Input integer number

Overview

IntInput is a Turbo Vision module that provides a custom input field for integer values with specified ranges. It extends the standard input line component to validate and handle integer input, ensuring the values fall within defined intervals.

Components

Types

• Interval: An enumerated type representing the range intervals:
  • a_b: [min, max]
  • a_inf: [min, ∞)
  • inf_b: (-∞, max]
  • inf_inf: (-∞, ∞)

TInputInt Object

• Fields:

  • min: The minimum value of the range.
  • max: The maximum value of the range.
  • int: The type of interval.

• Constructor:

  • Init(R: TRect; i: integer; mina, maxa: longint): Initializes the input line with specified rectangle R, max length i, minimum value mina, and maximum value maxa.

• Methods:

  • DataSize: word: Returns the size of the data.
  • GetData(var Rec): Retrieves the integer data from the input field.
  • SetData(var Rec): Sets the input field with the provided integer data.
  • Valid(com: word): boolean: Validates the input data against the defined range.

Example Application: IntegerInput

The IntegerInput program demonstrates the usage of the TInputInt object. It presents a dialog to the user for entering an integer within the specified range of -100 to 100.

TMyApp Object

• Methods:
  • Run: Executes the main functionality by showing the integer input dialog.
  • HandleEvent(var Event: TEvent): Handles application events, triggering the integer input dialog on a new command.
  • ShowDateDialog: Displays the dialog for entering an integer.

Main Program

• Initializes and runs an instance of TMyApp, showing the dialog for integer input and validating the input against the specified range.

Usage

1. Integration:

   • Include IntInput in your uses clause.
   • Create an instance of TInputInt and initialize it with the desired range.
   • Use GetData and SetData to interact with the input value.
   • Ensure Valid is called to validate the input.

2. Example:

   • The provided example in IntegerInput shows a dialog for inputting an integer within the range of -100 to 100.

Error Handling

• Displays error messages for invalid inputs, such as non-integer values or values outside the specified range, using message boxes.

Dependencies

• The module depends on standard Pascal units such as Objects, Views, Dialogs, and MsgBox.