darling-cocotron/Onyx2D/O2PDFPage.m

/* Copyright (c) 2007 Christopher J. W. Lloyd

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */

#import <Onyx2D/O2PDFArray.h>
#import <Onyx2D/O2PDFContentStream.h>
#import <Onyx2D/O2PDFDictionary.h>
#import <Onyx2D/O2PDFDocument.h>
#import <Onyx2D/O2PDFOperatorTable.h>
#import <Onyx2D/O2PDFPage.h>
#import <Onyx2D/O2PDFScanner.h>

@implementation O2PDFPage

- initWithDocument: (O2PDFDocument *) document
        pageNumber: (int) pageNumber
        dictionary: (O2PDFDictionary *) dictionary
{
    _document = [document retain];
    _pageNumber = pageNumber;
    _dictionary = [dictionary retain];
    return self;
}

- (void) dealloc {
    [_document release];
    [_dictionary release];
    [super dealloc];
}

+ (O2PDFPage *) pdfPageWithDocument: (O2PDFDocument *) document
                         pageNumber: (int) pageNumber
                         dictionary: (O2PDFDictionary *) dictionary
{
    return [[[self alloc] initWithDocument: document
                                pageNumber: pageNumber
                                dictionary: dictionary] autorelease];
}

- (O2PDFDocument *) document {
    return _document;
}

- (int) pageNumber {
    return _pageNumber;
}

- (O2PDFDictionary *) dictionary {
    return _dictionary;
}

BOOL O2PDFGetPageObjectForKey(O2PDFPage *page, const char *key,
                              O2PDFObject **object)
{
    O2PDFDictionary *dictionary = [page dictionary];

    do {
        O2PDFObject *check;

        if ([dictionary getObjectForKey: key value: &check]) {
            *object = check;
            return YES;
        }

    } while ([dictionary getDictionaryForKey: "Parent" value: &dictionary]);

    return NO;
}

BOOL O2PDFGetPageArrayForKey(O2PDFPage *page, const char *key,
                             O2PDFArray **arrayp)
{
    O2PDFObject *check;

    if (!O2PDFGetPageObjectForKey(page, key, &check))
        return NO;

    return [check checkForType: kO2PDFObjectTypeArray value: arrayp];
}

- (BOOL) getRect: (O2Rect *) rect forBox: (O2PDFBox) box {
    const char *string = NULL;
    O2PDFArray *array;
    O2PDFReal *numbers;
    NSUInteger count;

    switch (box) {
    case kO2PDFMediaBox:
        string = "MediaBox";
        break;
    case kO2PDFCropBox:
        string = "CropBox";
        break;
    case kO2PDFBleedBox:
        string = "BleedBox";
        break;
    case kO2PDFTrimBox:
        string = "TrimBox";
        break;
    case kO2PDFArtBox:
        string = "ArtBox";
        break;
    }

    if (string == NULL) {
        return NO;
    }
    if (!O2PDFGetPageArrayForKey(self, string, &array)) {
        return NO;
    }

    if (![array getNumbers: &numbers count: &count]) {
        return NO;
    }

    if (count != 4) {
        NSZoneFree(NULL, numbers);
        return NO;
    }

    rect->origin.x = numbers[0];
    rect->origin.y = numbers[1];
    rect->size.width = numbers[2] - numbers[0];
    rect->size.height = numbers[3] - numbers[1];

    NSZoneFree(NULL, numbers);

    return YES;
}

- (int) rotationAngle {
    return 0;
}

O2AffineTransform O2PDFPageGetDrawingTransform(O2PDFPageRef self, O2PDFBox box,
                                               O2Rect rect,
                                               int clockwiseDegrees,
                                               bool preserveAspectRatio)
{

    O2AffineTransform result = O2AffineTransformIdentity;
    O2Rect boxRect, mediaBoxRect;

    if (![self getRect: &boxRect forBox: box]) {
        return result;
    }

    if ([self getRect: &mediaBoxRect forBox: kO2PDFMediaBox]) {
        boxRect = O2RectIntersection(boxRect, mediaBoxRect);
    }

    // TODO: rotation

    O2Float scaleX = rect.size.width / boxRect.size.width;
    O2Float scaleY = rect.size.height / boxRect.size.height;

    if (preserveAspectRatio) {
        if (scaleX < scaleY)
            scaleY = scaleX;
        if (scaleY < scaleX)
            scaleX = scaleY;
    }

    // Move the origin to the center of the target rect.
    result = O2AffineTransformTranslate(result, rect.origin.x, rect.origin.y);
    result = O2AffineTransformTranslate(result, rect.size.width / 2,
                                        rect.size.height / 2);
    // From here on, the task is to render the page scaled & centered at the
    // origin.

    // Apply the scale.
    result = O2AffineTransformScale(result, scaleX, scaleY);
    // From here on, the task is to render the page at the origin, unscaled.

    // ...
    result = O2AffineTransformTranslate(result, -boxRect.origin.x,
                                        -boxRect.origin.y);
    result = O2AffineTransformTranslate(result, -boxRect.size.width / 2,
                                        -boxRect.size.height / 2);

    return result;
}

- (void) drawInContext: (O2Context *) context {
    O2PDFContentStream *contentStream =
            [[[O2PDFContentStream alloc] initWithPage: self] autorelease];
    O2PDFOperatorTable *operatorTable =
            [O2PDFOperatorTable renderingOperatorTable];
    O2PDFScanner *scanner =
            [[[O2PDFScanner alloc] initWithContentStream: contentStream
                                           operatorTable: operatorTable
                                                    info: context] autorelease];

    [scanner scan];
}

@end