layout/forms/nsSelectsAreaFrame.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5 #include "nsSelectsAreaFrame.h"
   6 #include "nsIContent.h"
   7 #include "nsListControlFrame.h"
   8 #include "nsDisplayList.h"
   9
  10 nsContainerFrame*
  11 NS_NewSelectsAreaFrame(nsIPresShell* aShell, nsStyleContext* aContext, nsFrameState aFlags)
  12 {
  13   nsSelectsAreaFrame* it = new (aShell) nsSelectsAreaFrame(aContext);
  14
  15   // We need NS_BLOCK_FLOAT_MGR to ensure that the options inside the select
  16   // aren't expanded by right floats outside the select.
  17   it->SetFlags(aFlags | NS_BLOCK_FLOAT_MGR);
  18
  19   return it;
  20 }
  21
  22 NS_IMPL_FRAMEARENA_HELPERS(nsSelectsAreaFrame)
  23
  24 //---------------------------------------------------------
  25 /**
  26  * This wrapper class lets us redirect mouse hits from the child frame of
  27  * an option element to the element's own frame.
  28  * REVIEW: This is what nsSelectsAreaFrame::GetFrameForPoint used to do
  29  */
  30 class nsDisplayOptionEventGrabber : public nsDisplayWrapList {
  31 public:
  32   nsDisplayOptionEventGrabber(nsDisplayListBuilder* aBuilder,
  33                               nsIFrame* aFrame, nsDisplayItem* aItem)
  34     : nsDisplayWrapList(aBuilder, aFrame, aItem) {}
  35   nsDisplayOptionEventGrabber(nsDisplayListBuilder* aBuilder,
  36                               nsIFrame* aFrame, nsDisplayList* aList)
  37     : nsDisplayWrapList(aBuilder, aFrame, aList) {}
  38   virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
  39                        HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE;
  40   virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE {
  41     return false;
  42   }
  43   NS_DISPLAY_DECL_NAME("OptionEventGrabber", TYPE_OPTION_EVENT_GRABBER)
  44 };
  45
  46 void nsDisplayOptionEventGrabber::HitTest(nsDisplayListBuilder* aBuilder,
  47     const nsRect& aRect, HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames)
  48 {
  49   nsTArray<nsIFrame*> outFrames;
  50   mList.HitTest(aBuilder, aRect, aState, &outFrames);
  51
  52   for (uint32_t i = 0; i < outFrames.Length(); i++) {
  53     nsIFrame* selectedFrame = outFrames.ElementAt(i);
  54     while (selectedFrame &&
  55            !(selectedFrame->GetContent() &&
  56              selectedFrame->GetContent()->IsHTML(nsGkAtoms::option))) {
  57       selectedFrame = selectedFrame->GetParent();
  58     }
  59     if (selectedFrame) {
  60       aOutFrames->AppendElement(selectedFrame);
  61     } else {
  62       // keep the original result, which could be this frame
  63       aOutFrames->AppendElement(outFrames.ElementAt(i));
  64     }
  65   }
  66 }
  67
  68 class nsOptionEventGrabberWrapper : public nsDisplayWrapper
  69 {
  70 public:
  71   nsOptionEventGrabberWrapper() {}
  72   virtual nsDisplayItem* WrapList(nsDisplayListBuilder* aBuilder,
  73                                   nsIFrame* aFrame, nsDisplayList* aList) {
  74     return new (aBuilder) nsDisplayOptionEventGrabber(aBuilder, aFrame, aList);
  75   }
  76   virtual nsDisplayItem* WrapItem(nsDisplayListBuilder* aBuilder,
  77                                   nsDisplayItem* aItem) {
  78     return new (aBuilder) nsDisplayOptionEventGrabber(aBuilder, aItem->Frame(), aItem);
  79   }
  80 };
  81
  82 static nsListControlFrame* GetEnclosingListFrame(nsIFrame* aSelectsAreaFrame)
  83 {
  84   nsIFrame* frame = aSelectsAreaFrame->GetParent();
  85   while (frame) {
  86     if (frame->GetType() == nsGkAtoms::listControlFrame)
  87       return static_cast<nsListControlFrame*>(frame);
  88     frame = frame->GetParent();
  89   }
  90   return nullptr;
  91 }
  92
  93 class nsDisplayListFocus : public nsDisplayItem {
  94 public:
  95   nsDisplayListFocus(nsDisplayListBuilder* aBuilder,
  96                      nsSelectsAreaFrame* aFrame) :
  97     nsDisplayItem(aBuilder, aFrame) {
  98     MOZ_COUNT_CTOR(nsDisplayListFocus);
  99   }
 100 #ifdef NS_BUILD_REFCNT_LOGGING
 101   virtual ~nsDisplayListFocus() {
 102     MOZ_COUNT_DTOR(nsDisplayListFocus);
 103   }
 104 #endif
 105
 106   virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE {
 107     *aSnap = false;
 108     // override bounds because the list item focus ring may extend outside
 109     // the nsSelectsAreaFrame
 110     nsListControlFrame* listFrame = GetEnclosingListFrame(Frame());
 111     return listFrame->GetVisualOverflowRectRelativeToSelf() +
 112            listFrame->GetOffsetToCrossDoc(ReferenceFrame());
 113   }
 114   virtual void Paint(nsDisplayListBuilder* aBuilder,
 115                      nsRenderingContext* aCtx) MOZ_OVERRIDE {
 116     nsListControlFrame* listFrame = GetEnclosingListFrame(Frame());
 117     // listFrame must be non-null or we wouldn't get called.
 118     listFrame->PaintFocus(*aCtx, aBuilder->ToReferenceFrame(listFrame));
 119   }
 120   NS_DISPLAY_DECL_NAME("ListFocus", TYPE_LIST_FOCUS)
 121 };
 122
 123 void
 124 nsSelectsAreaFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
 125                                      const nsRect&           aDirtyRect,
 126                                      const nsDisplayListSet& aLists)
 127 {
 128   if (!aBuilder->IsForEventDelivery()) {
 129     BuildDisplayListInternal(aBuilder, aDirtyRect, aLists);
 130     return;
 131   }
 132
 133   nsDisplayListCollection set;
 134   BuildDisplayListInternal(aBuilder, aDirtyRect, set);
 135
 136   nsOptionEventGrabberWrapper wrapper;
 137   wrapper.WrapLists(aBuilder, this, set, aLists);
 138 }
 139
 140 void
 141 nsSelectsAreaFrame::BuildDisplayListInternal(nsDisplayListBuilder*   aBuilder,
 142                                              const nsRect&           aDirtyRect,
 143                                              const nsDisplayListSet& aLists)
 144 {
 145   nsBlockFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);
 146
 147   nsListControlFrame* listFrame = GetEnclosingListFrame(this);
 148   if (listFrame && listFrame->IsFocused()) {
 149     // we can't just associate the display item with the list frame,
 150     // because then the list's scrollframe won't clip it (the scrollframe
 151     // only clips contained descendants).
 152     aLists.Outlines()->AppendNewToTop(new (aBuilder)
 153       nsDisplayListFocus(aBuilder, this));
 154   }
 155 }
 156
 157 void
 158 nsSelectsAreaFrame::Reflow(nsPresContext*           aPresContext,
 159                            nsHTMLReflowMetrics&     aDesiredSize,
 160                            const nsHTMLReflowState& aReflowState,
 161                            nsReflowStatus&          aStatus)
 162 {
 163   nsListControlFrame* list = GetEnclosingListFrame(this);
 164   NS_ASSERTION(list,
 165                "Must have an nsListControlFrame!  Frame constructor is "
 166                "broken");
 167
 168   bool isInDropdownMode = list->IsInDropDownMode();
 169
 170   // See similar logic in nsListControlFrame::Reflow and
 171   // nsListControlFrame::ReflowAsDropdown.  We need to match it here.
 172   nscoord oldHeight;
 173   if (isInDropdownMode) {
 174     // Store the height now in case it changes during
 175     // nsBlockFrame::Reflow for some odd reason.
 176     if (!(GetStateBits() & NS_FRAME_FIRST_REFLOW)) {
 177       oldHeight = GetSize().height;
 178     } else {
 179       oldHeight = NS_UNCONSTRAINEDSIZE;
 180     }
 181   }
 182
 183   nsBlockFrame::Reflow(aPresContext, aDesiredSize, aReflowState, aStatus);
 184
 185   // Check whether we need to suppress scrollbar updates.  We want to do that if
 186   // we're in a possible first pass and our height of a row has changed.
 187   if (list->MightNeedSecondPass()) {
 188     nscoord newHeightOfARow = list->CalcHeightOfARow();
 189     // We'll need a second pass if our height of a row changed.  For
 190     // comboboxes, we'll also need it if our height changed.  If we're going
 191     // to do a second pass, suppress scrollbar updates for this pass.
 192     if (newHeightOfARow != mHeightOfARow ||
 193         (isInDropdownMode && (oldHeight != aDesiredSize.Height() ||
 194                               oldHeight != GetSize().height))) {
 195       mHeightOfARow = newHeightOfARow;
 196       list->SetSuppressScrollbarUpdate(true);
 197     }
 198   }
 199 }