DataFlex Requires Chilkat v11.7.0+

Measure a QR Code without Rendering It

See more QR Code Examples

Demonstrates the measure operation, which does everything generate does except draw the image. It reports the version chosen and the exact size the image would have, which is useful for laying out a page or a label before any image is made. Unlike generate, a code that does not fit the limits is not a failure for measure: the call succeeds, fits is false, and reasons[] says why. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Variant vJson
    Handle hoJson
    Handle hoFmt
    Variant vJsonOut
    Handle hoJsonOut
    String sTemp1
    String sTemp2
    Integer iTemp1
    Integer iTemp2
    Boolean bTemp1

    Move False To iSuccess

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    Get Create (RefClass(cComChilkatJsonObject)) To hoJson
    If (Not(IsComObjectCreated(hoJson))) Begin
        Send CreateComObject of hoJson
    End
    Get ComUpdateString Of hoJson "payload.text" "https://www.chilkatsoft.com/barcode_overview.asp" To iSuccess
    Get ComUpdateInt Of hoJson "render.moduleSize" 8 To iSuccess

    Get Create (RefClass(cComChilkatFormats)) To hoFmt
    If (Not(IsComObjectCreated(hoFmt))) Begin
        Send CreateComObject of hoFmt
    End
    Get Create (RefClass(cComChilkatJsonObject)) To hoJsonOut
    If (Not(IsComObjectCreated(hoJsonOut))) Begin
        Send CreateComObject of hoJsonOut
    End
    Get pvComObject of hoJson to vJson
    Get pvComObject of hoJsonOut to vJsonOut
    Get ComQrCode Of hoFmt "measure" vJson vJsonOut To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoFmt To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComBoolOf Of hoJsonOut "fits" To bTemp1
    Showln "fits: " bTemp1
    Get ComIntOf Of hoJsonOut "symbols[0].selectedEncoding.version" To iTemp1
    Showln "QR version: " iTemp1
    Get ComIntOf Of hoJsonOut "measurements[0].canvasWidth" To iTemp1
    Get ComIntOf Of hoJsonOut "measurements[0].canvasHeight" To iTemp2
    Showln "image would be: " iTemp1 " x " iTemp2 " pixels"
    Get ComIntOf Of hoJsonOut "measurements[0].symbolWidth" To iTemp1
    Get ComIntOf Of hoJsonOut "measurements[0].symbolX" To iTemp2
    Showln "symbol: " iTemp1 " pixels wide at x = " iTemp2

    //  Would it fit in a space 200 pixels wide?
    Get ComUpdateInt Of hoJson "render.maxWidth" 200 To iSuccess
    Get pvComObject of hoJson to vJson
    Get pvComObject of hoJsonOut to vJsonOut
    Get ComQrCode Of hoFmt "measure" vJson vJsonOut To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoFmt To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComBoolOf Of hoJsonOut "fits" To bTemp1
    Showln "within 200 pixels, fits: " bTemp1
    Get ComBoolOf Of hoJsonOut "fits" To bTemp1
    If (bTemp1 = False) Begin
        Get ComStringOf Of hoJsonOut "reasons[0].code" To sTemp1
        Get ComStringOf Of hoJsonOut "reasons[0].message" To sTemp2
        Showln "reason: " sTemp1 " (" sTemp2 ")"
    End

    //  What measure reported, drawn as a diagram.  The measure operation itself makes no image:

    //  

    //  Sample output:

    //  fits: True
    //  QR version: 4
    //  image would be: 328 x 328 pixels
    //  symbol: 264 pixels wide at x = 32
    //  within 200 pixels, fits: False
    //  reason: noFit (exceedsMaxWidth)


End_Procedure