Bug 585817. Part 2: Change nsIPresShell::CreateRenderingContext to GetReferenceRenderingContext, that uses the shared 1x1 surface, and use it all over the place. r=mats,sr=dbaron

accessible/src/msaa/nsTextAccessibleWrap.cpp

@@ -259,8 +259,7 @@ __try {
     return E_FAIL;
   }
 
-  nsCOMPtr<nsIRenderingContext> rc;
-  presShell->CreateRenderingContext(frame, getter_AddRefs(rc));
+  nsCOMPtr<nsIRenderingContext> rc = presShell->GetReferenceRenderingContext();
   if (!rc) {
     return E_FAIL;
   }

layout/base/nsDocumentViewer.cpp

@@ -3264,8 +3264,8 @@ NS_IMETHODIMP DocumentViewerImpl::SizeToContent()
 
   nscoord prefWidth;
   {
-    nsCOMPtr<nsIRenderingContext> rcx;
-    presShell->CreateRenderingContext(root, getter_AddRefs(rcx));
+    nsCOMPtr<nsIRenderingContext> rcx =
+      presShell->GetReferenceRenderingContext();
     NS_ENSURE_TRUE(rcx, NS_ERROR_FAILURE);
     prefWidth = root->GetPrefWidth(rcx);
   }

layout/base/nsIPresShell.h

@@ -139,8 +139,8 @@ typedef struct CapturingContentInfo {
 } CapturingContentInfo;
 
 #define NS_IPRESSHELL_IID     \
-  { 0xe82aae32, 0x2d68, 0x452a, \
-    { 0x88, 0x95, 0x86, 0xc6, 0x07, 0xe1, 0xec, 0x91 } }
+  { 0xe63a350c, 0x4e04, 0x4056, \
+    { 0x8d, 0xa0, 0x51, 0xcc, 0x55, 0x68, 0x68, 0x42 } }
 
 // Constants for ScrollContentIntoView() function
 #define NS_PRESSHELL_SCROLL_TOP      0
@@ -479,11 +479,11 @@ public:
   virtual NS_HIDDEN_(void) ClearFrameRefs(nsIFrame* aFrame) = 0;
 
   /**
-   * Given a frame, create a rendering context suitable for use with
-   * the frame.
+   * Get a reference rendering context. This is a context that should not
+   * be rendered to, but is suitable for measuring text and performing
+   * other non-rendering operations.
    */
-  virtual NS_HIDDEN_(nsresult) CreateRenderingContext(nsIFrame *aFrame,
-                                                      nsIRenderingContext** aContext) = 0;
+  virtual already_AddRefed<nsIRenderingContext> GetReferenceRenderingContext() = 0;
 
   /**
    * Informs the pres shell that the document is now at the anchor with

layout/base/nsPresShell.cpp

@@ -753,8 +753,7 @@ public:
   virtual NS_HIDDEN_(void) CancelReflowCallback(nsIReflowCallback* aCallback);
 
   virtual NS_HIDDEN_(void) ClearFrameRefs(nsIFrame* aFrame);
-  virtual NS_HIDDEN_(nsresult) CreateRenderingContext(nsIFrame *aFrame,
-                                                      nsIRenderingContext** aContext);
+  virtual NS_HIDDEN_(already_AddRefed<nsIRenderingContext>) GetReferenceRenderingContext();
   virtual NS_HIDDEN_(nsresult) GoToAnchor(const nsAString& aAnchorName, PRBool aScroll);
   virtual NS_HIDDEN_(nsresult) ScrollToAnchor();
 
@@ -3675,51 +3674,22 @@ PresShell::ClearFrameRefs(nsIFrame* aFrame)
   }
 }
 
-nsresult
-PresShell::CreateRenderingContext(nsIFrame *aFrame,
-                                  nsIRenderingContext** aResult)
+already_AddRefed<nsIRenderingContext>
+PresShell::GetReferenceRenderingContext()
 {
   NS_TIME_FUNCTION_MIN(1.0);
 
-  NS_PRECONDITION(nsnull != aResult, "null ptr");
-  if (nsnull == aResult) {
-    return NS_ERROR_NULL_POINTER;
-  }
-
-  nsIWidget* widget = nsnull;
-  nsPoint offset(0,0);
+  nsIDeviceContext* devCtx = mPresContext->DeviceContext();
+  nsRefPtr<nsIRenderingContext> rc;
   if (mPresContext->IsScreen()) {
-    // Get the widget to create the rendering context for and calculate
-    // the offset from the frame to it.
-    nsPoint viewOffset;
-    nsIView* view = aFrame->GetClosestView(&viewOffset);
-    nsPoint widgetOffset;
-    widget = view->GetNearestWidget(&widgetOffset);
-    offset = viewOffset + widgetOffset;
+    devCtx->CreateRenderingContextInstance(*getter_AddRefs(rc));
+    if (rc) {
+      rc->Init(devCtx, gfxPlatform::GetPlatform()->ScreenReferenceSurface());
+    }
   } else {
-    nsIFrame* pageFrame = nsLayoutUtils::GetPageFrame(aFrame);
-    // This might not always come up with a frame, i.e. during reflow;
-    // that's fine, because the translation doesn't matter during reflow.
-    if (pageFrame)
-      offset = aFrame->GetOffsetTo(pageFrame);
+    devCtx->CreateRenderingContext(*getter_AddRefs(rc));
   }
-
-  nsresult rv;
-  nsIRenderingContext* result = nsnull;
-  nsIDeviceContext *deviceContext = mPresContext->DeviceContext();
-  if (widget) {
-    rv = deviceContext->CreateRenderingContext(widget, result);
-  }
-  else {
-    rv = deviceContext->CreateRenderingContext(result);
-  }
-  *aResult = result;
-
-  if (NS_SUCCEEDED(rv)) {
-    result->Translate(offset.x, offset.y);
-  }
-
-  return rv;
+  return rc.forget();
 }
 
 nsresult
@@ -7518,11 +7488,8 @@ PresShell::DoReflow(nsIFrame* target, PRBool aInterruptible)
 
   nsIFrame* rootFrame = FrameManager()->GetRootFrame();
 
-  nsCOMPtr<nsIRenderingContext> rcx;
-  // Always create the rendering context relative to the root frame during
-  // reflow; otherwise, it crashes on the mac (I'm not quite sure why)
-  nsresult rv = CreateRenderingContext(rootFrame, getter_AddRefs(rcx));
-  if (NS_FAILED(rv)) {
+  nsCOMPtr<nsIRenderingContext> rcx = GetReferenceRenderingContext();
+  if (!rcx) {
     NS_NOTREACHED("CreateRenderingContext failure");
     return PR_FALSE;
   }

layout/generic/nsSimplePageSequence.cpp

@@ -607,9 +607,8 @@ nsSimplePageSequenceFrame::PrintNextPage()
       PR_PL(("SeqFr::PrintNextPage -> %p PageNo: %d", pf, mPageNum));
 
       nsCOMPtr<nsIRenderingContext> renderingContext;
-      PresContext()->PresShell()->
-              CreateRenderingContext(mCurrentPageFrame,
-                                     getter_AddRefs(renderingContext));
+      dc->CreateRenderingContext(*getter_AddRefs(renderingContext));
+      NS_ENSURE_TRUE(renderingContext, NS_ERROR_OUT_OF_MEMORY);
 
 #if defined(XP_UNIX) && !defined(XP_MACOSX)
       // On linux, need to rotate landscape-mode output on printed surfaces

layout/generic/nsTextFrameThebes.cpp

@@ -1493,9 +1493,8 @@ GetReferenceRenderingContext(nsTextFrame* aTextFrame, nsIRenderingContext* aRC)
 {
   nsCOMPtr<nsIRenderingContext> tmp = aRC;
   if (!tmp) {
-    nsresult rv = aTextFrame->PresContext()->PresShell()->
-      CreateRenderingContext(aTextFrame, getter_AddRefs(tmp));
-    if (NS_FAILED(rv))
+    tmp = aTextFrame->PresContext()->PresShell()->GetReferenceRenderingContext();
+    if (!tmp)
       return nsnull;
   }
 

layout/inspector/src/inFlasher.cpp

@@ -155,23 +155,26 @@ inFlasher::DrawElementOutline(nsIDOMElement* aElement)
   PRBool isFirstFrame = PR_TRUE;
 
   while (frame) {
+    nsPoint offset;
+    nsIWidget* widget = frame->GetNearestWidget(offset);
+    if (widget) {
       nsCOMPtr<nsIRenderingContext> rcontext;
-    nsresult rv =
-      presShell->CreateRenderingContext(frame, getter_AddRefs(rcontext));
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    nsRect rect(nsPoint(0,0), frame->GetSize());
+      frame->PresContext()->DeviceContext()->
+        CreateRenderingContext(widget, *getter_AddRefs(rcontext));
+      if (rcontext) {
+        nsRect rect(offset, frame->GetSize());
         if (mInvert) {
           rcontext->InvertRect(rect);
         }
 
-    frame = frame->GetNextContinuation();
-
-    PRBool isLastFrame = (frame == nsnull);
+        PRBool isLastFrame = frame->GetNextContinuation() == nsnull;
         DrawOutline(rect.x, rect.y, rect.width, rect.height, rcontext,
                     isFirstFrame, isLastFrame);
         isFirstFrame = PR_FALSE;
       }
+    }
+    frame = frame->GetNextContinuation();
+  }
 
   return NS_OK;
 }

layout/svg/base/src/nsSVGForeignObjectFrame.cpp

@@ -569,10 +569,10 @@ nsSVGForeignObjectFrame::DoReflow()
 
   // initiate a synchronous reflow here and now:  
   nsSize availableSpace(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);
-  nsCOMPtr<nsIRenderingContext> renderingContext;
   nsIPresShell* presShell = presContext->PresShell();
   NS_ASSERTION(presShell, "null presShell");
-  presShell->CreateRenderingContext(this,getter_AddRefs(renderingContext));
+  nsCOMPtr<nsIRenderingContext> renderingContext =
+    presShell->GetReferenceRenderingContext();
   if (!renderingContext)
     return;
 

layout/xul/base/src/nsSplitterFrame.cpp

@@ -664,10 +664,9 @@ nsSplitterFrameInner::MouseDown(nsIDOMEvent* aMouseEvent)
   if (childIndex == childCount - 1 && GetResizeAfter() != Grow)
     return NS_OK;
 
-  nsCOMPtr<nsIRenderingContext> rc;
-  nsresult rv = outerPresContext->PresShell()->
-                  CreateRenderingContext(mOuter, getter_AddRefs(rc));
-  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIRenderingContext> rc =
+    outerPresContext->PresShell()->GetReferenceRenderingContext();
+  NS_ENSURE_TRUE(rc, NS_ERROR_FAILURE);
   nsBoxLayoutState state(outerPresContext, rc);
   mCurrentPos = 0;
   mPressed = PR_TRUE;

layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp

@@ -270,8 +270,10 @@ nsTreeBodyFrame::CalcMaxRowWidth()
   nscoord rowWidth;
   nsTreeColumn* col;
 
-  nsCOMPtr<nsIRenderingContext> rc;
-  PresContext()->PresShell()->CreateRenderingContext(this, getter_AddRefs(rc));
+  nsCOMPtr<nsIRenderingContext> rc =
+    PresContext()->PresShell()->GetReferenceRenderingContext();
+  if (!rc)
+    return 0;
 
   for (PRInt32 row = 0; row < mRowCount; ++row) {
     rowWidth = 0;
@@ -1173,8 +1175,10 @@ nsTreeBodyFrame::GetCoordsForCellItem(PRInt32 aRow, nsITreeColumn* aCol, const n
     // interfere with our computations.
     AdjustForBorderPadding(cellContext, cellRect);
 
-    nsCOMPtr<nsIRenderingContext> rc;
-    presContext->PresShell()->CreateRenderingContext(this, getter_AddRefs(rc));
+    nsCOMPtr<nsIRenderingContext> rc =
+      presContext->PresShell()->GetReferenceRenderingContext();
+    if (!rc)
+      return NS_ERROR_OUT_OF_MEMORY;
 
     // Now we'll start making our way across the cell, starting at the edge of 
     // the cell and proceeding until we hit the right edge. |cellX| is the 
@@ -1521,6 +1525,12 @@ nsTreeBodyFrame::GetItemWithinCellAt(nscoord aX, const nsRect& aCellRect,
   // Handle right alignment hit testing.
   PRBool isRTL = GetStyleVisibility()->mDirection == NS_STYLE_DIRECTION_RTL;
 
+  nsPresContext* presContext = PresContext();
+  nsCOMPtr<nsIRenderingContext> rc =
+    presContext->PresShell()->GetReferenceRenderingContext();
+  if (!rc)
+    return nsCSSAnonBoxes::moztreecell;
+
   if (aColumn->IsPrimary()) {
     // If we're the primary column, we have indentation and a twisty.
     PRInt32 level;
@@ -1548,10 +1558,6 @@ nsTreeBodyFrame::GetItemWithinCellAt(nscoord aX, const nsRect& aCellRect,
         hasTwisty = PR_TRUE;
     }
 
-    nsPresContext* presContext = PresContext();
-    nsCOMPtr<nsIRenderingContext> rc;
-    presContext->PresShell()->CreateRenderingContext(this, getter_AddRefs(rc));
-
     // Resolve style for the twisty.
     nsStyleContext* twistyContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty);
 
@@ -1622,12 +1628,9 @@ nsTreeBodyFrame::GetItemWithinCellAt(nscoord aX, const nsRect& aCellRect,
 
   AdjustForBorderPadding(textContext, textRect);
 
-  nsCOMPtr<nsIRenderingContext> renderingContext;
-  PresContext()->PresShell()->CreateRenderingContext(this, getter_AddRefs(renderingContext));
+  nsLayoutUtils::SetFontFromStyle(rc, textContext);
 
-  nsLayoutUtils::SetFontFromStyle(renderingContext, textContext);
-
-  AdjustForCellText(cellText, aRowIndex, aColumn, *renderingContext, textRect);
+  AdjustForCellText(cellText, aRowIndex, aColumn, *rc, textRect);
   if (isRTL)
     textRect.x = currX + remainingWidth - textRect.width;
 
@@ -1775,10 +1778,9 @@ nsTreeBodyFrame::IsCellCropped(PRInt32 aRow, nsITreeColumn* aCol, PRBool *_retva
   if (!col)
     return NS_ERROR_INVALID_ARG;
 
-  nsCOMPtr<nsIRenderingContext> rc;
-  rv = PresContext()->PresShell()->
-    CreateRenderingContext(this, getter_AddRefs(rc));
-  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIRenderingContext> rc =
+    PresContext()->PresShell()->GetReferenceRenderingContext();
+  NS_ENSURE_TRUE(rc, NS_ERROR_FAILURE);
 
   rv = GetCellWidth(aRow, col, rc, desiredSize, currentSize);
   NS_ENSURE_SUCCESS(rv, rv);