Common use of PROGRESS BAR Clause in Contracts

PROGRESS BAR. The progress bar (CW_PROGRESS_BAR) is a central element along with the user interaction. It gives the user feedback about a started process and also gives him an idea of how much time the operation will take. Figure 10 shows a screenshot of the progress dialog. The wizard uses the progress dialog when it: • parses the .NET assembly • reads the XML file containing the proxy classes’ representation • backs up the files in the project directory • generates the Eiffel proxy classes, the Ace and XML files • checks the syntax of the generated Eiffel files • compiles the classes to a new .NET assembly • does finish freezing • restores files from the project directory Every class that wants to indicate a progress inherits from the class CW_GUI_SUPPORT that provides an access point to the progress dialog called Progress_dialog. In order that every class accesses the same instance of the dialog, Progress_dialog is a once feature. A once feature executes its body only the first time it is called in a system execution. The result obtained by the first call is applicable to all instances of a class.