layout/forms/nsSelectsAreaFrame.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6 #include "nsSelectsAreaFrame.h"
   7
   8 #include "mozilla/PresShell.h"
   9 #include "nsIContent.h"
  10 #include "nsListControlFrame.h"
  11 #include "nsDisplayList.h"
  12 #include "WritingModes.h"
  13
  14 using namespace mozilla;
  15
  16 nsContainerFrame* NS_NewSelectsAreaFrame(PresShell* aShell,
  17                                          ComputedStyle* aStyle) {
  18   nsSelectsAreaFrame* it =
  19       new (aShell) nsSelectsAreaFrame(aStyle, aShell->GetPresContext());
  20   return it;
  21 }
  22
  23 NS_IMPL_FRAMEARENA_HELPERS(nsSelectsAreaFrame)
  24
  25 NS_QUERYFRAME_HEAD(nsSelectsAreaFrame)
  26   NS_QUERYFRAME_ENTRY(nsSelectsAreaFrame)
  27 NS_QUERYFRAME_TAIL_INHERITING(nsBlockFrame)
  28
  29 static nsListControlFrame* GetEnclosingListFrame(nsIFrame* aSelectsAreaFrame) {
  30   nsIFrame* frame = aSelectsAreaFrame->GetParent();
  31   while (frame) {
  32     if (frame->IsListControlFrame())
  33       return static_cast<nsListControlFrame*>(frame);
  34     frame = frame->GetParent();
  35   }
  36   return nullptr;
  37 }
  38
  39 void nsSelectsAreaFrame::Reflow(nsPresContext* aPresContext,
  40                                 ReflowOutput& aDesiredSize,
  41                                 const ReflowInput& aReflowInput,
  42                                 nsReflowStatus& aStatus) {
  43   MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
  44
  45   nsListControlFrame* list = GetEnclosingListFrame(this);
  46   NS_ASSERTION(list,
  47                "Must have an nsListControlFrame!  Frame constructor is "
  48                "broken");
  49
  50   nsBlockFrame::Reflow(aPresContext, aDesiredSize, aReflowInput, aStatus);
  51
  52   // Check whether we need to suppress scrollbar updates.  We want to do
  53   // that if we're in a possible first pass and our block size of a row
  54   // has changed.
  55   if (list->MightNeedSecondPass()) {
  56     nscoord newBSizeOfARow = list->CalcBSizeOfARow();
  57     // We'll need a second pass if our block size of a row changed.  For
  58     // comboboxes, we'll also need it if our block size changed.  If
  59     // we're going to do a second pass, suppress scrollbar updates for
  60     // this pass.
  61     if (newBSizeOfARow != mBSizeOfARow) {
  62       mBSizeOfARow = newBSizeOfARow;
  63       list->SetSuppressScrollbarUpdate(true);
  64     }
  65   }
  66 }
  67
  68 namespace mozilla {
  69 /**
  70  * This wrapper class lets us redirect mouse hits from the child frame of
  71  * an option element to the element's own frame.
  72  * REVIEW: This is what nsSelectsAreaFrame::GetFrameForPoint used to do
  73  */
  74 class nsDisplayOptionEventGrabber : public nsDisplayWrapList {
  75  public:
  76   nsDisplayOptionEventGrabber(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
  77                               nsDisplayItem* aItem)
  78       : nsDisplayWrapList(aBuilder, aFrame, aItem) {}
  79   nsDisplayOptionEventGrabber(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
  80                               nsDisplayList* aList)
  81       : nsDisplayWrapList(aBuilder, aFrame, aList) {}
  82   virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
  83                        HitTestState* aState,
  84                        nsTArray<nsIFrame*>* aOutFrames) override;
  85   virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
  86     return false;
  87   }
  88   void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override {
  89     GetChildren()->Paint(aBuilder, aCtx,
  90                          mFrame->PresContext()->AppUnitsPerDevPixel());
  91   }
  92   NS_DISPLAY_DECL_NAME("OptionEventGrabber", TYPE_OPTION_EVENT_GRABBER)
  93 };
  94
  95 void nsDisplayOptionEventGrabber::HitTest(nsDisplayListBuilder* aBuilder,
  96                                           const nsRect& aRect,
  97                                           HitTestState* aState,
  98                                           nsTArray<nsIFrame*>* aOutFrames) {
  99   nsTArray<nsIFrame*> outFrames;
 100   mList.HitTest(aBuilder, aRect, aState, &outFrames);
 101
 102   for (uint32_t i = 0; i < outFrames.Length(); i++) {
 103     nsIFrame* selectedFrame = outFrames.ElementAt(i);
 104     while (selectedFrame &&
 105            !(selectedFrame->GetContent() &&
 106              selectedFrame->GetContent()->IsHTMLElement(nsGkAtoms::option))) {
 107       selectedFrame = selectedFrame->GetParent();
 108     }
 109     if (selectedFrame) {
 110       aOutFrames->AppendElement(selectedFrame);
 111     } else {
 112       // keep the original result, which could be this frame
 113       aOutFrames->AppendElement(outFrames.ElementAt(i));
 114     }
 115   }
 116 }
 117
 118 class nsOptionEventGrabberWrapper : public nsDisplayItemWrapper {
 119  public:
 120   nsOptionEventGrabberWrapper() = default;
 121   virtual nsDisplayItem* WrapList(nsDisplayListBuilder* aBuilder,
 122                                   nsIFrame* aFrame,
 123                                   nsDisplayList* aList) override {
 124     return MakeDisplayItem<nsDisplayOptionEventGrabber>(aBuilder, aFrame,
 125                                                         aList);
 126   }
 127   virtual nsDisplayItem* WrapItem(nsDisplayListBuilder* aBuilder,
 128                                   nsDisplayItem* aItem) override {
 129     return MakeDisplayItem<nsDisplayOptionEventGrabber>(aBuilder,
 130                                                         aItem->Frame(), aItem);
 131   }
 132 };
 133
 134 class nsDisplayListFocus : public nsPaintedDisplayItem {
 135  public:
 136   nsDisplayListFocus(nsDisplayListBuilder* aBuilder, nsSelectsAreaFrame* aFrame)
 137       : nsPaintedDisplayItem(aBuilder, aFrame) {
 138     MOZ_COUNT_CTOR(nsDisplayListFocus);
 139   }
 140   MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayListFocus)
 141
 142   virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder,
 143                            bool* aSnap) const override {
 144     *aSnap = false;
 145     // override bounds because the list item focus ring may extend outside
 146     // the nsSelectsAreaFrame
 147     nsListControlFrame* listFrame = GetEnclosingListFrame(Frame());
 148     return listFrame->InkOverflowRectRelativeToSelf() +
 149            listFrame->GetOffsetToCrossDoc(Frame()) + ToReferenceFrame();
 150   }
 151   virtual void Paint(nsDisplayListBuilder* aBuilder,
 152                      gfxContext* aCtx) override {
 153     nsListControlFrame* listFrame = GetEnclosingListFrame(Frame());
 154     // listFrame must be non-null or we wouldn't get called.
 155     listFrame->PaintFocus(
 156         aCtx->GetDrawTarget(),
 157         listFrame->GetOffsetToCrossDoc(Frame()) + ToReferenceFrame());
 158   }
 159   NS_DISPLAY_DECL_NAME("ListFocus", TYPE_LIST_FOCUS)
 160 };
 161
 162 }  // namespace mozilla
 163
 164 void nsSelectsAreaFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
 165                                           const nsDisplayListSet& aLists) {
 166   if (!aBuilder->IsForEventDelivery()) {
 167     BuildDisplayListInternal(aBuilder, aLists);
 168     return;
 169   }
 170
 171   nsDisplayListCollection set(aBuilder);
 172   BuildDisplayListInternal(aBuilder, set);
 173
 174   nsOptionEventGrabberWrapper wrapper;
 175   wrapper.WrapLists(aBuilder, this, set, aLists);
 176 }
 177
 178 void nsSelectsAreaFrame::BuildDisplayListInternal(
 179     nsDisplayListBuilder* aBuilder, const nsDisplayListSet& aLists) {
 180   nsBlockFrame::BuildDisplayList(aBuilder, aLists);
 181
 182   nsListControlFrame* listFrame = GetEnclosingListFrame(this);
 183   if (listFrame && listFrame->IsFocused()) {
 184     // we can't just associate the display item with the list frame,
 185     // because then the list's scrollframe won't clip it (the scrollframe
 186     // only clips contained descendants).
 187     aLists.Outlines()->AppendNewToTop<nsDisplayListFocus>(aBuilder, this);
 188   }
 189 }