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, 8 insertions, 0 deletions

diff --git a/include/sway/tree/container.h b/include/sway/tree/container.h
index 751612e2..fe3ee8a8 100644
--- a/include/sway/tree/container.h
+++ b/include/sway/tree/container.h
@@ -113,6 +113,11 @@ struct sway_container {
 	// Hidden scratchpad containers have a NULL parent.
 	bool scratchpad;
 
+	// Stores last output size and position for adjusting coordinates of
+	// scratchpad windows.
+	// Unused for non-scratchpad windows.
+	struct wlr_box transform;
+
 	float alpha;
 
 	struct wlr_texture *title_focused;
@@ -196,6 +201,9 @@ size_t container_titlebar_height(void);
 void floating_calculate_constraints(int *min_width, int *max_width,
 		int *min_height, int *max_height);
 
+void floating_fix_coordinates(struct sway_container *con,
+		struct wlr_box *old, struct wlr_box *new);
+
 void container_floating_resize_and_center(struct sway_container *con);
 
 void container_floating_set_default_size(struct sway_container *con);