Bug 1721265 Part 2 - Send information about CSS page-size values to the print frontend through FinishPrintPreview r=emilio

This adds an optional paper orientation to PrintPreviewResultInfo populates it
from the CSS page size when finishing print preview. The value is then placed
in the PrintPreviewSuccessInfo to be sent to the frontend.

Differential Revision: https://phabricator.services.mozilla.com/D124248

dom/base/nsFrameLoader.cpp

@@ -3355,6 +3355,7 @@ already_AddRefed<Promise> nsFrameLoader::PrintPreview(
   return promise.forget();
 #else
   auto resolve = [promise](PrintPreviewResultInfo aInfo) {
+    using Orientation = dom::PrintPreviewOrientation;
     if (aInfo.sheetCount() > 0) {
       PrintPreviewSuccessInfo info;
       info.mSheetCount = aInfo.sheetCount();
@@ -3362,6 +3363,13 @@ already_AddRefed<Promise> nsFrameLoader::PrintPreview(
       info.mHasSelection = aInfo.hasSelection();
       info.mHasSelfSelection = aInfo.hasSelfSelection();
       info.mIsEmpty = aInfo.isEmpty();
+      if (aInfo.printLandscape()) {
+        info.mOrientation = aInfo.printLandscape().value()
+                                ? Orientation::Landscape
+                                : Orientation::Portrait;
+      } else {
+        MOZ_ASSERT(info.mOrientation == Orientation::Unspecified);
+      }
       promise->MaybeResolve(info);
     } else {
       promise->MaybeRejectWithUnknownError("Print preview failed");

dom/chrome-webidl/FrameLoader.webidl

@@ -203,6 +203,12 @@ interface mixin WebBrowserPersistable
                         nsIWebBrowserPersistDocumentReceiver aRecv);
 };
 
+enum PrintPreviewOrientation {
+    "landscape",
+    "portrait",
+    "unspecified"
+};
+
 /**
  * Interface for the object that's used to resolve the Promise returned from
  * FrameLoader.printPreview() if that method successfully creates the print
@@ -238,6 +244,11 @@ dictionary PrintPreviewSuccessInfo {
    * Whether the previewed document has a selection itself.
    */
   boolean hasSelfSelection = false;
+
+  /**
+   * Specified orientation of the document, or "unspecified".
+   */
+  PrintPreviewOrientation orientation = "unspecified";
 };
 
 FrameLoader includes WebBrowserPersistable;

dom/ipc/BrowserChild.cpp

@@ -2478,8 +2478,8 @@ mozilla::ipc::IPCResult BrowserChild::RecvPrintPreview(
   // went wrong.
   auto sendCallbackError = MakeScopeExit([&] {
     if (aCallback) {
-      aCallback(
-          PrintPreviewResultInfo(0, 0, false, false, false));  // signal error
+      // signal error
+      aCallback(PrintPreviewResultInfo(0, 0, false, false, false, {}));
     }
   });
 

dom/ipc/PBrowser.ipdl

@@ -168,6 +168,9 @@ struct PrintPreviewResultInfo
   bool hasSelection;
   // Whether there's a selection in the previewed page, excluding its subframes.
   bool hasSelfSelection;
+  // If present, indicates if the page should be printed landscape when true or
+  // portrait when false;
+  bool? printLandscape;
 };
 
 /**

layout/printing/nsPrintJob.cpp

@@ -23,6 +23,8 @@
 #include "mozilla/dom/ContentChild.h"
 #include "mozilla/dom/HTMLCanvasElement.h"
 #include "mozilla/dom/ScriptSettings.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/PresShellInlines.h"
 #include "mozilla/StaticPrefs_print.h"
 #include "mozilla/Telemetry.h"
 #include "nsIBrowserChild.h"
@@ -872,8 +874,9 @@ nsresult nsPrintJob::PrintPreview(Document* aSourceDoc,
       CommonPrint(true, aPrintSettings, aWebProgressListener, aSourceDoc);
   if (NS_FAILED(rv)) {
     if (mPrintPreviewCallback) {
+      // signal error
       mPrintPreviewCallback(
-          PrintPreviewResultInfo(0, 0, false, false, false));  // signal error
+          PrintPreviewResultInfo(0, 0, false, false, false, {}));
       mPrintPreviewCallback = nullptr;
     }
   }
@@ -1088,8 +1091,9 @@ nsresult nsPrintJob::CleanupOnFailure(nsresult aResult, bool aIsPrinting) {
 //---------------------------------------------------------------------
 void nsPrintJob::FirePrintingErrorEvent(nsresult aPrintError) {
   if (mPrintPreviewCallback) {
+    // signal error
     mPrintPreviewCallback(
-        PrintPreviewResultInfo(0, 0, false, false, false));  // signal error
+        PrintPreviewResultInfo(0, 0, false, false, false, {}));
     mPrintPreviewCallback = nullptr;
   }
 
@@ -2629,9 +2633,18 @@ nsresult nsPrintJob::FinishPrintPreview() {
   if (mPrintPreviewCallback) {
     const bool hasSelection =
         !mDisallowSelectionPrint && printData->mSelectionRoot;
+    // Determine if there is a specified page size, and if we should set the
+    // paper orientation to match it.
+    const Maybe<bool> maybeLandscape =
+        printData->mPrintObject->mPresShell->StyleSet()
+            ->GetDefaultPageOrientation()
+            .map([](StyleOrientation o) -> bool {
+              return o == StyleOrientation::Landscape;
+            });
     mPrintPreviewCallback(PrintPreviewResultInfo(
         GetPrintPreviewNumSheets(), GetRawNumPages(), GetIsEmpty(),
-        hasSelection, hasSelection && printData->mPrintObject->HasSelection()));
+        hasSelection, hasSelection && printData->mPrintObject->HasSelection(),
+        maybeLandscape));
     mPrintPreviewCallback = nullptr;
   }