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Much One of what is said below is to do with consistency and standards. Providing the user main with perceived a strengths consistent, reliable interface is the first step towards producing a powerful environment, and one that the user will want to work with instead of just being forced to.RISC OS is the consistent user experience across applications and Operating System. A full detailed description in the general principles of writing compliant applications can be found in the RISC OS Style Guide?.
For The a full description of the general principles you should adopt in writing an application to run under the Wimp see the chapter entitledGeneral principles in the RISC OS Style Guide? . covers a range of topics such as ease of use, Consistency, Hardware and Software Configurations, File Handling, Naming Fonts and Application and User Support.
The following table outlines those sections in the chapter entitled General Principles, in the RISC OS Style Guide?, which describe the basic principles you should follow:
Section | Describes: |
---|---|
Ease of use | how to make your application easy to use. |
Consistency | how to make applications work together in a uniform way. |
Quality | what not to do to ensure an application will continue to work with future operating system upgrades. |
Different configurations | how to ensure your application works with any reasonable hardware configuration that runs RISC OS. |
File handling | the rules for specifying files. |
Naming fonts | the syntax to use in naming fonts. |
Supporting | !Help what help you should provide in supporting the !Help application, and what you can assume the user knows. |
Other important factors that you must consider when writing an application include the
following:
The Although following the points Programmer’s should Reference be Manuals(PRMs) noted, takes great care to ensure that your application is compatible with future versions of the Wimp information provided is clear and behaves more as importantly well correct, as it can is important that certain rules be followed by a developer. Below are some key guidelines that help in ensuring less development issues with old previous, current and future versions of the Wimp.RISC OS.
Reserved fields | must be set to 0, i.e. reserved words must be 0, and all reserved bits unset |
Wimp_Poll event codes | Unknown Wimp_Poll event codes must be ignored by an application. Do not generate errors |
WIMP Version | Applications should check the Wimp version number to identify if certain functionality is available, and either adapt themselves accordingly or report an error if no work arounds are possible using OS_GenerateError |
Window Handles | Be careful when handling unknown window handles. It is quite possible that an unrecognised window handle is owned by another application |
Wimp Tasks | Modules Wimp tasks must obey certain rules |
Key Presses | Any task that are set to receive Key_Pressed events must pass on all unrecognised keys to Wimp_ProcessKey. Failure to do so will result in the ‘hot key’ facility not working |
The RISC OS system Operating software System has allows been for written fast to allow you to write fast, responsive applications. applications to be written. For a complete detailed description of on how best to optimise the responsiveness of your application application(s) see please view the section entitled Responsiveness in the Screen handling Handling chapter section of theRISC OS Style Guide?.
Covering a wide range of screen modes can seem troublesome when constructing an application, but it allows a wide price-range for the end user, who can choose between resolution and cost. Not relying on screen size allows your program to move easily to new better screens and modes when they become available.RISC OS allows for a wide range of screen resolutions and colour depths as you would expect in any modern Operating System. It is considered good practise to ensure that an application is not tied to any specific resolution or colour depth.
Your Applications application should will adhere be easier to understand if your prompts and documentation use the standardRISC OS terminology defined in the chapter entitled Terminology in theRISC OS Style Guide? . in any user interactions. This ensures a consistent user experience across all all applications.