//  PDFImageView.m

//  Copyright (c) 2003, Apple Computer, Inc. All rights reserved.

// See legal notice below.

#import "PDFImageView.h"
#import "DraggableScrollView.h"

@implementation PDFImageView

#pragma mark PRIVATE INSTANCE METHODS

//	pdfRep -- Return the image-representation used for PDFs. This
//	representation can tell us things like the PDF's page count.
- (NSPDFImageRep *) pdfRep
{
    //	Assume our sole representation is the PDF representation.
    return [[[self image] representations] lastObject];
}


#pragma mark PUBLIC INSTANCE METHODS

//	loadFromPath: -- Load the PDF at the specified path into the view.
//	This automatically resizes the view to fit all pages of the document.
- (void) loadFromPath: (NSString *) path
{
    NSPDFImageRep	*pdfRep;
    NSImage			*pdfImage;
    NSRect			frame;

    //	Load the file into an image-representation,
    //	then create an image and add the representation to it.
    pdfRep = [NSPDFImageRep imageRepWithContentsOfFile: path];
    pdfImage = [[[NSImage alloc] init] autorelease];
    [pdfImage addRepresentation: pdfRep];

    //	Figure our frame by getting the bounds, which is really the size
    //	of one page, and multiplying the height by the page count.
    frame = [pdfRep bounds];
    frame.size.height *= [pdfRep pageCount];

    //	Install the image (remember, we're an NSImageView subclass)
    [self setImage: pdfImage];

    //	Set our frame to match the PDF's full height (all pages)
    //	(don't involve our override of -setFrame:, or things won't work right)
    [super setFrame: frame];

    //	Always scroll to show the top of the image
    if ([self isFlipped])
        [self scrollPoint: NSMakePoint (0, 0)];
    else
        [self scrollPoint: NSMakePoint (0, frame.size.height)];
}


#pragma mark PUBLIC INSTANCE METHODS -- NSView OVERRIDES

//	drawRect: -- Display all pages of the PDF document.
- (void) drawRect: (NSRect) rect
{
    NSPDFImageRep	*rep;
    int				pageCount, pageNumber;
    NSRect			onePageBounds;

    //	Apparently, a PDF doesn't always draw its margins, so make them white
    //	by drawing our entire background as white.
    [[NSColor whiteColor] set];
    NSRectFill (rect);

    //	Get the information from the PDF image representation:
    //	how many pages, and how large is each one?
    rep = [self pdfRep];
    pageCount = [rep pageCount];

    //	Iterate through all pages
    for (pageNumber = 0; pageNumber < pageCount; pageNumber++)
    {
        //	Use the printing code (which uses one-based numbering) to find where
        //	this page appears.
        onePageBounds = [self rectForPage: (1+pageNumber)];

        //	Draw this page only if some of its bounds overlap the drawing area
        if (! NSIntersectsRect (rect, onePageBounds))
            continue;

        //	Draw by setting the image representation to the correct page,
        //	then having the image representation draw.
        [rep setCurrentPage: pageNumber];
        [rep drawInRect: onePageBounds];
    }
}

//	mouseDown: -- If we have an enclosing scroll-view which knows how to drag,
//	hand the event off to that scroll-view.
- (void) mouseDown:(NSEvent *) theEvent
{
    NSScrollView	*scrollView;

    scrollView = [self enclosingScrollView];

    if ([scrollView respondsToSelector: @selector(dragDocumentWithMouseDown:)])
        [(DraggableScrollView*)scrollView dragDocumentWithMouseDown: theEvent];
    else
        [super mouseDown: theEvent];
}

//	-setFrameSize: -- Override this method to make sure we keep our aspect ratio.
//	This assumes -setFrameSize: is a primitive method (i.e., -setFrame: invokes it)
- (void) setFrameSize: (NSSize) newSize
{
    NSSize	PDFsize;
    float	correctHeight;

    PDFsize = [[self pdfRep] bounds].size;
    correctHeight = [[self pdfRep] pageCount] * (PDFsize.height/PDFsize.width) * newSize.width;
    correctHeight = ceil (correctHeight); // not sure we need this

    //	If the height's almost right, don't fuss with it.
    if (abs (correctHeight - newSize.height) > 3.0)
        newSize.height = correctHeight;

    [super setFrameSize: newSize];
}


#pragma mark PUBLIC INSTANCE METHODS -- NSView OVERRIDES FOR PRINTING

- (BOOL) knowsPageRange: (NSRangePointer) range
{
    range->location = 1;				// page numbers are one-based
    range->length = [[self pdfRep] pageCount];

    return YES;
}

- (NSRect) rectForPage: (int) pageNumber // INPUT: ONE-based page number
{
    NSPDFImageRep	*rep;
    int				pageCount;
    NSRect			result;

    rep = [self pdfRep];
    pageCount = [rep pageCount];

    //	Start at the first page
    result = [rep bounds];
    if (! [self isFlipped])
        result = NSOffsetRect (result, 0.0, (pageCount-1)*result.size.height);

    //	Move to the N'th page
    if ([self isFlipped])
        result = NSOffsetRect (result, 0.0, (pageNumber-1) * result.size.height);
    else
        result = NSOffsetRect (result, 0.0, - (pageNumber-1) * result.size.height);

    return result;
}

@end



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