michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * base class for rendering objects that can be split across lines,
michael@0:  * columns, or pages
michael@0:  */
michael@0: 
michael@0: #include "nsSplittableFrame.h"
michael@0: #include "nsContainerFrame.h"
michael@0: #include "nsIFrameInlines.h"
michael@0: 
michael@0: NS_IMPL_FRAMEARENA_HELPERS(nsSplittableFrame)
michael@0: 
michael@0: void
michael@0: nsSplittableFrame::Init(nsIContent*      aContent,
michael@0:                         nsIFrame*        aParent,
michael@0:                         nsIFrame*        aPrevInFlow)
michael@0: {
michael@0:   nsFrame::Init(aContent, aParent, aPrevInFlow);
michael@0: 
michael@0:   if (aPrevInFlow) {
michael@0:     // Hook the frame into the flow
michael@0:     SetPrevInFlow(aPrevInFlow);
michael@0:     aPrevInFlow->SetNextInFlow(this);
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSplittableFrame::DestroyFrom(nsIFrame* aDestructRoot)
michael@0: {
michael@0:   // Disconnect from the flow list
michael@0:   if (mPrevContinuation || mNextContinuation) {
michael@0:     RemoveFromFlow(this);
michael@0:   }
michael@0: 
michael@0:   // Let the base class destroy the frame
michael@0:   nsFrame::DestroyFrom(aDestructRoot);
michael@0: }
michael@0: 
michael@0: nsSplittableType
michael@0: nsSplittableFrame::GetSplittableType() const
michael@0: {
michael@0:   return NS_FRAME_SPLITTABLE;
michael@0: }
michael@0: 
michael@0: nsIFrame* nsSplittableFrame::GetPrevContinuation() const
michael@0: {
michael@0:   return mPrevContinuation;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSplittableFrame::SetPrevContinuation(nsIFrame* aFrame)
michael@0: {
michael@0:   NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "setting a prev continuation with incorrect type!");
michael@0:   NS_ASSERTION (!IsInPrevContinuationChain(aFrame, this), "creating a loop in continuation chain!");
michael@0:   mPrevContinuation = aFrame;
michael@0:   RemoveStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
michael@0: }
michael@0: 
michael@0: nsIFrame* nsSplittableFrame::GetNextContinuation() const
michael@0: {
michael@0:   return mNextContinuation;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSplittableFrame::SetNextContinuation(nsIFrame* aFrame)
michael@0: {
michael@0:   NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(),  "setting a next continuation with incorrect type!");
michael@0:   NS_ASSERTION (!IsInNextContinuationChain(aFrame, this), "creating a loop in continuation chain!");
michael@0:   mNextContinuation = aFrame;
michael@0:   if (aFrame)
michael@0:     aFrame->RemoveStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
michael@0: }
michael@0: 
michael@0: nsIFrame*
michael@0: nsSplittableFrame::FirstContinuation() const
michael@0: {
michael@0:   nsSplittableFrame* firstContinuation = const_cast<nsSplittableFrame*>(this);
michael@0:   while (firstContinuation->mPrevContinuation)  {
michael@0:     firstContinuation = static_cast<nsSplittableFrame*>(firstContinuation->mPrevContinuation);
michael@0:   }
michael@0:   MOZ_ASSERT(firstContinuation, "post-condition failed");
michael@0:   return firstContinuation;
michael@0: }
michael@0: 
michael@0: nsIFrame*
michael@0: nsSplittableFrame::LastContinuation() const
michael@0: {
michael@0:   nsSplittableFrame* lastContinuation = const_cast<nsSplittableFrame*>(this);
michael@0:   while (lastContinuation->mNextContinuation)  {
michael@0:     lastContinuation = static_cast<nsSplittableFrame*>(lastContinuation->mNextContinuation);
michael@0:   }
michael@0:   MOZ_ASSERT(lastContinuation, "post-condition failed");
michael@0:   return lastContinuation;
michael@0: }
michael@0: 
michael@0: #ifdef DEBUG
michael@0: bool nsSplittableFrame::IsInPrevContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2)
michael@0: {
michael@0:   int32_t iterations = 0;
michael@0:   while (aFrame1 && iterations < 10) {
michael@0:     // Bail out after 10 iterations so we don't bog down debug builds too much
michael@0:     if (aFrame1 == aFrame2)
michael@0:       return true;
michael@0:     aFrame1 = aFrame1->GetPrevContinuation();
michael@0:     ++iterations;
michael@0:   }
michael@0:   return false;
michael@0: }
michael@0: 
michael@0: bool nsSplittableFrame::IsInNextContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2)
michael@0: {
michael@0:   int32_t iterations = 0;
michael@0:   while (aFrame1 && iterations < 10) {
michael@0:     // Bail out after 10 iterations so we don't bog down debug builds too much
michael@0:     if (aFrame1 == aFrame2)
michael@0:       return true;
michael@0:     aFrame1 = aFrame1->GetNextContinuation();
michael@0:     ++iterations;
michael@0:   }
michael@0:   return false;
michael@0: }
michael@0: #endif
michael@0: 
michael@0: nsIFrame* nsSplittableFrame::GetPrevInFlow() const
michael@0: {
michael@0:   return (GetStateBits() & NS_FRAME_IS_FLUID_CONTINUATION) ? mPrevContinuation : nullptr;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSplittableFrame::SetPrevInFlow(nsIFrame* aFrame)
michael@0: {
michael@0:   NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "setting a prev in flow with incorrect type!");
michael@0:   NS_ASSERTION (!IsInPrevContinuationChain(aFrame, this), "creating a loop in continuation chain!");
michael@0:   mPrevContinuation = aFrame;
michael@0:   AddStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
michael@0: }
michael@0: 
michael@0: nsIFrame* nsSplittableFrame::GetNextInFlow() const
michael@0: {
michael@0:   return mNextContinuation && (mNextContinuation->GetStateBits() & NS_FRAME_IS_FLUID_CONTINUATION) ? 
michael@0:     mNextContinuation : nullptr;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSplittableFrame::SetNextInFlow(nsIFrame* aFrame)
michael@0: {
michael@0:   NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(),  "setting a next in flow with incorrect type!");
michael@0:   NS_ASSERTION (!IsInNextContinuationChain(aFrame, this), "creating a loop in continuation chain!");
michael@0:   mNextContinuation = aFrame;
michael@0:   if (aFrame)
michael@0:     aFrame->AddStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
michael@0: }
michael@0: 
michael@0: nsIFrame*
michael@0: nsSplittableFrame::FirstInFlow() const
michael@0: {
michael@0:   nsSplittableFrame* firstInFlow = const_cast<nsSplittableFrame*>(this);
michael@0:   while (nsIFrame* prev = firstInFlow->GetPrevInFlow())  {
michael@0:     firstInFlow = static_cast<nsSplittableFrame*>(prev);
michael@0:   }
michael@0:   MOZ_ASSERT(firstInFlow, "post-condition failed");
michael@0:   return firstInFlow;
michael@0: }
michael@0: 
michael@0: nsIFrame*
michael@0: nsSplittableFrame::LastInFlow() const
michael@0: {
michael@0:   nsSplittableFrame* lastInFlow = const_cast<nsSplittableFrame*>(this);
michael@0:   while (nsIFrame* next = lastInFlow->GetNextInFlow())  {
michael@0:     lastInFlow = static_cast<nsSplittableFrame*>(next);
michael@0:   }
michael@0:   MOZ_ASSERT(lastInFlow, "post-condition failed");
michael@0:   return lastInFlow;
michael@0: }
michael@0: 
michael@0: // Remove this frame from the flow. Connects prev in flow and next in flow
michael@0: void
michael@0: nsSplittableFrame::RemoveFromFlow(nsIFrame* aFrame)
michael@0: {
michael@0:   nsIFrame* prevContinuation = aFrame->GetPrevContinuation();
michael@0:   nsIFrame* nextContinuation = aFrame->GetNextContinuation();
michael@0: 
michael@0:   // The new continuation is fluid only if the continuation on both sides
michael@0:   // of the removed frame was fluid
michael@0:   if (aFrame->GetPrevInFlow() && aFrame->GetNextInFlow()) {
michael@0:     if (prevContinuation) {
michael@0:       prevContinuation->SetNextInFlow(nextContinuation);
michael@0:     }
michael@0:     if (nextContinuation) {
michael@0:       nextContinuation->SetPrevInFlow(prevContinuation);
michael@0:     }
michael@0:   } else {
michael@0:     if (prevContinuation) {
michael@0:       prevContinuation->SetNextContinuation(nextContinuation);
michael@0:     }
michael@0:     if (nextContinuation) {
michael@0:       nextContinuation->SetPrevContinuation(prevContinuation);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   aFrame->SetPrevInFlow(nullptr);
michael@0:   aFrame->SetNextInFlow(nullptr);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsSplittableFrame::GetConsumedHeight() const
michael@0: {
michael@0:   nscoord height = 0;
michael@0: 
michael@0:   // Reduce the height by the computed height of prev-in-flows.
michael@0:   for (nsIFrame* prev = GetPrevInFlow(); prev; prev = prev->GetPrevInFlow()) {
michael@0:     height += prev->GetRect().height;
michael@0:   }
michael@0: 
michael@0:   return height;
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsSplittableFrame::GetEffectiveComputedHeight(const nsHTMLReflowState& aReflowState,
michael@0:                                               nscoord aConsumedHeight) const
michael@0: {
michael@0:   nscoord height = aReflowState.ComputedHeight();
michael@0:   if (height == NS_INTRINSICSIZE) {
michael@0:     return NS_INTRINSICSIZE;
michael@0:   }
michael@0: 
michael@0:   if (aConsumedHeight == NS_INTRINSICSIZE) {
michael@0:     aConsumedHeight = GetConsumedHeight();
michael@0:   }
michael@0: 
michael@0:   height -= aConsumedHeight;
michael@0: 
michael@0:   if (aConsumedHeight != 0 && aConsumedHeight != NS_INTRINSICSIZE) {
michael@0:     // We just subtracted our top-border padding, since it was included in the
michael@0:     // first frame's height. Add it back to get the content height.
michael@0:     height += aReflowState.ComputedPhysicalBorderPadding().top;
michael@0:   }
michael@0: 
michael@0:   // We may have stretched the frame beyond its computed height. Oh well.
michael@0:   height = std::max(0, height);
michael@0: 
michael@0:   return height;
michael@0: }
michael@0: 
michael@0: int
michael@0: nsSplittableFrame::GetLogicalSkipSides(const nsHTMLReflowState* aReflowState) const
michael@0: {
michael@0:   if (IS_TRUE_OVERFLOW_CONTAINER(this)) {
michael@0:     return LOGICAL_SIDES_B_BOTH;
michael@0:   }
michael@0: 
michael@0:   int skip = 0;
michael@0: 
michael@0:   if (GetPrevInFlow()) {
michael@0:     skip |= LOGICAL_SIDE_B_START;
michael@0:   }
michael@0: 
michael@0:   if (aReflowState) {
michael@0:     // We're in the midst of reflow right now, so it's possible that we haven't
michael@0:     // created a nif yet. If our content height is going to exceed our available
michael@0:     // height, though, then we're going to need a next-in-flow, it just hasn't
michael@0:     // been created yet.
michael@0: 
michael@0:     if (NS_UNCONSTRAINEDSIZE != aReflowState->AvailableHeight()) {
michael@0:       nscoord effectiveCH = this->GetEffectiveComputedHeight(*aReflowState);
michael@0:       if (effectiveCH > aReflowState->AvailableHeight()) {
michael@0:         // Our content height is going to exceed our available height, so we're
michael@0:         // going to need a next-in-flow.
michael@0:         skip |= LOGICAL_SIDE_B_END;
michael@0:       }
michael@0:     }
michael@0:   } else {
michael@0:     nsIFrame* nif = GetNextInFlow();
michael@0:     if (nif && !IS_TRUE_OVERFLOW_CONTAINER(nif)) {
michael@0:       skip |= LOGICAL_SIDE_B_END;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:  return skip;
michael@0: }
michael@0: 
michael@0: #ifdef DEBUG
michael@0: void
michael@0: nsSplittableFrame::DumpBaseRegressionData(nsPresContext* aPresContext, FILE* out, int32_t aIndent)
michael@0: {
michael@0:   nsFrame::DumpBaseRegressionData(aPresContext, out, aIndent);
michael@0:   if (nullptr != mNextContinuation) {
michael@0:     IndentBy(out, aIndent);
michael@0:     fprintf(out, "<next-continuation va=\"%p\"/>\n", (void*)mNextContinuation);
michael@0:   }
michael@0:   if (nullptr != mPrevContinuation) {
michael@0:     IndentBy(out, aIndent);
michael@0:     fprintf(out, "<prev-continuation va=\"%p\"/>\n", (void*)mPrevContinuation);
michael@0:   }
michael@0: 
michael@0: }
michael@0: #endif