root: Try to preserve relative positions of floating containers

This makes the behavior of floating containers more consistent with i3.
The coordinates of the container are scaled when the size of the
workspace it is on changes or when the container is moved
between workspaces on different outputs.

For scratchpad containers, add a new state that preserves the dimensions
of the last output the window appeared on. This is necessary because
after a container is hidden in the scratchpad, we expect it to be in the
same relative position on the output when it reappears. We can't just
use the container's attached workspace because that workspace's
dimensions might have been changed or the workspace as a whole could
have been destroyed.

1 files changed, 9 insertions, 5 deletions

diff --git a/sway/tree/arrange.c b/sway/tree/arrange.c
index 9c1a11e5..af925d05 100644
--- a/sway/tree/arrange.c
+++ b/sway/tree/arrange.c
@@ -264,6 +264,9 @@ void arrange_workspace(struct sway_workspace *workspace) {
                         area->width, area->height, area->x, area->y);
 
         bool first_arrange = workspace->width == 0 && workspace->height == 0;
+        struct wlr_box prev_box;
+        workspace_get_box(workspace, &prev_box);
+
         double prev_x = workspace->x - workspace->current_gaps.left;
         double prev_y = workspace->y - workspace->current_gaps.top;
         workspace->width = area->width;
@@ -277,13 +280,14 @@ void arrange_workspace(struct sway_workspace *workspace) {
         if (!first_arrange && (diff_x != 0 || diff_y != 0)) {
                 for (int i = 0; i < workspace->floating->length; ++i) {
                         struct sway_container *floater = workspace->floating->items[i];
-                        container_floating_translate(floater, diff_x, diff_y);
-                        double center_x = floater->pending.x + floater->pending.width / 2;
-                        double center_y = floater->pending.y + floater->pending.height / 2;
                         struct wlr_box workspace_box;
                         workspace_get_box(workspace, &workspace_box);
-                        if (!wlr_box_contains_point(&workspace_box, center_x, center_y)) {
-                                container_floating_move_to_center(floater);
+                        floating_fix_coordinates(floater, &prev_box, &workspace_box);
+                        // Set transformation for scratchpad windows.
+                        if (floater->scratchpad) {
+                                struct wlr_box output_box;
+                                output_get_box(output, &output_box);
+                                floater->transform = output_box;
                         }
                 }
         }