1 | /* |
2 | * Copyright (C) 2019 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. AND ITS CONTRIBUTORS ``AS IS'' |
14 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
15 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
16 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS |
17 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
18 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
19 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
20 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
21 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
22 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
23 | * THE POSSIBILITY OF SUCH DAMAGE. |
24 | */ |
25 | |
26 | #include "config.h" |
27 | #include "InlineFormattingContext.h" |
28 | |
29 | #if ENABLE(LAYOUT_FORMATTING_CONTEXT) |
30 | |
31 | #include "FloatingContext.h" |
32 | #include "FloatingState.h" |
33 | #include "InlineFormattingState.h" |
34 | #include "InlineLineBreaker.h" |
35 | #include "InlineRunProvider.h" |
36 | #include "LayoutBox.h" |
37 | #include "LayoutContainer.h" |
38 | #include "LayoutState.h" |
39 | #include "TextUtil.h" |
40 | |
41 | namespace WebCore { |
42 | namespace Layout { |
43 | |
44 | class Line { |
45 | public: |
46 | void init(const LayoutPoint& topLeft, LayoutUnit availableWidth, LayoutUnit minimalHeight); |
47 | void close(); |
48 | |
49 | void appendContent(const InlineRunProvider::Run&, const LayoutSize&); |
50 | |
51 | void adjustLogicalLeft(LayoutUnit delta); |
52 | void adjustLogicalRight(LayoutUnit delta); |
53 | |
54 | bool hasContent() const { return !m_inlineRuns.isEmpty(); } |
55 | bool isClosed() const { return m_closed; } |
56 | bool isFirstLine() const { return m_isFirstLine; } |
57 | Vector<InlineRun>& runs() { return m_inlineRuns; } |
58 | |
59 | LayoutUnit contentLogicalRight() const; |
60 | LayoutUnit contentLogicalLeft() const { return m_logicalRect.left(); } |
61 | LayoutUnit availableWidth() const { return m_availableWidth; } |
62 | Optional<InlineRunProvider::Run::Type> lastRunType() const { return m_lastRunType; } |
63 | |
64 | LayoutUnit logicalTop() const { return m_logicalRect.top(); } |
65 | LayoutUnit logicalBottom() const { return m_logicalRect.bottom(); } |
66 | LayoutUnit logicalHeight() const { return logicalBottom() - logicalTop(); } |
67 | |
68 | private: |
69 | struct TrailingTrimmableContent { |
70 | LayoutUnit width; |
71 | unsigned length; |
72 | }; |
73 | Optional<TrailingTrimmableContent> m_trailingTrimmableContent; |
74 | Optional<InlineRunProvider::Run::Type> m_lastRunType; |
75 | bool m_lastRunCanExpand { false }; |
76 | |
77 | Display::Box::Rect m_logicalRect; |
78 | LayoutUnit m_availableWidth; |
79 | |
80 | Vector<InlineRun> m_inlineRuns; |
81 | bool m_isFirstLine { true }; |
82 | bool m_closed { true }; |
83 | }; |
84 | |
85 | void Line::init(const LayoutPoint& topLeft, LayoutUnit availableWidth, LayoutUnit minimalHeight) |
86 | { |
87 | m_logicalRect.setTopLeft(topLeft); |
88 | m_logicalRect.setWidth(availableWidth); |
89 | m_logicalRect.setHeight(minimalHeight); |
90 | m_availableWidth = availableWidth; |
91 | |
92 | m_inlineRuns.clear(); |
93 | m_lastRunType = { }; |
94 | m_lastRunCanExpand = false; |
95 | m_trailingTrimmableContent = { }; |
96 | m_closed = false; |
97 | } |
98 | |
99 | void Line::adjustLogicalLeft(LayoutUnit delta) |
100 | { |
101 | ASSERT(delta > 0); |
102 | |
103 | m_availableWidth -= delta; |
104 | m_logicalRect.shiftLeftTo(m_logicalRect.left() + delta); |
105 | |
106 | for (auto& inlineRun : m_inlineRuns) |
107 | inlineRun.moveHorizontally(delta); |
108 | } |
109 | |
110 | void Line::adjustLogicalRight(LayoutUnit delta) |
111 | { |
112 | ASSERT(delta > 0); |
113 | |
114 | m_availableWidth -= delta; |
115 | m_logicalRect.shiftRightTo(m_logicalRect.right() - delta); |
116 | } |
117 | |
118 | static bool isTrimmableContent(const InlineRunProvider::Run& inlineRun) |
119 | { |
120 | return inlineRun.isWhitespace() && inlineRun.style().collapseWhiteSpace(); |
121 | } |
122 | |
123 | LayoutUnit Line::contentLogicalRight() const |
124 | { |
125 | if (m_inlineRuns.isEmpty()) |
126 | return m_logicalRect.left(); |
127 | |
128 | return m_inlineRuns.last().logicalRight(); |
129 | } |
130 | |
131 | void Line::appendContent(const InlineRunProvider::Run& run, const LayoutSize& runSize) |
132 | { |
133 | ASSERT(!isClosed()); |
134 | |
135 | // Append this text run to the end of the last text run, if the last run is continuous. |
136 | Optional<InlineRun::TextContext> textRun; |
137 | if (run.isText()) { |
138 | auto textContext = run.textContext(); |
139 | auto runLength = textContext->isCollapsed() ? 1 : textContext->length(); |
140 | textRun = InlineRun::TextContext { textContext->start(), runLength }; |
141 | } |
142 | |
143 | auto requiresNewInlineRun = !hasContent() || !run.isText() || !m_lastRunCanExpand; |
144 | if (requiresNewInlineRun) { |
145 | // FIXME: This needs proper baseline handling |
146 | auto inlineRun = InlineRun { { logicalTop(), contentLogicalRight(), runSize.width(), runSize.height() }, run.inlineItem() }; |
147 | if (textRun) |
148 | inlineRun.setTextContext({ textRun->start(), textRun->length() }); |
149 | m_inlineRuns.append(inlineRun); |
150 | m_logicalRect.setHeight(std::max(runSize.height(), m_logicalRect.height())); |
151 | } else { |
152 | // Non-text runs always require new inline run. |
153 | ASSERT(textRun); |
154 | auto& inlineRun = m_inlineRuns.last(); |
155 | ASSERT(runSize.height() == inlineRun.logicalHeight()); |
156 | inlineRun.setLogicalWidth(inlineRun.logicalWidth() + runSize.width()); |
157 | inlineRun.textContext()->setLength(inlineRun.textContext()->length() + textRun->length()); |
158 | } |
159 | |
160 | m_availableWidth -= runSize.width(); |
161 | m_lastRunType = run.type(); |
162 | m_lastRunCanExpand = run.isText() && !run.textContext()->isCollapsed(); |
163 | m_trailingTrimmableContent = { }; |
164 | if (isTrimmableContent(run)) |
165 | m_trailingTrimmableContent = TrailingTrimmableContent { runSize.width(), textRun->length() }; |
166 | } |
167 | |
168 | void Line::close() |
169 | { |
170 | auto trimTrailingContent = [&] { |
171 | if (!m_trailingTrimmableContent) |
172 | return; |
173 | auto& lastInlineRun = m_inlineRuns.last(); |
174 | lastInlineRun.setLogicalWidth(lastInlineRun.logicalWidth() - m_trailingTrimmableContent->width); |
175 | lastInlineRun.textContext()->setLength(lastInlineRun.textContext()->length() - m_trailingTrimmableContent->length); |
176 | |
177 | if (!lastInlineRun.textContext()->length()) |
178 | m_inlineRuns.removeLast(); |
179 | m_availableWidth += m_trailingTrimmableContent->width; |
180 | m_trailingTrimmableContent = { }; |
181 | }; |
182 | |
183 | if (!hasContent()) |
184 | return; |
185 | |
186 | trimTrailingContent(); |
187 | m_isFirstLine = false; |
188 | m_closed = true; |
189 | } |
190 | |
191 | InlineFormattingContext::LineLayout::LineLayout(const InlineFormattingContext& inlineFormattingContext) |
192 | : m_formattingContext(inlineFormattingContext) |
193 | , m_formattingState(m_formattingContext.formattingState()) |
194 | , m_floatingState(m_formattingState.floatingState()) |
195 | , m_formattingRoot(downcast<Container>(m_formattingContext.root())) |
196 | { |
197 | } |
198 | |
199 | static bool isTrimmableContent(const InlineLineBreaker::Run& run) |
200 | { |
201 | return run.content.isWhitespace() && run.content.style().collapseWhiteSpace(); |
202 | } |
203 | |
204 | void InlineFormattingContext::LineLayout::layout(const InlineRunProvider& inlineRunProvider) const |
205 | { |
206 | auto& layoutState = m_formattingContext.layoutState(); |
207 | auto floatingContext = FloatingContext { m_floatingState }; |
208 | |
209 | Line line; |
210 | initializeNewLine(line); |
211 | |
212 | InlineLineBreaker lineBreaker(layoutState, m_formattingState.inlineContent(), inlineRunProvider.runs()); |
213 | while (auto run = lineBreaker.nextRun(line.contentLogicalRight(), line.availableWidth(), !line.hasContent())) { |
214 | auto isFirstRun = run->position == InlineLineBreaker::Run::Position::LineBegin; |
215 | auto isLastRun = run->position == InlineLineBreaker::Run::Position::LineEnd; |
216 | auto generatesInlineRun = true; |
217 | |
218 | // Position float and adjust the runs on line. |
219 | if (run->content.isFloat()) { |
220 | auto& floatBox = run->content.inlineItem().layoutBox(); |
221 | computeFloatPosition(floatingContext, line, floatBox); |
222 | m_floatingState.append(floatBox); |
223 | |
224 | auto floatBoxWidth = layoutState.displayBoxForLayoutBox(floatBox).marginBox().width(); |
225 | // Shrink availble space for current line and move existing inline runs. |
226 | floatBox.isLeftFloatingPositioned() ? line.adjustLogicalLeft(floatBoxWidth) : line.adjustLogicalRight(floatBoxWidth); |
227 | |
228 | generatesInlineRun = false; |
229 | } |
230 | |
231 | // 1. Initialize new line if needed. |
232 | // 2. Append inline run unless it is skipped. |
233 | // 3. Close current line if needed. |
234 | if (isFirstRun) { |
235 | // When the first run does not generate an actual inline run, the next run comes in first-run as well. |
236 | // No need to spend time on closing/initializing. |
237 | // Skip leading whitespace. |
238 | if (!generatesInlineRun || isTrimmableContent(*run)) |
239 | continue; |
240 | |
241 | if (line.hasContent()) { |
242 | // Previous run ended up being at the line end. Adjust the line accordingly. |
243 | if (!line.isClosed()) |
244 | closeLine(line, IsLastLine::No); |
245 | initializeNewLine(line); |
246 | } |
247 | } |
248 | |
249 | if (generatesInlineRun) { |
250 | auto width = run->width; |
251 | auto height = run->content.isText() ? LayoutUnit(m_formattingRoot.style().computedLineHeight()) : layoutState.displayBoxForLayoutBox(run->content.inlineItem().layoutBox()).height(); |
252 | appendContentToLine(line, run->content, { width, height }); |
253 | } |
254 | |
255 | if (isLastRun) |
256 | closeLine(line, IsLastLine::No); |
257 | } |
258 | |
259 | closeLine(line, IsLastLine::Yes); |
260 | } |
261 | |
262 | void InlineFormattingContext::LineLayout::initializeNewLine(Line& line) const |
263 | { |
264 | auto& formattingRootDisplayBox = m_formattingContext.layoutState().displayBoxForLayoutBox(m_formattingRoot); |
265 | |
266 | auto lineLogicalLeft = formattingRootDisplayBox.contentBoxLeft(); |
267 | auto lineLogicalTop = line.isFirstLine() ? formattingRootDisplayBox.contentBoxTop() : line.logicalBottom(); |
268 | auto availableWidth = formattingRootDisplayBox.contentBoxWidth(); |
269 | |
270 | // Check for intruding floats and adjust logical left/available width for this line accordingly. |
271 | if (!m_floatingState.isEmpty()) { |
272 | auto floatConstraints = m_floatingState.constraints({ lineLogicalTop }, m_formattingRoot); |
273 | // Check if these constraints actually put limitation on the line. |
274 | if (floatConstraints.left && *floatConstraints.left <= formattingRootDisplayBox.contentBoxLeft()) |
275 | floatConstraints.left = { }; |
276 | |
277 | if (floatConstraints.right && *floatConstraints.right >= formattingRootDisplayBox.contentBoxRight()) |
278 | floatConstraints.right = { }; |
279 | |
280 | if (floatConstraints.left && floatConstraints.right) { |
281 | ASSERT(*floatConstraints.left < *floatConstraints.right); |
282 | availableWidth = *floatConstraints.right - *floatConstraints.left; |
283 | lineLogicalLeft = *floatConstraints.left; |
284 | } else if (floatConstraints.left) { |
285 | ASSERT(*floatConstraints.left > lineLogicalLeft); |
286 | availableWidth -= (*floatConstraints.left - lineLogicalLeft); |
287 | lineLogicalLeft = *floatConstraints.left; |
288 | } else if (floatConstraints.right) { |
289 | ASSERT(*floatConstraints.right > lineLogicalLeft); |
290 | availableWidth = *floatConstraints.right - lineLogicalLeft; |
291 | } |
292 | } |
293 | |
294 | line.init({ lineLogicalLeft, lineLogicalTop }, availableWidth, m_formattingRoot.style().computedLineHeight()); |
295 | } |
296 | |
297 | void InlineFormattingContext::LineLayout::splitInlineRunIfNeeded(const InlineRun& inlineRun, InlineRuns& splitRuns) const |
298 | { |
299 | ASSERT(inlineRun.textContext()); |
300 | ASSERT(inlineRun.overlapsMultipleInlineItems()); |
301 | // In certain cases, a run can overlap multiple inline elements like this: |
302 | // <span>normal text content</span><span style="position: relative; left: 10px;">but this one needs a dedicated run</span><span>end of text</span> |
303 | // The content above generates one long run <normal text contentbut this one needs dedicated runend of text> |
304 | // However, since the middle run is positioned, it needs to be moved independently from the rest of the content, hence it needs a dedicated inline run. |
305 | |
306 | // 1. Start with the first inline item (element) and travers the list until |
307 | // 2. either find an inline item that needs a dedicated run or we reach the end of the run |
308 | // 3. Create dedicate inline runs. |
309 | auto& inlineContent = m_formattingState.inlineContent(); |
310 | auto contentStart = inlineRun.logicalLeft(); |
311 | auto startPosition = inlineRun.textContext()->start(); |
312 | auto remaningLength = inlineRun.textContext()->length(); |
313 | |
314 | struct Uncommitted { |
315 | const InlineItem* firstInlineItem { nullptr }; |
316 | const InlineItem* lastInlineItem { nullptr }; |
317 | unsigned length { 0 }; |
318 | }; |
319 | Optional<Uncommitted> uncommitted; |
320 | |
321 | auto commit = [&] { |
322 | if (!uncommitted) |
323 | return; |
324 | |
325 | contentStart += uncommitted->firstInlineItem->nonBreakableStart(); |
326 | |
327 | auto runWidth = this->runWidth(inlineContent, *uncommitted->firstInlineItem, startPosition, uncommitted->length, contentStart); |
328 | auto run = InlineRun { { inlineRun.logicalTop(), contentStart, runWidth, inlineRun.logicalHeight() }, *uncommitted->firstInlineItem }; |
329 | run.setTextContext({ startPosition, uncommitted->length }); |
330 | splitRuns.append(run); |
331 | |
332 | contentStart += runWidth + uncommitted->lastInlineItem->nonBreakableEnd(); |
333 | |
334 | startPosition = 0; |
335 | uncommitted = { }; |
336 | }; |
337 | |
338 | for (auto iterator = inlineContent.find(const_cast<InlineItem*>(&inlineRun.inlineItem())); iterator != inlineContent.end() && remaningLength > 0; ++iterator) { |
339 | auto& inlineItem = **iterator; |
340 | |
341 | // Skip all non-inflow boxes (floats, out-of-flow positioned elements). They don't participate in the inline run context. |
342 | if (!inlineItem.layoutBox().isInFlow()) |
343 | continue; |
344 | |
345 | auto currentLength = [&] { |
346 | return std::min(remaningLength, inlineItem.textContent().length() - startPosition); |
347 | }; |
348 | |
349 | // 1. Break before/after -> requires dedicated run -> commit what we've got so far and also commit the current inline element as a separate inline run. |
350 | // 2. Break at the beginning of the inline element -> commit what we've got so far. Current element becomes the first uncommitted. |
351 | // 3. Break at the end of the inline element -> commit what we've got so far including the current element. |
352 | // 4. Inline element does not require run breaking -> add current inline element to uncommitted. Jump to the next element. |
353 | auto detachingRules = inlineItem.detachingRules(); |
354 | |
355 | // #1 |
356 | if (detachingRules.containsAll({ InlineItem::DetachingRule::BreakAtStart, InlineItem::DetachingRule::BreakAtEnd })) { |
357 | commit(); |
358 | auto contentLength = currentLength(); |
359 | uncommitted = Uncommitted { &inlineItem, &inlineItem, contentLength }; |
360 | remaningLength -= contentLength; |
361 | commit(); |
362 | continue; |
363 | } |
364 | |
365 | // #2 |
366 | if (detachingRules.contains(InlineItem::DetachingRule::BreakAtStart)) |
367 | commit(); |
368 | |
369 | // Add current inline item to uncommitted. |
370 | // #3 and #4 |
371 | auto contentLength = currentLength(); |
372 | if (!uncommitted) |
373 | uncommitted = Uncommitted { &inlineItem, &inlineItem, 0 }; |
374 | uncommitted->length += contentLength; |
375 | uncommitted->lastInlineItem = &inlineItem; |
376 | remaningLength -= contentLength; |
377 | |
378 | // #3 |
379 | if (detachingRules.contains(InlineItem::DetachingRule::BreakAtEnd)) |
380 | commit(); |
381 | } |
382 | // Either all inline elements needed dedicated runs or neither of them. |
383 | if (!remaningLength || remaningLength == inlineRun.textContext()->length()) |
384 | return; |
385 | |
386 | commit(); |
387 | } |
388 | |
389 | void InlineFormattingContext::LineLayout::createFinalRuns(Line& line) const |
390 | { |
391 | for (auto& inlineRun : line.runs()) { |
392 | if (inlineRun.overlapsMultipleInlineItems()) { |
393 | InlineRuns splitRuns; |
394 | splitInlineRunIfNeeded(inlineRun, splitRuns); |
395 | for (auto& splitRun : splitRuns) |
396 | m_formattingState.appendInlineRun(splitRun); |
397 | |
398 | if (!splitRuns.isEmpty()) |
399 | continue; |
400 | } |
401 | |
402 | auto finalRun = [&] { |
403 | auto& inlineItem = inlineRun.inlineItem(); |
404 | if (inlineItem.detachingRules().isEmpty()) |
405 | return inlineRun; |
406 | |
407 | InlineRun adjustedRun = inlineRun; |
408 | auto width = inlineRun.logicalWidth() - inlineItem.nonBreakableStart() - inlineItem.nonBreakableEnd(); |
409 | adjustedRun.setLogicalLeft(inlineRun.logicalLeft() + inlineItem.nonBreakableStart()); |
410 | adjustedRun.setLogicalWidth(width); |
411 | return adjustedRun; |
412 | }; |
413 | |
414 | m_formattingState.appendInlineRun(finalRun()); |
415 | } |
416 | } |
417 | |
418 | void InlineFormattingContext::LineLayout::postProcessInlineRuns(Line& line, IsLastLine isLastLine) const |
419 | { |
420 | alignRuns(m_formattingRoot.style().textAlign(), line, isLastLine); |
421 | auto firstRunIndex = m_formattingState.inlineRuns().size(); |
422 | createFinalRuns(line); |
423 | |
424 | placeInFlowPositionedChildren(firstRunIndex); |
425 | } |
426 | |
427 | void InlineFormattingContext::LineLayout::closeLine(Line& line, IsLastLine isLastLine) const |
428 | { |
429 | line.close(); |
430 | if (!line.hasContent()) |
431 | return; |
432 | |
433 | postProcessInlineRuns(line, isLastLine); |
434 | } |
435 | |
436 | void InlineFormattingContext::LineLayout::appendContentToLine(Line& line, const InlineRunProvider::Run& run, const LayoutSize& runSize) const |
437 | { |
438 | auto lastRunType = line.lastRunType(); |
439 | line.appendContent(run, runSize); |
440 | |
441 | if (m_formattingRoot.style().textAlign() == TextAlignMode::Justify) |
442 | computeExpansionOpportunities(line, run, lastRunType.valueOr(InlineRunProvider::Run::Type::NonWhitespace)); |
443 | } |
444 | |
445 | void InlineFormattingContext::LineLayout::computeFloatPosition(const FloatingContext& floatingContext, Line& line, const Box& floatBox) const |
446 | { |
447 | auto& layoutState = m_formattingContext.layoutState(); |
448 | ASSERT(layoutState.hasDisplayBox(floatBox)); |
449 | auto& displayBox = layoutState.displayBoxForLayoutBox(floatBox); |
450 | |
451 | // Set static position first. |
452 | displayBox.setTopLeft({ line.contentLogicalRight(), line.logicalTop() }); |
453 | // Float it. |
454 | displayBox.setTopLeft(floatingContext.positionForFloat(floatBox)); |
455 | } |
456 | |
457 | void InlineFormattingContext::LineLayout::placeInFlowPositionedChildren(unsigned fistRunIndex) const |
458 | { |
459 | auto& layoutState = m_formattingContext.layoutState(); |
460 | auto& inlineRuns = m_formattingState.inlineRuns(); |
461 | for (auto runIndex = fistRunIndex; runIndex < inlineRuns.size(); ++runIndex) { |
462 | auto& inlineRun = inlineRuns[runIndex]; |
463 | |
464 | auto positionOffset = [&](auto& layoutBox) { |
465 | // FIXME: Need to figure out whether in-flow offset should stick. This might very well be temporary. |
466 | Optional<LayoutSize> offset; |
467 | for (auto* box = &layoutBox; box != &m_formattingRoot; box = box->parent()) { |
468 | if (!box->isInFlowPositioned()) |
469 | continue; |
470 | offset = offset.valueOr(LayoutSize()) + Geometry::inFlowPositionedPositionOffset(layoutState, *box); |
471 | } |
472 | return offset; |
473 | }; |
474 | |
475 | if (auto offset = positionOffset(inlineRun.inlineItem().layoutBox())) { |
476 | inlineRun.moveVertically(offset->height()); |
477 | inlineRun.moveHorizontally(offset->width()); |
478 | } |
479 | } |
480 | } |
481 | |
482 | static LayoutUnit adjustedLineLogicalLeft(TextAlignMode align, LayoutUnit lineLogicalLeft, LayoutUnit remainingWidth) |
483 | { |
484 | switch (align) { |
485 | case TextAlignMode::Left: |
486 | case TextAlignMode::WebKitLeft: |
487 | case TextAlignMode::Start: |
488 | return lineLogicalLeft; |
489 | case TextAlignMode::Right: |
490 | case TextAlignMode::WebKitRight: |
491 | case TextAlignMode::End: |
492 | return lineLogicalLeft + std::max(remainingWidth, 0_lu); |
493 | case TextAlignMode::Center: |
494 | case TextAlignMode::WebKitCenter: |
495 | return lineLogicalLeft + std::max(remainingWidth / 2, 0_lu); |
496 | case TextAlignMode::Justify: |
497 | ASSERT_NOT_REACHED(); |
498 | break; |
499 | } |
500 | ASSERT_NOT_REACHED(); |
501 | return lineLogicalLeft; |
502 | } |
503 | |
504 | void InlineFormattingContext::LineLayout::justifyRuns(Line& line) |
505 | { |
506 | auto& inlineRuns = line.runs(); |
507 | auto& lastInlineRun = inlineRuns.last(); |
508 | |
509 | // Adjust (forbid) trailing expansion for the last text run on line. |
510 | auto expansionBehavior = lastInlineRun.expansionOpportunity().behavior; |
511 | // Remove allow and add forbid. |
512 | expansionBehavior ^= AllowTrailingExpansion; |
513 | expansionBehavior |= ForbidTrailingExpansion; |
514 | lastInlineRun.expansionOpportunity().behavior = expansionBehavior; |
515 | |
516 | // Collect expansion opportunities and justify the runs. |
517 | auto widthToDistribute = line.availableWidth(); |
518 | if (widthToDistribute <= 0) |
519 | return; |
520 | |
521 | auto expansionOpportunities = 0; |
522 | for (auto& inlineRun : inlineRuns) |
523 | expansionOpportunities += inlineRun.expansionOpportunity().count; |
524 | |
525 | if (!expansionOpportunities) |
526 | return; |
527 | |
528 | float expansion = widthToDistribute.toFloat() / expansionOpportunities; |
529 | LayoutUnit accumulatedExpansion; |
530 | for (auto& inlineRun : inlineRuns) { |
531 | auto expansionForRun = inlineRun.expansionOpportunity().count * expansion; |
532 | |
533 | inlineRun.expansionOpportunity().expansion = expansionForRun; |
534 | inlineRun.setLogicalLeft(inlineRun.logicalLeft() + accumulatedExpansion); |
535 | inlineRun.setLogicalWidth(inlineRun.logicalWidth() + expansionForRun); |
536 | accumulatedExpansion += expansionForRun; |
537 | } |
538 | } |
539 | |
540 | void InlineFormattingContext::LineLayout::computeExpansionOpportunities(Line& line, const InlineRunProvider::Run& run, InlineRunProvider::Run::Type lastRunType) const |
541 | { |
542 | auto isExpansionOpportunity = [](auto currentRunIsWhitespace, auto lastRunIsWhitespace) { |
543 | return currentRunIsWhitespace || (!currentRunIsWhitespace && !lastRunIsWhitespace); |
544 | }; |
545 | |
546 | auto expansionBehavior = [](auto isAtExpansionOpportunity) { |
547 | ExpansionBehavior expansionBehavior = AllowTrailingExpansion; |
548 | expansionBehavior |= isAtExpansionOpportunity ? ForbidLeadingExpansion : AllowLeadingExpansion; |
549 | return expansionBehavior; |
550 | }; |
551 | |
552 | auto isAtExpansionOpportunity = isExpansionOpportunity(run.isWhitespace(), lastRunType == InlineRunProvider::Run::Type::Whitespace); |
553 | |
554 | auto& currentInlineRun = line.runs().last(); |
555 | auto& expansionOpportunity = currentInlineRun.expansionOpportunity(); |
556 | if (isAtExpansionOpportunity) |
557 | ++expansionOpportunity.count; |
558 | |
559 | expansionOpportunity.behavior = expansionBehavior(isAtExpansionOpportunity); |
560 | } |
561 | |
562 | void InlineFormattingContext::LineLayout::alignRuns(TextAlignMode textAlign, Line& line, IsLastLine isLastLine) const |
563 | { |
564 | auto adjutedTextAlignment = textAlign != TextAlignMode::Justify ? textAlign : isLastLine == IsLastLine::No ? TextAlignMode::Justify : TextAlignMode::Left; |
565 | if (adjutedTextAlignment == TextAlignMode::Justify) { |
566 | justifyRuns(line); |
567 | return; |
568 | } |
569 | |
570 | auto lineLogicalLeft = line.contentLogicalLeft(); |
571 | auto adjustedLogicalLeft = adjustedLineLogicalLeft(adjutedTextAlignment, lineLogicalLeft, line.availableWidth()); |
572 | if (adjustedLogicalLeft == lineLogicalLeft) |
573 | return; |
574 | |
575 | auto delta = adjustedLogicalLeft - lineLogicalLeft; |
576 | for (auto& inlineRun : line.runs()) |
577 | inlineRun.setLogicalLeft(inlineRun.logicalLeft() + delta); |
578 | } |
579 | |
580 | LayoutUnit InlineFormattingContext::LineLayout::runWidth(const InlineContent& inlineContent, const InlineItem& inlineItem, ItemPosition from, unsigned length, LayoutUnit contentLogicalLeft) const |
581 | { |
582 | LayoutUnit width; |
583 | auto startPosition = from; |
584 | auto iterator = inlineContent.find(const_cast<InlineItem*>(&inlineItem)); |
585 | #if !ASSERT_DISABLED |
586 | auto inlineItemEnd = inlineContent.end(); |
587 | #endif |
588 | while (length) { |
589 | ASSERT(iterator != inlineItemEnd); |
590 | auto& currentInlineItem = **iterator; |
591 | auto endPosition = std::min<ItemPosition>(startPosition + length, currentInlineItem.textContent().length()); |
592 | auto textWidth = TextUtil::width(currentInlineItem, startPosition, endPosition, contentLogicalLeft); |
593 | |
594 | contentLogicalLeft += textWidth; |
595 | width += textWidth; |
596 | length -= (endPosition - startPosition); |
597 | |
598 | startPosition = 0; |
599 | ++iterator; |
600 | } |
601 | return width; |
602 | } |
603 | |
604 | } |
605 | } |
606 | |
607 | #endif |
608 | |