16.6 Design implement and test the subsystem for purchase order processing described in section 16.5.4 Assume that there are three levels of approval authorities: project manager, Engineering director, and cooperate finance. They can approve each purchase within $10,000, $100,000 and $ 1 million and not to exceed a total of $100,000, $ 1 million, and $ 10 million per year respectively.

Edit Diagram Controller stateBtnClicked(e:ActionEvent) transBtnClicked(e: ActionEvent) controller Cond moral Staderterts FIGURE 16.32 Applying adapter pattern 16.5.4 Providing Context-Dependent Help latex A user interface should be user friendly. For example, it should context-dependent help. That is, help information about the specific provided. For example, if the user wants to know what he should enter into the Condition text box in Figure 16.3. He should be able to right-click in to invoke a pop-up menu and select Help to view the help information. help capability is called context-dependent help. Usually, context-dependent helb i arranged from the more specific help to the more general h is n et widget should be the text box This type of elp. For example, if there o help information about the State Condition text box, then the system shoul s display the help information about the Edit State Dialog, which contains the text box If the dialog does not have help information either, then the help information about er the State Diagram Editor should be displayed. The state diagram editor may use help request handlers or helpers to provid context-dependent help. The idea is to relate each GUI widget with a helper so that the helper is called to provide the help information when it is requested. The helper are linked to each other forming a chain of helpers. If a helper does not have hel information, then it calls the next helper to provide help. This continues until a helper with help information is found, or the chain of helpers is exhausted. If the chains exhausted, then the last helper shows a "no help information" message. ithe t of the chain of responsibility pattern. The design problem solved by the pattem does one handle requests without knowing in advance the exact handler is how solution Edit Diagram Controller stateBtnClicked(e:ActionEvent) transBtnClicked(e: ActionEvent) controller Cond moral Staderterts FIGURE 16.32 Applying adapter pattern 16.5.4 Providing Context-Dependent Help latex A user interface should be user friendly. For example, it should context-dependent help. That is, help information about the specific provided. For example, if the user wants to know what he should enter into the Condition text box in Figure 16.3. He should be able to right-click in to invoke a pop-up menu and select Help to view the help information. help capability is called context-dependent help. Usually, context-dependent helb i arranged from the more specific help to the more general h is n et widget should be the text box This type of elp. For example, if there o help information about the State Condition text box, then the system shoul s display the help information about the Edit State Dialog, which contains the text box If the dialog does not have help information either, then the help information about er the State Diagram Editor should be displayed. The state diagram editor may use help request handlers or helpers to provid context-dependent help. The idea is to relate each GUI widget with a helper so that the helper is called to provide the help information when it is requested. The helper are linked to each other forming a chain of helpers. If a helper does not have hel information, then it calls the next helper to provide help. This continues until a helper with help information is found, or the chain of helpers is exhausted. If the chains exhausted, then the last helper shows a "no help information" message. ithe t of the chain of responsibility pattern. The design problem solved by the pattem does one handle requests without knowing in advance the exact handler is how solution