desktop: add new view abstraction with xdg shell implementation

desktop/view.c

@@ -0,0 +1,157 @@
+/*
+ * Cage: A Wayland kiosk.
+ *
+ * Copyright (C) 2018-2020 Jente Hidskes
+ *
+ * See the LICENSE file accompanying this file.
+ */
+
+#define _POSIX_C_SOURCE 200809L
+
+#include <assert.h>
+#include <stdbool.h>
+#include <string.h>
+#include <wlr/types/wlr_surface.h>
+
+#include "output.h"
+#include "view.h"
+
+static bool
+cage_view_extends_output_layout(struct cg_view *view, struct wlr_box *output_box)
+{
+	assert(view->impl->get_geometry != NULL);
+
+	int width, height;
+	view->impl->get_geometry(view, &width, &height);
+
+	return (output_box->height < height || output_box->width < width);
+}
+
+bool
+cage_view_is_primary(struct cg_view *view)
+{
+	assert(view != NULL);
+	assert(view->impl->is_primary != NULL);
+	return view->impl->is_primary(view);
+}
+
+static void
+cage_view_maximize(struct cg_view *view, struct wlr_box *output_box)
+{
+	assert(view->impl->maximize != NULL);
+
+	view->impl->maximize(view, output_box->width, output_box->height);
+}
+
+static void
+cage_view_center(struct cg_view *view, struct wlr_box *output_box)
+{
+	// No-op placeholder
+}
+
+void
+cage_view_position(struct cg_view *view)
+{
+	assert(view != NULL);
+
+	struct wlr_box output_box = {0};
+	cage_output_get_geometry(view->output, &output_box);
+
+	if (cage_view_is_primary(view) || cage_view_extends_output_layout(view, &output_box)) {
+		cage_view_maximize(view, &output_box);
+	} else {
+		cage_view_center(view, &output_box);
+	}
+}
+
+void
+cage_view_for_each_surface(struct cg_view *view, wlr_surface_iterator_func_t iterator, void *user_data)
+{
+	assert(view != NULL);
+	assert(view->impl->for_each_surface != NULL);
+	view->impl->for_each_surface(view, iterator, user_data);
+}
+
+char *
+cage_view_get_title(struct cg_view *view)
+{
+	assert(view != NULL);
+	assert(view->impl->get_title != NULL);
+
+	const char *title = view->impl->get_title(view);
+	if (!title) {
+		return NULL;
+	}
+	return strndup(title, strlen(title));
+}
+
+void
+cage_view_activate(struct cg_view *view, bool activate)
+{
+	assert(view != NULL);
+	assert(view->impl->activate != NULL);
+	view->impl->activate(view, activate);
+}
+
+bool
+cage_view_is_mapped(struct cg_view *view)
+{
+	assert(view != NULL);
+	return view->wlr_surface != NULL;
+}
+
+void
+cage_view_unmap(struct cg_view *view)
+{
+	assert(view != NULL);
+	assert(cage_view_is_mapped(view));
+
+	wl_signal_emit(&view->events.unmap, view);
+
+	wl_list_remove(&view->link);
+	wl_list_init(&view->link);
+
+	view->wlr_surface = NULL;
+
+	assert(!cage_view_is_mapped(view));
+}
+
+void
+cage_view_map(struct cg_view *view, struct wlr_surface *surface)
+{
+	assert(view != NULL);
+	assert(surface != NULL);
+	assert(!cage_view_is_mapped(view));
+
+	view->wlr_surface = surface;
+
+	wl_list_insert(&view->output->views, &view->link);
+	cage_view_position(view);
+
+	wl_signal_emit(&view->events.map, view);
+
+	assert(cage_view_is_mapped(view));
+}
+
+void
+cage_view_fini(struct cg_view *view)
+{
+	assert(view != NULL);
+	assert(!cage_view_is_mapped(view));
+	view->output = NULL;
+}
+
+void
+cage_view_init(struct cg_view *view, enum cg_view_type type, const struct cg_view_impl *impl, struct cg_output *output)
+{
+	assert(view != NULL);
+	assert(impl != NULL);
+	assert(output != NULL);
+
+	view->type = type;
+	view->impl = impl;
+	view->output = output;
+
+	wl_signal_init(&view->events.map);
+	wl_signal_init(&view->events.unmap);
+}