Files
iccery-v2-mac/Sources/ICCery/Print/TargetPageCanvasView.swift
gronod a2f994821f
macOS CI / build-and-test (push) Skipped
feat(print): 1:1 TIFF raster loader and headless page canvas (#201 Phase 3)
TargetRasterLoader decodes printtarg TIFFs via ImageIO and re-tags
into DeviceGray/DeviceRGB/DeviceCMYK around the decoder's own
dataProvider — no resample, no bit-depth change (D10). Skip-only
alpha padding (noneSkipLast/First, which ImageIO emits for opaque
RGB TIFFs) is accepted; real coverage alpha, indexed, float and
non-1/3/4-component layouts are rejected as unsupportedLayout.
DPI metadata drives pointSize (px/dpi*72) with a 72 dpi fallback +
warn; manifestDrift reports >0.5 mm disagreement with the printtarg
manifest (D9).

TargetPageCanvasView is the headless flipped canvas NSPrintOperation
paginates: rectForPage stacks pages top-down, destinationRect anchors
1:1 at the page's top-left snapped to 0.001 pt, and draw() forces
interpolation/antialias/font-smoothing off per page with a drawProbe
seam for tests.

PDF harness (NativeSpoolPDFTests, skippable via ICCERY_SKIP_PRINT_PDF=1)
ran on this host: run() -> true, 2 pages at A4 media box, and the
fixture's 72 pt patch verified 1:1 at the painted top-left (printer
unprintable-margin offset tolerated per R10).
2026-09-17 14:57:24 +01:00

87 lines
3.1 KiB
Swift

import AppKit
/// Headless print canvas (#201, docs/14 §6). Never installed in a
/// window; `NSPrintOperation` is its only client.
@MainActor
final class TargetPageCanvasView: NSView {
private let pages: [TargetPageRaster]
private let paperSize: NSSize
/// Test probe — invoked once per drawn page with the live context
/// so the interpolation/antialias contract is assertable without a
/// printer.
var drawProbe: ((NSGraphicsContext, Int, NSRect) -> Void)?
init(pages: [TargetPageRaster], paperSize: NSSize) {
self.pages = pages
self.paperSize = paperSize
super.init(frame: NSRect(
x: 0, y: 0,
width: paperSize.width,
height: paperSize.height * CGFloat(pages.count)))
}
@available(*, unavailable)
required init?(coder: NSCoder) {
fatalError("TargetPageCanvasView is code-only")
}
/// Flipped: the CoreGraphics coordinate space is correctly oriented
/// top-down, so page 1 is the TOP rect.
override var isFlipped: Bool { true }
override var isOpaque: Bool { true }
override func knowsPageRange(_ range: NSRangePointer) -> Bool {
range.pointee = NSRange(location: 1, length: pages.count)
return true
}
/// 1-based page → its paper-sized rect, stacked top-down.
override func rectForPage(_ page: Int) -> NSRect {
NSRect(x: 0,
y: CGFloat(page - 1) * paperSize.height,
width: paperSize.width,
height: paperSize.height)
}
/// Where page `page`'s image lands: top-left anchored inside
/// `rectForPage`, sized `raster.pointSize`, origin snapped to
/// 0.001 pt (docs/14 §6) so a fractional origin cannot trigger
/// device resampling. `internal` for unit tests.
func destinationRect(forPage page: Int) -> NSRect {
let pageRect = rectForPage(page)
let size = pages[page - 1].pointSize
return NSRect(x: Self.snap(pageRect.minX),
y: Self.snap(pageRect.minY),
width: size.width,
height: size.height)
}
override func draw(_ dirtyRect: NSRect) {
guard let ctx = NSGraphicsContext.current else { return }
ctx.imageInterpolation = .none
ctx.shouldAntialias = false
let cg = ctx.cgContext
cg.interpolationQuality = .none
cg.setShouldAntialias(false)
cg.setAllowsAntialiasing(false)
cg.setShouldSmoothFonts(false)
for index in pages.indices {
let pageRect = rectForPage(index + 1)
guard pageRect.intersects(dirtyRect) else { continue }
cg.saveGState() // page N never inherits N-1's CTM
NSColor.white.setFill()
pageRect.fill()
cg.draw(pages[index].cgImage,
in: destinationRect(forPage: index + 1))
cg.restoreGState()
drawProbe?(ctx, index + 1, destinationRect(forPage: index + 1))
}
}
private static func snap(_ value: CGFloat) -> CGFloat {
(value * 1000).rounded() / 1000
}
}