2 files changed, 128 insertions, 178 deletions

diff --git a/sway/commands/resize.c b/sway/commands/resize.c
index fad1ecb1..f6141afc 100644
--- a/sway/commands/resize.c
+++ b/sway/commands/resize.c
@@ -130,177 +130,108 @@ static bool is_horizontal(uint32_t axis) {
 	return axis & (WLR_EDGE_LEFT | WLR_EDGE_RIGHT);
 }
 
-static int parallel_coord(struct sway_container *c, uint32_t axis) {
-	return is_horizontal(axis) ? c->x : c->y;
-}
-
-static int parallel_size(struct sway_container *c, uint32_t axis) {
-	return is_horizontal(axis) ? c->width : c->height;
-}
-
-static void container_recursive_resize(struct sway_container *container,
-		double amount, enum wlr_edges edge) {
-	bool layout_match = true;
-	wlr_log(WLR_DEBUG, "Resizing %p with amount: %f", container, amount);
-	if (edge & (WLR_EDGE_LEFT | WLR_EDGE_RIGHT)) {
-		container->width += amount;
-		layout_match = container->layout == L_HORIZ;
-	} else if (edge & (WLR_EDGE_TOP | WLR_EDGE_BOTTOM)) {
-		container->height += amount;
-		layout_match = container->layout == L_VERT;
-	}
-	if (container->children) {
-		for (int i = 0; i < container->children->length; i++) {
-			struct sway_container *child = container->children->items[i];
-			double amt = layout_match ?
-				amount / container->children->length : amount;
-			container_recursive_resize(child, amt, edge);
+struct sway_container *container_find_resize_parent(struct sway_container *con,
+		uint32_t axis) {
+	enum sway_container_layout parallel_layout =
+		is_horizontal(axis) ? L_HORIZ : L_VERT;
+	bool allow_first = axis != WLR_EDGE_TOP && axis != WLR_EDGE_LEFT;
+	bool allow_last = axis != WLR_EDGE_RIGHT && axis != WLR_EDGE_BOTTOM;
+
+	while (con) {
+		list_t *siblings = container_get_siblings(con);
+		int index = container_sibling_index(con);
+		if (container_parent_layout(con) == parallel_layout &&
+				siblings->length > 1 && (allow_first || index > 0) &&
+				(allow_last || index < siblings->length - 1)) {
+			return con;
 		}
+		con = con->parent;
 	}
+
+	return NULL;
 }
 
-static void resize_tiled(struct sway_container *parent, int amount,
-		uint32_t axis) {
-	struct sway_container *focused = parent;
-	if (!parent) {
+void container_resize_tiled(struct sway_container *con,
+		uint32_t axis, int amount) {
+	if (!con) {
 		return;
 	}
 
-	enum sway_container_layout parallel_layout =
-		is_horizontal(axis) ? L_HORIZ : L_VERT;
-	int minor_weight = 0;
-	int major_weight = 0;
-	while (parent) {
-		list_t *siblings = container_get_siblings(parent);
-		if (container_parent_layout(parent) == parallel_layout) {
-			for (int i = 0; i < siblings->length; i++) {
-				struct sway_container *sibling = siblings->items[i];
-
-				int sibling_pos = parallel_coord(sibling, axis);
-				int focused_pos = parallel_coord(focused, axis);
-				int parent_pos = parallel_coord(parent, axis);
-
-				if (sibling_pos != focused_pos) {
-					if (sibling_pos < parent_pos) {
-						minor_weight++;
-					} else if (sibling_pos > parent_pos) {
-						major_weight++;
-					}
-				}
-			}
-			if (major_weight || minor_weight) {
-				break;
-			}
-		}
-		parent = parent->parent;
-	}
-	if (!parent) {
+	con = container_find_resize_parent(con, axis);
+	if (!con) {
 		// Can't resize in this direction
 		return;
 	}
 
-	// Implement up/down/left/right direction by zeroing one of the weights
-	if (axis == WLR_EDGE_TOP || axis == WLR_EDGE_LEFT) {
-		major_weight = 0;
-	} else if (axis == WLR_EDGE_RIGHT || axis == WLR_EDGE_BOTTOM) {
-		minor_weight = 0;
-	}
-
-	bool horizontal = is_horizontal(axis);
-	int min_sane = horizontal ? MIN_SANE_W : MIN_SANE_H;
-
-	//TODO: Ensure rounding is done in such a way that there are NO pixel leaks
-	// ^ ?????
-	list_t *siblings = container_get_siblings(parent);
-
-	for (int i = 0; i < siblings->length; i++) {
-		struct sway_container *sibling = siblings->items[i];
-
-		int sibling_pos = parallel_coord(sibling, axis);
-		int focused_pos = parallel_coord(focused, axis);
-		int parent_pos = parallel_coord(parent, axis);
-
-		int sibling_size = parallel_size(sibling, axis);
-		int parent_size = parallel_size(parent, axis);
-
-		if (sibling_pos != focused_pos) {
-			if (sibling_pos < parent_pos && minor_weight) {
-				double pixels = -amount / minor_weight;
-				if (major_weight && (sibling_size + pixels / 2) < min_sane) {
-					return; // Too small
-				} else if (!major_weight && sibling_size + pixels < min_sane) {
-					return; // Too small
-				}
-			} else if (sibling_pos > parent_pos && major_weight) {
-				double pixels = -amount / major_weight;
-				if (minor_weight && (sibling_size + pixels / 2) < min_sane) {
-					return; // Too small
-				} else if (!minor_weight && sibling_size + pixels < min_sane) {
-					return; // Too small
-				}
-			}
-		} else {
-			double pixels = amount;
-			if (parent_size + pixels < min_sane) {
-				return; // Too small
-			}
+	// For HORIZONTAL or VERTICAL, we are growing in two directions so select
+	// both adjacent siblings. For RIGHT or DOWN, just select the next sibling.
+	// For LEFT or UP, convert it to a RIGHT or DOWN resize and reassign con to
+	// the previous sibling.
+	struct sway_container *prev = NULL;
+	struct sway_container *next = NULL;
+	list_t *siblings = container_get_siblings(con);
+	int index = container_sibling_index(con);
+
+	if (axis == AXIS_HORIZONTAL || axis == AXIS_VERTICAL) {
+		prev = siblings->items[index - 1];
+		next = siblings->items[index + 1];
+	} else if (axis == WLR_EDGE_TOP || axis == WLR_EDGE_LEFT) {
+		if (!sway_assert(index > 0, "Didn't expect first child")) {
+			return;
 		}
+		next = con;
+		con = siblings->items[index - 1];
+		amount = -amount;
+	} else {
+		if (!sway_assert(index < siblings->length - 1,
+					"Didn't expect last child")) {
+			return;
+		}
+		next = siblings->items[index + 1];
 	}
 
-	enum wlr_edges minor_edge = horizontal ? WLR_EDGE_LEFT : WLR_EDGE_TOP;
-	enum wlr_edges major_edge = horizontal ? WLR_EDGE_RIGHT : WLR_EDGE_BOTTOM;
-
-	for (int i = 0; i < siblings->length; i++) {
-		struct sway_container *sibling = siblings->items[i];
-
-		int sibling_pos = parallel_coord(sibling, axis);
-		int focused_pos = parallel_coord(focused, axis);
-		int parent_pos = parallel_coord(parent, axis);
-
-		if (sibling_pos != focused_pos) {
-			if (sibling_pos < parent_pos && minor_weight) {
-				double pixels = -1 * amount;
-				pixels /= minor_weight;
-				if (major_weight) {
-					container_recursive_resize(sibling, pixels / 2, major_edge);
-				} else {
-					container_recursive_resize(sibling, pixels, major_edge);
-				}
-			} else if (sibling_pos > parent_pos && major_weight) {
-				double pixels = -1 * amount;
-				pixels /= major_weight;
-				if (minor_weight) {
-					container_recursive_resize(sibling, pixels / 2, minor_edge);
-				} else {
-					container_recursive_resize(sibling, pixels, minor_edge);
-				}
-			}
-		} else {
-			if (major_weight != 0 && minor_weight != 0) {
-				double pixels = amount;
-				pixels /= 2;
-				container_recursive_resize(parent, pixels, minor_edge);
-				container_recursive_resize(parent, pixels, major_edge);
-			} else if (major_weight) {
-				container_recursive_resize(parent, amount, major_edge);
-			} else if (minor_weight) {
-				container_recursive_resize(parent, amount, minor_edge);
-			}
+	// Apply new dimensions
+	int sibling_amount = prev ? amount / 2 : amount;
+
+	if (is_horizontal(axis)) {
+		if (con->width + amount < MIN_SANE_W) {
+			return;
+		}
+		if (next->width - sibling_amount < MIN_SANE_W) {
+			return;
+		}
+		if (prev && prev->width - sibling_amount < MIN_SANE_W) {
+			return;
+		}
+		con->width += amount;
+		next->width -= sibling_amount;
+		if (prev) {
+			prev->width -= sibling_amount;
+		}
+	} else {
+		if (con->height + amount < MIN_SANE_H) {
+			return;
+		}
+		if (next->height - sibling_amount < MIN_SANE_H) {
+			return;
+		}
+		if (prev && prev->height - sibling_amount < MIN_SANE_H) {
+			return;
+		}
+		con->height += amount;
+		next->height -= sibling_amount;
+		if (prev) {
+			prev->height -= sibling_amount;
 		}
 	}
 
-	if (parent->parent) {
-		arrange_container(parent->parent);
+	if (con->parent) {
+		arrange_container(con->parent);
 	} else {
-		arrange_workspace(parent->workspace);
+		arrange_workspace(con->workspace);
 	}
 }
 
-void container_resize_tiled(struct sway_container *parent,
-		enum wlr_edges edge, int amount) {
-	resize_tiled(parent, amount, edge);
-}
-
 /**
  * Implement `resize <grow|shrink>` for a floating container.
  */
@@ -379,7 +310,7 @@ static struct cmd_results *resize_adjust_tiled(uint32_t axis,
 
 	double old_width = current->width;
 	double old_height = current->height;
-	resize_tiled(current, amount->amount, axis);
+	container_resize_tiled(current, axis, amount->amount);
 	if (current->width == old_width && current->height == old_height) {
 		return cmd_results_new(CMD_INVALID, "Cannot resize any further");
 	}
@@ -407,7 +338,8 @@ static struct cmd_results *resize_set_tiled(struct sway_container *con,
 			width->unit = RESIZE_UNIT_PX;
 		}
 		if (width->unit == RESIZE_UNIT_PX) {
-			resize_tiled(con, width->amount - con->width, AXIS_HORIZONTAL);
+			container_resize_tiled(con, AXIS_HORIZONTAL,
+					width->amount - con->width);
 		}
 	}
 
@@ -427,7 +359,8 @@ static struct cmd_results *resize_set_tiled(struct sway_container *con,
 			height->unit = RESIZE_UNIT_PX;
 		}
 		if (height->unit == RESIZE_UNIT_PX) {
-			resize_tiled(con, height->amount - con->height, AXIS_VERTICAL);
+			container_resize_tiled(con, AXIS_VERTICAL,
+					height->amount - con->height);
 		}
 	}
 
diff --git a/sway/input/seatop_resize_tiling.c b/sway/input/seatop_resize_tiling.c
index 30431f04..cb0f723d 100644
--- a/sway/input/seatop_resize_tiling.c
+++ b/sway/input/seatop_resize_tiling.c
@@ -1,15 +1,22 @@
 #define _POSIX_C_SOURCE 200809L
 #include <wlr/types/wlr_cursor.h>
+#include <wlr/util/edges.h>
 #include "sway/commands.h"
 #include "sway/input/cursor.h"
 #include "sway/input/seat.h"
 
 struct seatop_resize_tiling_event {
-	struct sway_container *con;
+	struct sway_container *con;    // leaf container
+
+	// con, or ancestor of con which will be resized horizontally/vertically
+	struct sway_container *h_con;
+	struct sway_container *v_con;
+
 	enum wlr_edges edge;
+	enum wlr_edges edge_x, edge_y;
 	double ref_lx, ref_ly;         // cursor's x/y at start of op
-	double ref_width, ref_height;  // container's size at start of op
-	double ref_con_lx, ref_con_ly; // container's x/y at start of op
+	double h_con_orig_width;       // width of the horizontal ancestor at start
+	double v_con_orig_height;      // height of the vertical ancestor at start
 };
 
 static void handle_motion(struct sway_seat *seat, uint32_t time_msec) {
@@ -18,30 +25,27 @@ static void handle_motion(struct sway_seat *seat, uint32_t time_msec) {
 	int amount_y = 0;
 	int moved_x = seat->cursor->cursor->x - e->ref_lx;
 	int moved_y = seat->cursor->cursor->y - e->ref_ly;
-	enum wlr_edges edge_x = WLR_EDGE_NONE;
-	enum wlr_edges edge_y = WLR_EDGE_NONE;
-	struct sway_container *con = e->con;
-
-	if (e->edge & WLR_EDGE_TOP) {
-		amount_y = (e->ref_height - moved_y) - con->height;
-		edge_y = WLR_EDGE_TOP;
-	} else if (e->edge & WLR_EDGE_BOTTOM) {
-		amount_y = (e->ref_height + moved_y) - con->height;
-		edge_y = WLR_EDGE_BOTTOM;
+
+	if (e->h_con) {
+		if (e->edge & WLR_EDGE_LEFT) {
+			amount_x = (e->h_con_orig_width - moved_x) - e->h_con->width;
+		} else if (e->edge & WLR_EDGE_RIGHT) {
+			amount_x = (e->h_con_orig_width + moved_x) - e->h_con->width;
+		}
 	}
-	if (e->edge & WLR_EDGE_LEFT) {
-		amount_x = (e->ref_width - moved_x) - con->width;
-		edge_x = WLR_EDGE_LEFT;
-	} else if (e->edge & WLR_EDGE_RIGHT) {
-		amount_x = (e->ref_width + moved_x) - con->width;
-		edge_x = WLR_EDGE_RIGHT;
+	if (e->v_con) {
+		if (e->edge & WLR_EDGE_TOP) {
+			amount_y = (e->v_con_orig_height - moved_y) - e->v_con->height;
+		} else if (e->edge & WLR_EDGE_BOTTOM) {
+			amount_y = (e->v_con_orig_height + moved_y) - e->v_con->height;
+		}
 	}
 
 	if (amount_x != 0) {
-		container_resize_tiled(e->con, edge_x, amount_x);
+		container_resize_tiled(e->h_con, e->edge_x, amount_x);
 	}
 	if (amount_y != 0) {
-		container_resize_tiled(e->con, edge_y, amount_y);
+		container_resize_tiled(e->v_con, e->edge_y, amount_y);
 	}
 }
 
@@ -81,10 +85,23 @@ void seatop_begin_resize_tiling(struct sway_seat *seat,
 
 	e->ref_lx = seat->cursor->cursor->x;
 	e->ref_ly = seat->cursor->cursor->y;
-	e->ref_con_lx = con->x;
-	e->ref_con_ly = con->y;
-	e->ref_width = con->width;
-	e->ref_height = con->height;
+
+	if (edge & (WLR_EDGE_LEFT | WLR_EDGE_RIGHT)) {
+		e->edge_x = edge & (WLR_EDGE_LEFT | WLR_EDGE_RIGHT);
+		e->h_con = container_find_resize_parent(e->con, e->edge_x);
+
+		if (e->h_con) {
+			e->h_con_orig_width = e->h_con->width;
+		}
+	}
+	if (edge & (WLR_EDGE_TOP | WLR_EDGE_BOTTOM)) {
+		e->edge_y = edge & (WLR_EDGE_TOP | WLR_EDGE_BOTTOM);
+		e->v_con = container_find_resize_parent(e->con, e->edge_y);
+
+		if (e->v_con) {
+			e->v_con_orig_height = e->v_con->height;
+		}
+	}
 
 	seat->seatop_impl = &seatop_impl;
 	seat->seatop_data = e;