1 files changed, 339 insertions, 0 deletions

diff --git a/rootston/layer_shell.c b/rootston/layer_shell.c
new file mode 100644
index 00000000..06ab15c3
--- /dev/null
+++ b/rootston/layer_shell.c
@@ -0,0 +1,339 @@
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <wayland-server.h>
+#include <wlr/types/wlr_box.h>
+#include <wlr/types/wlr_surface.h>
+#include <wlr/types/wlr_layer_shell.h>
+#include <wlr/util/log.h>
+#include "rootston/desktop.h"
+#include "rootston/layers.h"
+#include "rootston/output.h"
+#include "rootston/server.h"
+
+static void apply_exclusive(struct wlr_box *usable_area,
+		uint32_t anchor, int32_t exclusive,
+		int32_t margin_top, int32_t margin_right,
+		int32_t margin_bottom, int32_t margin_left) {
+	if (exclusive <= 0) {
+		return;
+	}
+	struct {
+		uint32_t anchors;
+		int *positive_axis;
+		int *negative_axis;
+		int margin;
+	} edges[] = {
+		{
+			.anchors =
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP,
+			.positive_axis = &usable_area->y,
+			.negative_axis = &usable_area->height,
+			.margin = margin_top,
+		},
+		{
+			.anchors =
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM,
+			.positive_axis = NULL,
+			.negative_axis = &usable_area->height,
+			.margin = margin_bottom,
+		},
+		{
+			.anchors =
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM,
+			.positive_axis = &usable_area->x,
+			.negative_axis = &usable_area->width,
+			.margin = margin_left,
+		},
+		{
+			.anchors =
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM,
+			.positive_axis = NULL,
+			.negative_axis = &usable_area->width,
+			.margin = margin_right,
+		},
+	};
+	for (size_t i = 0; i < sizeof(edges) / sizeof(edges[0]); ++i) {
+		if ((anchor & edges[i].anchors) == edges[i].anchors) {
+			if (edges[i].positive_axis) {
+				*edges[i].positive_axis += exclusive + edges[i].margin;
+			}
+			if (edges[i].negative_axis) {
+				*edges[i].negative_axis -= exclusive + edges[i].margin;
+			}
+		}
+	}
+}
+
+static void arrange_layer(struct wlr_output *output, struct wl_list *list,
+		struct wlr_box *usable_area, bool exclusive) {
+	struct roots_layer_surface *roots_surface;
+	struct wlr_box full_area = { 0 };
+	wlr_output_effective_resolution(output,
+			&full_area.width, &full_area.height);
+	wl_list_for_each(roots_surface, list, link) {
+		struct wlr_layer_surface *layer = roots_surface->layer_surface;
+		struct wlr_layer_surface_state *state = &layer->current;
+		if (exclusive != (state->exclusive_zone >0)) {
+			continue;
+		}
+		struct wlr_box bounds;
+		if (state->exclusive_zone == -1) {
+			bounds = full_area;
+		} else {
+			bounds = *usable_area;
+		}
+		struct wlr_box box = {
+			.width = state->desired_width,
+			.height = state->desired_height
+		};
+		// Horizontal axis
+		const uint32_t both_horiz = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT
+			| ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
+		if ((state->anchor & both_horiz) && box.width == 0) {
+			box.x = bounds.x;
+			box.width = bounds.width;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT)) {
+			box.x = bounds.x;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT)) {
+			box.x = bounds.x + (bounds.width - box.width);
+		} else {
+			box.x = bounds.x + ((bounds.width / 2) - (box.width / 2));
+		}
+		// Vertical axis
+		const uint32_t both_vert = ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP
+			| ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
+		if ((state->anchor & both_vert) && box.height == 0) {
+			box.y = bounds.y;
+			box.height = bounds.height;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP)) {
+			box.y = bounds.y;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM)) {
+			box.y = bounds.y + (bounds.height - box.height);
+		} else {
+			box.y = bounds.y + ((bounds.height / 2) - (box.height / 2));
+		}
+		// Margin
+		if ((state->anchor & both_horiz) == both_horiz) {
+			box.x += state->margin.left;
+			box.width -= state->margin.left + state->margin.right;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT)) {
+			box.x += state->margin.left;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT)) {
+			box.x -= state->margin.right;
+		}
+		if ((state->anchor & both_vert) == both_vert) {
+			box.y += state->margin.top;
+			box.height -= state->margin.top + state->margin.bottom;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP)) {
+			box.y += state->margin.top;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM)) {
+			box.y -= state->margin.bottom;
+		}
+		if (box.width < 0 || box.height < 0) {
+			// TODO: Bubble up a protocol error?
+			wlr_layer_surface_close(layer);
+			continue;
+		}
+		// Apply
+		roots_surface->geo = box;
+		apply_exclusive(usable_area, state->anchor, state->exclusive_zone,
+				state->margin.top, state->margin.right,
+				state->margin.bottom, state->margin.left);
+		wlr_layer_surface_configure(layer, box.width, box.height);
+	}
+}
+
+static void arrange_layers(struct wlr_output *_output) {
+	struct roots_output *output = _output->data;
+
+	struct wlr_box usable_area = { 0 };
+	wlr_output_effective_resolution(output->wlr_output,
+			&usable_area.width, &usable_area.height);
+
+	// Arrange exclusive surfaces from top->bottom
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY],
+			&usable_area, true);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP],
+			&usable_area, true);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM],
+			&usable_area, true);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND],
+			&usable_area, true);
+	memcpy(&output->usable_area, &usable_area, sizeof(struct wlr_box));
+
+	struct roots_view *view;
+	wl_list_for_each(view, &output->desktop->views, link) {
+		if (view->maximized) {
+			view_arrange_maximized(view);
+		}
+	}
+
+	// Arrange non-exlusive surfaces from top->bottom
+	usable_area.x = usable_area.y = 0;
+	wlr_output_effective_resolution(output->wlr_output,
+			&usable_area.width, &usable_area.height);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY],
+			&usable_area, false);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP],
+			&usable_area, false);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM],
+			&usable_area, false);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND],
+			&usable_area, false);
+}
+
+static void handle_output_destroy(struct wl_listener *listener, void *data) {
+	struct roots_layer_surface *layer =
+		wl_container_of(listener, layer, output_destroy);
+	layer->layer_surface->output = NULL;
+	wl_list_remove(&layer->output_destroy.link);
+	wl_list_remove(&layer->output_mode.link);
+	wlr_layer_surface_close(layer->layer_surface);
+}
+
+static void handle_output_mode(struct wl_listener *listener, void *data) {
+	arrange_layers((struct wlr_output *)data);
+}
+
+static void handle_output_transform(struct wl_listener *listener, void *data) {
+	arrange_layers((struct wlr_output *)data);
+}
+
+static void handle_surface_commit(struct wl_listener *listener, void *data) {
+	struct roots_layer_surface *layer =
+		wl_container_of(listener, layer, surface_commit);
+	struct wlr_layer_surface *layer_surface = layer->layer_surface;
+	struct wlr_output *wlr_output = layer_surface->output;
+	if (wlr_output != NULL) {
+		struct roots_output *output = wlr_output->data;
+		struct wlr_box old_geo = layer->geo;
+		arrange_layers(wlr_output);
+		if (memcmp(&old_geo, &layer->geo, sizeof(struct wlr_box)) != 0) {
+			output_damage_whole_local_surface(output, layer_surface->surface,
+					old_geo.x, old_geo.y, 0);
+			output_damage_whole_local_surface(output, layer_surface->surface,
+					layer->geo.x, layer->geo.y, 0);
+		} else {
+			output_damage_from_local_surface(output, layer_surface->surface,
+					layer->geo.x, layer->geo.y, 0);
+		}
+	}
+}
+
+static void unmap(struct wlr_layer_surface *layer_surface) {
+	struct roots_layer_surface *layer = layer_surface->data;
+	struct wlr_output *wlr_output = layer_surface->output;
+	if (wlr_output != NULL) {
+		struct roots_output *output = wlr_output->data;
+		wlr_output_damage_add_box(output->damage, &layer->geo);
+	}
+}
+
+static void handle_destroy(struct wl_listener *listener, void *data) {
+	struct roots_layer_surface *layer = wl_container_of(
+			listener, layer, destroy);
+	if (layer->layer_surface->mapped) {
+		unmap(layer->layer_surface);
+	}
+	wl_list_remove(&layer->link);
+	wl_list_remove(&layer->destroy.link);
+	wl_list_remove(&layer->map.link);
+	wl_list_remove(&layer->unmap.link);
+	wl_list_remove(&layer->surface_commit.link);
+	wl_list_remove(&layer->output_destroy.link);
+	wl_list_remove(&layer->output_mode.link);
+	wl_list_remove(&layer->output_transform.link);
+	arrange_layers(layer->layer_surface->output);
+	free(layer);
+}
+
+static void handle_map(struct wl_listener *listener, void *data) {
+	struct wlr_layer_surface *layer_surface = data;
+	struct roots_layer_surface *layer = layer_surface->data;
+	struct wlr_output *wlr_output = layer_surface->output;
+	struct roots_output *output = wlr_output->data;
+	wlr_output_damage_add_box(output->damage, &layer->geo);
+}
+
+static void handle_unmap(struct wl_listener *listener, void *data) {
+	struct roots_layer_surface *layer = wl_container_of(
+			listener, layer, unmap);
+	unmap(layer->layer_surface);
+}
+
+void handle_layer_shell_surface(struct wl_listener *listener, void *data) {
+	struct wlr_layer_surface *layer_surface = data;
+	struct roots_desktop *desktop =
+		wl_container_of(listener, desktop, layer_shell_surface);
+	wlr_log(L_DEBUG, "new layer surface: namespace %s layer %d anchor %d "
+			"size %dx%d margin %d,%d,%d,%d",
+		layer_surface->namespace, layer_surface->layer, layer_surface->layer,
+		layer_surface->client_pending.desired_width,
+		layer_surface->client_pending.desired_height,
+		layer_surface->client_pending.margin.top,
+		layer_surface->client_pending.margin.right,
+		layer_surface->client_pending.margin.bottom,
+		layer_surface->client_pending.margin.left);
+
+	struct roots_layer_surface *roots_surface =
+		calloc(1, sizeof(struct roots_layer_surface));
+	if (!roots_surface) {
+		return;
+	}
+
+	roots_surface->surface_commit.notify = handle_surface_commit;
+	wl_signal_add(&layer_surface->surface->events.commit,
+		&roots_surface->surface_commit);
+
+	roots_surface->output_destroy.notify = handle_output_destroy;
+	wl_signal_add(&layer_surface->output->events.destroy,
+		&roots_surface->output_destroy);
+
+	roots_surface->output_mode.notify = handle_output_mode;
+	wl_signal_add(&layer_surface->output->events.mode,
+		&roots_surface->output_mode);
+
+	roots_surface->output_transform.notify = handle_output_transform;
+	wl_signal_add(&layer_surface->output->events.transform,
+		&roots_surface->output_transform);
+
+	roots_surface->destroy.notify = handle_destroy;
+	wl_signal_add(&layer_surface->events.destroy, &roots_surface->destroy);
+	roots_surface->map.notify = handle_map;
+	wl_signal_add(&layer_surface->events.map, &roots_surface->map);
+	roots_surface->unmap.notify = handle_unmap;
+	wl_signal_add(&layer_surface->events.unmap, &roots_surface->unmap);
+	// TODO: Listen for subsurfaces
+
+	roots_surface->layer_surface = layer_surface;
+	layer_surface->data = roots_surface;
+
+	struct roots_output *output = layer_surface->output->data;
+	wl_list_insert(&output->layers[layer_surface->layer], &roots_surface->link);
+
+	// Temporarily set the layer's current state to client_pending
+	// So that we can easily arrange it
+	struct wlr_layer_surface_state old_state = layer_surface->current;
+	layer_surface->current = layer_surface->client_pending;
+
+	arrange_layers(output->wlr_output);
+
+	layer_surface->current = old_state;
+}