Làm thế nào nhiều bài nhạc bạn sẽ có? Xác định từng yếu tố mà bạn nghĩ rằng sẽ được Oe DVD BD. Có một tiêu đề đơn giản với chỉ một theo dõi video và trình chiếu? Hoặc, nó là một Sử dụng mũi tên trái và phải để điều hướng thông qua các hình ảnh | 58 DAVID ENGLAND AND MIN DU informal descriptions in PUAN. PUAN borrows the table format of UAN for part of its representation. The tables have three columns for user actions system feedback and system or agent state. PUAN like UAN tries to be neutral about the cognitive state of the user s and the application logic of the system. These separate concerns are dealt with in the task or user object modelling phase and the systems development phases respectively. This separation of concerns allows the designer to concentrate on human-computer interaction issues. In the tables there is a partial ordering of events from left-to-right and top-to-bottom. Additionally with PUAN we can add temporal constraints to further specify the temporal behaviour of the interface. In the following descriptions we can parameterise the device-independent patterns in order to adapt them to the temporal context of use of a specific platform. Thus we can re-use platform-independent interaction patterns across a range of platforms. However we still need to assess the validity of the derived pattern. We can do this by inspecting the parameterised pattern and by executing the pattern and evaluating the resulting user interface. . ACTION SELECTION PATTERN We first describe our platform-independent patterns. These are rather simple but will prove useful when we come to our high-level patterns. Firstly we have our display driver pattern that models the interaction between the display device and the input device. This is the base pattern that supports all user input face component selection operations . buttons menu items or text insertion points . Here we are modelling the low level Fitts Law and the control display ratio for inclusion in higher-level patterns. Our Action Selection Pattern Table describes the simple steps of moving an input device getting feedback from the display and acquiring a displayed object Here x and y are input control coordinates and sx and sy are the initial
