layout/forms/nsSelectsAreaFrame.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is mozilla.org code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   Pierre Phaneuf <pp@ludusdesign.com>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either of the GNU General Public License Version 2 or later (the "GPL"),
  27  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
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  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38 #include "nsSelectsAreaFrame.h"
  39 #include "nsCOMPtr.h"
  40 #include "nsIDOMHTMLOptionElement.h"
  41 #include "nsIContent.h"
  42 #include "nsListControlFrame.h"
  43 #include "nsDisplayList.h"
  44
  45 nsIFrame*
  46 NS_NewSelectsAreaFrame(nsIPresShell* aShell, nsStyleContext* aContext, PRUint32 aFlags)
  47 {
  48   nsSelectsAreaFrame* it = new (aShell) nsSelectsAreaFrame(aContext);
  49
  50   if (it) {
  51     // We need NS_BLOCK_FLOAT_MGR to ensure that the options inside the select
  52     // aren't expanded by right floats outside the select.
  53     it->SetFlags(aFlags | NS_BLOCK_FLOAT_MGR);
  54   }
  55
  56   return it;
  57 }
  58
  59 //---------------------------------------------------------
  60 PRBool
  61 nsSelectsAreaFrame::IsOptionElement(nsIContent* aContent)
  62 {
  63   PRBool result = PR_FALSE;
  64
  65   nsCOMPtr<nsIDOMHTMLOptionElement> optElem;
  66   if (NS_SUCCEEDED(aContent->QueryInterface(NS_GET_IID(nsIDOMHTMLOptionElement),(void**) getter_AddRefs(optElem)))) {
  67     if (optElem != nsnull) {
  68       result = PR_TRUE;
  69     }
  70   }
  71
  72   return result;
  73 }
  74
  75 //---------------------------------------------------------
  76 PRBool
  77 nsSelectsAreaFrame::IsOptionElementFrame(nsIFrame *aFrame)
  78 {
  79   nsIContent *content = aFrame->GetContent();
  80   if (content) {
  81     return IsOptionElement(content);
  82   }
  83   return PR_FALSE;
  84 }
  85
  86 /**
  87  * This wrapper class lets us redirect mouse hits from the child frame of
  88  * an option element to the element's own frame.
  89  * REVIEW: This is what nsSelectsAreaFrame::GetFrameForPoint used to do
  90  */
  91 class nsDisplayOptionEventGrabber : public nsDisplayWrapList {
  92 public:
  93   nsDisplayOptionEventGrabber(nsIFrame* aFrame, nsDisplayItem* aItem)
  94     : nsDisplayWrapList(aFrame, aItem) {}
  95   nsDisplayOptionEventGrabber(nsIFrame* aFrame, nsDisplayList* aList)
  96     : nsDisplayWrapList(aFrame, aList) {}
  97   virtual nsIFrame* HitTest(nsDisplayListBuilder* aBuilder, nsPoint aPt,
  98                             HitTestState* aState);
  99   NS_DISPLAY_DECL_NAME("OptionEventGrabber")
 100
 101   virtual nsDisplayWrapList* WrapWithClone(nsDisplayListBuilder* aBuilder,
 102                                            nsDisplayItem* aItem);
 103 };
 104
 105 nsIFrame* nsDisplayOptionEventGrabber::HitTest(nsDisplayListBuilder* aBuilder,
 106     nsPoint aPt, HitTestState* aState)
 107 {
 108   nsIFrame* frame = mList.HitTest(aBuilder, aPt, aState);
 109
 110   if (frame) {
 111     nsIFrame* selectedFrame = frame;
 112     while (selectedFrame &&
 113            !nsSelectsAreaFrame::IsOptionElementFrame(selectedFrame)) {
 114       selectedFrame = selectedFrame->GetParent();
 115     }
 116     if (selectedFrame) {
 117       return selectedFrame;
 118     }
 119     // else, keep the original result, which could be this frame
 120   }
 121
 122   return frame;
 123 }
 124
 125 nsDisplayWrapList* nsDisplayOptionEventGrabber::WrapWithClone(
 126     nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) {
 127   return new (aBuilder) nsDisplayOptionEventGrabber(aItem->GetUnderlyingFrame(), aItem);
 128 }
 129
 130 class nsOptionEventGrabberWrapper : public nsDisplayWrapper
 131 {
 132 public:
 133   nsOptionEventGrabberWrapper() {}
 134   virtual nsDisplayItem* WrapList(nsDisplayListBuilder* aBuilder,
 135                                   nsIFrame* aFrame, nsDisplayList* aList) {
 136     // We can't specify the underlying frame here. We need this list to be
 137     // exploded if sorted.
 138     return new (aBuilder) nsDisplayOptionEventGrabber(nsnull, aList);
 139   }
 140   virtual nsDisplayItem* WrapItem(nsDisplayListBuilder* aBuilder,
 141                                   nsDisplayItem* aItem) {
 142     return new (aBuilder) nsDisplayOptionEventGrabber(aItem->GetUnderlyingFrame(), aItem);
 143   }
 144 };
 145
 146 static nsListControlFrame* GetEnclosingListFrame(nsIFrame* aSelectsAreaFrame)
 147 {
 148   nsIFrame* frame = aSelectsAreaFrame->GetParent();
 149   while (frame) {
 150     if (frame->GetType() == nsGkAtoms::listControlFrame)
 151       return static_cast<nsListControlFrame*>(frame);
 152     frame = frame->GetParent();
 153   }
 154   return nsnull;
 155 }
 156
 157 class nsDisplayListFocus : public nsDisplayItem {
 158 public:
 159   nsDisplayListFocus(nsSelectsAreaFrame* aFrame) : nsDisplayItem(aFrame) {
 160     MOZ_COUNT_CTOR(nsDisplayListFocus);
 161   }
 162 #ifdef NS_BUILD_REFCNT_LOGGING
 163   virtual ~nsDisplayListFocus() {
 164     MOZ_COUNT_DTOR(nsDisplayListFocus);
 165   }
 166 #endif
 167
 168   virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder) {
 169     // override bounds because the list item focus ring may extend outside
 170     // the nsSelectsAreaFrame
 171     nsListControlFrame* listFrame = GetEnclosingListFrame(GetUnderlyingFrame());
 172     return listFrame->GetOverflowRect() + aBuilder->ToReferenceFrame(listFrame);
 173   }
 174   virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx,
 175      const nsRect& aDirtyRect) {
 176     nsListControlFrame* listFrame = GetEnclosingListFrame(GetUnderlyingFrame());
 177     // listFrame must be non-null or we wouldn't get called.
 178     listFrame->PaintFocus(*aCtx, aBuilder->ToReferenceFrame(listFrame));
 179   }
 180   NS_DISPLAY_DECL_NAME("ListFocus")
 181 };
 182
 183 NS_IMETHODIMP
 184 nsSelectsAreaFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
 185                                      const nsRect&           aDirtyRect,
 186                                      const nsDisplayListSet& aLists)
 187 {
 188   if (!aBuilder->IsForEventDelivery())
 189     return BuildDisplayListInternal(aBuilder, aDirtyRect, aLists);
 190
 191   nsDisplayListCollection set;
 192   nsresult rv = BuildDisplayListInternal(aBuilder, aDirtyRect, set);
 193   NS_ENSURE_SUCCESS(rv, rv);
 194
 195   nsOptionEventGrabberWrapper wrapper;
 196   return wrapper.WrapLists(aBuilder, this, set, aLists);
 197 }
 198
 199 nsresult
 200 nsSelectsAreaFrame::BuildDisplayListInternal(nsDisplayListBuilder*   aBuilder,
 201                                              const nsRect&           aDirtyRect,
 202                                              const nsDisplayListSet& aLists)
 203 {
 204   nsresult rv = nsBlockFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);
 205   NS_ENSURE_SUCCESS(rv, rv);
 206
 207   nsListControlFrame* listFrame = GetEnclosingListFrame(this);
 208   if (listFrame && listFrame->IsFocused()) {
 209     // we can't just associate the display item with the list frame,
 210     // because then the list's scrollframe won't clip it (the scrollframe
 211     // only clips contained descendants).
 212     return aLists.Outlines()->AppendNewToTop(new (aBuilder)
 213       nsDisplayListFocus(this));
 214   }
 215
 216   return NS_OK;
 217 }
 218
 219 NS_IMETHODIMP
 220 nsSelectsAreaFrame::Reflow(nsPresContext*           aPresContext,
 221                            nsHTMLReflowMetrics&     aDesiredSize,
 222                            const nsHTMLReflowState& aReflowState,
 223                            nsReflowStatus&          aStatus)
 224 {
 225   nsListControlFrame* list = GetEnclosingListFrame(this);
 226   NS_ASSERTION(list,
 227                "Must have an nsListControlFrame!  Frame constructor is "
 228                "broken");
 229
 230   PRBool isInDropdownMode = list->IsInDropDownMode();
 231
 232   // See similar logic in nsListControlFrame::Reflow and
 233   // nsListControlFrame::ReflowAsDropdown.  We need to match it here.
 234   nscoord oldHeight;
 235   if (isInDropdownMode) {
 236     // Store the height now in case it changes during
 237     // nsBlockFrame::Reflow for some odd reason.
 238     if (!(GetStateBits() & NS_FRAME_FIRST_REFLOW)) {
 239       oldHeight = GetSize().height;
 240     } else {
 241       oldHeight = NS_UNCONSTRAINEDSIZE;
 242     }
 243   }
 244
 245   nsresult rv = nsBlockFrame::Reflow(aPresContext, aDesiredSize,
 246                                     aReflowState, aStatus);
 247   NS_ENSURE_SUCCESS(rv, rv);
 248
 249   // Check whether we need to suppress scrolbar updates.  We want to do that if
 250   // we're in a possible first pass and our height of a row has changed.
 251   if (list->MightNeedSecondPass()) {
 252     nscoord newHeightOfARow = list->CalcHeightOfARow();
 253     // We'll need a second pass if our height of a row changed.  For
 254     // comboboxes, we'll also need it if our height changed.  If we're going
 255     // to do a second pass, suppress scrollbar updates for this pass.
 256     if (newHeightOfARow != mHeightOfARow ||
 257         (isInDropdownMode && (oldHeight != aDesiredSize.height ||
 258                               oldHeight != GetSize().height))) {
 259       mHeightOfARow = newHeightOfARow;
 260       list->SetSuppressScrollbarUpdate(PR_TRUE);
 261     }
 262   }
 263
 264   return rv;
 265 }