weston-keyboard: Enable to set as overlay panel

input-method-v1 protocol provides two surface type for the input
panel, `toplevel` and `overlay`. But there is no example for the later
one. This change enables to set weston-keyboard as overlay panel by the
environment variable `WESTON_KEYBOARD_SURFACE_TYPE=overlay` to
demonstrate this feature. In Addition, add weston.ini option
`overlay-keyboard` to set it.

Signed-off-by: Takuro Ashie <ashie@clear-code.com>

clients/keyboard.c

@@ -60,6 +60,7 @@ struct virtual_keyboard {
 	uint32_t surrounding_cursor;
 	struct keyboard *keyboard;
 	bool toplevel;
+	bool overlay;
 	struct zwp_input_panel_surface_v1 *ips;
 };
 
@@ -970,15 +971,38 @@ set_toplevel(struct output *output, struct virtual_keyboard *virtual_keyboard)
 						ZWP_INPUT_PANEL_SURFACE_V1_POSITION_CENTER_BOTTOM);
 
 	virtual_keyboard->toplevel = true;
+	virtual_keyboard->overlay = false;
+	virtual_keyboard->ips = ips;
+}
+
+static void
+set_overlay(struct output *output, struct virtual_keyboard *virtual_keyboard)
+{
+	struct zwp_input_panel_surface_v1 *ips;
+	struct keyboard *keyboard = virtual_keyboard->keyboard;
+
+	ips = zwp_input_panel_v1_get_input_panel_surface(virtual_keyboard->input_panel,
+							 window_get_wl_surface(keyboard->window));
+
+	zwp_input_panel_surface_v1_set_overlay_panel(ips);
+
+	virtual_keyboard->toplevel = false;
+	virtual_keyboard->overlay = true;
 	virtual_keyboard->ips = ips;
 }
 
 static void
 display_output_handler(struct output *output, void *data) {
 	struct virtual_keyboard *keyboard = data;
+	const char *type = getenv("WESTON_KEYBOARD_SURFACE_TYPE");
 
+	if (type && strcasecmp("overlay", type) == 0) {
+		if (!keyboard->overlay)
+			set_overlay(output, keyboard);
+	} else {
 		if (!keyboard->toplevel)
 			set_toplevel(output, keyboard);
+	}
 }
 
 static void

compositor/text-backend.c

@@ -103,6 +103,7 @@ struct text_backend {
 
 	struct {
 		char *path;
+		bool overlay_keyboard;
 		struct wl_client *client;
 
 		unsigned deathcount;
@@ -993,6 +994,9 @@ launch_input_method(struct text_backend *text_backend)
 	if (strcmp(text_backend->input_method.path, "") == 0)
 		return;
 
+	if (text_backend->input_method.overlay_keyboard)
+		setenv("WESTON_KEYBOARD_SURFACE_TYPE", "overlay", 1);
+
 	text_backend->input_method.client =
 		weston_client_start(text_backend->compositor,
 				    text_backend->input_method.path);
@@ -1060,6 +1064,9 @@ text_backend_configuration(struct text_backend *text_backend)
 	weston_config_section_get_string(section, "path",
 					 &text_backend->input_method.path,
 					 client);
+	weston_config_section_get_bool(section, "overlay-keyboard",
+				       &text_backend->input_method.overlay_keyboard,
+				       false);
 	free(client);
 }
 

man/weston.ini.man

@@ -574,6 +574,11 @@ request. Currently, this option is supported by kiosk-shell.
 sets the path of the on screen keyboard input method (string).
 .RE
 .RE
+.TP 7
+.BI "overlay-keyboard=" false
+sets weston-keyboard as overlay panel.
+.RE
+.RE
 .SH "KEYBOARD SECTION"
 This section contains the following keys:
 .TP 7