layout/generic/nsFirstLetterFrame.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 Communicator client 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  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either of the GNU General Public License Version 2 or later (the "GPL"),
  26  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  27  * in which case the provisions of the GPL or the LGPL are applicable instead
  28  * of those above. If you wish to allow use of your version of this file only
  29  * under the terms of either the GPL or the LGPL, and not to allow others to
  30  * use your version of this file under the terms of the MPL, indicate your
  31  * decision by deleting the provisions above and replace them with the notice
  32  * and other provisions required by the GPL or the LGPL. If you do not delete
  33  * the provisions above, a recipient may use your version of this file under
  34  * the terms of any one of the MPL, the GPL or the LGPL.
  35  *
  36  * ***** END LICENSE BLOCK ***** */
  37
  38 /* rendering object for CSS :first-letter pseudo-element */
  39
  40 #include "nsCOMPtr.h"
  41 #include "nsFirstLetterFrame.h"
  42 #include "nsPresContext.h"
  43 #include "nsStyleContext.h"
  44 #include "nsIContent.h"
  45 #include "nsLineLayout.h"
  46 #include "nsGkAtoms.h"
  47 #include "nsAutoPtr.h"
  48 #include "nsStyleSet.h"
  49 #include "nsFrameManager.h"
  50
  51 nsIFrame*
  52 NS_NewFirstLetterFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
  53 {
  54   return new (aPresShell) nsFirstLetterFrame(aContext);
  55 }
  56
  57 #ifdef NS_DEBUG
  58 NS_IMETHODIMP
  59 nsFirstLetterFrame::GetFrameName(nsAString& aResult) const
  60 {
  61   return MakeFrameName(NS_LITERAL_STRING("Letter"), aResult);
  62 }
  63 #endif
  64
  65 nsIAtom*
  66 nsFirstLetterFrame::GetType() const
  67 {
  68   return nsGkAtoms::letterFrame;
  69 }
  70
  71 PRIntn
  72 nsFirstLetterFrame::GetSkipSides() const
  73 {
  74   return 0;
  75 }
  76
  77 NS_IMETHODIMP
  78 nsFirstLetterFrame::Init(nsIContent*      aContent,
  79                          nsIFrame*        aParent,
  80                          nsIFrame*        aPrevInFlow)
  81 {
  82   nsRefPtr<nsStyleContext> newSC;
  83   if (aPrevInFlow) {
  84     // Get proper style context for ourselves.  We're creating the frame
  85     // that represents everything *except* the first letter, so just create
  86     // a style context like we would for a text node.
  87     nsStyleContext* parentStyleContext = mStyleContext->GetParent();
  88     if (parentStyleContext) {
  89       newSC = mStyleContext->GetRuleNode()->GetPresContext()->StyleSet()->
  90         ResolveStyleForNonElement(parentStyleContext);
  91       if (newSC)
  92         SetStyleContextWithoutNotification(newSC);
  93     }
  94   }
  95
  96   return nsFirstLetterFrameSuper::Init(aContent, aParent, aPrevInFlow);
  97 }
  98
  99 NS_IMETHODIMP
 100 nsFirstLetterFrame::SetInitialChildList(nsIAtom*  aListName,
 101                                         nsIFrame* aChildList)
 102 {
 103   mFrames.SetFrames(aChildList);
 104   nsFrameManager *frameManager = PresContext()->FrameManager();
 105
 106   for (nsIFrame* frame = aChildList; frame; frame = frame->GetNextSibling()) {
 107     NS_ASSERTION(frame->GetParent() == this, "Unexpected parent");
 108     frameManager->ReParentStyleContext(frame);
 109   }
 110   return NS_OK;
 111 }
 112
 113 NS_IMETHODIMP
 114 nsFirstLetterFrame::SetSelected(nsPresContext* aPresContext, nsIDOMRange *aRange,PRBool aSelected, nsSpread aSpread, SelectionType aType)
 115 {
 116   if (aSelected && ParentDisablesSelection())
 117     return NS_OK;
 118   nsIFrame *child = GetFirstChild(nsnull);
 119   while (child)
 120   {
 121     child->SetSelected(aPresContext, aRange, aSelected, aSpread, aType);
 122     // don't worry about result. there are more frames to come
 123     child = child->GetNextSibling();
 124   }
 125   return NS_OK;
 126 }
 127
 128 NS_IMETHODIMP
 129 nsFirstLetterFrame::GetChildFrameContainingOffset(PRInt32 inContentOffset,
 130                                                   PRBool inHint,
 131                                                   PRInt32* outFrameContentOffset,
 132                                                   nsIFrame **outChildFrame)
 133 {
 134   nsIFrame *kid = mFrames.FirstChild();
 135   if (kid)
 136   {
 137     return kid->GetChildFrameContainingOffset(inContentOffset, inHint, outFrameContentOffset, outChildFrame);
 138   }
 139   else
 140     return nsFrame::GetChildFrameContainingOffset(inContentOffset, inHint, outFrameContentOffset, outChildFrame);
 141 }
 142
 143 // Needed for non-floating first-letter frames and for the continuations
 144 // following the first-letter that we also use nsFirstLetterFrame for.
 145 /* virtual */ void
 146 nsFirstLetterFrame::AddInlineMinWidth(nsIRenderingContext *aRenderingContext,
 147                                       nsIFrame::InlineMinWidthData *aData)
 148 {
 149   DoInlineIntrinsicWidth(aRenderingContext, aData, nsLayoutUtils::MIN_WIDTH);
 150 }
 151
 152 // Needed for non-floating first-letter frames and for the continuations
 153 // following the first-letter that we also use nsFirstLetterFrame for.
 154 /* virtual */ void
 155 nsFirstLetterFrame::AddInlinePrefWidth(nsIRenderingContext *aRenderingContext,
 156                                        nsIFrame::InlinePrefWidthData *aData)
 157 {
 158   DoInlineIntrinsicWidth(aRenderingContext, aData, nsLayoutUtils::PREF_WIDTH);
 159 }
 160
 161 // Needed for floating first-letter frames.
 162 /* virtual */ nscoord
 163 nsFirstLetterFrame::GetMinWidth(nsIRenderingContext *aRenderingContext)
 164 {
 165   return nsLayoutUtils::MinWidthFromInline(this, aRenderingContext);
 166 }
 167
 168 // Needed for floating first-letter frames.
 169 /* virtual */ nscoord
 170 nsFirstLetterFrame::GetPrefWidth(nsIRenderingContext *aRenderingContext)
 171 {
 172   return nsLayoutUtils::PrefWidthFromInline(this, aRenderingContext);
 173 }
 174
 175 /* virtual */ nsSize
 176 nsFirstLetterFrame::ComputeSize(nsIRenderingContext *aRenderingContext,
 177                                 nsSize aCBSize, nscoord aAvailableWidth,
 178                                 nsSize aMargin, nsSize aBorder, nsSize aPadding,
 179                                 PRBool aShrinkWrap)
 180 {
 181   if (GetPrevInFlow()) {
 182     // We're wrapping the text *after* the first letter, so behave like an
 183     // inline frame.
 184     return nsSize(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);
 185   }
 186   return nsFirstLetterFrameSuper::ComputeSize(aRenderingContext,
 187       aCBSize, aAvailableWidth, aMargin, aBorder, aPadding, aShrinkWrap);
 188 }
 189
 190 NS_IMETHODIMP
 191 nsFirstLetterFrame::Reflow(nsPresContext*          aPresContext,
 192                            nsHTMLReflowMetrics&     aMetrics,
 193                            const nsHTMLReflowState& aReflowState,
 194                            nsReflowStatus&          aReflowStatus)
 195 {
 196   DO_GLOBAL_REFLOW_COUNT("nsFirstLetterFrame");
 197   DISPLAY_REFLOW(aPresContext, this, aReflowState, aMetrics, aReflowStatus);
 198   nsresult rv = NS_OK;
 199
 200   // Grab overflow list
 201   DrainOverflowFrames(aPresContext);
 202
 203   nsIFrame* kid = mFrames.FirstChild();
 204
 205   // Setup reflow state for our child
 206   nsSize availSize(aReflowState.availableWidth, aReflowState.availableHeight);
 207   const nsMargin& bp = aReflowState.mComputedBorderPadding;
 208   nscoord lr = bp.left + bp.right;
 209   nscoord tb = bp.top + bp.bottom;
 210   NS_ASSERTION(availSize.width != NS_UNCONSTRAINEDSIZE,
 211                "should no longer use unconstrained widths");
 212   availSize.width -= lr;
 213   if (NS_UNCONSTRAINEDSIZE != availSize.height) {
 214     availSize.height -= tb;
 215   }
 216
 217   // Reflow the child
 218   if (!aReflowState.mLineLayout) {
 219     // When there is no lineLayout provided, we provide our own. The
 220     // only time that the first-letter-frame is not reflowing in a
 221     // line context is when its floating.
 222     nsHTMLReflowState rs(aPresContext, aReflowState, kid, availSize);
 223     nsLineLayout ll(aPresContext, nsnull, &aReflowState, nsnull);
 224     ll.BeginLineReflow(bp.left, bp.top, availSize.width, NS_UNCONSTRAINEDSIZE,
 225                        PR_FALSE, PR_TRUE);
 226     rs.mLineLayout = &ll;
 227     ll.SetFirstLetterStyleOK(PR_TRUE);
 228
 229     kid->WillReflow(aPresContext);
 230     kid->Reflow(aPresContext, aMetrics, rs, aReflowStatus);
 231
 232     ll.EndLineReflow();
 233   }
 234   else {
 235     // Pretend we are a span and reflow the child frame
 236     nsLineLayout* ll = aReflowState.mLineLayout;
 237     PRBool        pushedFrame;
 238
 239     NS_ASSERTION(ll->GetFirstLetterStyleOK() || GetPrevInFlow(),
 240                  "First-in-flow first-letter should have first-letter style enabled in nsLineLayout!");
 241     ll->BeginSpan(this, &aReflowState, bp.left, availSize.width);
 242     ll->ReflowFrame(kid, aReflowStatus, &aMetrics, pushedFrame);
 243     ll->EndSpan(this);
 244   }
 245
 246   // Place and size the child and update the output metrics
 247   kid->SetRect(nsRect(bp.left, bp.top, aMetrics.width, aMetrics.height));
 248   kid->FinishAndStoreOverflow(&aMetrics);
 249   kid->DidReflow(aPresContext, nsnull, NS_FRAME_REFLOW_FINISHED);
 250
 251   aMetrics.width += lr;
 252   aMetrics.height += tb;
 253   aMetrics.ascent += bp.top;
 254   mBaseline = aMetrics.ascent;
 255
 256   // Ensure that the overflow rect contains the child textframe's overflow rect.
 257   // Note that if this is floating, the overline/underline drawable area is in
 258   // the overflow rect of the child textframe.
 259   aMetrics.mOverflowArea.UnionRect(aMetrics.mOverflowArea,
 260                            nsRect(0, 0, aMetrics.width, aMetrics.height));
 261   ConsiderChildOverflow(aMetrics.mOverflowArea, kid);
 262
 263   // Create a continuation or remove existing continuations based on
 264   // the reflow completion status.
 265   if (NS_FRAME_IS_COMPLETE(aReflowStatus)) {
 266     if (aReflowState.mLineLayout) {
 267       aReflowState.mLineLayout->SetFirstLetterStyleOK(PR_FALSE);
 268     }
 269     nsIFrame* kidNextInFlow = kid->GetNextInFlow();
 270     if (kidNextInFlow) {
 271       // Remove all of the childs next-in-flows
 272       static_cast<nsContainerFrame*>(kidNextInFlow->GetParent())
 273         ->DeleteNextInFlowChild(aPresContext, kidNextInFlow);
 274     }
 275   }
 276   else {
 277     // Create a continuation for the child frame if it doesn't already
 278     // have one.
 279     nsIFrame* nextInFlow;
 280     rv = CreateNextInFlow(aPresContext, this, kid, nextInFlow);
 281     if (NS_FAILED(rv)) {
 282       return rv;
 283     }
 284
 285     // And then push it to our overflow list
 286     if (nextInFlow) {
 287       kid->SetNextSibling(nsnull);
 288       SetOverflowFrames(aPresContext, nextInFlow);
 289     }
 290     else {
 291       nsIFrame* nextSib = kid->GetNextSibling();
 292       if (nextSib) {
 293         kid->SetNextSibling(nsnull);
 294         SetOverflowFrames(aPresContext, nextSib);
 295       }
 296     }
 297   }
 298
 299   FinishAndStoreOverflow(&aMetrics);
 300
 301   NS_FRAME_SET_TRUNCATION(aReflowStatus, aReflowState, aMetrics);
 302   return rv;
 303 }
 304
 305 /* virtual */ PRBool
 306 nsFirstLetterFrame::CanContinueTextRun() const
 307 {
 308   // We can continue a text run through a first-letter frame.
 309   return PR_TRUE;
 310 }
 311
 312 void
 313 nsFirstLetterFrame::DrainOverflowFrames(nsPresContext* aPresContext)
 314 {
 315   nsIFrame* overflowFrames;
 316
 317   // Check for an overflow list with our prev-in-flow
 318   nsFirstLetterFrame* prevInFlow = (nsFirstLetterFrame*)GetPrevInFlow();
 319   if (nsnull != prevInFlow) {
 320     overflowFrames = prevInFlow->GetOverflowFrames(aPresContext, PR_TRUE);
 321     if (overflowFrames) {
 322       NS_ASSERTION(mFrames.IsEmpty(), "bad overflow list");
 323
 324       // When pushing and pulling frames we need to check for whether any
 325       // views need to be reparented.
 326       nsIFrame* f = overflowFrames;
 327       while (f) {
 328         nsHTMLContainerFrame::ReparentFrameView(aPresContext, f, prevInFlow, this);
 329         f = f->GetNextSibling();
 330       }
 331       mFrames.InsertFrames(this, nsnull, overflowFrames);
 332     }
 333   }
 334
 335   // It's also possible that we have an overflow list for ourselves
 336   overflowFrames = GetOverflowFrames(aPresContext, PR_TRUE);
 337   if (overflowFrames) {
 338     NS_ASSERTION(mFrames.NotEmpty(), "overflow list w/o frames");
 339     mFrames.AppendFrames(nsnull, overflowFrames);
 340   }
 341
 342   // Now repair our first frames style context (since we only reflow
 343   // one frame there is no point in doing any other ones until they
 344   // are reflowed)
 345   nsIFrame* kid = mFrames.FirstChild();
 346   if (kid) {
 347     nsRefPtr<nsStyleContext> sc;
 348     nsIContent* kidContent = kid->GetContent();
 349     if (kidContent) {
 350       NS_ASSERTION(kidContent->IsNodeOfType(nsINode::eTEXT),
 351                    "should contain only text nodes");
 352       sc = aPresContext->StyleSet()->ResolveStyleForNonElement(mStyleContext);
 353       if (sc) {
 354         kid->SetStyleContext(sc);
 355       }
 356     }
 357   }
 358 }