,
+	G_GNUC_UNUSED gpointer data)
+{
+	open(path);
+}
+
 // Cursor keys, e.g., simply cannot be bound through accelerators
 // (and GtkWidget::keynav-failed would arguably be an awful solution).
 //
@@ -268,6 +277,14 @@ on_key_press(G_GNUC_UNUSED GtkWidget *widget, GdkEvent *event,
 		case GDK_KEY_space:
 			on_next();
 			return TRUE;
+
+		case GDK_KEY_Tab:
+		case GDK_KEY_Return:
+			gtk_stack_set_visible_child(GTK_STACK(g.stack),
+				gtk_stack_get_visible_child(GTK_STACK(g.stack)) == g.view
+					? g.browser_scroller
+					: g.view);
+			return TRUE;
 		}
 	}
 	return FALSE;
@@ -318,15 +335,17 @@ main(int argc, char *argv[])
 	g.browser = g_object_new(FASTIV_TYPE_BROWSER, NULL);
 	gtk_widget_set_vexpand(g.browser, TRUE);
 	gtk_widget_set_hexpand(g.browser, TRUE);
+	g_signal_connect(g.browser, "item-activated",
+		G_CALLBACK(on_item_activated), NULL);
 	gtk_container_add(GTK_CONTAINER(g.browser_scroller), g.browser);
 	// TODO(p): Can we not do it here separately?
 	gtk_widget_show_all(g.browser_scroller);
 
-	GtkWidget *stack = gtk_stack_new();
+	g.stack = gtk_stack_new();
 	gtk_stack_set_transition_type(
-		GTK_STACK(stack), GTK_STACK_TRANSITION_TYPE_NONE);
+		GTK_STACK(g.stack), GTK_STACK_TRANSITION_TYPE_NONE);
-	gtk_container_add(GTK_CONTAINER(stack), g.view);
+	gtk_container_add(GTK_CONTAINER(g.stack), g.view);
-	gtk_container_add(GTK_CONTAINER(stack), g.browser_scroller);
+	gtk_container_add(GTK_CONTAINER(g.stack), g.browser_scroller);
 
 	g.window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
 	gtk_window_set_default_size (GTK_WINDOW (g.window), 800, 600);
@@ -334,7 +353,7 @@ main(int argc, char *argv[])
 		G_CALLBACK(gtk_main_quit), NULL);
 	g_signal_connect(g.window, "key-press-event",
 		G_CALLBACK(on_key_press), NULL);
-	gtk_container_add(GTK_CONTAINER(g.window), stack);
+	gtk_container_add(GTK_CONTAINER(g.window), g.stack);
 
 	g.supported_globs = extract_mime_globs(fastiv_io_supported_media_types);
 	g.files = g_ptr_array_new_full(16, g_free);
@@ -359,7 +378,7 @@ main(int argc, char *argv[])
 	g_free(cwd);
 
 	if (g.files_index < 0)
-		gtk_stack_set_visible_child(GTK_STACK(stack), g.browser_scroller);
+		gtk_stack_set_visible_child(GTK_STACK(g.stack), g.browser_scroller);
 
 	gtk_widget_show_all(g.window);
 	gtk_main();