"

 COPYRIGHT (c) 1993 by Claus Gittinger

              All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

ImageReader subclass:#ST80FormReader

         instanceVariableNames:''

         classVariableNames:''

         poolDictionaries:''

         category:'Graphics-Support'

!

ST80FormReader comment:'

COPYRIGHT (c) 1993 by Claus Gittinger

              All Rights Reserved

this class provides methods for loading and saving st80-bitmap-file images.

written Nov 93 by claus

'!

!ST80FormReader methodsFor:'writing to file'!

save:image onFile:aFileName

    "save image as XBM file on aFileName"

    outStream := FileStream newFileNamed:aFileName.

    outStream isNil ifTrue:[

        'create error' printNewline. 

        ^ nil

    ].

    width := image width.

    height := image height.

    photometric := image photometric.

    samplesPerPixel := image samplesPerPixel.

    bitsPerSample := image bitsPerSample.

    colorMap := image colorMap.

    ((samplesPerPixel ~~ 1)

    or:[((bitsPerSample at:1) ~~ 1)

    or:[(photometric ~~ #blackIs0) and:[photometric ~~ #whiteIs0]]]) ifTrue:[

        self error:'can only save Depth1Images'.

        outStream close.

        ^ nil.

    ].

    outStream binary.

    outStream nextPutWord:1.

    outStream nextPutWord:width.

    outStream nextPutWord:height.

    outStream nextPutWord:0.

    outStream nextPutWord:0.

    outStream nextPutBytes:(data size) from:data.

    outStream close

    "ST80FormReader save:(Image fromFile:'bitmaps/SBrowser.xbm') onFile:'test.form'"

! !

!ST80FormReader class methodsFor:'testing'!

isValidImageFile:aFileName

    "return true, if aFileName contains an st80-bitmap-file image"

    inStream := FileStream readonlyFileNamed:aFileName.

    inStream isNil ifTrue:[^ false].

    inStream binary.

    code := inStream nextWord.

    code == 1 ifFalse:[

        inStream close.

        ^ false

    ].

    inStream close.

    ^ true

! !

!ST80FormReader methodsFor:'reading from file'!

fromFile:aFileName

    inStream := FileStream readonlyFileNamed:aFileName.

    inStream isNil ifTrue:[

        'open error' printNewline.

        ^ nil

    ].

    inStream binary.

    code := inStream nextWord.

    code isNil ifTrue:[

        inStream close.

        ^ nil

    ].

    width := inStream nextWord.

    height := inStream nextWord.

    offsetX := inStream nextWord.

    offsetY := inStream nextWord.

    nBytes := width + 15 // 16 * 2 * height.

    data := ByteArray new:nBytes.

    inStream close.

    photometric := #whiteIs0.

    samplesPerPixel := 1.

    bitsPerSample := #(1)

    "ST80FormReader fromFile:''" 

! !