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 nsIFrame*
  11 NS_NewSelectsAreaFrame(nsIPresShell* aShell, nsStyleContext* aContext, uint32_t 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);
  40   NS_DISPLAY_DECL_NAME("OptionEventGrabber", TYPE_OPTION_EVENT_GRABBER)
  41 };
  42
  43 void nsDisplayOptionEventGrabber::HitTest(nsDisplayListBuilder* aBuilder,
  44     const nsRect& aRect, HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames)
  45 {
  46   nsTArray<nsIFrame*> outFrames;
  47   mList.HitTest(aBuilder, aRect, aState, &outFrames);
  48
  49   for (uint32_t i = 0; i < outFrames.Length(); i++) {
  50     nsIFrame* selectedFrame = outFrames.ElementAt(i);
  51     while (selectedFrame &&
  52            !(selectedFrame->GetContent() &&
  53              selectedFrame->GetContent()->IsHTML(nsGkAtoms::option))) {
  54       selectedFrame = selectedFrame->GetParent();
  55     }
  56     if (selectedFrame) {
  57       aOutFrames->AppendElement(selectedFrame);
  58     } else {
  59       // keep the original result, which could be this frame
  60       aOutFrames->AppendElement(outFrames.ElementAt(i));
  61     }
  62   }
  63 }
  64
  65 class nsOptionEventGrabberWrapper : public nsDisplayWrapper
  66 {
  67 public:
  68   nsOptionEventGrabberWrapper() {}
  69   virtual nsDisplayItem* WrapList(nsDisplayListBuilder* aBuilder,
  70                                   nsIFrame* aFrame, nsDisplayList* aList) {
  71     return new (aBuilder) nsDisplayOptionEventGrabber(aBuilder, aFrame, aList);
  72   }
  73   virtual nsDisplayItem* WrapItem(nsDisplayListBuilder* aBuilder,
  74                                   nsDisplayItem* aItem) {
  75     return new (aBuilder) nsDisplayOptionEventGrabber(aBuilder, aItem->Frame(), aItem);
  76   }
  77 };
  78
  79 static nsListControlFrame* GetEnclosingListFrame(nsIFrame* aSelectsAreaFrame)
  80 {
  81   nsIFrame* frame = aSelectsAreaFrame->GetParent();
  82   while (frame) {
  83     if (frame->GetType() == nsGkAtoms::listControlFrame)
  84       return static_cast<nsListControlFrame*>(frame);
  85     frame = frame->GetParent();
  86   }
  87   return nullptr;
  88 }
  89
  90 class nsDisplayListFocus : public nsDisplayItem {
  91 public:
  92   nsDisplayListFocus(nsDisplayListBuilder* aBuilder,
  93                      nsSelectsAreaFrame* aFrame) :
  94     nsDisplayItem(aBuilder, aFrame) {
  95     MOZ_COUNT_CTOR(nsDisplayListFocus);
  96   }
  97 #ifdef NS_BUILD_REFCNT_LOGGING
  98   virtual ~nsDisplayListFocus() {
  99     MOZ_COUNT_DTOR(nsDisplayListFocus);
 100   }
 101 #endif
 102
 103   virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) {
 104     *aSnap = false;
 105     // override bounds because the list item focus ring may extend outside
 106     // the nsSelectsAreaFrame
 107     nsListControlFrame* listFrame = GetEnclosingListFrame(Frame());
 108     return listFrame->GetVisualOverflowRectRelativeToSelf() +
 109            listFrame->GetOffsetToCrossDoc(ReferenceFrame());
 110   }
 111   virtual void Paint(nsDisplayListBuilder* aBuilder,
 112                      nsRenderingContext* aCtx) {
 113     nsListControlFrame* listFrame = GetEnclosingListFrame(Frame());
 114     // listFrame must be non-null or we wouldn't get called.
 115     listFrame->PaintFocus(*aCtx, aBuilder->ToReferenceFrame(listFrame));
 116   }
 117   NS_DISPLAY_DECL_NAME("ListFocus", TYPE_LIST_FOCUS)
 118 };
 119
 120 void
 121 nsSelectsAreaFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
 122                                      const nsRect&           aDirtyRect,
 123                                      const nsDisplayListSet& aLists)
 124 {
 125   if (!aBuilder->IsForEventDelivery()) {
 126     BuildDisplayListInternal(aBuilder, aDirtyRect, aLists);
 127     return;
 128   }
 129
 130   nsDisplayListCollection set;
 131   BuildDisplayListInternal(aBuilder, aDirtyRect, set);
 132
 133   nsOptionEventGrabberWrapper wrapper;
 134   wrapper.WrapLists(aBuilder, this, set, aLists);
 135 }
 136
 137 void
 138 nsSelectsAreaFrame::BuildDisplayListInternal(nsDisplayListBuilder*   aBuilder,
 139                                              const nsRect&           aDirtyRect,
 140                                              const nsDisplayListSet& aLists)
 141 {
 142   nsBlockFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);
 143
 144   nsListControlFrame* listFrame = GetEnclosingListFrame(this);
 145   if (listFrame && listFrame->IsFocused()) {
 146     // we can't just associate the display item with the list frame,
 147     // because then the list's scrollframe won't clip it (the scrollframe
 148     // only clips contained descendants).
 149     aLists.Outlines()->AppendNewToTop(new (aBuilder)
 150       nsDisplayListFocus(aBuilder, this));
 151   }
 152 }
 153
 154 NS_IMETHODIMP
 155 nsSelectsAreaFrame::Reflow(nsPresContext*           aPresContext,
 156                            nsHTMLReflowMetrics&     aDesiredSize,
 157                            const nsHTMLReflowState& aReflowState,
 158                            nsReflowStatus&          aStatus)
 159 {
 160   nsListControlFrame* list = GetEnclosingListFrame(this);
 161   NS_ASSERTION(list,
 162                "Must have an nsListControlFrame!  Frame constructor is "
 163                "broken");
 164
 165   bool isInDropdownMode = list->IsInDropDownMode();
 166
 167   // See similar logic in nsListControlFrame::Reflow and
 168   // nsListControlFrame::ReflowAsDropdown.  We need to match it here.
 169   nscoord oldHeight;
 170   if (isInDropdownMode) {
 171     // Store the height now in case it changes during
 172     // nsBlockFrame::Reflow for some odd reason.
 173     if (!(GetStateBits() & NS_FRAME_FIRST_REFLOW)) {
 174       oldHeight = GetSize().height;
 175     } else {
 176       oldHeight = NS_UNCONSTRAINEDSIZE;
 177     }
 178   }
 179
 180   nsresult rv = nsBlockFrame::Reflow(aPresContext, aDesiredSize,
 181                                     aReflowState, aStatus);
 182   NS_ENSURE_SUCCESS(rv, rv);
 183
 184   // Check whether we need to suppress scrollbar updates.  We want to do that if
 185   // we're in a possible first pass and our height of a row has changed.
 186   if (list->MightNeedSecondPass()) {
 187     nscoord newHeightOfARow = list->CalcHeightOfARow();
 188     // We'll need a second pass if our height of a row changed.  For
 189     // comboboxes, we'll also need it if our height changed.  If we're going
 190     // to do a second pass, suppress scrollbar updates for this pass.
 191     if (newHeightOfARow != mHeightOfARow ||
 192         (isInDropdownMode && (oldHeight != aDesiredSize.Height() ||
 193                               oldHeight != GetSize().height))) {
 194       mHeightOfARow = newHeightOfARow;
 195       list->SetSuppressScrollbarUpdate(true);
 196     }
 197   }
 198
 199   return rv;
 200 }