Implement resizing tiled containers via cursor

* The OP_RESIZE seat operation has been renamed to OP_RESIZE_FLOATING,
and OP_RESIZE_TILING has been introduced.
* Similar to the above, seat_begin_resize and handle_resize_motion have
been renamed and tiling variants introduced.
* resize.c's resize_tiled has to be used, so container_resize_tiled has
been introduced in resize.c to allow external code to call it.

common/list.c

@@ -77,6 +77,15 @@ int list_seq_find(list_t *list, int compare(const void *item, const void *data),
 	return -1;
 }
 
+int list_find(list_t *list, void *item) {
+	for (int i = 0; i < list->length; i++) {
+		if (list->items[i] == item) {
+			return i;
+		}
+	}
+	return -1;
+}
+
 void list_swap(list_t *list, int src, int dest) {
 	void *tmp = list->items[src];
 	list->items[src] = list->items[dest];

include/list.h

@@ -20,6 +20,7 @@ void list_qsort(list_t *list, int compare(const void *left, const void *right));
 // Return index for first item in list that returns 0 for given compare
 // function or -1 if none matches.
 int list_seq_find(list_t *list, int compare(const void *item, const void *cmp_to), const void *cmp_to);
+int list_find(list_t *list, void *item);
 // stable sort since qsort is not guaranteed to be stable
 void list_stable_sort(list_t *list, int compare(const void *a, const void *b));
 // swap two elements in a list

include/sway/commands.h

@@ -1,6 +1,7 @@
 #ifndef _SWAY_COMMANDS_H
 #define _SWAY_COMMANDS_H
 
+#include <wlr/util/edges.h>
 #include "config.h"
 
 typedef struct cmd_results *sway_cmd(int argc, char **argv);
@@ -84,6 +85,12 @@ char *cmd_results_to_json(struct cmd_results *results);
 struct cmd_results *add_color(const char *name,
 		char *buffer, const char *color);
 
+/**
+ * TODO: Move this function and its dependent functions to container.c.
+ */
+void container_resize_tiled(struct sway_container *parent, enum wlr_edges edge,
+		int amount);
+
 sway_cmd cmd_assign;
 sway_cmd cmd_bar;
 sway_cmd cmd_bindcode;

include/sway/input/seat.h

@@ -57,7 +57,8 @@ struct sway_seat {
 	enum {
 		OP_NONE,
 		OP_MOVE,
-		OP_RESIZE,
+		OP_RESIZE_FLOATING,
+		OP_RESIZE_TILING,
 	} operation;
 
 	struct sway_container *op_container;
@@ -159,8 +160,11 @@ void drag_icon_update_position(struct sway_drag_icon *icon);
 void seat_begin_move(struct sway_seat *seat, struct sway_container *con,
 		uint32_t button);
 
-void seat_begin_resize(struct sway_seat *seat, struct sway_container *con,
-		uint32_t button, enum wlr_edges edge);
+void seat_begin_resize_floating(struct sway_seat *seat,
+		struct sway_container *con, uint32_t button, enum wlr_edges edge);
+
+void seat_begin_resize_tiling(struct sway_seat *seat,
+		struct sway_container *con, uint32_t button, enum wlr_edges edge);
 
 void seat_end_mouse_operation(struct sway_seat *seat);
 

sway/commands/resize.c

@@ -158,8 +158,8 @@ static int parallel_size(struct sway_container *c, enum resize_axis a) {
 	return normalize_axis(a) == RESIZE_AXIS_HORIZONTAL ? c->width : c->height;
 }
 
-static void resize_tiled(int amount, enum resize_axis axis) {
-	struct sway_container *parent = config->handler_context.current_container;
+static void resize_tiled(struct sway_container *parent, int amount,
+		enum resize_axis axis) {
 	struct sway_container *focused = parent;
 	if (!parent) {
 		return;
@@ -297,6 +297,28 @@ static void resize_tiled(int amount, enum resize_axis axis) {
 	arrange_windows(parent->parent);
 }
 
+void container_resize_tiled(struct sway_container *parent,
+		enum wlr_edges edge, int amount) {
+	enum resize_axis axis = RESIZE_AXIS_INVALID;
+	switch (edge) {
+	case WLR_EDGE_TOP:
+		axis = RESIZE_AXIS_UP;
+		break;
+	case WLR_EDGE_RIGHT:
+		axis = RESIZE_AXIS_RIGHT;
+		break;
+	case WLR_EDGE_BOTTOM:
+		axis = RESIZE_AXIS_DOWN;
+		break;
+	case WLR_EDGE_LEFT:
+		axis = RESIZE_AXIS_LEFT;
+		break;
+	case WLR_EDGE_NONE:
+		break;
+	}
+	resize_tiled(parent, amount, axis);
+}
+
 /**
  * Implement `resize <grow|shrink>` for a floating container.
  */
@@ -398,7 +420,7 @@ static struct cmd_results *resize_adjust_tiled(enum resize_axis axis,
 		}
 	}
 
-	resize_tiled(amount->amount, axis);
+	resize_tiled(current, amount->amount, axis);
 	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
 }
 
@@ -421,7 +443,8 @@ static struct cmd_results *resize_set_tiled(struct sway_container *con,
 			}
 		}
 		if (width->unit == RESIZE_UNIT_PX) {
-			resize_tiled(width->amount - con->width, RESIZE_AXIS_HORIZONTAL);
+			resize_tiled(con, width->amount - con->width,
+					RESIZE_AXIS_HORIZONTAL);
 		}
 	}
 
@@ -439,7 +462,8 @@ static struct cmd_results *resize_set_tiled(struct sway_container *con,
 			}
 		}
 		if (height->unit == RESIZE_UNIT_PX) {
-			resize_tiled(height->amount - con->height, RESIZE_AXIS_VERTICAL);
+			resize_tiled(con, height->amount - con->height,
+					RESIZE_AXIS_HORIZONTAL);
 		}
 	}
 

sway/desktop/xdg_shell.c

@@ -331,7 +331,8 @@ static void handle_request_resize(struct wl_listener *listener, void *data) {
 	struct wlr_xdg_toplevel_resize_event *e = data;
 	struct sway_seat *seat = e->seat->seat->data;
 	if (e->serial == seat->last_button_serial) {
-		seat_begin_resize(seat, view->swayc, seat->last_button, e->edges);
+		seat_begin_resize_floating(seat, view->swayc,
+				seat->last_button, e->edges);
 	}
 }
 

sway/desktop/xdg_shell_v6.c

@@ -327,7 +327,8 @@ static void handle_request_resize(struct wl_listener *listener, void *data) {
 	struct wlr_xdg_toplevel_v6_resize_event *e = data;
 	struct sway_seat *seat = e->seat->seat->data;
 	if (e->serial == seat->last_button_serial) {
-		seat_begin_resize(seat, view->swayc, seat->last_button, e->edges);
+		seat_begin_resize_floating(seat, view->swayc,
+				seat->last_button, e->edges);
 	}
 }
 

sway/desktop/xwayland.c

@@ -432,7 +432,7 @@ static void handle_request_resize(struct wl_listener *listener, void *data) {
 	}
 	struct wlr_xwayland_resize_event *e = data;
 	struct sway_seat *seat = input_manager_current_seat(input_manager);
-	seat_begin_resize(seat, view->swayc, seat->last_button, e->edges);
+	seat_begin_resize_floating(seat, view->swayc, seat->last_button, e->edges);
 }
 
 static void handle_set_title(struct wl_listener *listener, void *data) {

sway/input/cursor.c

@@ -12,6 +12,7 @@
 #include "list.h"
 #include "log.h"
 #include "config.h"
+#include "sway/commands.h"
 #include "sway/desktop.h"
 #include "sway/desktop/transaction.h"
 #include "sway/input/cursor.h"
@@ -136,6 +137,44 @@ static struct sway_container *container_at_coords(
 	return output->swayc;
 }
 
+/**
+ * Determine if the edge of the given container is on the edge of the
+ * workspace/output.
+ */
+static bool edge_is_external(struct sway_container *cont, enum wlr_edges edge) {
+	enum sway_container_layout layout = L_NONE;
+	switch (edge) {
+	case WLR_EDGE_TOP:
+	case WLR_EDGE_BOTTOM:
+		layout = L_VERT;
+		break;
+	case WLR_EDGE_LEFT:
+	case WLR_EDGE_RIGHT:
+		layout = L_HORIZ;
+		break;
+	case WLR_EDGE_NONE:
+		sway_assert(false, "Never reached");
+		return false;
+	}
+
+	// Iterate the parents until we find one with the layout we want,
+	// then check if the child has siblings between it and the edge.
+	while (cont->type != C_OUTPUT) {
+		if (cont->parent->layout == layout) {
+			int index = list_find(cont->parent->children, cont);
+			if (index > 0 && (edge == WLR_EDGE_LEFT || edge == WLR_EDGE_TOP)) {
+				return false;
+			}
+			if (index < cont->parent->children->length - 1 &&
+					(edge == WLR_EDGE_RIGHT || edge == WLR_EDGE_BOTTOM)) {
+				return false;
+			}
+		}
+		cont = cont->parent;
+	}
+	return true;
+}
+
 static enum wlr_edges find_resize_edge(struct sway_container *cont,
 		struct sway_cursor *cursor) {
 	if (cont->type != C_VIEW) {
@@ -159,6 +198,11 @@ static enum wlr_edges find_resize_edge(struct sway_container *cont,
 	if (cursor->cursor->y >= cont->y + cont->height - view->border_thickness) {
 		edge |= WLR_EDGE_BOTTOM;
 	}
+
+	if (edge && !container_is_floating(cont) && edge_is_external(cont, edge)) {
+		return WLR_EDGE_NONE;
+	}
+
 	return edge;
 }
 
@@ -209,7 +253,7 @@ static void calculate_floating_constraints(struct sway_container *con,
 	}
 }
 
-static void handle_resize_motion(struct sway_seat *seat,
+static void handle_resize_floating_motion(struct sway_seat *seat,
 		struct sway_cursor *cursor) {
 	struct sway_container *con = seat->op_container;
 	enum wlr_edges edge = seat->op_resize_edge;
@@ -301,6 +345,31 @@ static void handle_resize_motion(struct sway_seat *seat,
 	arrange_windows(con);
 }
 
+static void handle_resize_tiling_motion(struct sway_seat *seat,
+		struct sway_cursor *cursor) {
+	int amount = 0;
+	int moved_x = cursor->cursor->x - seat->op_ref_lx;
+	int moved_y = cursor->cursor->y - seat->op_ref_ly;
+	struct sway_container *con = seat->op_container;
+	switch (seat->op_resize_edge) {
+	case WLR_EDGE_TOP:
+		amount = (seat->op_ref_height - moved_y) - con->height;
+		break;
+	case WLR_EDGE_BOTTOM:
+		amount = (seat->op_ref_height + moved_y) - con->height;
+		break;
+	case WLR_EDGE_LEFT:
+		amount = (seat->op_ref_width - moved_x) - con->width;
+		break;
+	case WLR_EDGE_RIGHT:
+		amount = (seat->op_ref_width + moved_x) - con->width;
+		break;
+	case WLR_EDGE_NONE:
+		break;
+	}
+	container_resize_tiled(seat->op_container, seat->op_resize_edge, amount);
+}
+
 void cursor_send_pointer_motion(struct sway_cursor *cursor, uint32_t time_msec,
 		bool allow_refocusing) {
 	if (time_msec == 0) {
@@ -310,10 +379,18 @@ void cursor_send_pointer_motion(struct sway_cursor *cursor, uint32_t time_msec,
 	struct sway_seat *seat = cursor->seat;
 
 	if (seat->operation != OP_NONE) {
-		if (seat->operation == OP_MOVE) {
+		switch (seat->operation) {
+		case OP_MOVE:
 			handle_move_motion(seat, cursor);
-		} else {
-			handle_resize_motion(seat, cursor);
+			break;
+		case OP_RESIZE_FLOATING:
+			handle_resize_floating_motion(seat, cursor);
+			break;
+		case OP_RESIZE_TILING:
+			handle_resize_tiling_motion(seat, cursor);
+			break;
+		case OP_NONE:
+			break;
 		}
 		cursor->previous.x = cursor->cursor->x;
 		cursor->previous.y = cursor->cursor->y;
@@ -375,8 +452,8 @@ void cursor_send_pointer_motion(struct sway_cursor *cursor, uint32_t time_msec,
 		if (client != cursor->image_client) {
 			cursor_set_image(cursor, "left_ptr", client);
 		}
-	} else if (c && container_is_floating(c)) {
-		// Try a floating container's resize edge
+	} else if (c) {
+		// Try a container's resize edge
 		enum wlr_edges edge = find_resize_edge(c, cursor);
 		const char *image = edge == WLR_EDGE_NONE ?
 			"left_ptr" : wlr_xcursor_get_resize_name(edge);
@@ -467,7 +544,7 @@ static void dispatch_cursor_button_floating(struct sway_cursor *cursor,
 			edge |= cursor->cursor->y > floater->y + floater->height / 2 ?
 				WLR_EDGE_BOTTOM : WLR_EDGE_TOP;
 		}
-		seat_begin_resize(seat, floater, button, edge);
+		seat_begin_resize_floating(seat, floater, button, edge);
 		return;
 	}
 
@@ -592,6 +669,8 @@ void dispatch_cursor_button(struct sway_cursor *cursor,
 		// TODO: do we want to pass on the event?
 	}
 
+	enum wlr_edges edge = cont ? find_resize_edge(cont, cursor) : WLR_EDGE_NONE;
+
 	if (surface && wlr_surface_is_layer_surface(surface)) {
 		struct wlr_layer_surface *layer =
 			wlr_layer_surface_from_wlr_surface(surface);
@@ -599,6 +678,10 @@ void dispatch_cursor_button(struct sway_cursor *cursor,
 			seat_set_focus_layer(cursor->seat, layer);
 		}
 		seat_pointer_notify_button(cursor->seat, time_msec, button, state);
+	} else if (edge && button == BTN_LEFT &&
+			!container_is_floating(cont)) {
+		seat_set_focus(cursor->seat, cont);
+		seat_begin_resize_tiling(cursor->seat, cont, BTN_LEFT, edge);
 	} else if (cont && container_is_floating_or_child(cont)) {
 		dispatch_cursor_button_floating(cursor, time_msec, button, state,
 				surface, sx, sy, cont);

sway/input/seat.c

@@ -942,14 +942,14 @@ void seat_begin_move(struct sway_seat *seat, struct sway_container *con,
 	cursor_set_image(seat->cursor, "grab", NULL);
 }
 
-void seat_begin_resize(struct sway_seat *seat, struct sway_container *con,
-		uint32_t button, enum wlr_edges edge) {
+void seat_begin_resize_floating(struct sway_seat *seat,
+		struct sway_container *con, uint32_t button, enum wlr_edges edge) {
 	if (!seat->cursor) {
 		wlr_log(WLR_DEBUG, "Ignoring resize request due to no cursor device");
 		return;
 	}
 	struct wlr_keyboard *keyboard = wlr_seat_get_keyboard(seat->wlr_seat);
-	seat->operation = OP_RESIZE;
+	seat->operation = OP_RESIZE_FLOATING;
 	seat->op_container = con;
 	seat->op_resize_preserve_ratio = keyboard &&
 		(wlr_keyboard_get_modifiers(keyboard) & WLR_MODIFIER_SHIFT);
@@ -968,20 +968,29 @@ void seat_begin_resize(struct sway_seat *seat, struct sway_container *con,
 	cursor_set_image(seat->cursor, image, NULL);
 }
 
+void seat_begin_resize_tiling(struct sway_seat *seat,
+		struct sway_container *con, uint32_t button, enum wlr_edges edge) {
+	seat->operation = OP_RESIZE_TILING;
+	seat->op_container = con;
+	seat->op_resize_edge = edge;
+	seat->op_button = button;
+	seat->op_ref_lx = seat->cursor->cursor->x;
+	seat->op_ref_ly = seat->cursor->cursor->y;
+	seat->op_ref_con_lx = con->x;
+	seat->op_ref_con_ly = con->y;
+	seat->op_ref_width = con->width;
+	seat->op_ref_height = con->height;
+
+	const char *image = wlr_xcursor_get_resize_name(edge);
+	cursor_set_image(seat->cursor, image, NULL);
+}
+
 void seat_end_mouse_operation(struct sway_seat *seat) {
-	switch (seat->operation) {
-	case OP_MOVE:
-		{
-			// We "move" the container to its own location so it discovers its
-			// output again.
-			struct sway_container *con = seat->op_container;
-			container_floating_move_to(con, con->x, con->y);
-		}
-	case OP_RESIZE:
-		// Don't need to do anything here.
-		break;
-	case OP_NONE:
-		break;
+	if (seat->operation == OP_MOVE) {
+		// We "move" the container to its own location so it discovers its
+		// output again.
+		struct sway_container *con = seat->op_container;
+		container_floating_move_to(con, con->x, con->y);
 	}
 	seat->operation = OP_NONE;
 	seat->op_container = NULL;