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) {