Implement pid->workspace tracking

When you spawn a process with the exec command, sway now notes the
workspace you had focused and the pid of the child process, then assigns
that workspace to the child when its window appears.

Some of this is carried over from sway 0.15, but with some major
refactoring and centralization of state.

1 files changed, 5 insertions, 0 deletions

diff --git a/include/sway/tree/workspace.h b/include/sway/tree/workspace.h
index c72a4ac0..d84e4a02 100644
--- a/include/sway/tree/workspace.h
+++ b/include/sway/tree/workspace.h
@@ -42,4 +42,9 @@ void workspace_output_add_priority(struct sway_container *workspace,
 
 struct sway_container *workspace_output_get_highest_available(
                 struct sway_container *ws, struct sway_container *exclude);
+
+struct sway_container *workspace_for_pid(pid_t pid);
+
+void workspace_record_pid(pid_t pid);
+
 #endif