From 42b00957181cc0a62c824f9a8940d85b5ad8f5ff Mon Sep 17 00:00:00 2001
From: Matt Woodrow <mwoodrow@mozilla.com>
Date: Thu, 20 Sep 2012 11:26:35 +1200
Subject: [PATCH] Bug 792314 - Build full display lists for
 nsSimplePageSequence. r=roc

---
 layout/generic/nsSimplePageSequence.cpp    | 52 ++++++----------------
 layout/generic/nsSimplePageSequence.h      |  4 --
 layout/reftests/printing/745025-1-ref.html |  2 +-
 3 files changed, 15 insertions(+), 43 deletions(-)

diff --git a/layout/generic/nsSimplePageSequence.cpp b/layout/generic/nsSimplePageSequence.cpp
index 01121fcbcf4d..05490b928464 100644
--- a/layout/generic/nsSimplePageSequence.cpp
+++ b/layout/generic/nsSimplePageSequence.cpp
@@ -815,42 +815,11 @@ nsSimplePageSequenceFrame::DoPageEnd()
   return rv;
 }
 
-static void PaintPageSequence(nsIFrame* aFrame, nsRenderingContext* aCtx,
-                             const nsRect& aDirtyRect, nsPoint aPt)
+static gfx3DMatrix
+ComputePageSequenceTransform(nsIFrame* aFrame, float aAppUnitsPerPixel)
 {
-  static_cast<nsSimplePageSequenceFrame*>(aFrame)->PaintPageSequence(*aCtx, aDirtyRect, aPt);
-}
-
-//------------------------------------------------------------------------------
-void
-nsSimplePageSequenceFrame::PaintPageSequence(nsRenderingContext& aRenderingContext,
-                                             const nsRect&        aDirtyRect,
-                                             nsPoint              aPt) {
-  nsRect rect = aDirtyRect;
-  float scale = PresContext()->GetPrintPreviewScale();
-  aRenderingContext.PushState();
-  nsPoint framePos = aPt;
-  aRenderingContext.Translate(framePos);
-  rect -= framePos;
-  aRenderingContext.Scale(scale, scale);
-  rect.ScaleRoundOut(1.0f / scale);
-
-  // Now the rect and the rendering coordinates are are relative to this frame.
-  // Loop over the pages and paint them.
-  nsIFrame* child = GetFirstPrincipalChild();
-  while (child) {
-    nsPoint pt = child->GetPosition();
-    // The rendering context has to be translated before each call to PaintFrame
-    aRenderingContext.PushState();
-    aRenderingContext.Translate(pt);
-    nsLayoutUtils::PaintFrame(&aRenderingContext, child,
-                              nsRegion(rect - pt), NS_RGBA(0,0,0,0),
-                              nsLayoutUtils::PAINT_SYNC_DECODE_IMAGES);
-    aRenderingContext.PopState();
-    child = child->GetNextSibling();
-  }
-
-  aRenderingContext.PopState();
+  float scale = aFrame->PresContext()->GetPrintPreviewScale();
+  return gfx3DMatrix::ScalingMatrix(scale, scale, 1);
 }
 
 NS_IMETHODIMP
@@ -861,11 +830,18 @@ nsSimplePageSequenceFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
   nsresult rv = DisplayBorderBackgroundOutline(aBuilder, aLists);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  rv = aLists.Content()->AppendNewToTop(new (aBuilder)
-        nsDisplayGeneric(aBuilder, this, ::PaintPageSequence, "PageSequence",
-                         nsDisplayItem::TYPE_PAGE_SEQUENCE));
+  nsDisplayList content;
+  nsIFrame* child = GetFirstPrincipalChild();
+  while (child) {
+    rv = child->BuildDisplayListForStackingContext(aBuilder, aDirtyRect - child->GetOffsetTo(this), &content);
+    NS_ENSURE_SUCCESS(rv, rv);
+    child = child->GetNextSibling();
+  }
+
+  rv = content.AppendNewToTop(new (aBuilder) nsDisplayTransform(aBuilder, this, &content, ::ComputePageSequenceTransform));
   NS_ENSURE_SUCCESS(rv, rv);
 
+  aLists.Content()->AppendToTop(&content);
   return NS_OK;
 }
 
diff --git a/layout/generic/nsSimplePageSequence.h b/layout/generic/nsSimplePageSequence.h
index e5a8ff73ec57..c4474b981351 100644
--- a/layout/generic/nsSimplePageSequence.h
+++ b/layout/generic/nsSimplePageSequence.h
@@ -106,10 +106,6 @@ public:
   NS_IMETHOD  GetFrameName(nsAString& aResult) const;
 #endif
 
-  void PaintPageSequence(nsRenderingContext& aRenderingContext,
-                         const nsRect&        aDirtyRect,
-                         nsPoint              aPt);
-
 protected:
   nsSimplePageSequenceFrame(nsStyleContext* aContext);
   virtual ~nsSimplePageSequenceFrame();
diff --git a/layout/reftests/printing/745025-1-ref.html b/layout/reftests/printing/745025-1-ref.html
index 34b106a966ba..44f0b10dabdf 100644
--- a/layout/reftests/printing/745025-1-ref.html
+++ b/layout/reftests/printing/745025-1-ref.html
@@ -4,6 +4,6 @@
 
 </head>
 <body>
-<!-- A 10x10 red image --><img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAFElEQVQYlWP4z8DwnxjMMKqQvgoBksPHOVp9kXEAAAAASUVORK5CYII=">
+<!-- A 10x10 red image --><img style="-moz-transform: perspective(1px)" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAFElEQVQYlWP4z8DwnxjMMKqQvgoBksPHOVp9kXEAAAAASUVORK5CYII=">
 </body>
 </html>