In the same vein, if the imagery of an existing icon is changed (e.g. the application creates a reduced version of the project for use as the icon imagery) the icon should be saved without a specific position. To make the common operation of starting up programs more powerful, the Amiga provides ways of passing along more specific information to the application. This process of providing additional information to a program that's about to run is known as argument passing. When using the Shell, the system is straightforward. The user runs an application by typing its name along with additional information such as the name of a file to operate on and any command options. The entire command line is then passed to the program as an argument. The Workbench also provides means of passing arguments - but it is tied to icons instead of lines of type.Īpplications started from Workbench receive startup information from the system in the form of a WBStartup message. If you click once on any tool icon and choose "Information." from the Workbench's Icon menu, you should see a requester with a field for Tool Types.Īn Information requester for a project icon Altering Icons The WBStartup message can be used to get various Workbench arguments including those found in the Tool Types and Default Tool fields of the icon the user clicked on. If your application needs to alter an icon for some reason, change only the things you intend to change and preserve the rest. If your application needs to change the Tool Types field, for instance, leave the imagery, position and Default Tool field alone.
More important, change only the Tool Types entries relevant to your application - do not rewrite Tool Types from scratch for an existing project. If the icon has a Tool Types entry that your application does not recognize, that entry should be preserved. You should support project-specific Tool Types arguments.
0 kommentar(er)
