1. Lecture 5(b), Slide 1 CP2030 Copyright © University of Wolverhampton CP2030 Visual Basic for C++ Programmers v Component 5(b) HCI aspects of VB programming Choice of control Careful design of interfaces Giving a “Windows” feel to applications

2. Lecture 5(b), Slide 2 CP2030 Copyright © University of Wolverhampton Aims & Objectives v Be able to select appropriate controls v Understand basic form design guidelines v Appreciate need to design interface with user in mind

3. Lecture 5(b), Slide 3 CP2030 Copyright © University of Wolverhampton Appropriate controls Label v Text box v Label – displays information that user cannot change – use for headings, text box labels etc – use for displaying information v Text box – display text entered at design time – display text assigned at run time – data entry area – N.B. Can “disable” Text box - read only

4. Lecture 5(b), Slide 4 CP2030 Copyright © University of Wolverhampton List box v Combo box v List box – List of “optional” values – Select one (or more) from list v Combo Box – combination of Text & List boxes – Can select (as List box) – Can enter new value (as Text box)

5. Lecture 5(b), Slide 5 CP2030 Copyright © University of Wolverhampton List/Combo Box v Scroll Bar & Text box v Scroll bars – horizontal or vertical – analogue representation of value in a range – used for input and output – can be used with Text box to select/display data from an array – program needs to maintain link between scroll bar & data v List/Combo boxes – have built-in scroll bars if needed – automatic link to data elements

6. Lecture 5(b), Slide 6 CP2030 Copyright © University of Wolverhampton Option (Radio) button v Check box v Normally grouped within “Frames” v Option button – Only one option selected from group – Other options in group are “deselected” v Check Box – Each option is separate from others – May select as many as wish

7. Lecture 5(b), Slide 7 CP2030 Copyright © University of Wolverhampton Command buttons v Menus v Command buttons – Obvious, clear features on form – Cover the normal operations v Menus – Less clear - often group functionality – Cover less common operations – May duplicate Command buttons

8. Lecture 5(b), Slide 8 CP2030 Copyright © University of Wolverhampton Design considerations v Schneiderman – Consistency u sequence of operations u layout – Shortcuts through familiar areas – Informative feedback – Arrange into logical groups – Simple error handling – Possible to “undo” operations – Reduce short-term memory load – Let user feel that they are in control

9. Lecture 5(b), Slide 9 CP2030 Copyright © University of Wolverhampton Use of colour v Use sparingly!! – design Form in black and White – use colour to make things stand out – use 4 colours maximum v Don’t use colour to carry information – colours mean different things to different people

10. Lecture 5(b), Slide 10 CP2030 Copyright © University of Wolverhampton Use of Colour v Ensure good contrast between foreground and background v Colour blindness – affects 10% of adults

11. Lecture 5(b), Slide 11 CP2030 Copyright © University of Wolverhampton Layout of the Form v Not too much on a Form – Split, logically, over several Forms – hide/reveal controls v Information in centre of visual field is most likely to be seen. – Put important info in obvious positions

12. Lecture 5(b), Slide 12 CP2030 Copyright © University of Wolverhampton Layout of the Form v Arrange controls in a logical sequence – especially for data entry – work from left - right, top-bottom – consistency of layout over Forms u e.g. “exit” button in same position on all Forms v Arrange order using “Tab-key” v Set Focus after major operation – e.g. after pressing a Command button when loading/returning to a Form – clear text boxes on data entry forms?

13. Lecture 5(b), Slide 13 CP2030 Copyright © University of Wolverhampton Summary of Component 5(b) v Choose appropriate controls for VB applications v Understand design considerations