1 files changed, 87 insertions, 0 deletions
diff --git a/widget/nsPaper.cpp b/widget/nsPaper.cpp
new file mode 100644
index 0000000000..a940d3c1cb
--- /dev/null
+++ b/widget/nsPaper.cpp
@@ -0,0 +1,87 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsPaper.h"
+#include "nsPaperMargin.h"
+#include "nsPrinterBase.h"
+#include "mozilla/ErrorResult.h"
+#include "mozilla/dom/Promise.h"
+
+using mozilla::ErrorResult;
+using mozilla::PaperInfo;
+
+NS_IMPL_CYCLE_COLLECTION(nsPaper, mMarginPromise, mPrinter)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsPaper)
+  NS_INTERFACE_MAP_ENTRY(nsIPaper)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIPaper)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsPaper)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsPaper)
+
+nsPaper::nsPaper(const mozilla::PaperInfo& aInfo)
+    : mPrinter(nullptr), mInfo(aInfo) {}
+
+nsPaper::nsPaper(nsPrinterBase& aPrinter, const mozilla::PaperInfo& aInfo)
+    : mPrinter(&aPrinter), mInfo(aInfo) {}
+
+nsPaper::~nsPaper() = default;
+
+NS_IMETHODIMP
+nsPaper::GetId(nsAString& aId) {
+  aId = mInfo.mId;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPaper::GetName(nsAString& aName) {
+  aName = mInfo.mName.IsEmpty() ? mInfo.mId : mInfo.mName;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPaper::GetWidth(double* aWidth) {
+  NS_ENSURE_ARG_POINTER(aWidth);
+  *aWidth = mInfo.mSize.Width();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPaper::GetHeight(double* aHeight) {
+  NS_ENSURE_ARG_POINTER(aHeight);
+  *aHeight = mInfo.mSize.Height();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPaper::GetUnwriteableMargin(JSContext* aCx, Promise** aPromise) {
+  if (RefPtr<Promise> existing = mMarginPromise) {
+    existing.forget(aPromise);
+    return NS_OK;
+  }
+  ErrorResult rv;
+  RefPtr<Promise> promise = Promise::Create(xpc::CurrentNativeGlobal(aCx), rv);
+  if (MOZ_UNLIKELY(rv.Failed())) {
+    return rv.StealNSResult();
+  }
+
+  mMarginPromise = promise;
+
+  if (mInfo.mUnwriteableMargin) {
+    auto margin = mozilla::MakeRefPtr<nsPaperMargin>(*mInfo.mUnwriteableMargin);
+    mMarginPromise->MaybeResolve(margin);
+  } else {
+    if (mPrinter) {
+      mPrinter->QueryMarginsForPaper(*mMarginPromise, mInfo.mId);
+    } else {
+      MOZ_ASSERT_UNREACHABLE("common paper sizes should know their margins");
+      mMarginPromise->MaybeRejectWithNotSupportedError("Margins unavailable");
+    }
+  }
+
+  promise.forget(aPromise);
+  return NS_OK;
+}