switch (widget) {

			case WID_EM_MESSAGE: {

				CopyInDParam(0, this->decode_params, lengthof(this->decode_params));

				if (this->textref_stack_size > 0) StartTextRefStackUsage(this->textref_stack_grffile, this->textref_stack_size, this->textref_stack);

				int text_width = max(0, (int)size->width - WD_FRAMETEXT_LEFT - WD_FRAMETEXT_RIGHT);

				this->height_summary = GetStringHeight(this->summary_msg, text_width);

				this->height_detailed = (this->detailed_msg == INVALID_STRING_ID) ? 0 : GetStringHeight(this->detailed_msg, text_width);

				if (this->textref_stack_size > 0) StopTextRefStackUsage();

				uint panel_height = WD_FRAMERECT_TOP + this->height_summary + WD_FRAMERECT_BOTTOM;

				if (this->detailed_msg != INVALID_STRING_ID) panel_height += this->height_detailed + WD_PAR_VSEP_WIDE;

				size->height = max(size->height, panel_height);

				break;

			}

			case WID_EM_FACE: {

				Dimension face_size = GetSpriteSize(SPR_GRADIENT);

				size->width = max(size->width, face_size.width);

				size->height = max(size->height, face_size.height);

				break;

			}

		}