1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/generic/nsSplittableFrame.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,301 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/*
1.10 + * base class for rendering objects that can be split across lines,
1.11 + * columns, or pages
1.12 + */
1.13 +
1.14 +#include "nsSplittableFrame.h"
1.15 +#include "nsContainerFrame.h"
1.16 +#include "nsIFrameInlines.h"
1.17 +
1.18 +NS_IMPL_FRAMEARENA_HELPERS(nsSplittableFrame)
1.19 +
1.20 +void
1.21 +nsSplittableFrame::Init(nsIContent* aContent,
1.22 + nsIFrame* aParent,
1.23 + nsIFrame* aPrevInFlow)
1.24 +{
1.25 + nsFrame::Init(aContent, aParent, aPrevInFlow);
1.26 +
1.27 + if (aPrevInFlow) {
1.28 + // Hook the frame into the flow
1.29 + SetPrevInFlow(aPrevInFlow);
1.30 + aPrevInFlow->SetNextInFlow(this);
1.31 + }
1.32 +}
1.33 +
1.34 +void
1.35 +nsSplittableFrame::DestroyFrom(nsIFrame* aDestructRoot)
1.36 +{
1.37 + // Disconnect from the flow list
1.38 + if (mPrevContinuation || mNextContinuation) {
1.39 + RemoveFromFlow(this);
1.40 + }
1.41 +
1.42 + // Let the base class destroy the frame
1.43 + nsFrame::DestroyFrom(aDestructRoot);
1.44 +}
1.45 +
1.46 +nsSplittableType
1.47 +nsSplittableFrame::GetSplittableType() const
1.48 +{
1.49 + return NS_FRAME_SPLITTABLE;
1.50 +}
1.51 +
1.52 +nsIFrame* nsSplittableFrame::GetPrevContinuation() const
1.53 +{
1.54 + return mPrevContinuation;
1.55 +}
1.56 +
1.57 +void
1.58 +nsSplittableFrame::SetPrevContinuation(nsIFrame* aFrame)
1.59 +{
1.60 + NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "setting a prev continuation with incorrect type!");
1.61 + NS_ASSERTION (!IsInPrevContinuationChain(aFrame, this), "creating a loop in continuation chain!");
1.62 + mPrevContinuation = aFrame;
1.63 + RemoveStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
1.64 +}
1.65 +
1.66 +nsIFrame* nsSplittableFrame::GetNextContinuation() const
1.67 +{
1.68 + return mNextContinuation;
1.69 +}
1.70 +
1.71 +void
1.72 +nsSplittableFrame::SetNextContinuation(nsIFrame* aFrame)
1.73 +{
1.74 + NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "setting a next continuation with incorrect type!");
1.75 + NS_ASSERTION (!IsInNextContinuationChain(aFrame, this), "creating a loop in continuation chain!");
1.76 + mNextContinuation = aFrame;
1.77 + if (aFrame)
1.78 + aFrame->RemoveStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
1.79 +}
1.80 +
1.81 +nsIFrame*
1.82 +nsSplittableFrame::FirstContinuation() const
1.83 +{
1.84 + nsSplittableFrame* firstContinuation = const_cast<nsSplittableFrame*>(this);
1.85 + while (firstContinuation->mPrevContinuation) {
1.86 + firstContinuation = static_cast<nsSplittableFrame*>(firstContinuation->mPrevContinuation);
1.87 + }
1.88 + MOZ_ASSERT(firstContinuation, "post-condition failed");
1.89 + return firstContinuation;
1.90 +}
1.91 +
1.92 +nsIFrame*
1.93 +nsSplittableFrame::LastContinuation() const
1.94 +{
1.95 + nsSplittableFrame* lastContinuation = const_cast<nsSplittableFrame*>(this);
1.96 + while (lastContinuation->mNextContinuation) {
1.97 + lastContinuation = static_cast<nsSplittableFrame*>(lastContinuation->mNextContinuation);
1.98 + }
1.99 + MOZ_ASSERT(lastContinuation, "post-condition failed");
1.100 + return lastContinuation;
1.101 +}
1.102 +
1.103 +#ifdef DEBUG
1.104 +bool nsSplittableFrame::IsInPrevContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2)
1.105 +{
1.106 + int32_t iterations = 0;
1.107 + while (aFrame1 && iterations < 10) {
1.108 + // Bail out after 10 iterations so we don't bog down debug builds too much
1.109 + if (aFrame1 == aFrame2)
1.110 + return true;
1.111 + aFrame1 = aFrame1->GetPrevContinuation();
1.112 + ++iterations;
1.113 + }
1.114 + return false;
1.115 +}
1.116 +
1.117 +bool nsSplittableFrame::IsInNextContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2)
1.118 +{
1.119 + int32_t iterations = 0;
1.120 + while (aFrame1 && iterations < 10) {
1.121 + // Bail out after 10 iterations so we don't bog down debug builds too much
1.122 + if (aFrame1 == aFrame2)
1.123 + return true;
1.124 + aFrame1 = aFrame1->GetNextContinuation();
1.125 + ++iterations;
1.126 + }
1.127 + return false;
1.128 +}
1.129 +#endif
1.130 +
1.131 +nsIFrame* nsSplittableFrame::GetPrevInFlow() const
1.132 +{
1.133 + return (GetStateBits() & NS_FRAME_IS_FLUID_CONTINUATION) ? mPrevContinuation : nullptr;
1.134 +}
1.135 +
1.136 +void
1.137 +nsSplittableFrame::SetPrevInFlow(nsIFrame* aFrame)
1.138 +{
1.139 + NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "setting a prev in flow with incorrect type!");
1.140 + NS_ASSERTION (!IsInPrevContinuationChain(aFrame, this), "creating a loop in continuation chain!");
1.141 + mPrevContinuation = aFrame;
1.142 + AddStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
1.143 +}
1.144 +
1.145 +nsIFrame* nsSplittableFrame::GetNextInFlow() const
1.146 +{
1.147 + return mNextContinuation && (mNextContinuation->GetStateBits() & NS_FRAME_IS_FLUID_CONTINUATION) ?
1.148 + mNextContinuation : nullptr;
1.149 +}
1.150 +
1.151 +void
1.152 +nsSplittableFrame::SetNextInFlow(nsIFrame* aFrame)
1.153 +{
1.154 + NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "setting a next in flow with incorrect type!");
1.155 + NS_ASSERTION (!IsInNextContinuationChain(aFrame, this), "creating a loop in continuation chain!");
1.156 + mNextContinuation = aFrame;
1.157 + if (aFrame)
1.158 + aFrame->AddStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
1.159 +}
1.160 +
1.161 +nsIFrame*
1.162 +nsSplittableFrame::FirstInFlow() const
1.163 +{
1.164 + nsSplittableFrame* firstInFlow = const_cast<nsSplittableFrame*>(this);
1.165 + while (nsIFrame* prev = firstInFlow->GetPrevInFlow()) {
1.166 + firstInFlow = static_cast<nsSplittableFrame*>(prev);
1.167 + }
1.168 + MOZ_ASSERT(firstInFlow, "post-condition failed");
1.169 + return firstInFlow;
1.170 +}
1.171 +
1.172 +nsIFrame*
1.173 +nsSplittableFrame::LastInFlow() const
1.174 +{
1.175 + nsSplittableFrame* lastInFlow = const_cast<nsSplittableFrame*>(this);
1.176 + while (nsIFrame* next = lastInFlow->GetNextInFlow()) {
1.177 + lastInFlow = static_cast<nsSplittableFrame*>(next);
1.178 + }
1.179 + MOZ_ASSERT(lastInFlow, "post-condition failed");
1.180 + return lastInFlow;
1.181 +}
1.182 +
1.183 +// Remove this frame from the flow. Connects prev in flow and next in flow
1.184 +void
1.185 +nsSplittableFrame::RemoveFromFlow(nsIFrame* aFrame)
1.186 +{
1.187 + nsIFrame* prevContinuation = aFrame->GetPrevContinuation();
1.188 + nsIFrame* nextContinuation = aFrame->GetNextContinuation();
1.189 +
1.190 + // The new continuation is fluid only if the continuation on both sides
1.191 + // of the removed frame was fluid
1.192 + if (aFrame->GetPrevInFlow() && aFrame->GetNextInFlow()) {
1.193 + if (prevContinuation) {
1.194 + prevContinuation->SetNextInFlow(nextContinuation);
1.195 + }
1.196 + if (nextContinuation) {
1.197 + nextContinuation->SetPrevInFlow(prevContinuation);
1.198 + }
1.199 + } else {
1.200 + if (prevContinuation) {
1.201 + prevContinuation->SetNextContinuation(nextContinuation);
1.202 + }
1.203 + if (nextContinuation) {
1.204 + nextContinuation->SetPrevContinuation(prevContinuation);
1.205 + }
1.206 + }
1.207 +
1.208 + aFrame->SetPrevInFlow(nullptr);
1.209 + aFrame->SetNextInFlow(nullptr);
1.210 +}
1.211 +
1.212 +nscoord
1.213 +nsSplittableFrame::GetConsumedHeight() const
1.214 +{
1.215 + nscoord height = 0;
1.216 +
1.217 + // Reduce the height by the computed height of prev-in-flows.
1.218 + for (nsIFrame* prev = GetPrevInFlow(); prev; prev = prev->GetPrevInFlow()) {
1.219 + height += prev->GetRect().height;
1.220 + }
1.221 +
1.222 + return height;
1.223 +}
1.224 +
1.225 +nscoord
1.226 +nsSplittableFrame::GetEffectiveComputedHeight(const nsHTMLReflowState& aReflowState,
1.227 + nscoord aConsumedHeight) const
1.228 +{
1.229 + nscoord height = aReflowState.ComputedHeight();
1.230 + if (height == NS_INTRINSICSIZE) {
1.231 + return NS_INTRINSICSIZE;
1.232 + }
1.233 +
1.234 + if (aConsumedHeight == NS_INTRINSICSIZE) {
1.235 + aConsumedHeight = GetConsumedHeight();
1.236 + }
1.237 +
1.238 + height -= aConsumedHeight;
1.239 +
1.240 + if (aConsumedHeight != 0 && aConsumedHeight != NS_INTRINSICSIZE) {
1.241 + // We just subtracted our top-border padding, since it was included in the
1.242 + // first frame's height. Add it back to get the content height.
1.243 + height += aReflowState.ComputedPhysicalBorderPadding().top;
1.244 + }
1.245 +
1.246 + // We may have stretched the frame beyond its computed height. Oh well.
1.247 + height = std::max(0, height);
1.248 +
1.249 + return height;
1.250 +}
1.251 +
1.252 +int
1.253 +nsSplittableFrame::GetLogicalSkipSides(const nsHTMLReflowState* aReflowState) const
1.254 +{
1.255 + if (IS_TRUE_OVERFLOW_CONTAINER(this)) {
1.256 + return LOGICAL_SIDES_B_BOTH;
1.257 + }
1.258 +
1.259 + int skip = 0;
1.260 +
1.261 + if (GetPrevInFlow()) {
1.262 + skip |= LOGICAL_SIDE_B_START;
1.263 + }
1.264 +
1.265 + if (aReflowState) {
1.266 + // We're in the midst of reflow right now, so it's possible that we haven't
1.267 + // created a nif yet. If our content height is going to exceed our available
1.268 + // height, though, then we're going to need a next-in-flow, it just hasn't
1.269 + // been created yet.
1.270 +
1.271 + if (NS_UNCONSTRAINEDSIZE != aReflowState->AvailableHeight()) {
1.272 + nscoord effectiveCH = this->GetEffectiveComputedHeight(*aReflowState);
1.273 + if (effectiveCH > aReflowState->AvailableHeight()) {
1.274 + // Our content height is going to exceed our available height, so we're
1.275 + // going to need a next-in-flow.
1.276 + skip |= LOGICAL_SIDE_B_END;
1.277 + }
1.278 + }
1.279 + } else {
1.280 + nsIFrame* nif = GetNextInFlow();
1.281 + if (nif && !IS_TRUE_OVERFLOW_CONTAINER(nif)) {
1.282 + skip |= LOGICAL_SIDE_B_END;
1.283 + }
1.284 + }
1.285 +
1.286 + return skip;
1.287 +}
1.288 +
1.289 +#ifdef DEBUG
1.290 +void
1.291 +nsSplittableFrame::DumpBaseRegressionData(nsPresContext* aPresContext, FILE* out, int32_t aIndent)
1.292 +{
1.293 + nsFrame::DumpBaseRegressionData(aPresContext, out, aIndent);
1.294 + if (nullptr != mNextContinuation) {
1.295 + IndentBy(out, aIndent);
1.296 + fprintf(out, "<next-continuation va=\"%p\"/>\n", (void*)mNextContinuation);
1.297 + }
1.298 + if (nullptr != mPrevContinuation) {
1.299 + IndentBy(out, aIndent);
1.300 + fprintf(out, "<prev-continuation va=\"%p\"/>\n", (void*)mPrevContinuation);
1.301 + }
1.302 +
1.303 +}
1.304 +#endif
