// MSAECoercions.c

//

// Original version by Jon Lansdell and Nigel Humphreys.

// 4.0 and 3.1 updates by Greg Sutton.

// ©Apple Computer Inc 1996, all rights reserved.

/*

    Changes for 4.0

    29-Feb-96 : GS : Added coercion of document to window.

    29-Feb-96 : GS : Changed coercion of window to text to document to text.

*/

#include "MSAECoercions.h"

#include "MSAEUtils.h"

#include "MSAETextUtils.h"

#include "MSAccessors.h"

#include "MSAESelect.h"

#include "MSToken.h"

#pragma segment AppleEvent

// Install coercion handlers that coerce a descriptor from one type to another.

OSErr   InstallCoercions(void)

{

    OSErr   err;

    err = AEInstallCoercionHandler(typeObjectSpecifier, typeMyAppl,      (AECoercionHandlerUPP)NewAECoerceDescProc(CoerceObjToAnything), 0, true, false);

    err = AEInstallCoercionHandler(typeObjectSpecifier, typeMyWndw,      (AECoercionHandlerUPP)NewAECoerceDescProc(CoerceObjToAnything), 0, true, false);

    err = AEInstallCoercionHandler(typeObjectSpecifier, typeMyDocument,  (AECoercionHandlerUPP)NewAECoerceDescProc(CoerceObjToAnything), 0, true, false);

    err = AEInstallCoercionHandler(typeObjectSpecifier, typeMyText,      (AECoercionHandlerUPP)NewAECoerceDescProc(CoerceObjToAnything), 0, true, false);

    err = AEInstallCoercionHandler(typeObjectSpecifier, typeMyTextProp,  (AECoercionHandlerUPP)NewAECoerceDescProc(CoerceObjToAnything), 0, true, false);

    err = AEInstallCoercionHandler(typeObjectSpecifier, typeMyWindowProp,(AECoercionHandlerUPP)NewAECoerceDescProc(CoerceObjToAnything), 0, true, false);

    err = AEInstallCoercionHandler(typeObjectSpecifier, typeMyApplProp,  (AECoercionHandlerUPP)NewAECoerceDescProc(CoerceObjToAnything), 0, true, false);

    err = AEInstallCoercionHandler(typeMyDocument, typeMyWndw,  (AECoercionHandlerUPP)NewAECoercePtrProc(CoerceDocumentToWindow), 0, false, false);

    err = AEInstallCoercionHandler(typeMyDocument, typeMyText,  (AECoercionHandlerUPP)NewAECoerceDescProc(CoerceDocumentToText), 0, true, false);

    err = AEInstallCoercionHandler(typeMyDocumentProp, typeMyText,  (AECoercionHandlerUPP)NewAECoerceDescProc(CoerceDocumentPropertyToText), 0, true, false);

    return(err);

}

// Takes an object specifier that it resolves using AEResolve

// then tries to coerce this result into the type specified by toType.

pascal OSErr    CoerceObjToAnything(const AEDesc    *theAEDesc,

                                    DescType        toType,

                                    long            handlerRefCon,

                                    AEDesc          *result)

{

#ifdef __MWERKS__

    #pragma unused (handlerRefCon)

#endif

    AEDesc  objDesc = {typeNull, NULL};

    OSErr   err;    

    if (theAEDesc->descriptorType != typeObjectSpecifier)

        return(errAEWrongDataType);

        // resolve the object specifier

    err = AEResolve(theAEDesc, kAEIDoMinimum, &objDesc);

    if (noErr != err) goto done;

        // hopefully it's the right type by now, but we'll give it a nudge

    err = AECoerceDesc(&objDesc, toType, result);

done:

    if (objDesc.dataHandle)

        AEDisposeDesc(&objDesc);

    return(err);

}   // CoerceObjToAnything

// A document is effectively a text item that contains all the text in the document

// so allow coercion of documents to text.

pascal OSErr    CoerceDocumentToText(AEDesc *theAEDesc,

                                    DescType        toType,

                                    long            handlerRefCon,

                                    AEDesc          *result)

{

#ifdef __MWERKS__

    #pragma unused (toType, handlerRefCon)

#endif

    return(TextDescFromDocumentDesc(theAEDesc, result));

}

// Some document properties are effectively text so allow a coercion

// e.g. set selection of document 1 to "Something"

pascal OSErr    CoerceDocumentPropertyToText(AEDesc     *theAEDesc,

                                            DescType    toType,

                                            long        handlerRefCon,

                                            AEDesc      *result)

{

#ifdef __MWERKS__

    #pragma unused (toType, handlerRefCon)

#endif

    WindowPropToken     aWindowPropToken;

    TextToken           aTextToken;

    Size                actualSize;

    short               ignore;

    OSErr               err;

    GetRawDataFromDescriptor(theAEDesc, (Ptr)&aWindowPropToken,

                                        sizeof(aWindowPropToken), &actualSize);

    switch (aWindowPropToken.tokenProperty)

    {

        case pText:

        case pContents:

            err = TextDescFromDocumentToken(&(aWindowPropToken.tokenWindowToken), result);

            break;

        case pSelection:

            err = GetWindowSelection(aWindowPropToken.tokenWindowToken.tokenWindow,

                                                                    &aTextToken, &ignore);

            if (noErr != err) goto done;

            err = AECreateDesc(typeMyText, (Ptr)&aTextToken, sizeof(aTextToken), result);

            break;

        default:            // Most properties don't make sense to be coerced from

            err = errAECoercionFail;

    }                       // e.g 'select insertion point before bounds of document 1'

done:   

    return(err);

}

// Many actions are the same whether a window or a document e.g. close

//  so allow a document to be coerced back to a window.

pascal OSErr    CoerceDocumentToWindow( DescType    typeCode,

                                        Ptr         dataPtr,

                                        Size        dataSize,

                                        DescType    toType,

                                        long        handlerRefcon,

                                        AEDesc*     result )

{

#ifdef __MWERKS__

    #pragma unused ( handlerRefcon )

#endif

    OSErr   err;

    if ( typeMyDocument == typeCode && typeMyWndw == toType )

        err = AECreateDesc( typeMyWndw, dataPtr, dataSize, result );

    else

        err = errAEWrongDataType;

    return err;

}