WIP: Atomic layout updates ground work

5 files changed, 317 insertions, 59 deletions

diff --git a/sway/desktop/output.c b/sway/desktop/output.c
index 3142bdb4..c5d445a6 100644
--- a/sway/desktop/output.c
+++ b/sway/desktop/output.c
@@ -69,6 +69,7 @@ struct render_data {
 	struct root_geometry root_geo;
 	struct sway_output *output;
 	pixman_region32_t *damage;
+	struct sway_view *view;
 	float alpha;
 };
 
@@ -108,6 +109,38 @@ static bool get_surface_box(struct root_geometry *geo,
 	return wlr_box_intersection(&output_box, &rotated_box, &intersection);
 }
 
+static bool get_view_box(struct root_geometry *geo,
+		struct sway_output *output, struct sway_view *view, int sx, int sy,
+		struct wlr_box *surface_box) {
+	int sw = view->width;
+	int sh = view->height;
+
+	double _sx = sx, _sy = sy;
+	rotate_child_position(&_sx, &_sy, sw, sh, geo->width, geo->height,
+		geo->rotation);
+
+	struct wlr_box box = {
+		.x = geo->x + _sx,
+		.y = geo->y + _sy,
+		.width = sw,
+		.height = sh,
+	};
+	if (surface_box != NULL) {
+		memcpy(surface_box, &box, sizeof(struct wlr_box));
+	}
+
+	struct wlr_box rotated_box;
+	wlr_box_rotated_bounds(&box, geo->rotation, &rotated_box);
+
+	struct wlr_box output_box = {
+		.width = output->swayc->width,
+		.height = output->swayc->height,
+	};
+
+	struct wlr_box intersection;
+	return wlr_box_intersection(&output_box, &rotated_box, &intersection);
+}
+
 static void surface_for_each_surface(struct wlr_surface *surface,
 		double ox, double oy, struct root_geometry *geo,
 		wlr_surface_iterator_func_t iterator, void *user_data) {
@@ -225,13 +258,26 @@ static void render_surface_iterator(struct wlr_surface *surface, int sx, int sy,
 	pixman_region32_t *output_damage = data->damage;
 	float alpha = data->alpha;
 
-	if (!wlr_surface_has_buffer(surface)) {
-		return;
+	struct wlr_texture *texture = NULL;
+	struct wlr_box box;
+	bool intersects;
+
+	// If this is the main surface of a view, render the saved_texture instead
+	// if it exists. It exists when we are mid-transaction.
+	if (data->view && data->view->saved_texture &&
+			data->view->surface == surface) {
+		texture = data->view->saved_texture;
+		intersects = get_view_box(&data->root_geo, data->output, data->view,
+				sx, sy, &box);
+	} else {
+		if (!wlr_surface_has_buffer(surface)) {
+			return;
+		}
+		texture = surface->texture;
+		intersects = get_surface_box(&data->root_geo, data->output, surface,
+				sx, sy, &box);
 	}
 
-	struct wlr_box box;
-	bool intersects = get_surface_box(&data->root_geo, data->output, surface,
-		sx, sy, &box);
 	if (!intersects) {
 		return;
 	}
@@ -244,8 +290,7 @@ static void render_surface_iterator(struct wlr_surface *surface, int sx, int sy,
 	wlr_matrix_project_box(matrix, &box, transform, rotation,
 		wlr_output->transform_matrix);
 
-	render_texture(wlr_output, output_damage, surface->texture, &box, matrix,
-		alpha);
+	render_texture(wlr_output, output_damage, texture, &box, matrix, alpha);
 }
 
 static void render_layer(struct sway_output *output,
@@ -315,6 +360,7 @@ static void render_view_surfaces(struct sway_view *view,
 	struct render_data data = {
 		.output = output,
 		.damage = damage,
+		.view = view,
 		.alpha = alpha,
 	};
 	output_view_for_each_surface(
@@ -1134,6 +1180,16 @@ void output_damage_from_view(struct sway_output *output,
 	output_damage_view(output, view, false);
 }
 
+// Expecting an unscaled box in layout coordinates
+void output_damage_box(struct sway_output *output, struct wlr_box *_box) {
+	struct wlr_box box;
+	memcpy(&box, _box, sizeof(struct wlr_box));
+	box.x -= output->swayc->x;
+	box.y -= output->swayc->y;
+	scale_box(&box, output->wlr_output->scale);
+	wlr_output_damage_add_box(output->damage, &box);
+}
+
 static void output_damage_whole_container_iterator(struct sway_container *con,
 		void *data) {
 	struct sway_output *output = data;
diff --git a/sway/desktop/transaction.c b/sway/desktop/transaction.c
new file mode 100644
index 00000000..69f97e3d
--- /dev/null
+++ b/sway/desktop/transaction.c
@@ -0,0 +1,214 @@
+#define _POSIX_C_SOURCE 200809L
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <wlr/types/wlr_linux_dmabuf.h>
+#include "sway/debug.h"
+#include "sway/desktop/transaction.h"
+#include "sway/output.h"
+#include "sway/tree/container.h"
+#include "sway/tree/view.h"
+#include "list.h"
+#include "log.h"
+
+/**
+ * How long we should wait for views to respond to the configure before giving
+ * up and applying the transaction anyway.
+ */
+#define TIMEOUT_MS 200
+
+struct sway_transaction_instruction {
+	struct sway_transaction *transaction;
+	struct sway_container *container;
+	struct sway_container_state state;
+	uint32_t serial;
+};
+
+struct sway_transaction *transaction_create() {
+	struct sway_transaction *transaction =
+		calloc(1, sizeof(struct sway_transaction));
+	transaction->instructions = create_list();
+	transaction->damage = create_list();
+	return transaction;
+}
+
+static void transaction_destroy(struct sway_transaction *transaction) {
+	int i;
+	// Free instructions
+	for (i = 0; i < transaction->instructions->length; ++i) {
+		struct sway_transaction_instruction *instruction =
+			transaction->instructions->items[i];
+		if (instruction->container->type == C_VIEW) {
+			struct sway_view *view = instruction->container->sway_view;
+			for (int j = 0; j < view->instructions->length; ++j) {
+				if (view->instructions->items[j] == instruction) {
+					list_del(view->instructions, j);
+					break;
+				}
+			}
+		}
+		free(instruction);
+	}
+	list_free(transaction->instructions);
+
+	// Free damage
+	for (i = 0; i < transaction->damage->length; ++i) {
+		struct wlr_box *box = transaction->damage->items[i];
+		free(box);
+	}
+	list_free(transaction->damage);
+
+	free(transaction);
+}
+
+void transaction_add_container(struct sway_transaction *transaction,
+		struct sway_container *container) {
+	struct sway_transaction_instruction *instruction =
+		calloc(1, sizeof(struct sway_transaction_instruction));
+	instruction->transaction = transaction;
+	instruction->container = container;
+	memcpy(&instruction->state, &container->pending,
+			sizeof(struct sway_container_state));
+	list_add(transaction->instructions, instruction);
+}
+
+void transaction_add_damage(struct sway_transaction *transaction,
+		struct wlr_box *_box) {
+	struct wlr_box *box = calloc(1, sizeof(struct wlr_box));
+	memcpy(box, _box, sizeof(struct wlr_box));
+	list_add(transaction->damage, box);
+}
+
+static void save_view_texture(struct sway_view *view) {
+	wlr_texture_destroy(view->saved_texture);
+	view->saved_texture = NULL;
+
+	// TODO: Copy the texture and store it in view->saved_texture.
+}
+
+static void remove_saved_view_texture(struct sway_view *view) {
+	wlr_texture_destroy(view->saved_texture);
+	view->saved_texture = NULL;
+}
+
+/**
+ * Apply a transaction to the "current" state of the tree.
+ *
+ * This is mostly copying stuff from the pending state into the main swayc
+ * properties, but also includes reparenting and deleting containers.
+ */
+static void transaction_apply(struct sway_transaction *transaction) {
+	int i;
+	for (i = 0; i < transaction->instructions->length; ++i) {
+		struct sway_transaction_instruction *instruction =
+			transaction->instructions->items[i];
+		struct sway_container_state *state = &instruction->state;
+		struct sway_container *container = instruction->container;
+
+		container->layout = state->layout;
+		container->x = state->swayc_x;
+		container->y = state->swayc_y;
+		container->width = state->swayc_width;
+		container->height = state->swayc_height;
+
+		if (container->type == C_VIEW) {
+			struct sway_view *view = container->sway_view;
+			view->x = state->view_x;
+			view->y = state->view_y;
+			view->width = state->view_width;
+			view->height = state->view_height;
+			view->is_fullscreen = state->is_fullscreen;
+			view->border = state->border;
+			view->border_thickness = state->border_thickness;
+			view->border_top = state->border_top;
+			view->border_left = state->border_left;
+			view->border_right = state->border_right;
+			view->border_bottom = state->border_bottom;
+
+			remove_saved_view_texture(view);
+		}
+	}
+
+	// Damage
+	for (i = 0; i < transaction->damage->length; ++i) {
+		struct wlr_box *box = transaction->damage->items[i];
+		for (int j = 0; j < root_container.children->length; ++j) {
+			struct sway_container *output = root_container.children->items[j];
+			output_damage_box(output->sway_output, box);
+		}
+	}
+
+	update_debug_tree();
+}
+
+static int handle_timeout(void *data) {
+	struct sway_transaction *transaction = data;
+	wlr_log(L_DEBUG, "Transaction %p timed out (%li waiting), applying anyway",
+			transaction, transaction->num_waiting);
+	transaction_apply(transaction);
+	transaction_destroy(transaction);
+	return 0;
+}
+
+void transaction_commit(struct sway_transaction *transaction) {
+	wlr_log(L_DEBUG, "Transaction %p committing with %i instructions",
+			transaction, transaction->instructions->length);
+	transaction->num_waiting = 0;
+	for (int i = 0; i < transaction->instructions->length; ++i) {
+		struct sway_transaction_instruction *instruction =
+			transaction->instructions->items[i];
+		if (instruction->container->type == C_VIEW) {
+			struct sway_view *view = instruction->container->sway_view;
+			instruction->serial = view_configure(view,
+					instruction->state.view_x,
+					instruction->state.view_y,
+					instruction->state.view_width,
+					instruction->state.view_height);
+			if (instruction->serial) {
+				save_view_texture(view);
+				list_add(view->instructions, instruction);
+				++transaction->num_waiting;
+			}
+		}
+	}
+	if (!transaction->num_waiting) {
+		// This can happen if the transaction only contains xwayland views
+		wlr_log(L_DEBUG, "Transaction %p has nothing to wait for, applying",
+				transaction);
+		transaction_apply(transaction);
+		transaction_destroy(transaction);
+		return;
+	}
+
+	// Set up a timer which the views must respond within
+	transaction->timer = wl_event_loop_add_timer(server.wl_event_loop,
+			handle_timeout, transaction);
+	wl_event_source_timer_update(transaction->timer, TIMEOUT_MS);
+}
+
+void transaction_notify_view_ready(struct sway_view *view, uint32_t serial) {
+	// Find the instruction
+	struct sway_transaction_instruction *instruction = NULL;
+	for (int i = 0; i < view->instructions->length; ++i) {
+		struct sway_transaction_instruction *tmp_instruction =
+			view->instructions->items[i];
+		if (tmp_instruction->serial == serial) {
+			instruction = tmp_instruction;
+			list_del(view->instructions, i);
+			break;
+		}
+	}
+	if (!instruction) {
+		// This can happen if the view acknowledges the configure after the
+		// transaction has timed out and applied.
+		return;
+	}
+	// If all views are ready, apply the transaction
+	struct sway_transaction *transaction = instruction->transaction;
+	if (--transaction->num_waiting == 0) {
+		wlr_log(L_DEBUG, "Transaction %p is ready, applying", transaction);
+		wl_event_source_timer_update(transaction->timer, 0);
+		transaction_apply(transaction);
+		transaction_destroy(transaction);
+	}
+}
diff --git a/sway/desktop/xdg_shell.c b/sway/desktop/xdg_shell.c
index d2b8822c..f43a0a1b 100644
--- a/sway/desktop/xdg_shell.c
+++ b/sway/desktop/xdg_shell.c
@@ -5,6 +5,7 @@
 #include <wlr/types/wlr_xdg_shell.h>
 #include <wlr/util/edges.h>
 #include "log.h"
+#include "sway/desktop/transaction.h"
 #include "sway/input/input-manager.h"
 #include "sway/input/seat.h"
 #include "sway/server.h"
@@ -87,18 +88,14 @@ static const char *get_string_prop(struct sway_view *view, enum sway_view_prop p
 	}
 }
 
-static void configure(struct sway_view *view, double lx, double ly, int width,
-		int height) {
+static uint32_t configure(struct sway_view *view, double lx, double ly,
+		int width, int height) {
 	struct sway_xdg_shell_view *xdg_shell_view =
 		xdg_shell_view_from_view(view);
 	if (xdg_shell_view == NULL) {
-		return;
+		return 0;
 	}
-
-	xdg_shell_view->pending_width = width;
-	xdg_shell_view->pending_height = height;
-	wlr_xdg_toplevel_set_size(view->wlr_xdg_surface, width, height);
-	view_update_position(view, lx, ly);
+	return wlr_xdg_toplevel_set_size(view->wlr_xdg_surface, width, height);
 }
 
 static void set_activated(struct sway_view *view, bool activated) {
@@ -174,18 +171,12 @@ static void handle_commit(struct wl_listener *listener, void *data) {
 	struct sway_xdg_shell_view *xdg_shell_view =
 		wl_container_of(listener, xdg_shell_view, commit);
 	struct sway_view *view = &xdg_shell_view->view;
-	if (view->swayc && container_is_floating(view->swayc)) {
-		int width = view->wlr_xdg_surface->geometry.width;
-		int height = view->wlr_xdg_surface->geometry.height;
-		if (!width && !height) {
-			width = view->wlr_xdg_surface->surface->current->width;
-			height = view->wlr_xdg_surface->surface->current->height;
-		}
-		view_update_size(view, width, height);
-	} else {
-		view_update_size(view, xdg_shell_view->pending_width,
-				xdg_shell_view->pending_height);
+	struct wlr_xdg_surface *xdg_surface = view->wlr_xdg_surface;
+
+	if (view->instructions->length) {
+		transaction_notify_view_ready(view, xdg_surface->configure_serial);
 	}
+
 	view_update_title(view, false);
 	view_damage_from(view);
 }
diff --git a/sway/desktop/xdg_shell_v6.c b/sway/desktop/xdg_shell_v6.c
index 6ffe334a..bce59174 100644
--- a/sway/desktop/xdg_shell_v6.c
+++ b/sway/desktop/xdg_shell_v6.c
@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <wayland-server.h>
 #include <wlr/types/wlr_xdg_shell_v6.h>
+#include "sway/desktop/transaction.h"
 #include "sway/tree/container.h"
 #include "sway/tree/layout.h"
 #include "sway/server.h"
@@ -86,18 +87,15 @@ static const char *get_string_prop(struct sway_view *view, enum sway_view_prop p
 	}
 }
 
-static void configure(struct sway_view *view, double lx, double ly, int width,
-		int height) {
+static uint32_t configure(struct sway_view *view, double lx, double ly,
+		int width, int height) {
 	struct sway_xdg_shell_v6_view *xdg_shell_v6_view =
 		xdg_shell_v6_view_from_view(view);
 	if (xdg_shell_v6_view == NULL) {
-		return;
+		return 0;
 	}
-
-	xdg_shell_v6_view->pending_width = width;
-	xdg_shell_v6_view->pending_height = height;
-	wlr_xdg_toplevel_v6_set_size(view->wlr_xdg_surface_v6, width, height);
-	view_update_position(view, lx, ly);
+	return wlr_xdg_toplevel_v6_set_size(
+			view->wlr_xdg_surface_v6, width, height);
 }
 
 static void set_activated(struct sway_view *view, bool activated) {
@@ -173,18 +171,12 @@ static void handle_commit(struct wl_listener *listener, void *data) {
 	struct sway_xdg_shell_v6_view *xdg_shell_v6_view =
 		wl_container_of(listener, xdg_shell_v6_view, commit);
 	struct sway_view *view = &xdg_shell_v6_view->view;
-	if (view->swayc && container_is_floating(view->swayc)) {
-		int width = view->wlr_xdg_surface_v6->geometry.width;
-		int height = view->wlr_xdg_surface_v6->geometry.height;
-		if (!width && !height) {
-			width = view->wlr_xdg_surface_v6->surface->current->width;
-			height = view->wlr_xdg_surface_v6->surface->current->height;
-		}
-		view_update_size(view, width, height);
-	} else {
-		view_update_size(view, xdg_shell_v6_view->pending_width,
-				xdg_shell_v6_view->pending_height);
+	struct wlr_xdg_surface_v6 *xdg_surface_v6 = view->wlr_xdg_surface_v6;
+
+	if (view->instructions->length) {
+		transaction_notify_view_ready(view, xdg_surface_v6->configure_serial);
 	}
+
 	view_update_title(view, false);
 	view_damage_from(view);
 }
diff --git a/sway/desktop/xwayland.c b/sway/desktop/xwayland.c
index 6447b711..6a3c1b66 100644
--- a/sway/desktop/xwayland.c
+++ b/sway/desktop/xwayland.c
@@ -167,19 +167,18 @@ static uint32_t get_int_prop(struct sway_view *view, enum sway_view_prop prop) {
 	}
 }
 
-static void configure(struct sway_view *view, double lx, double ly, int width,
+static uint32_t configure(struct sway_view *view, double lx, double ly, int width,
 		int height) {
 	struct sway_xwayland_view *xwayland_view = xwayland_view_from_view(view);
 	if (xwayland_view == NULL) {
-		return;
+		return 0;
 	}
 	struct wlr_xwayland_surface *xsurface = view->wlr_xwayland_surface;
 
-	xwayland_view->pending_lx = lx;
-	xwayland_view->pending_ly = ly;
-	xwayland_view->pending_width = width;
-	xwayland_view->pending_height = height;
 	wlr_xwayland_surface_configure(xsurface, lx, ly, width, height);
+
+	// xwayland doesn't give us a serial for the configure
+	return 0;
 }
 
 static void set_activated(struct sway_view *view, bool activated) {
@@ -250,15 +249,21 @@ static void handle_commit(struct wl_listener *listener, void *data) {
 		wl_container_of(listener, xwayland_view, commit);
 	struct sway_view *view = &xwayland_view->view;
 	struct wlr_xwayland_surface *xsurface = view->wlr_xwayland_surface;
-	if (view->swayc && container_is_floating(view->swayc)) {
-		view_update_size(view, xsurface->width, xsurface->height);
-	} else {
-		view_update_size(view, xwayland_view->pending_width,
-				xwayland_view->pending_height);
+
+	// Don't allow xwayland views to do resize or reposition themselves if
+	// they're involved in a transaction. Once the transaction has finished
+	// they'll apply the next time a commit happens.
+	if (view->instructions->length) {
+		if (view->swayc && container_is_floating(view->swayc)) {
+			view_update_size(view, xsurface->width, xsurface->height);
+		} else {
+			view_update_size(view, view->swayc->pending.swayc_width,
+					view->swayc->pending.swayc_height);
+		}
+		view_update_position(view,
+				view->swayc->pending.view_x, view->swayc->pending.view_y);
+		view_damage_from(view);
 	}
-	view_update_position(view,
-			xwayland_view->pending_lx, xwayland_view->pending_ly);
-	view_damage_from(view);
 }
 
 static void handle_unmap(struct wl_listener *listener, void *data) {