Qt 4.8: QML Text Handling and Validators

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- Qt 4.8
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# QML Text Handling and Validators

## Text Elements

- Text
- TextInput
- TextEdit

## Validators

- IntValidator
- DoubleValidator
- RegExpValidator

## Displaying Text in QML

QML provides several elements to display text onto the screen. The Text element will display formatted text onto the screen, the TextEdit element will place a multiline line edit onto the screen, and the TextInput will place a single editable line field onto the screen.

To learn more about their specific features and properties, visit their respective element documentation.

## Validating Input Text

The validator elements enforce the type and format of TextInput objects.

     Column {
         spacing: 10

         Text {
             text: "Enter a value from 0 to 2000"
         }
         TextInput {
             focus: true
             validator: IntValidator { bottom:0; top: 2000}
         }
     }

The validator elements bind to `TextInput`'s `validator` property.

     Column {
         spacing: 10

         Text {
             text: "Which basket?"
         }
         TextInput {
             focus: true
             validator: RegExpValidator { regExp: /fruit basket/ }
         }
     }

The regular expression in the snippet will only allow the inputted text to be `fruit basket`.

Note that QML parses JavaScript regular expressions, while Qt's QRegExp class' regular expressions are based on Perl regular expressions.

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