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, 123 insertions, 35 deletions

diff --git a/sway/output.c b/sway/output.c
index 5044b7aa..cf8ed9a5 100644
--- a/sway/output.c
+++ b/sway/output.c
@@ -2,15 +2,15 @@
 #include "output.h"
 #include "log.h"
 
-swayc_t *output_by_name(const char* name) {
+swayc_t *output_by_name(const char* name, const struct wlc_point *abs_pos) {
 	if (strcasecmp(name, "left") == 0) {
-		return swayc_adjacent_output(NULL, MOVE_LEFT);
+		return swayc_adjacent_output(NULL, MOVE_LEFT, abs_pos, true);
 	} else if (strcasecmp(name, "right") == 0) {
-		return swayc_adjacent_output(NULL, MOVE_RIGHT);
+		return swayc_adjacent_output(NULL, MOVE_RIGHT, abs_pos, true);
 	} else if (strcasecmp(name, "up") == 0) {
-		return swayc_adjacent_output(NULL, MOVE_UP);
+		return swayc_adjacent_output(NULL, MOVE_UP, abs_pos, true);
 	} else if (strcasecmp(name, "down") == 0) {
-		return swayc_adjacent_output(NULL, MOVE_DOWN);
+		return swayc_adjacent_output(NULL, MOVE_DOWN, abs_pos, true);
 	} else {
 		for(int i = 0; i < root_container.children->length; ++i) {
 			swayc_t *c = root_container.children->items[i];
@@ -22,66 +22,126 @@ swayc_t *output_by_name(const char* name) {
 	return NULL;
 }
 
-swayc_t *swayc_adjacent_output(swayc_t *output, enum movement_direction dir) {
-	// TODO: This implementation is naïve: We assume all outputs are
-	// perfectly aligned (ie. only a single output per edge which covers
-	// the whole edge).
+// Position is where on the edge (as absolute position) the adjacent output should be searched for.
+swayc_t *swayc_adjacent_output(swayc_t *output, enum movement_direction dir,
+		const struct wlc_point *abs_pos, bool pick_closest) {
+
 	if (!output) {
 		output = swayc_active_output();
 	}
+	// In order to find adjacent outputs we need to test that the outputs are
+	// aligned on one axis (decided by the direction given) and that the given
+	// position is within the edge of the adjacent output. If no such output
+	// exists we pick the adjacent output within the edge that is closest to
+	// the given position, if any.
 	swayc_t *adjacent = NULL;
+	char *dir_text = NULL;
 	switch(dir) {
 		case MOVE_LEFT:
+		case MOVE_RIGHT: ;
+			double delta_y = 0;
 			for(int i = 0; i < root_container.children->length; ++i) {
 				swayc_t *c = root_container.children->items[i];
 				if (c == output || c->type != C_OUTPUT) {
 					continue;
 				}
-				if (c->y == output->y && c->x + c->width == output->x) {
-					sway_log(L_DEBUG, "%s is left of current output %s", c->name, output->name);
-					adjacent = c;
-					break;
-				}
-			}
-			break;
-		case MOVE_RIGHT:
-			for(int i = 0; i < root_container.children->length; ++i) {
-				swayc_t *c = root_container.children->items[i];
-				if (c == output || c->type != C_OUTPUT) {
+				bool x_aligned = dir == MOVE_LEFT ?
+					c->x + c->width == output->x :
+					c->x == output->x + output->width;
+				if (!x_aligned) {
 					continue;
 				}
-				if (c->y == output->y && output->x + output->width == c->x) {
-					sway_log(L_DEBUG, "%s is right of current output %s", c->name, output->name);
+				if (abs_pos->y >= c->y && abs_pos->y <= c->y + c->height) {
+					delta_y = 0;
 					adjacent = c;
 					break;
+				} else if (pick_closest) {
+					// track closest adjacent output
+					double top_y = c->y, bottom_y = c->y + c->height;
+					if (top_y >= output->y && top_y <= output->y + output->height) {
+						double delta = top_y - abs_pos->y;
+						if (delta < 0) delta = -delta;
+						if (delta < delta_y || !adjacent) {
+							delta_y = delta;
+							adjacent = c;
+						}
+					}
+					// we check both points and pick the closest
+					if (bottom_y >= output->y && bottom_y <= output->y + output->height) {
+						double delta = bottom_y - abs_pos->y;
+						if (delta < 0) delta = -delta;
+						if (delta < delta_y || !adjacent) {
+							delta_y = delta;
+							adjacent = c;
+						}
+					}
 				}
 			}
+			dir_text = dir == MOVE_LEFT ? "left of" : "right of";
+			if (adjacent && delta_y == 0) {
+				sway_log(L_DEBUG, "%s (%.0fx%.0f+%.0f+%.0f) is %s current output %s (y-position %i)",
+						adjacent->name, adjacent->width, adjacent->height, adjacent->x, adjacent->y,
+						dir_text, output->name, abs_pos->y);
+			} else if (adjacent) {
+				// so we end up picking the closest adjacent output because
+				// there is no directly adjacent to the given position
+				sway_log(L_DEBUG, "%s (%.0fx%.0f+%.0f+%.0f) is %s current output %s (y-position %i, delta: %.0f)",
+					adjacent->name, adjacent->width, adjacent->height, adjacent->x, adjacent->y,
+					dir_text, output->name, abs_pos->y, delta_y);
+			}
 			break;
 		case MOVE_UP:
+		case MOVE_DOWN: ;
+			double delta_x = 0;
 			for(int i = 0; i < root_container.children->length; ++i) {
 				swayc_t *c = root_container.children->items[i];
 				if (c == output || c->type != C_OUTPUT) {
 					continue;
 				}
-				if (output->x == c->x && c->y + c->height == output->y) {
-					sway_log(L_DEBUG, "%s is above current output %s", c->name, output->name);
-					adjacent = c;
-					break;
-				}
-			}
-			break;
-		case MOVE_DOWN:
-			for(int i = 0; i < root_container.children->length; ++i) {
-				swayc_t *c = root_container.children->items[i];
-				if (c == output || c->type != C_OUTPUT) {
+				bool y_aligned = dir == MOVE_UP ?
+					c->y + c->height == output->y :
+					c->y == output->y + output->height;
+				if (!y_aligned) {
 					continue;
 				}
-				if (output->x == c->x && output->y + output->height == c->y) {
-					sway_log(L_DEBUG, "%s is below current output %s", c->name, output->name);
+				if (abs_pos->x >= c->x && abs_pos->x <= c->x + c->width) {
+					delta_x = 0;
 					adjacent = c;
 					break;
+				} else if (pick_closest) {
+					// track closest adjacent output
+					double left_x = c->x, right_x = c->x + c->width;
+					if (left_x >= output->x && left_x <= output->x + output->width) {
+						double delta = left_x - abs_pos->x;
+						if (delta < 0) delta = -delta;
+						if (delta < delta_x || !adjacent) {
+							delta_x = delta;
+							adjacent = c;
+						}
+					}
+					// we check both points and pick the closest
+					if (right_x >= output->x && right_x <= output->x + output->width) {
+						double delta = right_x - abs_pos->x;
+						if (delta < 0) delta = -delta;
+						if (delta < delta_x || !adjacent) {
+							delta_x = delta;
+							adjacent = c;
+						}
+					}
 				}
 			}
+			dir_text = dir == MOVE_UP ? "above" : "below";
+			if (adjacent && delta_x == 0) {
+				sway_log(L_DEBUG, "%s (%.0fx%.0f+%.0f+%.0f) is %s current output %s (x-position %i)",
+						adjacent->name, adjacent->width, adjacent->height, adjacent->x, adjacent->y,
+						dir_text, output->name, abs_pos->x);
+			} else if (adjacent) {
+				// so we end up picking the closest adjacent output because
+				// there is no directly adjacent to the given position
+				sway_log(L_DEBUG, "%s (%.0fx%.0f+%.0f+%.0f) is %s current output %s (x-position %i, delta: %.0f)",
+					adjacent->name, adjacent->width, adjacent->height, adjacent->x, adjacent->y,
+					dir_text, output->name, abs_pos->x, delta_x);
+			}
 			break;
 		default:
 			sway_abort("Function called with invalid argument.");
@@ -89,3 +149,31 @@ swayc_t *swayc_adjacent_output(swayc_t *output, enum movement_direction dir) {
 	}
 	return adjacent;
 }
+
+void get_absolute_position(swayc_t *container, struct wlc_point *point) {
+	if (!container || !point)
+		sway_abort("Need container and wlc_point (was %p, %p).", container, point);
+
+	if (container->type == C_OUTPUT) {
+		// Coordinates are already absolute.
+		point->x = container->x;
+		point->y = container->y;
+	} else {
+		swayc_t *output = swayc_parent_by_type(container, C_OUTPUT);
+		if (container->type == C_WORKSPACE) {
+			// Workspace coordinates are actually wrong/arbitrary, but should
+			// be same as output.
+			point->x = output->x;
+			point->y = output->y;
+		} else {
+			point->x = output->x + container->x;
+			point->y = output->y + container->y;
+		}
+	}
+}
+
+void get_absolute_center_position(swayc_t *container, struct wlc_point *point) {
+	get_absolute_position(container, point);
+	point->x += container->width/2;
+	point->y += container->height/2;
+}