► |  | How to Design Programs Teachpacks

1 | Ht DP Teachpacks
2 | Ht DP/ 2e Teachpacks

▼ | 1 | Ht DP Teachpacks

1.1 | Manipulating Images: "image.rkt"
1.2 | Simulations and Animations: "world.rkt"
1.3 | Converting Temperatures: "convert.rkt"
1.4 | Guessing Numbers: "guess.rkt"
1.5 | Master Minding: "master.rkt"
1.6 | Playing Master Mind: "master-play.rkt"
1.7 | Simple Drawing: "draw.rkt"
1.8 | Hangman: "hangman.rkt"
1.9 | Playing Hangman: "hangman-play.rkt"
1.10 | Managing Control Arrows: "arrow.rkt"
1.11 | Manipulating Simple HTML Documents: "docs.rkt"
1.12 | Working with Files and Directories: "dir.rkt"
1.13 | Graphing Functions: "graphing.rkt"
1.14 | Simple Graphical User Interfaces: "gui.rkt"
1.15 | An Arrow GUI: "arrow-gui.rkt"
1.16 | Controlling an Elevator: "elevator.rkt"
1.17 | Lookup GUI: "lkup-gui.rkt"
1.18 | Guess GUI: "guess-gui.rkt"
1.19 | Queens: "show-queen.rkt"
1.20 | Matrix Functions: "matrix.rkt"

On this page:

control
view
connect

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#### 1.17`` Lookup GUI: "lkup-gui.rkt"

(require htdp/lkup-gui) | package: htdp-lib

The teachpack provides three functions:

> procedure (control index) → symbol?
> index : natural-number?

reads out the indexth guess choice, starting with 0

> procedure (view msg) → true/c
> msg : (or/c string? symbol?)

displays its msg argument in the message panel

> procedure (connect event-handler) → true/c
> event-handler : (-> button% event% true/c)

connects a controller (handler) with the Check button displays frame

Example:

> (connect
> (lambda (e b)
> (view (control))))

This example simply mirrors what the user types in to the message field.
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