/*

 Copyright (C) 2017 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Demonstrates using Quartz for drawing PDF files

 */

import UIKit

class QuartzPDFView: QuartzView {

    let pdfDocument: CGPDFDocument = {

        return CGPDFDocument(Bundle.main.url(forResource: "Quartz", withExtension: "pdf")! as CFURL)!

    }()

    override func drawInContext(_ context: CGContext) {

        // PDF page drawing expects a Lower-Left coordinate system, so we flip the coordinate system

        // before we start drawing.

        context.translateBy(x: 0.0, y: bounds.size.height)

        context.scaleBy(x: 1.0, y: -1.0)

        // Grab the first PDF page

        let page = pdfDocument.page(at: 1)!

        // We're about to modify the context CTM to draw the PDF page where we want it, so save the graphics state in case we want to do more drawing

        context.saveGState()

        // page.getDrawingTransform provides an easy way to get the transform for a PDF page. It will scale down to fit, including any

        // base rotations necessary to display the PDF page correctly.

        let pdfTransform = page.getDrawingTransform(.cropBox, rect: bounds, rotate: 0, preserveAspectRatio: true)

        // And apply the transform.

        context.concatenate(pdfTransform)

        // Finally, we draw the page

        context.drawPDFPage(page)

        // restore the graphics state for further manipulations!

        context.restoreGState()

    }

}