1 files changed, 191 insertions, 0 deletions
diff --git a/layout/forms/nsSelectsAreaFrame.cpp b/layout/forms/nsSelectsAreaFrame.cpp
new file mode 100644
index 0000000000..64fcdbd029
--- /dev/null
+++ b/layout/forms/nsSelectsAreaFrame.cpp
@@ -0,0 +1,191 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "nsSelectsAreaFrame.h"
+
+#include "mozilla/PresShell.h"
+#include "nsIContent.h"
+#include "nsListControlFrame.h"
+#include "nsDisplayList.h"
+#include "WritingModes.h"
+
+using namespace mozilla;
+
+nsContainerFrame* NS_NewSelectsAreaFrame(PresShell* aShell,
+                                         ComputedStyle* aStyle,
+                                         nsFrameState aFlags) {
+  nsSelectsAreaFrame* it =
+      new (aShell) nsSelectsAreaFrame(aStyle, aShell->GetPresContext());
+
+  // We need NS_BLOCK_FLOAT_MGR to ensure that the options inside the select
+  // aren't expanded by right floats outside the select.
+  it->AddStateBits(aFlags | NS_BLOCK_FLOAT_MGR);
+
+  return it;
+}
+
+NS_IMPL_FRAMEARENA_HELPERS(nsSelectsAreaFrame)
+
+static nsListControlFrame* GetEnclosingListFrame(nsIFrame* aSelectsAreaFrame) {
+  nsIFrame* frame = aSelectsAreaFrame->GetParent();
+  while (frame) {
+    if (frame->IsListControlFrame())
+      return static_cast<nsListControlFrame*>(frame);
+    frame = frame->GetParent();
+  }
+  return nullptr;
+}
+
+void nsSelectsAreaFrame::Reflow(nsPresContext* aPresContext,
+                                ReflowOutput& aDesiredSize,
+                                const ReflowInput& aReflowInput,
+                                nsReflowStatus& aStatus) {
+  MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
+
+  nsListControlFrame* list = GetEnclosingListFrame(this);
+  NS_ASSERTION(list,
+               "Must have an nsListControlFrame!  Frame constructor is "
+               "broken");
+
+  nsBlockFrame::Reflow(aPresContext, aDesiredSize, aReflowInput, aStatus);
+
+  // Check whether we need to suppress scrollbar updates.  We want to do
+  // that if we're in a possible first pass and our block size of a row
+  // has changed.
+  if (list->MightNeedSecondPass()) {
+    nscoord newBSizeOfARow = list->CalcBSizeOfARow();
+    // We'll need a second pass if our block size of a row changed.  For
+    // comboboxes, we'll also need it if our block size changed.  If
+    // we're going to do a second pass, suppress scrollbar updates for
+    // this pass.
+    if (newBSizeOfARow != mBSizeOfARow) {
+      mBSizeOfARow = newBSizeOfARow;
+      list->SetSuppressScrollbarUpdate(true);
+    }
+  }
+}
+
+namespace mozilla {
+/**
+ * This wrapper class lets us redirect mouse hits from the child frame of
+ * an option element to the element's own frame.
+ * REVIEW: This is what nsSelectsAreaFrame::GetFrameForPoint used to do
+ */
+class nsDisplayOptionEventGrabber : public nsDisplayWrapList {
+ public:
+  nsDisplayOptionEventGrabber(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
+                              nsDisplayItem* aItem)
+      : nsDisplayWrapList(aBuilder, aFrame, aItem) {}
+  nsDisplayOptionEventGrabber(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
+                              nsDisplayList* aList)
+      : nsDisplayWrapList(aBuilder, aFrame, aList) {}
+  virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
+                       HitTestState* aState,
+                       nsTArray<nsIFrame*>* aOutFrames) override;
+  virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
+    return false;
+  }
+  void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override {
+    GetChildren()->Paint(aBuilder, aCtx,
+                         mFrame->PresContext()->AppUnitsPerDevPixel());
+  }
+  NS_DISPLAY_DECL_NAME("OptionEventGrabber", TYPE_OPTION_EVENT_GRABBER)
+};
+
+void nsDisplayOptionEventGrabber::HitTest(nsDisplayListBuilder* aBuilder,
+                                          const nsRect& aRect,
+                                          HitTestState* aState,
+                                          nsTArray<nsIFrame*>* aOutFrames) {
+  nsTArray<nsIFrame*> outFrames;
+  mList.HitTest(aBuilder, aRect, aState, &outFrames);
+
+  for (uint32_t i = 0; i < outFrames.Length(); i++) {
+    nsIFrame* selectedFrame = outFrames.ElementAt(i);
+    while (selectedFrame &&
+           !(selectedFrame->GetContent() &&
+             selectedFrame->GetContent()->IsHTMLElement(nsGkAtoms::option))) {
+      selectedFrame = selectedFrame->GetParent();
+    }
+    if (selectedFrame) {
+      aOutFrames->AppendElement(selectedFrame);
+    } else {
+      // keep the original result, which could be this frame
+      aOutFrames->AppendElement(outFrames.ElementAt(i));
+    }
+  }
+}
+
+class nsOptionEventGrabberWrapper : public nsDisplayItemWrapper {
+ public:
+  nsOptionEventGrabberWrapper() = default;
+  virtual nsDisplayItem* WrapList(nsDisplayListBuilder* aBuilder,
+                                  nsIFrame* aFrame,
+                                  nsDisplayList* aList) override {
+    return MakeDisplayItem<nsDisplayOptionEventGrabber>(aBuilder, aFrame,
+                                                        aList);
+  }
+  virtual nsDisplayItem* WrapItem(nsDisplayListBuilder* aBuilder,
+                                  nsDisplayItem* aItem) override {
+    return MakeDisplayItem<nsDisplayOptionEventGrabber>(aBuilder,
+                                                        aItem->Frame(), aItem);
+  }
+};
+
+class nsDisplayListFocus : public nsPaintedDisplayItem {
+ public:
+  nsDisplayListFocus(nsDisplayListBuilder* aBuilder, nsSelectsAreaFrame* aFrame)
+      : nsPaintedDisplayItem(aBuilder, aFrame) {
+    MOZ_COUNT_CTOR(nsDisplayListFocus);
+  }
+  MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayListFocus)
+
+  virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder,
+                           bool* aSnap) const override {
+    *aSnap = false;
+    // override bounds because the list item focus ring may extend outside
+    // the nsSelectsAreaFrame
+    nsListControlFrame* listFrame = GetEnclosingListFrame(Frame());
+    return listFrame->InkOverflowRectRelativeToSelf() +
+           listFrame->GetOffsetToCrossDoc(Frame()) + ToReferenceFrame();
+  }
+  virtual void Paint(nsDisplayListBuilder* aBuilder,
+                     gfxContext* aCtx) override {
+    nsListControlFrame* listFrame = GetEnclosingListFrame(Frame());
+    // listFrame must be non-null or we wouldn't get called.
+    listFrame->PaintFocus(
+        aCtx->GetDrawTarget(),
+        listFrame->GetOffsetToCrossDoc(Frame()) + ToReferenceFrame());
+  }
+  NS_DISPLAY_DECL_NAME("ListFocus", TYPE_LIST_FOCUS)
+};
+
+}  // namespace mozilla
+
+void nsSelectsAreaFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
+                                          const nsDisplayListSet& aLists) {
+  if (!aBuilder->IsForEventDelivery()) {
+    BuildDisplayListInternal(aBuilder, aLists);
+    return;
+  }
+
+  nsDisplayListCollection set(aBuilder);
+  BuildDisplayListInternal(aBuilder, set);
+
+  nsOptionEventGrabberWrapper wrapper;
+  wrapper.WrapLists(aBuilder, this, set, aLists);
+}
+
+void nsSelectsAreaFrame::BuildDisplayListInternal(
+    nsDisplayListBuilder* aBuilder, const nsDisplayListSet& aLists) {
+  nsBlockFrame::BuildDisplayList(aBuilder, aLists);
+
+  nsListControlFrame* listFrame = GetEnclosingListFrame(this);
+  if (listFrame && listFrame->IsFocused()) {
+    // we can't just associate the display item with the list frame,
+    // because then the list's scrollframe won't clip it (the scrollframe
+    // only clips contained descendants).
+    aLists.Outlines()->AppendNewToTop<nsDisplayListFocus>(aBuilder, this);
+  }
+}