1 files changed, 87 insertions, 0 deletions
diff --git a/widget/nsIDeviceContextSpec.cpp b/widget/nsIDeviceContextSpec.cpp
new file mode 100644
index 0000000000..5ab442415d
--- /dev/null
+++ b/widget/nsIDeviceContextSpec.cpp
@@ -0,0 +1,87 @@
+/* -*- Mode: C++; tab-width: 2; 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 "nsIDeviceContextSpec.h"
+
+#include "gfxPoint.h"
+#include "mozilla/gfx/PrintPromise.h"
+#include "nsError.h"
+#include "nsIPrintSettings.h"
+
+#include "mozilla/Components.h"
+#include "mozilla/TaskQueue.h"
+
+using mozilla::MakeRefPtr;
+using mozilla::gfx::PrintEndDocumentPromise;
+
+// We have some platform specific code here rather than in the appropriate
+// nsIDeviceContextSpec subclass. We structure the code this way so that
+// nsIDeviceContextSpecProxy gets the correct behavior without us having to
+// instantiate a platform specific nsIDeviceContextSpec subclass in content
+// processes. That is necessary for sandboxing.
+
+float nsIDeviceContextSpec::GetPrintingScale() {
+#ifdef XP_WIN
+  if (mPrintSettings->GetOutputFormat() != nsIPrintSettings::kOutputFormatPDF
+#  ifdef MOZ_ENABLE_SKIA_PDF
+      && !mPrintViaSkPDF
+#  endif
+  ) {
+    // The print settings will have the resolution stored from the real device.
+    int32_t resolution;
+    mPrintSettings->GetResolution(&resolution);
+    return float(resolution) / GetDPI();
+  }
+#endif
+
+  return 72.0f / GetDPI();
+}
+
+gfxPoint nsIDeviceContextSpec::GetPrintingTranslate() {
+#ifdef XP_WIN
+  // The underlying surface on windows is the size of the printable region. When
+  // the region is smaller than the actual paper size the (0, 0) coordinate
+  // refers top-left of that unwritable region. To instead have (0, 0) become
+  // the top-left of the actual paper, translate it's coordinate system by the
+  // unprintable region's width.
+  double marginTop, marginLeft;
+  mPrintSettings->GetUnwriteableMarginTop(&marginTop);
+  mPrintSettings->GetUnwriteableMarginLeft(&marginLeft);
+  int32_t resolution;
+  mPrintSettings->GetResolution(&resolution);
+  return gfxPoint(-marginLeft * resolution, -marginTop * resolution);
+#else
+  return gfxPoint(0, 0);
+#endif
+}
+
+RefPtr<PrintEndDocumentPromise>
+nsIDeviceContextSpec::EndDocumentPromiseFromResult(nsresult aResult,
+                                                   const char* aSite) {
+  return NS_SUCCEEDED(aResult)
+             ? PrintEndDocumentPromise::CreateAndResolve(true, aSite)
+             : PrintEndDocumentPromise::CreateAndReject(aResult, aSite);
+}
+
+RefPtr<PrintEndDocumentPromise> nsIDeviceContextSpec::EndDocumentAsync(
+    const char* aCallSite, AsyncEndDocumentFunction aFunction) {
+  auto promise =
+      MakeRefPtr<PrintEndDocumentPromise::Private>("PrintEndDocumentPromise");
+
+  NS_DispatchBackgroundTask(
+      NS_NewRunnableFunction(
+          "EndDocumentAsync",
+          [promise, function = std::move(aFunction)]() mutable {
+            const auto result = function();
+            if (NS_SUCCEEDED(result)) {
+              promise->Resolve(true, __func__);
+            } else {
+              promise->Reject(result, __func__);
+            }
+          }),
+      NS_DISPATCH_EVENT_MAY_BLOCK);
+
+  return promise;
+}