/* * Copyright (C) 2012 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "config.h" #include "RenderMultiColumnBlock.h" #include "RenderMultiColumnFlowThread.h" #include "RenderMultiColumnSet.h" #include "StyleInheritedData.h" using namespace std; namespace WebCore { RenderMultiColumnBlock::RenderMultiColumnBlock(Node* node) : RenderBlock(node) , m_flowThread(0) , m_columnCount(1) , m_columnWidth(0) , m_columnHeight(0) { } void RenderMultiColumnBlock::computeColumnCountAndWidth() { // Calculate our column width and column count. // FIXME: Can overflow on fast/block/float/float-not-removed-from-next-sibling4.html, see https://bugs.webkit.org/show_bug.cgi?id=68744 m_columnCount = 1; m_columnWidth = contentLogicalWidth(); ASSERT(!style()->hasAutoColumnCount() || !style()->hasAutoColumnWidth()); LayoutUnit availWidth = m_columnWidth; LayoutUnit colGap = columnGap(); LayoutUnit colWidth = max(1, LayoutUnit(style()->columnWidth())); int colCount = max(1, style()->columnCount()); if (style()->hasAutoColumnWidth() && !style()->hasAutoColumnCount()) { m_columnCount = colCount; m_columnWidth = max(0, (availWidth - ((m_columnCount - 1) * colGap)) / m_columnCount); } else if (!style()->hasAutoColumnWidth() && style()->hasAutoColumnCount()) { m_columnCount = max(1, (availWidth + colGap) / (colWidth + colGap)); m_columnWidth = ((availWidth + colGap) / m_columnCount) - colGap; } else { m_columnCount = max(min(colCount, (availWidth + colGap) / (colWidth + colGap)), 1); m_columnWidth = ((availWidth + colGap) / m_columnCount) - colGap; } } bool RenderMultiColumnBlock::updateLogicalWidthAndColumnWidth() { bool relayoutChildren = RenderBlock::updateLogicalWidthAndColumnWidth(); LayoutUnit oldColumnWidth = m_columnWidth; computeColumnCountAndWidth(); if (m_columnWidth != oldColumnWidth) relayoutChildren = true; return relayoutChildren; } void RenderMultiColumnBlock::checkForPaginationLogicalHeightChange(LayoutUnit& /*pageLogicalHeight*/, bool& /*pageLogicalHeightChanged*/, bool& /*hasSpecifiedPageLogicalHeight*/) { // We don't actually update any of the variables. We just subclassed to adjust our column height. updateLogicalHeight(); LayoutUnit newContentLogicalHeight = contentLogicalHeight(); if (newContentLogicalHeight > 0) { // The regions will be invalidated when we lay them out and they change size to // the new column height. if (columnHeight() != newContentLogicalHeight) setColumnHeight(newContentLogicalHeight); } setLogicalHeight(0); // Set up our column sets. ensureColumnSets(); } bool RenderMultiColumnBlock::relayoutForPagination(bool, LayoutUnit, LayoutStateMaintainer&) { // FIXME: Implement. return false; } void RenderMultiColumnBlock::addChild(RenderObject* newChild, RenderObject* beforeChild) { if (!m_flowThread) { m_flowThread = new (renderArena()) RenderMultiColumnFlowThread(document()); m_flowThread->setStyle(RenderStyle::createAnonymousStyleWithDisplay(style(), BLOCK)); RenderBlock::addChild(m_flowThread); // Always put the flow thread at the end. } // Column sets are siblings of the flow thread. All children designed to be in the columns, however, are part // of the flow thread itself. if (newChild->isRenderMultiColumnSet()) RenderBlock::addChild(newChild, beforeChild); else m_flowThread->addChild(newChild, beforeChild); } void RenderMultiColumnBlock::ensureColumnSets() { // This function ensures we have the correct column set information before we get into layout. // For a simple multi-column layout in continuous media, only one column set child is required. // Once a column is nested inside an enclosing pagination context, the number of column sets // required becomes 2n-1, where n is the total number of nested pagination contexts. For example: // // Column layout with no enclosing pagination model = 2 * 1 - 1 = 1 column set. // Columns inside pages = 2 * 2 - 1 = 3 column sets (bottom of first page, all the subsequent pages, then the last page). // Columns inside columns inside pages = 2 * 3 - 1 = 5 column sets. // // In addition, column spans will force a column set to "split" into before/after sets around the spanning region. // // Finally, we will need to deal with columns inside regions. If regions have variable widths, then there will need // to be unique column sets created inside any region whose width is different from its surrounding regions. This is // actually pretty similar to the spanning case, in that we break up the column sets whenever the width varies. // // FIXME: For now just make one column set. This matches the old multi-column code. // Right now our goal is just feature parity with the old multi-column code so that we can switch over to the // new code as soon as possible. if (flowThread() && !firstChild()->isRenderMultiColumnSet()) { RenderMultiColumnSet* columnSet = new (renderArena()) RenderMultiColumnSet(document(), flowThread()); columnSet->setStyle(RenderStyle::createAnonymousStyleWithDisplay(style(), BLOCK)); RenderBlock::addChild(columnSet, firstChild()); } } const char* RenderMultiColumnBlock::renderName() const { if (isFloating()) return "RenderMultiColumnBlock (floating)"; if (isOutOfFlowPositioned()) return "RenderMultiColumnBlock (positioned)"; if (isAnonymousBlock()) return "RenderMultiColumnBlock (anonymous)"; if (isAnonymous()) return "RenderMultiColumnBlock (generated)"; if (isRelPositioned()) return "RenderMultiColumnBlock (relative positioned)"; return "RenderMultiColumnBlock"; } }