[PATCH weston 12/16] shell: Add transient XWayland shell surfaces

[Tiago Vignatti]

Worth to note this type of shell surface is not exposed for clients but just
used internally. XWayland compositor counter-part is not implemented yet; next
commit will bring it on.

weston_shell_interface was also documented on this commit.

Signed-off-by: Tiago Vignatti <tiago.vignatti at intel.com>
---
 src/compositor.h |   35 +++++++++++++++++++++++++++++++----
 src/shell.c      |   30 +++++++++++++++++++++++++++---
 2 files changed, 58 insertions(+), 7 deletions(-)

diff --git a/src/compositor.h b/src/compositor.h
index 15d6939..5f5e47e 100644
--- a/src/compositor.h
+++ b/src/compositor.h
@@ -73,6 +73,25 @@ struct weston_shell_client {
 			       uint32_t edges, int32_t width, int32_t height);
 };
 
+enum weston_xwayland {
+	XWAYLAND_ACTIVE = (1 << 0),
+	XWAYLAND_INACTIVE = (1 << 1)
+};
+
+/*
+ * weston_shell_interface is the interface for the WM compositor module
+ * (window-manager.c) access the shell implementation. Its methods need to be
+ * implemented and hooked for XWayland usage only.
+ *
+ * Once a handler is received (create_shell_surface), window types are set by
+ * the WM, so windows are mapped on the screen (wm_xwin.set_window, 'flags'
+ * argument). The WM compositor module has in particular two types for
+ * mapping: set_toplevel and set_transient_xwayland. Worth to mention that the
+ * latter is an XWayland specific type and shells are not exposing it to
+ * regular clients via Wayland protocol; it differs from the regular
+ * set_transient protocol type because set_transient_xwayland maps a surface
+ * in a absolute coordinate on the screen, a peculiar feature of X.
+ */
 struct weston_shell_interface {
 	void *shell;			/* either desktop or tablet */
 
@@ -82,13 +101,21 @@ struct weston_shell_interface {
 
 	void (*set_toplevel)(struct shell_surface *shsurf);
 
-	void (*set_transient)(struct shell_surface *shsurf,
-			      struct weston_surface *parent,
-			      int x, int y, uint32_t flags);
+	/*
+	 * 'x' and 'y' arguments accept global absolute coordinates, while
+	 * 'flags' is used for receiving keyboard focus or not.
+	 *
+	 * As a side note, ICCCM 'transient' has a slightly different meaning
+	 * than this here. On that one it requires a parent top-level window,
+	 * which is not the case here. So set_transient_xwayland is
+	 * 'transient' in the sense of "lasting only for a short time;
+	 * impermanent", used for tooltips, dropdown, dialogs, among others.
+	 */
+	void (*set_transient_xwayland)(struct shell_surface *shsurf,
+			int x, int y, enum weston_xwayland flags);
 	int (*move)(struct shell_surface *shsurf, struct weston_seat *ws);
 	int (*resize)(struct shell_surface *shsurf,
 		      struct weston_seat *ws, uint32_t edges);
-
 };
 
 struct weston_border {
diff --git a/src/shell.c b/src/shell.c
index aa1c7c1..7a0e24c 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -141,6 +141,7 @@ enum shell_surface_type {
 	SHELL_SURFACE_NONE,
 	SHELL_SURFACE_TOPLEVEL,
 	SHELL_SURFACE_TRANSIENT,
+	SHELL_SURFACE_TRANSIENT_XWAYLAND,
 	SHELL_SURFACE_FULLSCREEN,
 	SHELL_SURFACE_MAXIMIZED,
 	SHELL_SURFACE_POPUP
@@ -192,6 +193,11 @@ struct shell_surface {
 		struct weston_surface *black_surface;
 	} fullscreen;
 
+	struct {
+		int32_t x, y;
+		enum weston_xwayland flags;
+	} xwayland;
+
 	struct ping_timer *ping_timer;
 
 	struct weston_transform workspace_transform;
@@ -1469,6 +1475,7 @@ reset_shell_surface_type(struct shell_surface *surface)
 	case SHELL_SURFACE_NONE:
 	case SHELL_SURFACE_TOPLEVEL:
 	case SHELL_SURFACE_TRANSIENT:
+	case SHELL_SURFACE_TRANSIENT_XWAYLAND:
 	case SHELL_SURFACE_POPUP:
 		break;
 	}
@@ -1496,7 +1503,10 @@ set_surface_type(struct shell_surface *shsurf)
 				pes->geometry.x + shsurf->transient.x,
 				pes->geometry.y + shsurf->transient.y);
 		break;
-
+	case SHELL_SURFACE_TRANSIENT_XWAYLAND:
+		weston_surface_set_position(surface, shsurf->xwayland.x,
+					    shsurf->xwayland.y);
+		break;
 	case SHELL_SURFACE_MAXIMIZED:
 		shsurf->saved_x = surface->geometry.x;
 		shsurf->saved_y = surface->geometry.y;
@@ -1515,7 +1525,6 @@ set_surface_type(struct shell_surface *shsurf)
 			shsurf->saved_rotation_valid = true;
 		}
 		break;
-
 	default:
 		break;
 	}
@@ -1560,6 +1569,16 @@ shell_surface_set_transient(struct wl_client *client,
 	set_transient(shsurf, parent, x, y, flags);
 }
 
+static void
+set_transient_xwayland(struct shell_surface *shsurf, int x, int y,
+		       enum weston_xwayland flags)
+{
+	shsurf->xwayland.x = x;
+	shsurf->xwayland.y = y;
+	shsurf->xwayland.flags = flags;
+	shsurf->next_type = SHELL_SURFACE_TRANSIENT_XWAYLAND;
+}
+
 static struct desktop_shell *
 shell_surface_get_shell(struct shell_surface *shsurf)
 {
@@ -2928,6 +2947,7 @@ map(struct desktop_shell *shell, struct weston_surface *surface,
 					    surface->geometry.x + sx,
 					    surface->geometry.y + sy);
 		break;
+	case SHELL_SURFACE_TRANSIENT_XWAYLAND:
 	default:
 		;
 	}
@@ -2942,6 +2962,7 @@ map(struct desktop_shell *shell, struct weston_surface *surface,
 	case SHELL_SURFACE_FULLSCREEN:
 	case SHELL_SURFACE_NONE:
 		break;
+	case SHELL_SURFACE_TRANSIENT_XWAYLAND:
 	default:
 		ws = get_current_workspace(shell);
 		wl_list_insert(&ws->layer.surface_list, &surface->layer_link);
@@ -2959,6 +2980,9 @@ map(struct desktop_shell *shell, struct weston_surface *surface,
 		if (shsurf->transient.flags ==
 				WL_SHELL_SURFACE_TRANSIENT_INACTIVE)
 			break;
+	case SHELL_SURFACE_TRANSIENT_XWAYLAND:
+		if (shsurf->xwayland.flags == XWAYLAND_INACTIVE)
+			break;
 	case SHELL_SURFACE_TOPLEVEL:
 	case SHELL_SURFACE_FULLSCREEN:
 	case SHELL_SURFACE_MAXIMIZED:
@@ -3841,7 +3865,7 @@ module_init(struct weston_compositor *ec)
 	ec->shell_interface.shell = shell;
 	ec->shell_interface.create_shell_surface = create_shell_surface;
 	ec->shell_interface.set_toplevel = set_toplevel;
-	ec->shell_interface.set_transient = set_transient;
+	ec->shell_interface.set_transient_xwayland = set_transient_xwayland;
 	ec->shell_interface.move = surface_move;
 	ec->shell_interface.resize = surface_resize;
 
-- 
1.7.9.5