| OLD | NEW |
|---|
| (Empty) |
| 1 /* | |
| 2 * Copyright (C) 2012 Apple Inc. All rights reserved. | |
| 3 * | |
| 4 * Redistribution and use in source and binary forms, with or without | |
| 5 * modification, are permitted provided that the following conditions | |
| 6 * are met: | |
| 7 * 1. Redistributions of source code must retain the above copyright | |
| 8 * notice, this list of conditions and the following disclaimer. | |
| 9 * 2. Redistributions in binary form must reproduce the above copyright | |
| 10 * notice, this list of conditions and the following disclaimer in the | |
| 11 * documentation and/or other materials provided with the distribution. | |
| 12 * | |
| 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY | |
| 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
| 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR | |
| 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | |
| 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | |
| 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | |
| 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY | |
| 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
| 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 24 */ | |
| 25 | |
| 26 #include "config.h" | |
| 27 #include "core/rendering/RenderMultiColumnSet.h" | |
| 28 | |
| 29 #include "core/rendering/PaintInfo.h" | |
| 30 #include "core/rendering/RenderLayer.h" | |
| 31 #include "core/rendering/RenderMultiColumnBlock.h" | |
| 32 #include "core/rendering/RenderMultiColumnFlowThread.h" | |
| 33 | |
| 34 using namespace std; | |
| 35 | |
| 36 namespace WebCore { | |
| 37 | |
| 38 RenderMultiColumnSet::RenderMultiColumnSet(RenderFlowThread* flowThread) | |
| 39 : RenderRegionSet(0, flowThread) | |
| 40 , m_computedColumnCount(1) | |
| 41 , m_computedColumnWidth(0) | |
| 42 , m_computedColumnHeight(0) | |
| 43 , m_maxColumnHeight(LayoutUnit::max()) | |
| 44 , m_minSpaceShortage(LayoutUnit::max()) | |
| 45 , m_minimumColumnHeight(0) | |
| 46 , m_forcedBreaksCount(0) | |
| 47 , m_maximumDistanceBetweenForcedBreaks(0) | |
| 48 , m_forcedBreakOffset(0) | |
| 49 { | |
| 50 } | |
| 51 | |
| 52 RenderMultiColumnSet* RenderMultiColumnSet::createAnonymous(RenderFlowThread* fl
owThread) | |
| 53 { | |
| 54 Document& document = flowThread->document(); | |
| 55 RenderMultiColumnSet* renderer = new RenderMultiColumnSet(flowThread); | |
| 56 renderer->setDocumentForAnonymous(&document); | |
| 57 return renderer; | |
| 58 } | |
| 59 | |
| 60 LayoutUnit RenderMultiColumnSet::heightAdjustedForSetOffset(LayoutUnit height) c
onst | |
| 61 { | |
| 62 RenderMultiColumnBlock* multicolBlock = toRenderMultiColumnBlock(parent()); | |
| 63 LayoutUnit contentLogicalTop = logicalTop() - multicolBlock->borderBefore()
- multicolBlock->paddingBefore(); | |
| 64 | |
| 65 height -= contentLogicalTop; | |
| 66 return max(height, LayoutUnit(1)); // Let's avoid zero height, as that would
probably cause an infinite amount of columns to be created. | |
| 67 } | |
| 68 | |
| 69 LayoutUnit RenderMultiColumnSet::pageLogicalTopForOffset(LayoutUnit offset) cons
t | |
| 70 { | |
| 71 LayoutUnit portionLogicalTop = (isHorizontalWritingMode() ? flowThreadPortio
nRect().y() : flowThreadPortionRect().x()); | |
| 72 unsigned columnIndex = columnIndexAtOffset(offset, AssumeNewColumns); | |
| 73 return portionLogicalTop + columnIndex * computedColumnHeight(); | |
| 74 } | |
| 75 | |
| 76 void RenderMultiColumnSet::setAndConstrainColumnHeight(LayoutUnit newHeight) | |
| 77 { | |
| 78 m_computedColumnHeight = newHeight; | |
| 79 if (m_computedColumnHeight > m_maxColumnHeight) | |
| 80 m_computedColumnHeight = m_maxColumnHeight; | |
| 81 // FIXME: the height may also be affected by the enclosing pagination contex
t, if any. | |
| 82 } | |
| 83 | |
| 84 bool RenderMultiColumnSet::calculateBalancedHeight(bool initial) | |
| 85 { | |
| 86 ASSERT(toRenderMultiColumnBlock(parent())->requiresBalancing()); | |
| 87 LayoutUnit oldColumnHeight = m_computedColumnHeight; | |
| 88 LayoutUnit currentMinSpaceShortage = m_minSpaceShortage; | |
| 89 m_minSpaceShortage = LayoutUnit::max(); | |
| 90 | |
| 91 if (initial) { | |
| 92 // Start with the lowest imaginable column height. | |
| 93 LayoutUnit logicalHeightGuess = ceilf(float(flowThread()->logicalHeight(
)) / float(m_computedColumnCount)); | |
| 94 logicalHeightGuess = max(logicalHeightGuess, m_minimumColumnHeight); | |
| 95 setAndConstrainColumnHeight(logicalHeightGuess); | |
| 96 | |
| 97 // The multicol container now typically needs at least one more layout p
ass with a new | |
| 98 // column height, but if height was specified, we only need to do this i
f we found that we | |
| 99 // might need less space than that. On the other hand, if we determined
that the columns | |
| 100 // need to be as tall as the specified height of the container, we have
already laid it out | |
| 101 // correctly, and there's no need for another pass. | |
| 102 return m_computedColumnHeight != oldColumnHeight; | |
| 103 } | |
| 104 | |
| 105 if (columnCount() <= computedColumnCount()) { | |
| 106 // With the current column height, the content fits without creating ove
rflowing columns. We're done. | |
| 107 return false; | |
| 108 } | |
| 109 | |
| 110 // If the initial guessed column height wasn't enough, stretch it now. Stret
ch by the lowest | |
| 111 // amount of space shortage found during layout. | |
| 112 | |
| 113 ASSERT(currentMinSpaceShortage != LayoutUnit::max()); // If this can actuall
y happen, we probably have a bug. | |
| 114 if (currentMinSpaceShortage == LayoutUnit::max()) | |
| 115 return false; // So bail out rather than looping infinitely. | |
| 116 | |
| 117 setAndConstrainColumnHeight(m_computedColumnHeight + currentMinSpaceShortage
); | |
| 118 | |
| 119 // If we reach the maximum column height (typically set by the height or max
-height property), | |
| 120 // we may not be allowed to stretch further. Return true only if stretching | |
| 121 // succeeded. Otherwise, we're done. | |
| 122 ASSERT(m_computedColumnHeight >= oldColumnHeight); // We shouldn't be able t
o shrink the height! | |
| 123 return m_computedColumnHeight > oldColumnHeight; | |
| 124 } | |
| 125 | |
| 126 void RenderMultiColumnSet::recordSpaceShortage(LayoutUnit spaceShortage) | |
| 127 { | |
| 128 if (spaceShortage >= m_minSpaceShortage) | |
| 129 return; | |
| 130 | |
| 131 // The space shortage is what we use as our stretch amount. We need a positi
ve number here in | |
| 132 // order to get anywhere. | |
| 133 ASSERT(spaceShortage > 0); | |
| 134 | |
| 135 m_minSpaceShortage = spaceShortage; | |
| 136 } | |
| 137 | |
| 138 void RenderMultiColumnSet::updateLogicalWidth() | |
| 139 { | |
| 140 RenderMultiColumnBlock* parentBlock = toRenderMultiColumnBlock(parent()); | |
| 141 setComputedColumnWidthAndCount(parentBlock->columnWidth(), parentBlock->colu
mnCount()); // FIXME: This will eventually vary if we are contained inside regio
ns. | |
| 142 | |
| 143 // FIXME: When we add regions support, we'll start it off at the width of th
e multi-column | |
| 144 // block in that particular region. | |
| 145 setLogicalWidth(parentBox()->contentLogicalWidth()); | |
| 146 | |
| 147 // If we overflow, increase our logical width. | |
| 148 unsigned colCount = columnCount(); | |
| 149 LayoutUnit colGap = columnGap(); | |
| 150 LayoutUnit minimumContentLogicalWidth = colCount * computedColumnWidth() + (
colCount - 1) * colGap; | |
| 151 LayoutUnit currentContentLogicalWidth = contentLogicalWidth(); | |
| 152 LayoutUnit delta = max(LayoutUnit(), minimumContentLogicalWidth - currentCon
tentLogicalWidth); | |
| 153 if (!delta) | |
| 154 return; | |
| 155 | |
| 156 // Increase our logical width by the delta. | |
| 157 setLogicalWidth(logicalWidth() + delta); | |
| 158 } | |
| 159 | |
| 160 void RenderMultiColumnSet::prepareForLayout() | |
| 161 { | |
| 162 RenderMultiColumnBlock* multicolBlock = toRenderMultiColumnBlock(parent()); | |
| 163 RenderStyle* multicolStyle = multicolBlock->style(); | |
| 164 | |
| 165 // Set box logical top. | |
| 166 ASSERT(!previousSiblingBox() || !previousSiblingBox()->isRenderMultiColumnSe
t()); // FIXME: multiple set not implemented; need to examine previous set to ca
lculate the correct logical top. | |
| 167 setLogicalTop(multicolBlock->borderBefore() + multicolBlock->paddingBefore()
); | |
| 168 | |
| 169 // Set box width. | |
| 170 updateLogicalWidth(); | |
| 171 | |
| 172 if (multicolBlock->requiresBalancing()) { | |
| 173 // Set maximum column height. We will not stretch beyond this. | |
| 174 m_maxColumnHeight = LayoutUnit::max(); | |
| 175 if (!multicolStyle->logicalHeight().isAuto()) | |
| 176 m_maxColumnHeight = multicolBlock->computeContentLogicalHeight(multi
colStyle->logicalHeight(), -1); | |
| 177 if (!multicolStyle->logicalMaxHeight().isUndefined()) { | |
| 178 LayoutUnit logicalMaxHeight = multicolBlock->computeContentLogicalHe
ight(multicolStyle->logicalMaxHeight(), -1); | |
| 179 if (m_maxColumnHeight > logicalMaxHeight) | |
| 180 m_maxColumnHeight = logicalMaxHeight; | |
| 181 } | |
| 182 m_maxColumnHeight = heightAdjustedForSetOffset(m_maxColumnHeight); | |
| 183 m_computedColumnHeight = 0; // Restart balancing. | |
| 184 } else { | |
| 185 setAndConstrainColumnHeight(heightAdjustedForSetOffset(multicolBlock->co
lumnHeightAvailable())); | |
| 186 } | |
| 187 | |
| 188 // Nuke previously stored minimum column height. Contents may have changed f
or all we know. | |
| 189 m_minimumColumnHeight = 0; | |
| 190 } | |
| 191 | |
| 192 void RenderMultiColumnSet::computeLogicalHeight(LayoutUnit, LayoutUnit logicalTo
p, LogicalExtentComputedValues& computedValues) const | |
| 193 { | |
| 194 computedValues.m_extent = m_computedColumnHeight; | |
| 195 computedValues.m_position = logicalTop; | |
| 196 } | |
| 197 | |
| 198 LayoutUnit RenderMultiColumnSet::columnGap() const | |
| 199 { | |
| 200 // FIXME: Eventually we will cache the column gap when the widths of columns
start varying, but for now we just | |
| 201 // go to the parent block to get the gap. | |
| 202 RenderMultiColumnBlock* parentBlock = toRenderMultiColumnBlock(parent()); | |
| 203 if (parentBlock->style()->hasNormalColumnGap()) | |
| 204 return parentBlock->style()->fontDescription().computedPixelSize(); // "
1em" is recommended as the normal gap setting. Matches <p> margins. | |
| 205 return parentBlock->style()->columnGap(); | |
| 206 } | |
| 207 | |
| 208 unsigned RenderMultiColumnSet::columnCount() const | |
| 209 { | |
| 210 // We must always return a value of 1 or greater. Column count = 0 is a mean
ingless situation, | |
| 211 // and will confuse and cause problems in other parts of the code. | |
| 212 if (!computedColumnHeight()) | |
| 213 return 1; | |
| 214 | |
| 215 // Our portion rect determines our column count. We have as many columns as
needed to fit all the content. | |
| 216 LayoutUnit logicalHeightInColumns = flowThread()->isHorizontalWritingMode()
? flowThreadPortionRect().height() : flowThreadPortionRect().width(); | |
| 217 unsigned count = ceil(static_cast<float>(logicalHeightInColumns) / computedC
olumnHeight()); | |
| 218 ASSERT(count >= 1); | |
| 219 return count; | |
| 220 } | |
| 221 | |
| 222 LayoutRect RenderMultiColumnSet::columnRectAt(unsigned index) const | |
| 223 { | |
| 224 LayoutUnit colLogicalWidth = computedColumnWidth(); | |
| 225 LayoutUnit colLogicalHeight = computedColumnHeight(); | |
| 226 LayoutUnit colLogicalTop = borderBefore() + paddingBefore(); | |
| 227 LayoutUnit colLogicalLeft = borderAndPaddingLogicalLeft(); | |
| 228 LayoutUnit colGap = columnGap(); | |
| 229 if (style()->isLeftToRightDirection()) | |
| 230 colLogicalLeft += index * (colLogicalWidth + colGap); | |
| 231 else | |
| 232 colLogicalLeft += contentLogicalWidth() - colLogicalWidth - index * (col
LogicalWidth + colGap); | |
| 233 | |
| 234 if (isHorizontalWritingMode()) | |
| 235 return LayoutRect(colLogicalLeft, colLogicalTop, colLogicalWidth, colLog
icalHeight); | |
| 236 return LayoutRect(colLogicalTop, colLogicalLeft, colLogicalHeight, colLogica
lWidth); | |
| 237 } | |
| 238 | |
| 239 unsigned RenderMultiColumnSet::columnIndexAtOffset(LayoutUnit offset, ColumnInde
xCalculationMode mode) const | |
| 240 { | |
| 241 LayoutRect portionRect(flowThreadPortionRect()); | |
| 242 | |
| 243 // Handle the offset being out of range. | |
| 244 LayoutUnit flowThreadLogicalTop = isHorizontalWritingMode() ? portionRect.y(
) : portionRect.x(); | |
| 245 if (offset < flowThreadLogicalTop) | |
| 246 return 0; | |
| 247 // If we're laying out right now, we cannot constrain against some logical b
ottom, since it | |
| 248 // isn't known yet. Otherwise, just return the last column if we're past the
logical bottom. | |
| 249 if (mode == ClampToExistingColumns) { | |
| 250 LayoutUnit flowThreadLogicalBottom = isHorizontalWritingMode() ? portion
Rect.maxY() : portionRect.maxX(); | |
| 251 if (offset >= flowThreadLogicalBottom) | |
| 252 return columnCount() - 1; | |
| 253 } | |
| 254 | |
| 255 // Just divide by the column height to determine the correct column. | |
| 256 return static_cast<float>(offset - flowThreadLogicalTop) / computedColumnHei
ght(); | |
| 257 } | |
| 258 | |
| 259 LayoutRect RenderMultiColumnSet::flowThreadPortionRectAt(unsigned index) const | |
| 260 { | |
| 261 LayoutRect portionRect = flowThreadPortionRect(); | |
| 262 if (isHorizontalWritingMode()) | |
| 263 portionRect = LayoutRect(portionRect.x(), portionRect.y() + index * comp
utedColumnHeight(), portionRect.width(), computedColumnHeight()); | |
| 264 else | |
| 265 portionRect = LayoutRect(portionRect.x() + index * computedColumnHeight(
), portionRect.y(), computedColumnHeight(), portionRect.height()); | |
| 266 return portionRect; | |
| 267 } | |
| 268 | |
| 269 LayoutRect RenderMultiColumnSet::flowThreadPortionOverflowRect(const LayoutRect&
portionRect, unsigned index, unsigned colCount, LayoutUnit colGap) const | |
| 270 { | |
| 271 // This function determines the portion of the flow thread that paints for t
he column. Along the inline axis, columns are | |
| 272 // unclipped at outside edges (i.e., the first and last column in the set),
and they clip to half the column | |
| 273 // gap along interior edges. | |
| 274 // | |
| 275 // In the block direction, we will not clip overflow out of the top of the f
irst column, or out of the bottom of | |
| 276 // the last column. This applies only to the true first column and last colu
mn across all column sets. | |
| 277 // | |
| 278 // FIXME: Eventually we will know overflow on a per-column basis, but we can
't do this until we have a painting | |
| 279 // mode that understands not to paint contents from a previous column in the
overflow area of a following column. | |
| 280 // This problem applies to regions and pages as well and is not unique to co
lumns. | |
| 281 bool isFirstColumn = !index; | |
| 282 bool isLastColumn = index == colCount - 1; | |
| 283 bool isLeftmostColumn = style()->isLeftToRightDirection() ? isFirstColumn :
isLastColumn; | |
| 284 bool isRightmostColumn = style()->isLeftToRightDirection() ? isLastColumn :
isFirstColumn; | |
| 285 | |
| 286 // Calculate the overflow rectangle, based on the flow thread's, clipped at
column logical | |
| 287 // top/bottom unless it's the first/last column. | |
| 288 LayoutRect overflowRect = overflowRectForFlowThreadPortion(portionRect, isFi
rstColumn && isFirstRegion(), isLastColumn && isLastRegion()); | |
| 289 | |
| 290 // Avoid overflowing into neighboring columns, by clipping in the middle of
adjacent column | |
| 291 // gaps. Also make sure that we avoid rounding errors. | |
| 292 if (isHorizontalWritingMode()) { | |
| 293 if (!isLeftmostColumn) | |
| 294 overflowRect.shiftXEdgeTo(portionRect.x() - colGap / 2); | |
| 295 if (!isRightmostColumn) | |
| 296 overflowRect.shiftMaxXEdgeTo(portionRect.maxX() + colGap - colGap /
2); | |
| 297 } else { | |
| 298 if (!isLeftmostColumn) | |
| 299 overflowRect.shiftYEdgeTo(portionRect.y() - colGap / 2); | |
| 300 if (!isRightmostColumn) | |
| 301 overflowRect.shiftMaxYEdgeTo(portionRect.maxY() + colGap - colGap /
2); | |
| 302 } | |
| 303 return overflowRect; | |
| 304 } | |
| 305 | |
| 306 void RenderMultiColumnSet::paintObject(PaintInfo& paintInfo, const LayoutPoint&
paintOffset) | |
| 307 { | |
| 308 if (style()->visibility() != VISIBLE) | |
| 309 return; | |
| 310 | |
| 311 RenderBlock::paintObject(paintInfo, paintOffset); | |
| 312 | |
| 313 // FIXME: Right now we're only painting in the foreground phase. | |
| 314 // Columns should technically respect phases and allow for background/float/
foreground overlap etc., just like | |
| 315 // RenderBlocks do. Note this is a pretty minor issue, since the old column
implementation clipped columns | |
| 316 // anyway, thus making it impossible for them to overlap one another. It's a
lso really unlikely that the columns | |
| 317 // would overlap another block. | |
| 318 if (!m_flowThread || !isValid() || (paintInfo.phase != PaintPhaseForeground
&& paintInfo.phase != PaintPhaseSelection)) | |
| 319 return; | |
| 320 | |
| 321 paintColumnRules(paintInfo, paintOffset); | |
| 322 } | |
| 323 | |
| 324 void RenderMultiColumnSet::paintColumnRules(PaintInfo& paintInfo, const LayoutPo
int& paintOffset) | |
| 325 { | |
| 326 if (paintInfo.context->paintingDisabled()) | |
| 327 return; | |
| 328 | |
| 329 RenderStyle* blockStyle = toRenderMultiColumnBlock(parent())->style(); | |
| 330 const Color& ruleColor = resolveColor(blockStyle, CSSPropertyWebkitColumnRul
eColor); | |
| 331 bool ruleTransparent = blockStyle->columnRuleIsTransparent(); | |
| 332 EBorderStyle ruleStyle = blockStyle->columnRuleStyle(); | |
| 333 LayoutUnit ruleThickness = blockStyle->columnRuleWidth(); | |
| 334 LayoutUnit colGap = columnGap(); | |
| 335 bool renderRule = ruleStyle > BHIDDEN && !ruleTransparent; | |
| 336 if (!renderRule) | |
| 337 return; | |
| 338 | |
| 339 unsigned colCount = columnCount(); | |
| 340 if (colCount <= 1) | |
| 341 return; | |
| 342 | |
| 343 bool antialias = shouldAntialiasLines(paintInfo.context); | |
| 344 | |
| 345 bool leftToRight = style()->isLeftToRightDirection(); | |
| 346 LayoutUnit currLogicalLeftOffset = leftToRight ? LayoutUnit() : contentLogic
alWidth(); | |
| 347 LayoutUnit ruleAdd = borderAndPaddingLogicalLeft(); | |
| 348 LayoutUnit ruleLogicalLeft = leftToRight ? LayoutUnit() : contentLogicalWidt
h(); | |
| 349 LayoutUnit inlineDirectionSize = computedColumnWidth(); | |
| 350 BoxSide boxSide = isHorizontalWritingMode() | |
| 351 ? leftToRight ? BSLeft : BSRight | |
| 352 : leftToRight ? BSTop : BSBottom; | |
| 353 | |
| 354 for (unsigned i = 0; i < colCount; i++) { | |
| 355 // Move to the next position. | |
| 356 if (leftToRight) { | |
| 357 ruleLogicalLeft += inlineDirectionSize + colGap / 2; | |
| 358 currLogicalLeftOffset += inlineDirectionSize + colGap; | |
| 359 } else { | |
| 360 ruleLogicalLeft -= (inlineDirectionSize + colGap / 2); | |
| 361 currLogicalLeftOffset -= (inlineDirectionSize + colGap); | |
| 362 } | |
| 363 | |
| 364 // Now paint the column rule. | |
| 365 if (i < colCount - 1) { | |
| 366 LayoutUnit ruleLeft = isHorizontalWritingMode() ? paintOffset.x() +
ruleLogicalLeft - ruleThickness / 2 + ruleAdd : paintOffset.x() + borderLeft() +
paddingLeft(); | |
| 367 LayoutUnit ruleRight = isHorizontalWritingMode() ? ruleLeft + ruleTh
ickness : ruleLeft + contentWidth(); | |
| 368 LayoutUnit ruleTop = isHorizontalWritingMode() ? paintOffset.y() + b
orderTop() + paddingTop() : paintOffset.y() + ruleLogicalLeft - ruleThickness /
2 + ruleAdd; | |
| 369 LayoutUnit ruleBottom = isHorizontalWritingMode() ? ruleTop + conten
tHeight() : ruleTop + ruleThickness; | |
| 370 IntRect pixelSnappedRuleRect = pixelSnappedIntRectFromEdges(ruleLeft
, ruleTop, ruleRight, ruleBottom); | |
| 371 drawLineForBoxSide(paintInfo.context, pixelSnappedRuleRect.x(), pixe
lSnappedRuleRect.y(), pixelSnappedRuleRect.maxX(), pixelSnappedRuleRect.maxY(),
boxSide, ruleColor, ruleStyle, 0, 0, antialias); | |
| 372 } | |
| 373 | |
| 374 ruleLogicalLeft = currLogicalLeftOffset; | |
| 375 } | |
| 376 } | |
| 377 | |
| 378 void RenderMultiColumnSet::repaintFlowThreadContent(const LayoutRect& repaintRec
t) const | |
| 379 { | |
| 380 // Figure out the start and end columns and only check within that range so
that we don't walk the | |
| 381 // entire column set. Put the repaint rect into flow thread coordinates by f
lipping it first. | |
| 382 LayoutRect flowThreadRepaintRect(repaintRect); | |
| 383 flowThread()->flipForWritingMode(flowThreadRepaintRect); | |
| 384 | |
| 385 // Now we can compare this rect with the flow thread portions owned by each
column. First let's | |
| 386 // just see if the repaint rect intersects our flow thread portion at all. | |
| 387 LayoutRect clippedRect(flowThreadRepaintRect); | |
| 388 clippedRect.intersect(RenderRegion::flowThreadPortionOverflowRect()); | |
| 389 if (clippedRect.isEmpty()) | |
| 390 return; | |
| 391 | |
| 392 // Now we know we intersect at least one column. Let's figure out the logica
l top and logical | |
| 393 // bottom of the area we're repainting. | |
| 394 LayoutUnit repaintLogicalTop = isHorizontalWritingMode() ? flowThreadRepaint
Rect.y() : flowThreadRepaintRect.x(); | |
| 395 LayoutUnit repaintLogicalBottom = (isHorizontalWritingMode() ? flowThreadRep
aintRect.maxY() : flowThreadRepaintRect.maxX()) - 1; | |
| 396 | |
| 397 unsigned startColumn = columnIndexAtOffset(repaintLogicalTop); | |
| 398 unsigned endColumn = columnIndexAtOffset(repaintLogicalBottom); | |
| 399 | |
| 400 LayoutUnit colGap = columnGap(); | |
| 401 unsigned colCount = columnCount(); | |
| 402 for (unsigned i = startColumn; i <= endColumn; i++) { | |
| 403 LayoutRect colRect = columnRectAt(i); | |
| 404 | |
| 405 // Get the portion of the flow thread that corresponds to this column. | |
| 406 LayoutRect flowThreadPortion = flowThreadPortionRectAt(i); | |
| 407 | |
| 408 // Now get the overflow rect that corresponds to the column. | |
| 409 LayoutRect flowThreadOverflowPortion = flowThreadPortionOverflowRect(flo
wThreadPortion, i, colCount, colGap); | |
| 410 | |
| 411 // Do a repaint for this specific column. | |
| 412 repaintFlowThreadContentRectangle(repaintRect, flowThreadPortion, flowTh
readOverflowPortion, colRect.location()); | |
| 413 } | |
| 414 } | |
| 415 | |
| 416 void RenderMultiColumnSet::collectLayerFragments(LayerFragments& fragments, cons
t LayoutRect& layerBoundingBox, const LayoutRect& dirtyRect) | |
| 417 { | |
| 418 // The two rectangles passed to this method are physical, except that we pre
tend that there's | |
| 419 // only one long column (that's how a flow thread works). | |
| 420 // | |
| 421 // Then there's the output from this method - the stuff we put into the list
of fragments. The | |
| 422 // fragment.paginationOffset point is the actual physical translation requir
ed to get from a | |
| 423 // location in the flow thread to a location in a given column. The fragment
.paginationClip | |
| 424 // rectangle, on the other hand, is in the same coordinate system as the two
rectangles passed | |
| 425 // to this method (flow thread coordinates). | |
| 426 // | |
| 427 // All other rectangles in this method are sized physically, and the inline
direction coordinate | |
| 428 // is physical too, but the block direction coordinate is "logical top". Thi
s is the same as | |
| 429 // e.g. RenderBox::frameRect(). These rectangles also pretend that there's o
nly one long column, | |
| 430 // i.e. they are for the flow thread. | |
| 431 | |
| 432 // Put the layer bounds into flow thread-local coordinates by flipping it fi
rst. Since we're in | |
| 433 // a renderer, most rectangles are represented this way. | |
| 434 LayoutRect layerBoundsInFlowThread(layerBoundingBox); | |
| 435 flowThread()->flipForWritingMode(layerBoundsInFlowThread); | |
| 436 | |
| 437 // Now we can compare with the flow thread portions owned by each column. Fi
rst let's | |
| 438 // see if the rect intersects our flow thread portion at all. | |
| 439 LayoutRect clippedRect(layerBoundsInFlowThread); | |
| 440 clippedRect.intersect(RenderRegion::flowThreadPortionOverflowRect()); | |
| 441 if (clippedRect.isEmpty()) | |
| 442 return; | |
| 443 | |
| 444 // Now we know we intersect at least one column. Let's figure out the logica
l top and logical | |
| 445 // bottom of the area we're checking. | |
| 446 LayoutUnit layerLogicalTop = isHorizontalWritingMode() ? layerBoundsInFlowTh
read.y() : layerBoundsInFlowThread.x(); | |
| 447 LayoutUnit layerLogicalBottom = (isHorizontalWritingMode() ? layerBoundsInFl
owThread.maxY() : layerBoundsInFlowThread.maxX()) - 1; | |
| 448 | |
| 449 // Figure out the start and end columns and only check within that range so
that we don't walk the | |
| 450 // entire column set. | |
| 451 unsigned startColumn = columnIndexAtOffset(layerLogicalTop); | |
| 452 unsigned endColumn = columnIndexAtOffset(layerLogicalBottom); | |
| 453 | |
| 454 LayoutUnit colLogicalWidth = computedColumnWidth(); | |
| 455 LayoutUnit colGap = columnGap(); | |
| 456 unsigned colCount = columnCount(); | |
| 457 | |
| 458 for (unsigned i = startColumn; i <= endColumn; i++) { | |
| 459 // Get the portion of the flow thread that corresponds to this column. | |
| 460 LayoutRect flowThreadPortion = flowThreadPortionRectAt(i); | |
| 461 | |
| 462 // Now get the overflow rect that corresponds to the column. | |
| 463 LayoutRect flowThreadOverflowPortion = flowThreadPortionOverflowRect(flo
wThreadPortion, i, colCount, colGap); | |
| 464 | |
| 465 // In order to create a fragment we must intersect the portion painted b
y this column. | |
| 466 LayoutRect clippedRect(layerBoundsInFlowThread); | |
| 467 clippedRect.intersect(flowThreadOverflowPortion); | |
| 468 if (clippedRect.isEmpty()) | |
| 469 continue; | |
| 470 | |
| 471 // We also need to intersect the dirty rect. We have to apply a translat
ion and shift based off | |
| 472 // our column index. | |
| 473 LayoutPoint translationOffset; | |
| 474 LayoutUnit inlineOffset = i * (colLogicalWidth + colGap); | |
| 475 if (!style()->isLeftToRightDirection()) | |
| 476 inlineOffset = -inlineOffset; | |
| 477 translationOffset.setX(inlineOffset); | |
| 478 LayoutUnit blockOffset = isHorizontalWritingMode() ? -flowThreadPortion.
y() : -flowThreadPortion.x(); | |
| 479 if (isFlippedBlocksWritingMode(style()->writingMode())) | |
| 480 blockOffset = -blockOffset; | |
| 481 translationOffset.setY(blockOffset); | |
| 482 if (!isHorizontalWritingMode()) | |
| 483 translationOffset = translationOffset.transposedPoint(); | |
| 484 // FIXME: The translation needs to include the multicolumn set's content
offset within the | |
| 485 // multicolumn block as well. This won't be an issue until we start crea
ting multiple multicolumn sets. | |
| 486 | |
| 487 // Shift the dirty rect to be in flow thread coordinates with this trans
lation applied. | |
| 488 LayoutRect translatedDirtyRect(dirtyRect); | |
| 489 translatedDirtyRect.moveBy(-translationOffset); | |
| 490 | |
| 491 // See if we intersect the dirty rect. | |
| 492 clippedRect = layerBoundingBox; | |
| 493 clippedRect.intersect(translatedDirtyRect); | |
| 494 if (clippedRect.isEmpty()) | |
| 495 continue; | |
| 496 | |
| 497 // Something does need to paint in this column. Make a fragment now and
supply the physical translation | |
| 498 // offset and the clip rect for the column with that offset applied. | |
| 499 LayerFragment fragment; | |
| 500 fragment.paginationOffset = translationOffset; | |
| 501 | |
| 502 LayoutRect flippedFlowThreadOverflowPortion(flowThreadOverflowPortion); | |
| 503 // Flip it into more a physical (RenderLayer-style) rectangle. | |
| 504 flowThread()->flipForWritingMode(flippedFlowThreadOverflowPortion); | |
| 505 fragment.paginationClip = flippedFlowThreadOverflowPortion; | |
| 506 fragments.append(fragment); | |
| 507 } | |
| 508 } | |
| 509 | |
| 510 const char* RenderMultiColumnSet::renderName() const | |
| 511 { | |
| 512 return "RenderMultiColumnSet"; | |
| 513 } | |
| 514 | |
| 515 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 143323014:
*** DO NOT LAND *** Attempt to understand Regions complexity
Base URL: svn://svn.chromium.org/blink/trunk