Customize Barcode Text and Captions in Java

This article describes how to work with text placed on barcode images. Aspose.BarCode for Java enables customizing various parameters of barcode text: visibility, font, spacings, text location, and wrapping modes.

If you need any clarifications, feel free to reach out Aspose Technical Support: ask your questions at Aspose.Barcode Forum or contact Aspose Paid Support Helpdesk.

Overview

Aspose.BarCode for Java allows developers to add human-readable text on barcode images in three different forms shown in the scheme below: main text label, top caption, and bottom caption. Any of these elements can be placed optionally or hidden.

Barcode Text Settings

The main barcode text label contains short text information detached from bars by spacings. This text label can take six positions, as explained in the figure below: top center, top left, top right, bottom center, bottom left, or bottom right.

Set Text Visibility

Aspose.BarCode for Java allows developers to visualize or hide barcode text. If there is no need to put human-readable text on a barcode image, barcode images can be generated without text labels, as shown in the example below.

Set Text Positioning

The position of a barcode text label can be modified by customizing two parameters: alignment and location. These parameters can be adjusted through setLocation and setAlignment methods of class CodetextParameters.

Location

The setLocation method allows setting the vertical position of a text label, namely, placing it above or below bars, as shown in the figures below. The default setting is Below.

Text Location	Above Barcode	Below Barcode

Alignment

The setAlignment method is used to set the horizontal position of a text label in a barcode image: right-side, left-side, or center, as illustrated in the figures below. The default setting of barcode text alignment is Center.

Text Alignment	Left	Center	Right

Set Spacing between Bars and Text Label

The default spacing (gap) between bars and a text label is equal to 2pt. It is possible to modify this spacing using the setSpace method of class CodetextParameters. This method is not applicable to several barcode types, including EAN 13, EAN 8, UPC-E, UPC-A, ISMN, ISBN, ISSN, and UpcaGs1DatabarCoupon.

Sample barcode images shown below have been created with various spacing settings (five and forty pixels).

Text Spacing	Is Set to 5 Pixels	Is Set to 40 Pixels

Set Text Font

To manage barcode text font, Aspose.BarCode for Java provides setFont and setFontMode methods of class CodetextParameters. The default font setting is Arial 5pt regular. This setting is ignored if the Auto mode is enabled using the setFontMode method. This method is used to manage font size settings automatically. If it is called passing the Auto value, font size is determined automatically based on xDimension in such a way that the text label should take only one text line. FontMode.AUTO is recommended when AutoSizeMode.NEAREST or AutoSizeMode.INTERPOLATION settings are enabled. Alternatilvely, setting FontMode.MANUAL allows managing font size manually. Other font parameters, including font style, are set similarly in both Auto and Manual modes.

Barcode images shown below have been created with these two font modes.

Font Setting Mode	Auto	Manual

Set NoWrap Mode for Text

It is possible to avoid line breaks in a text that is too long for a single row using the setNoWrap method of class CodetextParameters. When the True setting is enabled, the text label is displayed in a single row regardless of the text length. The default setting is False. Barcode images shown below have been created with different NoWrap settings.

Text Wrapping Mode	Wrap	No Wrap

Replace Barcode Text in 2D Barcodes

To replace barcode text in 2D barcodes with some other text label with improved readability without modifications to the barcode image itself, it is possible to call the setTwoDDisplayText method of class CodetextParameters and pass new text to be placed. This is applicable to selected 2D symbologies, including QR Code, Aztec Code, Data Matrix, MaxiCode, PDF417, and DotCode.

The sample barcode image shown below has been created using the TwoDDisplayText setting.

Barcode Caption Settings

Aspose.BarCode for Java allows developers to place additional text labels in a barcode image in form of captions above and below barcodes. As demonstrated in the figure below, such text captions have a parameter called Padding that allows modifying spacing size between captions and the nearest element (barcodes, main text label, or borders). Both text captions are disabled by default. If required, they can be shown by one or both simultaneously.

Set Caption Visibility

As stated above, additional text captions CaptionAbove and CaptionBelow are disabled by default. When required, top and bottom caption labels can be shown independently from each other or enabled simultaneously. The setVisible method of class CaptionParameters can be used to display one or two captions. Then, caption text can be inserted through the setText method. If required, caption labels can replace main text in 1D barcodes by enabling the former and disabling the latter. The figures given below demonstrate how to caption positioning options.

Caption Visibility	Above	Below

Set Caption Positioning

The setAlignment method of class CaptionParameters allows modifying horizontal positions of caption labels in three directions: right, left, and center. The default position of captions is center. The figures shown below demonstrate barcode images with the top caption label with different alignment positions.

Caption Alignment	Left	Center	Right

Set Caption Padding

The setPadding method of class CaptionParameters can be used to manage spacings for text captions. By default, the spacing value is set to {5pt; 5pt; 0; 5pt} for the top caption and {0; 5pt; 5pt; 5pt} for the bottom one according to the standard Rectangle setting {Top, Left, Bottom, Right}. This method is inapplicable when captions are disabled. Barcode images shown below have been generated with different padding settings.

Caption Padding	Is Set to 5 Pixels	Is Set to 40 Pixels

Set Caption Font

Aspose.BarCode for Java does not enable automatic font size settings based on barcode size. Accordingly, caption font size requires manual setting. For top and bottom captions, various parameters, including font style and size can be set independently. Caption font can be customized through special methods of class FontUnit. The default setting for caption font is Arial 8pt regular. The barcode image shown below explains different caption font settings.

Set NoWrap Mode for Caption

The setNoWrap method of class CaptionParameters allows disabling text line breaks when a text string is too large to fit in one line. When this method is called passing the True value, caption text is always displayed as a single line. Barcode images below show the difference between setNoWrap.TRUE and setNoWrap.FALSE settings.

Caption Wrapping	Is Set to Wrap	Is Set to No Wrap

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