output: Support multiple adjacent outputs.

When querying for an adjacent output we now need an absolute position in
order to know which adjacent output that matches. (The position is
either the current mouse position or the center of the currently focused
container, depending on context.)

If two outputs have one edge each that at least partially align with
each other they now count as adjacent.

Seamless mouse is affected by this and now properly moves and positions
itself between outputs with "uneven" placement (as long as they have at
least some part of the edge adjacent to each other).

When focusing or moving a container in a specified direction the center
of the current focused container decides where to look for an adjacent
output. So if e.g. an output has two adjacent outputs to the right and a
"focus right" command is issued then it's the placement of the currently
focused container that decides which output actually gets focused.

Also, if an output has at least one output adjacent in some direction
but the entire edge is not covered (ie. it has "holes" with no outputs),
then the algorithm will choose the output that is closest to the
currently focused container (this does not apply to seamless mouse, the
pointer will just stop at the edge in that case).

1 files changed, 15 insertions, 4 deletions

diff --git a/sway/handlers.c b/sway/handlers.c
index cadfce5c..3f3c1bdd 100644
--- a/sway/handlers.c
+++ b/sway/handlers.c
@@ -305,28 +305,39 @@ static bool handle_pointer_motion(wlc_handle handle, uint32_t time, const struct
                         !pointer_state.left.held && !pointer_state.right.held && !pointer_state.scroll.held) {
 
                 swayc_t *output = swayc_active_output(), *adjacent = NULL;
+                struct wlc_point abs_pos = *origin;
+                abs_pos.x += output->x;
+                abs_pos.y += output->y;
                 if (origin->x == 0) { // Left edge
-                        if ((adjacent = swayc_adjacent_output(output, MOVE_LEFT))) {
+                        if ((adjacent = swayc_adjacent_output(output, MOVE_LEFT, &abs_pos, false))) {
                                 if (workspace_switch(swayc_active_workspace_for(adjacent))) {
                                         new_origin.x = adjacent->width;
+                                        // adjust for differently aligned outputs (well, this is
+                                        // only correct when the two outputs have the same
+                                        // resolution or the same dpi I guess, it should take
+                                        // physical attributes into account)
+                                        new_origin.y += (output->y - adjacent->y);
                                 }
                         }
                 } else if ((double)origin->x == output->width) { // Right edge
-                        if ((adjacent = swayc_adjacent_output(output, MOVE_RIGHT))) {
+                        if ((adjacent = swayc_adjacent_output(output, MOVE_RIGHT, &abs_pos, false))) {
                                 if (workspace_switch(swayc_active_workspace_for(adjacent))) {
                                         new_origin.x = 0;
+                                        new_origin.y += (output->y - adjacent->y);
                                 }
                         }
                 } else if (origin->y == 0) { // Top edge
-                        if ((adjacent = swayc_adjacent_output(output, MOVE_UP))) {
+                        if ((adjacent = swayc_adjacent_output(output, MOVE_UP, &abs_pos, false))) {
                                 if (workspace_switch(swayc_active_workspace_for(adjacent))) {
                                         new_origin.y = adjacent->height;
+                                        new_origin.x += (output->x - adjacent->x);
                                 }
                         }
                 } else if ((double)origin->y == output->height) { // Bottom edge
-                        if ((adjacent = swayc_adjacent_output(output, MOVE_DOWN))) {
+                        if ((adjacent = swayc_adjacent_output(output, MOVE_DOWN, &abs_pos, false))) {
                                 if (workspace_switch(swayc_active_workspace_for(adjacent))) {
                                         new_origin.y = 0;
+                                        new_origin.x += (output->x - adjacent->x);
                                 }
                         }
                 }