Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(258)

Side by Side Diff: ui/gfx/render_text_pango.cc

Issue 854713003: More old files deletion. (Closed) Base URL: https://github.com/domokit/mojo.git@master
Patch Set: Fix tryjobs? Created 5 years, 11 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View unified diff | Download patch
« no previous file with comments | « ui/gfx/render_text_pango.h ('k') | ui/gfx/render_text_unittest.cc » ('j') | no next file with comments »
Toggle Intra-line Diffs ('i') | Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
OLDNEW
(Empty)
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "ui/gfx/render_text_pango.h"
6
7 #include <pango/pangocairo.h>
8 #include <algorithm>
9 #include <string>
10 #include <vector>
11
12 #include "base/i18n/break_iterator.h"
13 #include "base/logging.h"
14 #include "third_party/skia/include/core/SkTypeface.h"
15 #include "ui/gfx/canvas.h"
16 #include "ui/gfx/font.h"
17 #include "ui/gfx/font_list.h"
18 #include "ui/gfx/font_render_params.h"
19 #include "ui/gfx/pango_util.h"
20 #include "ui/gfx/platform_font_pango.h"
21 #include "ui/gfx/utf16_indexing.h"
22
23 namespace gfx {
24
25 namespace {
26
27 // Returns the preceding element in a GSList (O(n)).
28 GSList* GSListPrevious(GSList* head, GSList* item) {
29 GSList* prev = NULL;
30 for (GSList* cur = head; cur != item; cur = cur->next) {
31 DCHECK(cur);
32 prev = cur;
33 }
34 return prev;
35 }
36
37 // Returns true if the given visual cursor |direction| is logically forward
38 // motion in the given Pango |item|.
39 bool IsForwardMotion(VisualCursorDirection direction, const PangoItem* item) {
40 bool rtl = item->analysis.level & 1;
41 return rtl == (direction == CURSOR_LEFT);
42 }
43
44 // Checks whether |range| contains |index|. This is not the same as calling
45 // range.Contains(Range(index)), which returns true if |index| == |range.end()|.
46 bool IndexInRange(const Range& range, size_t index) {
47 return index >= range.start() && index < range.end();
48 }
49
50 // Sets underline metrics on |renderer| according to Pango font |desc|.
51 void SetPangoUnderlineMetrics(PangoFontDescription *desc,
52 internal::SkiaTextRenderer* renderer) {
53 PangoFontMetrics* metrics = GetPangoFontMetrics(desc);
54 int thickness = pango_font_metrics_get_underline_thickness(metrics);
55 // Pango returns the position "above the baseline". Change its sign to convert
56 // it to a vertical offset from the baseline.
57 int position = -pango_font_metrics_get_underline_position(metrics);
58
59 // Note: pango_quantize_line_geometry() guarantees pixel boundaries, so
60 // PANGO_PIXELS() is safe to use.
61 pango_quantize_line_geometry(&thickness, &position);
62 int thickness_pixels = PANGO_PIXELS(thickness);
63 int position_pixels = PANGO_PIXELS(position);
64
65 // Ugly hack: make sure that underlines don't get clipped. See
66 // http://crbug.com/393117.
67 int descent_pixels = PANGO_PIXELS(pango_font_metrics_get_descent(metrics));
68 position_pixels = std::min(position_pixels,
69 descent_pixels - thickness_pixels);
70
71 renderer->SetUnderlineMetrics(thickness_pixels, position_pixels);
72 }
73
74 } // namespace
75
76 // TODO(xji): index saved in upper layer is utf16 index. Pango uses utf8 index.
77 // Since caret_pos is used internally, we could save utf8 index for caret_pos
78 // to avoid conversion.
79
80 RenderTextPango::RenderTextPango()
81 : layout_(NULL),
82 current_line_(NULL),
83 log_attrs_(NULL),
84 num_log_attrs_(0),
85 layout_text_(NULL) {
86 }
87
88 RenderTextPango::~RenderTextPango() {
89 ResetLayout();
90 }
91
92 Size RenderTextPango::GetStringSize() {
93 EnsureLayout();
94 int width = 0, height = 0;
95 pango_layout_get_pixel_size(layout_, &width, &height);
96
97 // Pango returns 0 widths for very long strings (of 0x40000 chars or more).
98 // This is caused by an int overflow in pango_glyph_string_extents_range.
99 // Absurdly long strings may even report non-zero garbage values for width;
100 // while detecting that isn't worthwhile, this handles the 0 width cases.
101 const long kAbsurdLength = 100000;
102 if (width == 0 && g_utf8_strlen(layout_text_, -1) > kAbsurdLength)
103 width = font_list().GetExpectedTextWidth(g_utf8_strlen(layout_text_, -1));
104
105 // Keep a consistent height between this particular string's PangoLayout and
106 // potentially larger text supported by the FontList.
107 // For example, if a text field contains a Japanese character, which is
108 // smaller than Latin ones, and then later a Latin one is inserted, this
109 // ensures that the text baseline does not shift.
110 return Size(width, std::max(height, font_list().GetHeight()));
111 }
112
113 SelectionModel RenderTextPango::FindCursorPosition(const Point& point) {
114 EnsureLayout();
115
116 if (text().empty())
117 return SelectionModel(0, CURSOR_FORWARD);
118
119 Point p(ToTextPoint(point));
120
121 // When the point is outside of text, return HOME/END position.
122 if (p.x() < 0)
123 return EdgeSelectionModel(CURSOR_LEFT);
124 if (p.x() > GetStringSize().width())
125 return EdgeSelectionModel(CURSOR_RIGHT);
126
127 int caret_pos = 0, trailing = 0;
128 pango_layout_xy_to_index(layout_, p.x() * PANGO_SCALE, p.y() * PANGO_SCALE,
129 &caret_pos, &trailing);
130
131 DCHECK_GE(trailing, 0);
132 if (trailing > 0) {
133 caret_pos = g_utf8_offset_to_pointer(layout_text_ + caret_pos,
134 trailing) - layout_text_;
135 DCHECK_LE(static_cast<size_t>(caret_pos), strlen(layout_text_));
136 }
137
138 return SelectionModel(LayoutIndexToTextIndex(caret_pos),
139 (trailing > 0) ? CURSOR_BACKWARD : CURSOR_FORWARD);
140 }
141
142 std::vector<RenderText::FontSpan> RenderTextPango::GetFontSpansForTesting() {
143 EnsureLayout();
144
145 std::vector<RenderText::FontSpan> spans;
146 for (GSList* it = current_line_->runs; it; it = it->next) {
147 PangoItem* item = reinterpret_cast<PangoLayoutRun*>(it->data)->item;
148 const int start = LayoutIndexToTextIndex(item->offset);
149 const int end = LayoutIndexToTextIndex(item->offset + item->length);
150 const Range range(start, end);
151
152 ScopedPangoFontDescription desc(pango_font_describe(item->analysis.font));
153 spans.push_back(RenderText::FontSpan(Font(desc.get()), range));
154 }
155
156 return spans;
157 }
158
159 int RenderTextPango::GetLayoutTextBaseline() {
160 EnsureLayout();
161 return PANGO_PIXELS(pango_layout_get_baseline(layout_));
162 }
163
164 SelectionModel RenderTextPango::AdjacentCharSelectionModel(
165 const SelectionModel& selection,
166 VisualCursorDirection direction) {
167 GSList* run = GetRunContainingCaret(selection);
168 if (!run) {
169 // The cursor is not in any run: we're at the visual and logical edge.
170 SelectionModel edge = EdgeSelectionModel(direction);
171 if (edge.caret_pos() == selection.caret_pos())
172 return edge;
173 else
174 run = (direction == CURSOR_RIGHT) ?
175 current_line_->runs : g_slist_last(current_line_->runs);
176 } else {
177 // If the cursor is moving within the current run, just move it by one
178 // grapheme in the appropriate direction.
179 PangoItem* item = reinterpret_cast<PangoLayoutRun*>(run->data)->item;
180 size_t caret = selection.caret_pos();
181 if (IsForwardMotion(direction, item)) {
182 if (caret < LayoutIndexToTextIndex(item->offset + item->length)) {
183 caret = IndexOfAdjacentGrapheme(caret, CURSOR_FORWARD);
184 return SelectionModel(caret, CURSOR_BACKWARD);
185 }
186 } else {
187 if (caret > LayoutIndexToTextIndex(item->offset)) {
188 caret = IndexOfAdjacentGrapheme(caret, CURSOR_BACKWARD);
189 return SelectionModel(caret, CURSOR_FORWARD);
190 }
191 }
192 // The cursor is at the edge of a run; move to the visually adjacent run.
193 // TODO(xji): Keep a vector of runs to avoid using a singly-linked list.
194 run = (direction == CURSOR_RIGHT) ?
195 run->next : GSListPrevious(current_line_->runs, run);
196 if (!run)
197 return EdgeSelectionModel(direction);
198 }
199 PangoItem* item = reinterpret_cast<PangoLayoutRun*>(run->data)->item;
200 return IsForwardMotion(direction, item) ?
201 FirstSelectionModelInsideRun(item) : LastSelectionModelInsideRun(item);
202 }
203
204 SelectionModel RenderTextPango::AdjacentWordSelectionModel(
205 const SelectionModel& selection,
206 VisualCursorDirection direction) {
207 if (obscured())
208 return EdgeSelectionModel(direction);
209
210 base::i18n::BreakIterator iter(text(), base::i18n::BreakIterator::BREAK_WORD);
211 bool success = iter.Init();
212 DCHECK(success);
213 if (!success)
214 return selection;
215
216 SelectionModel cur(selection);
217 for (;;) {
218 cur = AdjacentCharSelectionModel(cur, direction);
219 GSList* run = GetRunContainingCaret(cur);
220 if (!run)
221 break;
222 PangoItem* item = reinterpret_cast<PangoLayoutRun*>(run->data)->item;
223 size_t cursor = cur.caret_pos();
224 if (IsForwardMotion(direction, item) ?
225 iter.IsEndOfWord(cursor) : iter.IsStartOfWord(cursor))
226 break;
227 }
228
229 return cur;
230 }
231
232 Range RenderTextPango::GetGlyphBounds(size_t index) {
233 EnsureLayout();
234 PangoRectangle pos;
235 pango_layout_index_to_pos(layout_, TextIndexToLayoutIndex(index), &pos);
236 // TODO(derat): Support fractional ranges for subpixel positioning?
237 return Range(PANGO_PIXELS(pos.x), PANGO_PIXELS(pos.x + pos.width));
238 }
239
240 std::vector<Rect> RenderTextPango::GetSubstringBounds(const Range& range) {
241 DCHECK_LE(range.GetMax(), text().length());
242 if (range.is_empty())
243 return std::vector<Rect>();
244
245 EnsureLayout();
246 int* ranges = NULL;
247 int n_ranges = 0;
248 pango_layout_line_get_x_ranges(current_line_,
249 TextIndexToLayoutIndex(range.GetMin()),
250 TextIndexToLayoutIndex(range.GetMax()),
251 &ranges,
252 &n_ranges);
253
254 const int height = GetStringSize().height();
255
256 std::vector<Rect> bounds;
257 for (int i = 0; i < n_ranges; ++i) {
258 // TODO(derat): Support fractional bounds for subpixel positioning?
259 int x = PANGO_PIXELS(ranges[2 * i]);
260 int width = PANGO_PIXELS(ranges[2 * i + 1]) - x;
261 Rect rect(x, 0, width, height);
262 rect.set_origin(ToViewPoint(rect.origin()));
263 bounds.push_back(rect);
264 }
265 g_free(ranges);
266 return bounds;
267 }
268
269 size_t RenderTextPango::TextIndexToLayoutIndex(size_t index) const {
270 DCHECK(layout_);
271 ptrdiff_t offset = UTF16IndexToOffset(text(), 0, index);
272 // Clamp layout indices to the length of the text actually used for layout.
273 offset = std::min<size_t>(offset, g_utf8_strlen(layout_text_, -1));
274 const char* layout_pointer = g_utf8_offset_to_pointer(layout_text_, offset);
275 return (layout_pointer - layout_text_);
276 }
277
278 size_t RenderTextPango::LayoutIndexToTextIndex(size_t index) const {
279 DCHECK(layout_);
280 const char* layout_pointer = layout_text_ + index;
281 const long offset = g_utf8_pointer_to_offset(layout_text_, layout_pointer);
282 return UTF16OffsetToIndex(text(), 0, offset);
283 }
284
285 bool RenderTextPango::IsValidCursorIndex(size_t index) {
286 if (index == 0 || index == text().length())
287 return true;
288 if (!IsValidLogicalIndex(index))
289 return false;
290
291 EnsureLayout();
292 ptrdiff_t offset = UTF16IndexToOffset(text(), 0, index);
293 // Check that the index is marked as a legitimate cursor position by Pango.
294 return offset < num_log_attrs_ && log_attrs_[offset].is_cursor_position;
295 }
296
297 void RenderTextPango::ResetLayout() {
298 // set_cached_bounds_and_offset_valid(false) is done in RenderText for every
299 // operation that triggers ResetLayout().
300 if (layout_) {
301 // TODO(msw): Keep |layout_| across text changes, etc.; it can be re-used.
302 g_object_unref(layout_);
303 layout_ = NULL;
304 }
305 if (current_line_) {
306 pango_layout_line_unref(current_line_);
307 current_line_ = NULL;
308 }
309 if (log_attrs_) {
310 g_free(log_attrs_);
311 log_attrs_ = NULL;
312 num_log_attrs_ = 0;
313 }
314 layout_text_ = NULL;
315 }
316
317 void RenderTextPango::EnsureLayout() {
318 if (layout_ == NULL) {
319 cairo_surface_t* surface =
320 cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 0, 0);
321 CHECK_EQ(CAIRO_STATUS_SUCCESS, cairo_surface_status(surface));
322 cairo_t* cr = cairo_create(surface);
323 CHECK_EQ(CAIRO_STATUS_SUCCESS, cairo_status(cr));
324
325 layout_ = pango_cairo_create_layout(cr);
326 CHECK_NE(static_cast<PangoLayout*>(NULL), layout_);
327 cairo_destroy(cr);
328 cairo_surface_destroy(surface);
329
330 SetUpPangoLayout(layout_, GetLayoutText(), font_list(), GetTextDirection(),
331 Canvas::DefaultCanvasTextAlignment());
332
333 // No width set so that the x-axis position is relative to the start of the
334 // text. ToViewPoint and ToTextPoint take care of the position conversion
335 // between text space and view spaces.
336 pango_layout_set_width(layout_, -1);
337 // TODO(xji): If RenderText will be used for displaying purpose, such as
338 // label, we will need to remove the single-line-mode setting.
339 pango_layout_set_single_paragraph_mode(layout_, true);
340
341 layout_text_ = pango_layout_get_text(layout_);
342 SetupPangoAttributes(layout_);
343
344 current_line_ = pango_layout_get_line_readonly(layout_, 0);
345 CHECK_NE(static_cast<PangoLayoutLine*>(NULL), current_line_);
346 pango_layout_line_ref(current_line_);
347
348 pango_layout_get_log_attrs(layout_, &log_attrs_, &num_log_attrs_);
349 }
350 }
351
352 void RenderTextPango::SetupPangoAttributes(PangoLayout* layout) {
353 PangoAttrList* attrs = pango_attr_list_new();
354
355 // Splitting text runs to accommodate styling can break Arabic glyph shaping.
356 // Only split text runs as needed for bold and italic font styles changes.
357 BreakList<bool>::const_iterator bold = styles()[BOLD].breaks().begin();
358 BreakList<bool>::const_iterator italic = styles()[ITALIC].breaks().begin();
359 while (bold != styles()[BOLD].breaks().end() &&
360 italic != styles()[ITALIC].breaks().end()) {
361 const int style = (bold->second ? Font::BOLD : 0) |
362 (italic->second ? Font::ITALIC : 0);
363 const size_t bold_end = styles()[BOLD].GetRange(bold).end();
364 const size_t italic_end = styles()[ITALIC].GetRange(italic).end();
365 const size_t style_end = std::min(bold_end, italic_end);
366 if (style != font_list().GetFontStyle()) {
367 // TODO(derat): Don't interpret gfx::FontList font descriptions as Pango
368 // font descriptions: http://crbug.com/393067
369 FontList derived_font_list = font_list().DeriveWithStyle(style);
370 ScopedPangoFontDescription desc(
371 derived_font_list.GetFontDescriptionString());
372
373 PangoAttribute* pango_attr = pango_attr_font_desc_new(desc.get());
374 pango_attr->start_index =
375 TextIndexToLayoutIndex(std::max(bold->first, italic->first));
376 pango_attr->end_index = TextIndexToLayoutIndex(style_end);
377 pango_attr_list_insert(attrs, pango_attr);
378 }
379 bold += bold_end == style_end ? 1 : 0;
380 italic += italic_end == style_end ? 1 : 0;
381 }
382 DCHECK(bold == styles()[BOLD].breaks().end());
383 DCHECK(italic == styles()[ITALIC].breaks().end());
384
385 pango_layout_set_attributes(layout, attrs);
386 pango_attr_list_unref(attrs);
387 }
388
389 void RenderTextPango::DrawVisualText(Canvas* canvas) {
390 DCHECK(layout_);
391
392 // Skia will draw glyphs with respect to the baseline.
393 Vector2d offset(GetLineOffset(0) + Vector2d(0, GetLayoutTextBaseline()));
394
395 SkScalar x = SkIntToScalar(offset.x());
396 SkScalar y = SkIntToScalar(offset.y());
397
398 std::vector<SkPoint> pos;
399 std::vector<uint16> glyphs;
400
401 internal::SkiaTextRenderer renderer(canvas);
402 ApplyFadeEffects(&renderer);
403 ApplyTextShadows(&renderer);
404 renderer.SetFontRenderParams(
405 font_list().GetPrimaryFont().GetFontRenderParams(),
406 background_is_transparent());
407
408 // Temporarily apply composition underlines and selection colors.
409 ApplyCompositionAndSelectionStyles();
410
411 internal::StyleIterator style(colors(), styles());
412 for (GSList* it = current_line_->runs; it; it = it->next) {
413 // Skip painting runs outside the display area.
414 if (SkScalarTruncToInt(x) >= display_rect().right())
415 break;
416
417 PangoLayoutRun* run = reinterpret_cast<PangoLayoutRun*>(it->data);
418 int glyph_count = run->glyphs->num_glyphs;
419 if (glyph_count == 0)
420 continue;
421
422 ScopedPangoFontDescription desc(
423 pango_font_describe(run->item->analysis.font));
424 const std::string family_name =
425 pango_font_description_get_family(desc.get());
426 renderer.SetTextSize(GetPangoFontSizeInPixels(desc.get()));
427
428 glyphs.resize(glyph_count);
429 pos.resize(glyph_count);
430
431 // Track the current glyph and the glyph at the start of its styled range.
432 int glyph_index = 0;
433 int style_start_glyph_index = glyph_index;
434
435 // Track the x-coordinates for each styled range (|x| marks the current).
436 SkScalar style_start_x = x;
437
438 // Track the current style and its text (not layout) index range.
439 style.UpdatePosition(GetGlyphTextIndex(run, style_start_glyph_index));
440 Range style_range = style.GetRange();
441
442 do {
443 const PangoGlyphInfo& glyph = run->glyphs->glyphs[glyph_index];
444 glyphs[glyph_index] = static_cast<uint16>(glyph.glyph);
445 // Use pango_units_to_double() rather than PANGO_PIXELS() here, so units
446 // are not rounded to the pixel grid if subpixel positioning is enabled.
447 pos[glyph_index].set(x + pango_units_to_double(glyph.geometry.x_offset),
448 y + pango_units_to_double(glyph.geometry.y_offset));
449 x += pango_units_to_double(glyph.geometry.width);
450
451 ++glyph_index;
452 // If this is the last glyph of the range or the last glyph inside the
453 // display area (which would cause early termination of the loop), paint
454 // the range.
455 const size_t glyph_text_index = (glyph_index == glyph_count) ?
456 style_range.end() : GetGlyphTextIndex(run, glyph_index);
457 if (!IndexInRange(style_range, glyph_text_index) ||
458 SkScalarTruncToInt(x) >= display_rect().right()) {
459 // TODO(asvitkine): For cases like "fi", where "fi" is a single glyph
460 // but can span multiple styles, Pango splits the
461 // styles evenly over the glyph. We can do this too by
462 // clipping and drawing the glyph several times.
463 renderer.SetForegroundColor(style.color());
464 const int font_style = (style.style(BOLD) ? Font::BOLD : 0) |
465 (style.style(ITALIC) ? Font::ITALIC : 0);
466 renderer.SetFontFamilyWithStyle(family_name, font_style);
467 renderer.DrawPosText(&pos[style_start_glyph_index],
468 &glyphs[style_start_glyph_index],
469 glyph_index - style_start_glyph_index);
470 if (style.style(UNDERLINE))
471 SetPangoUnderlineMetrics(desc.get(), &renderer);
472 renderer.DrawDecorations(style_start_x, y, x - style_start_x,
473 style.style(UNDERLINE), style.style(STRIKE),
474 style.style(DIAGONAL_STRIKE));
475 style.UpdatePosition(glyph_text_index);
476 style_range = style.GetRange();
477 style_start_glyph_index = glyph_index;
478 style_start_x = x;
479 }
480 // Terminates loop when the end of the range has been reached or the next
481 // glyph falls outside the display area.
482 } while (glyph_index < glyph_count &&
483 SkScalarTruncToInt(x) < display_rect().right());
484 }
485
486 renderer.EndDiagonalStrike();
487
488 // Undo the temporarily applied composition underlines and selection colors.
489 UndoCompositionAndSelectionStyles();
490 }
491
492 GSList* RenderTextPango::GetRunContainingCaret(
493 const SelectionModel& caret) const {
494 size_t position = TextIndexToLayoutIndex(caret.caret_pos());
495 LogicalCursorDirection affinity = caret.caret_affinity();
496 GSList* run = current_line_->runs;
497 while (run) {
498 PangoItem* item = reinterpret_cast<PangoLayoutRun*>(run->data)->item;
499 Range item_range(item->offset, item->offset + item->length);
500 if (RangeContainsCaret(item_range, position, affinity))
501 return run;
502 run = run->next;
503 }
504 return NULL;
505 }
506
507 SelectionModel RenderTextPango::FirstSelectionModelInsideRun(
508 const PangoItem* item) {
509 size_t caret = IndexOfAdjacentGrapheme(
510 LayoutIndexToTextIndex(item->offset), CURSOR_FORWARD);
511 return SelectionModel(caret, CURSOR_BACKWARD);
512 }
513
514 SelectionModel RenderTextPango::LastSelectionModelInsideRun(
515 const PangoItem* item) {
516 size_t caret = IndexOfAdjacentGrapheme(
517 LayoutIndexToTextIndex(item->offset + item->length), CURSOR_BACKWARD);
518 return SelectionModel(caret, CURSOR_FORWARD);
519 }
520
521 size_t RenderTextPango::GetGlyphTextIndex(PangoLayoutRun* run,
522 int glyph_index) const {
523 return LayoutIndexToTextIndex(run->item->offset +
524 run->glyphs->log_clusters[glyph_index]);
525 }
526
527 RenderText* RenderText::CreateNativeInstance() {
528 return new RenderTextPango;
529 }
530
531 } // namespace gfx
OLDNEW
« no previous file with comments | « ui/gfx/render_text_pango.h ('k') | ui/gfx/render_text_unittest.cc » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698