[PATCH 3/3 weston] Implement optional resize-from-center mode.

[Scott Moreau]

---
 clients/window.c | 15 ++++++++++-----
 src/shell.c      | 40 +++++++++++++++++++++++++++++++---------
 weston.ini       |  1 +
 3 files changed, 42 insertions(+), 14 deletions(-)

diff --git a/clients/window.c b/clients/window.c
index 9a11571..6468e85 100644
--- a/clients/window.c
+++ b/clients/window.c
@@ -342,9 +342,7 @@ enum window_location {
 	WINDOW_RESIZING_TOP_RIGHT = 9,
 	WINDOW_RESIZING_BOTTOM_RIGHT = 10,
 	WINDOW_RESIZING_MASK = 15,
-	WINDOW_EXTERIOR = 16,
-	WINDOW_TITLEBAR = 17,
-	WINDOW_CLIENT_AREA = 18,
+	WINDOW_RESIZING_FROM_CENTER = 16,
 };
 
 static const cairo_user_data_key_t surface_data_key;
@@ -803,12 +801,19 @@ display_get_pointer_image(struct display *display, int pointer)
 static void
 window_get_resize_dx_dy(struct window *window, int *x, int *y)
 {
-	if (window->resize_edges & WINDOW_RESIZING_LEFT)
+	if (window->resize_edges & WINDOW_RESIZING_FROM_CENTER) {
+		*x = window->server_allocation.width - window->allocation.width;
+		*x /= 2;
+	} else if (window->resize_edges & WINDOW_RESIZING_LEFT)
 		*x = window->server_allocation.width - window->allocation.width;
 	else
 		*x = 0;
 
-	if (window->resize_edges & WINDOW_RESIZING_TOP)
+	if (window->resize_edges & WINDOW_RESIZING_FROM_CENTER) {
+		*y = window->server_allocation.height -
+			window->allocation.height;
+		*y /= 2;
+	} else if (window->resize_edges & WINDOW_RESIZING_TOP)
 		*y = window->server_allocation.height -
 			window->allocation.height;
 	else
diff --git a/src/shell.c b/src/shell.c
index 26068cd..299fd25 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -102,6 +102,7 @@ struct desktop_shell {
 	bool locked;
 	bool showing_input_panels;
 	bool prepare_event_sent;
+	bool resize_from_center;
 
 	struct weston_surface *lock_surface;
 	struct wl_listener lock_surface_listener;
@@ -356,10 +357,12 @@ shell_configuration(struct desktop_shell *shell)
 	unsigned int num_workspaces = DEFAULT_NUM_WORKSPACES;
 	char *modifier = NULL;
 	char *win_animation = NULL;
+	bool resize_from_center;
 
 	struct config_key shell_keys[] = {
 		{ "binding-modifier",   CONFIG_KEY_STRING, &modifier },
 		{ "animation",          CONFIG_KEY_STRING, &win_animation},
+		{ "resize-from-center", CONFIG_KEY_BOOLEAN, &resize_from_center},
 		{ "num-workspaces",
 			CONFIG_KEY_UNSIGNED_INTEGER, &num_workspaces },
 	};
@@ -383,6 +386,7 @@ shell_configuration(struct desktop_shell *shell)
 	shell->binding_modifier = get_modifier(modifier);
 	shell->win_animation_type = get_animation_type(win_animation);
 	shell->workspaces.num = num_workspaces > 0 ? num_workspaces : 1;
+	shell->resize_from_center = resize_from_center;
 }
 
 static void
@@ -1097,7 +1101,7 @@ resize_grab_motion(struct wl_pointer_grab *grab,
 	struct weston_resize_grab *resize = (struct weston_resize_grab *) grab;
 	struct wl_pointer *pointer = grab->pointer;
 	struct shell_surface *shsurf = resize->base.shsurf;
-	int32_t width, height;
+	int32_t width, height, offset;
 	wl_fixed_t from_x, from_y;
 	wl_fixed_t to_x, to_y;
 
@@ -1112,17 +1116,29 @@ resize_grab_motion(struct wl_pointer_grab *grab,
 
 	width = resize->width;
 	if (resize->edges & WL_SHELL_SURFACE_RESIZE_LEFT) {
-		width += wl_fixed_to_int(from_x - to_x);
+		offset = wl_fixed_to_int(from_x - to_x);
 	} else if (resize->edges & WL_SHELL_SURFACE_RESIZE_RIGHT) {
-		width += wl_fixed_to_int(to_x - from_x);
-	}
+		offset = wl_fixed_to_int(to_x - from_x);
+	} else
+		offset = 0;
+
+	if (resize->edges & WL_SHELL_SURFACE_RESIZE_FROM_CENTER)
+		offset *= 2;
+
+	width += offset;
 
 	height = resize->height;
 	if (resize->edges & WL_SHELL_SURFACE_RESIZE_TOP) {
-		height += wl_fixed_to_int(from_y - to_y);
+		offset = wl_fixed_to_int(from_y - to_y);
 	} else if (resize->edges & WL_SHELL_SURFACE_RESIZE_BOTTOM) {
-		height += wl_fixed_to_int(to_y - from_y);
-	}
+		offset = wl_fixed_to_int(to_y - from_y);
+	} else
+		offset = 0;
+
+	if (resize->edges & WL_SHELL_SURFACE_RESIZE_FROM_CENTER)
+		offset *= 2;
+
+	height += offset;
 
 	shsurf->client->send_configure(shsurf->surface,
 				       resize->edges, width, height);
@@ -1172,7 +1188,7 @@ surface_resize(struct shell_surface *shsurf,
 	if (shsurf->type == SHELL_SURFACE_FULLSCREEN)
 		return 0;
 
-	if (edges == 0 || edges > 15 ||
+	if (edges == 0 || (edges & 0x0f) > 15 ||
 	    (edges & 3) == 3 || (edges & 12) == 12)
 		return 0;
 
@@ -1185,7 +1201,7 @@ surface_resize(struct shell_surface *shsurf,
 	resize->height = shsurf->surface->geometry.height;
 
 	shell_grab_start(&resize->base, &resize_grab_interface, shsurf,
-			 ws->seat.pointer, edges);
+			 ws->seat.pointer, edges & 0x0f);
 
 	return 0;
 }
@@ -1206,6 +1222,9 @@ shell_surface_resize(struct wl_client *client, struct wl_resource *resource,
 	    ws->seat.pointer->focus != &shsurf->surface->surface)
 		return;
 
+	if (shsurf->shell->resize_from_center)
+		edges |= WL_SHELL_SURFACE_RESIZE_FROM_CENTER;
+
 	if (surface_resize(shsurf, ws, edges) < 0)
 		wl_resource_post_no_memory(resource);
 }
@@ -2763,6 +2782,9 @@ resize_binding(struct wl_seat *seat, uint32_t time, uint32_t button, void *data)
 	else
 		edges |= WL_SHELL_SURFACE_RESIZE_BOTTOM;
 
+	if (shsurf->shell->resize_from_center)
+		edges |= WL_SHELL_SURFACE_RESIZE_FROM_CENTER;
+
 	surface_resize(shsurf, (struct weston_seat *) seat, edges);
 }
 
diff --git a/weston.ini b/weston.ini
index cb88eba..6a74368 100644
--- a/weston.ini
+++ b/weston.ini
@@ -7,6 +7,7 @@ locking=true
 animation=zoom
 #binding-modifier=ctrl
 #num-workspaces=6
+#resize-from-center=true
 
 #type=tablet-shell.so
 #lockscreen-icon=/usr/share/icons/gnome/256x256/actions/lock.png
-- 
1.7.11.7