blob: 87fd6313f5d81eacf1bebfbd6b7ff1a7ba1266e9 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "ui/gfx/render_text.h"
#include <limits.h>
#include <algorithm>
#include <climits>
#include "base/command_line.h"
#include "base/feature_list.h"
#include "base/i18n/break_iterator.h"
#include "base/logging.h"
#include "base/numerics/ranges.h"
#include "base/stl_util.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/trace_event/trace_event.h"
#include "build/build_config.h"
#include "cc/paint/paint_canvas.h"
#include "cc/paint/paint_shader.h"
#include "third_party/icu/source/common/unicode/rbbi.h"
#include "third_party/icu/source/common/unicode/utf16.h"
#include "third_party/skia/include/core/SkDrawLooper.h"
#include "third_party/skia/include/core/SkFontStyle.h"
#include "third_party/skia/include/core/SkTypeface.h"
#include "third_party/skia/include/effects/SkGradientShader.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/geometry/insets.h"
#include "ui/gfx/geometry/safe_integer_conversions.h"
#include "ui/gfx/platform_font.h"
#include "ui/gfx/render_text_harfbuzz.h"
#include "ui/gfx/scoped_canvas.h"
#include "ui/gfx/skia_paint_util.h"
#include "ui/gfx/skia_util.h"
#include "ui/gfx/text_elider.h"
#include "ui/gfx/text_utils.h"
#include "ui/gfx/utf16_indexing.h"
#if defined(OS_MACOSX)
#include "third_party/skia/include/ports/SkTypeface_mac.h"
#include "ui/gfx/render_text_mac.h"
#endif // defined(OS_MACOSX)
namespace gfx {
namespace {
// Default color used for the text and cursor.
const SkColor kDefaultColor = SK_ColorBLACK;
// Default color used for drawing selection background.
const SkColor kDefaultSelectionBackgroundColor = SK_ColorGRAY;
// Fraction of the text size to raise the center of a strike-through line above
// the baseline.
const SkScalar kStrikeThroughOffset = (SK_Scalar1 * 65 / 252);
// Fraction of the text size to lower an underline below the baseline.
const SkScalar kUnderlineOffset = (SK_Scalar1 / 9);
// Default fraction of the text size to use for a strike-through or underline.
const SkScalar kLineThicknessFactor = (SK_Scalar1 / 18);
// Invalid value of baseline. Assigning this value to |baseline_| causes
// re-calculation of baseline.
const int kInvalidBaseline = INT_MAX;
// Float comparison needs epsilon to consider rounding errors in float
// arithmetic. Epsilon should be dependent on the context and here, we are
// dealing with glyph widths, use a fairly large number.
const float kFloatComparisonEpsilon = 0.001f;
float Clamp(float f) {
return f < kFloatComparisonEpsilon ? 0 : f;
}
// Given |font| and |display_width|, returns the width of the fade gradient.
int CalculateFadeGradientWidth(const FontList& font_list, int display_width) {
// Fade in/out about 3 characters of the beginning/end of the string.
// Use a 1/3 of the display width if the display width is very short.
const int narrow_width = font_list.GetExpectedTextWidth(3);
const int gradient_width =
std::min(narrow_width, gfx::ToRoundedInt(display_width / 3.f));
DCHECK_GE(gradient_width, 0);
return gradient_width;
}
// Appends to |positions| and |colors| values corresponding to the fade over
// |fade_rect| from color |c0| to color |c1|.
void AddFadeEffect(const Rect& text_rect,
const Rect& fade_rect,
SkColor c0,
SkColor c1,
std::vector<SkScalar>* positions,
std::vector<SkColor>* colors) {
const SkScalar left = static_cast<SkScalar>(fade_rect.x() - text_rect.x());
const SkScalar width = static_cast<SkScalar>(fade_rect.width());
const SkScalar p0 = left / text_rect.width();
const SkScalar p1 = (left + width) / text_rect.width();
// Prepend 0.0 to |positions|, as required by Skia.
if (positions->empty() && p0 != 0.0) {
positions->push_back(0.0);
colors->push_back(c0);
}
positions->push_back(p0);
colors->push_back(c0);
positions->push_back(p1);
colors->push_back(c1);
}
// Creates a SkShader to fade the text, with |left_part| specifying the left
// fade effect, if any, and |right_part| specifying the right fade effect.
sk_sp<cc::PaintShader> CreateFadeShader(const FontList& font_list,
const Rect& text_rect,
const Rect& left_part,
const Rect& right_part,
SkColor color) {
// The shader should only specify transparency of the fade itself, not the
// original transparency, which will be applied by the actual renderer.
DCHECK_EQ(SkColorGetA(color), static_cast<uint8_t>(0xff));
// In general, fade down to 0 alpha. But when the available width is less
// than four characters, linearly ramp up the fade target alpha to as high as
// 20% at zero width. This allows the user to see the last faded characters a
// little better when there are only a few characters shown.
const float width_fraction =
text_rect.width() / static_cast<float>(font_list.GetExpectedTextWidth(4));
const SkAlpha kAlphaAtZeroWidth = 51;
const SkAlpha alpha =
(width_fraction < 1)
? gfx::ToRoundedInt((1 - width_fraction) * kAlphaAtZeroWidth)
: 0;
const SkColor fade_color = SkColorSetA(color, alpha);
std::vector<SkScalar> positions;
std::vector<SkColor> colors;
if (!left_part.IsEmpty())
AddFadeEffect(text_rect, left_part, fade_color, color,
&positions, &colors);
if (!right_part.IsEmpty())
AddFadeEffect(text_rect, right_part, color, fade_color,
&positions, &colors);
DCHECK(!positions.empty());
// Terminate |positions| with 1.0, as required by Skia.
if (positions.back() != 1.0) {
positions.push_back(1.0);
colors.push_back(colors.back());
}
const SkPoint points[2] = { PointToSkPoint(text_rect.origin()),
PointToSkPoint(text_rect.top_right()) };
return cc::PaintShader::MakeLinearGradient(
&points[0], &colors[0], &positions[0], static_cast<int>(colors.size()),
SkTileMode::kClamp);
}
// Converts a FontRenderParams::Hinting value to the corresponding
// SkFontHinting value.
SkFontHinting FontRenderParamsHintingToSkFontHinting(
FontRenderParams::Hinting params_hinting) {
switch (params_hinting) {
case FontRenderParams::HINTING_NONE:
return SkFontHinting::kNone;
case FontRenderParams::HINTING_SLIGHT:
return SkFontHinting::kSlight;
case FontRenderParams::HINTING_MEDIUM:
return SkFontHinting::kNormal;
case FontRenderParams::HINTING_FULL:
return SkFontHinting::kFull;
}
return SkFontHinting::kNone;
}
// Make sure ranges don't break text graphemes. If a range in |break_list|
// does break a grapheme in |render_text|, the range will be slightly
// extended to encompass the grapheme.
template <typename T>
void RestoreBreakList(RenderText* render_text, BreakList<T>* break_list) {
break_list->SetMax(render_text->text().length());
Range range;
while (range.end() < break_list->max()) {
const auto& current_break = break_list->GetBreak(range.end());
range = break_list->GetRange(current_break);
if (range.end() < break_list->max() &&
!render_text->IsValidCursorIndex(range.end())) {
range.set_end(
render_text->IndexOfAdjacentGrapheme(range.end(), CURSOR_FORWARD));
break_list->ApplyValue(current_break->second, range);
}
}
}
} // namespace
namespace internal {
SkiaTextRenderer::SkiaTextRenderer(Canvas* canvas)
: canvas_(canvas), canvas_skia_(canvas->sk_canvas()) {
DCHECK(canvas_skia_);
flags_.setStyle(cc::PaintFlags::kFill_Style);
font_.setEdging(SkFont::Edging::kSubpixelAntiAlias);
font_.setSubpixel(true);
font_.setHinting(SkFontHinting::kNormal);
}
SkiaTextRenderer::~SkiaTextRenderer() {
}
void SkiaTextRenderer::SetDrawLooper(sk_sp<SkDrawLooper> draw_looper) {
flags_.setLooper(std::move(draw_looper));
}
void SkiaTextRenderer::SetFontRenderParams(const FontRenderParams& params,
bool subpixel_rendering_suppressed) {
ApplyRenderParams(params, subpixel_rendering_suppressed, &font_);
}
void SkiaTextRenderer::SetTypeface(sk_sp<SkTypeface> typeface) {
font_.setTypeface(std::move(typeface));
}
void SkiaTextRenderer::SetTextSize(SkScalar size) {
font_.setSize(size);
}
void SkiaTextRenderer::SetForegroundColor(SkColor foreground) {
flags_.setColor(foreground);
}
void SkiaTextRenderer::SetShader(sk_sp<cc::PaintShader> shader) {
flags_.setShader(std::move(shader));
}
void SkiaTextRenderer::DrawPosText(const SkPoint* pos,
const uint16_t* glyphs,
size_t glyph_count) {
SkTextBlobBuilder builder;
const auto& run_buffer = builder.allocRunPos(font_, glyph_count);
static_assert(sizeof(*glyphs) == sizeof(*run_buffer.glyphs), "");
memcpy(run_buffer.glyphs, glyphs, glyph_count * sizeof(*glyphs));
static_assert(sizeof(*pos) == 2 * sizeof(*run_buffer.pos), "");
memcpy(run_buffer.pos, pos, glyph_count * sizeof(*pos));
canvas_skia_->drawTextBlob(builder.make(), 0, 0, flags_);
}
void SkiaTextRenderer::DrawUnderline(int x,
int y,
int width,
SkScalar thickness_factor) {
SkScalar x_scalar = SkIntToScalar(x);
const SkScalar text_size = font_.getSize();
SkRect r = SkRect::MakeLTRB(
x_scalar, y + text_size * kUnderlineOffset, x_scalar + width,
y + (text_size *
(kUnderlineOffset + (thickness_factor * kLineThicknessFactor))));
canvas_skia_->drawRect(r, flags_);
}
void SkiaTextRenderer::DrawStrike(int x,
int y,
int width,
SkScalar thickness_factor) {
const SkScalar text_size = font_.getSize();
const SkScalar height = text_size * thickness_factor;
const SkScalar top = y - text_size * kStrikeThroughOffset - height / 2;
SkScalar x_scalar = SkIntToScalar(x);
const SkRect r =
SkRect::MakeLTRB(x_scalar, top, x_scalar + width, top + height);
canvas_skia_->drawRect(r, flags_);
}
StyleIterator::StyleIterator(const BreakList<SkColor>& colors,
const BreakList<BaselineStyle>& baselines,
const BreakList<int>& font_size_overrides,
const BreakList<Font::Weight>& weights,
const std::vector<BreakList<bool>>& styles)
: colors_(colors),
baselines_(baselines),
font_size_overrides_(font_size_overrides),
weights_(weights),
styles_(styles) {
color_ = colors_.breaks().begin();
baseline_ = baselines_.breaks().begin();
font_size_override_ = font_size_overrides_.breaks().begin();
weight_ = weights_.breaks().begin();
for (size_t i = 0; i < styles_.size(); ++i)
style_.push_back(styles_[i].breaks().begin());
}
StyleIterator::~StyleIterator() {}
Range StyleIterator::GetRange() const {
Range range(colors_.GetRange(color_));
range = range.Intersect(baselines_.GetRange(baseline_));
range = range.Intersect(font_size_overrides_.GetRange(font_size_override_));
range = range.Intersect(weights_.GetRange(weight_));
for (size_t i = 0; i < TEXT_STYLE_COUNT; ++i)
range = range.Intersect(styles_[i].GetRange(style_[i]));
return range;
}
void StyleIterator::UpdatePosition(size_t position) {
color_ = colors_.GetBreak(position);
baseline_ = baselines_.GetBreak(position);
font_size_override_ = font_size_overrides_.GetBreak(position);
weight_ = weights_.GetBreak(position);
for (size_t i = 0; i < TEXT_STYLE_COUNT; ++i)
style_[i] = styles_[i].GetBreak(position);
}
LineSegment::LineSegment() : run(0) {}
LineSegment::~LineSegment() {}
Line::Line() : preceding_heights(0), baseline(0) {}
Line::Line(const Line& other) = default;
Line::~Line() {}
void ApplyRenderParams(const FontRenderParams& params,
bool subpixel_rendering_suppressed,
SkFont* font) {
if (!params.antialiasing) {
font->setEdging(SkFont::Edging::kAlias);
} else if (subpixel_rendering_suppressed ||
params.subpixel_rendering ==
FontRenderParams::SUBPIXEL_RENDERING_NONE) {
font->setEdging(SkFont::Edging::kAntiAlias);
} else {
font->setEdging(SkFont::Edging::kSubpixelAntiAlias);
}
font->setSubpixel(params.subpixel_positioning);
font->setForceAutoHinting(params.autohinter);
font->setHinting(FontRenderParamsHintingToSkFontHinting(params.hinting));
}
} // namespace internal
// static
constexpr base::char16 RenderText::kPasswordReplacementChar;
constexpr bool RenderText::kDragToEndIfOutsideVerticalBounds;
RenderText::~RenderText() {
}
// static
std::unique_ptr<RenderText> RenderText::CreateHarfBuzzInstance() {
return std::make_unique<RenderTextHarfBuzz>();
}
// static
std::unique_ptr<RenderText> RenderText::CreateFor(Typesetter typesetter) {
#if defined(OS_MACOSX)
if (typesetter == Typesetter::NATIVE)
return std::make_unique<RenderTextMac>();
#endif // defined(OS_MACOSX)
return CreateHarfBuzzInstance();
}
// static
std::unique_ptr<RenderText> RenderText::CreateInstanceDeprecated() {
return CreateFor(Typesetter::BROWSER);
}
std::unique_ptr<RenderText> RenderText::CreateInstanceOfSameStyle(
const base::string16& text) const {
std::unique_ptr<RenderText> render_text = CreateInstanceOfSameType();
// |SetText()| must be called before styles are set.
render_text->SetText(text);
render_text->SetFontList(font_list_);
render_text->SetDirectionalityMode(directionality_mode_);
render_text->SetCursorEnabled(cursor_enabled_);
render_text->set_truncate_length(truncate_length_);
render_text->styles_ = styles_;
render_text->baselines_ = baselines_;
render_text->font_size_overrides_ = font_size_overrides_;
render_text->colors_ = colors_;
render_text->weights_ = weights_;
render_text->glyph_width_for_test_ = glyph_width_for_test_;
return render_text;
}
void RenderText::SetText(const base::string16& text) {
DCHECK(!composition_range_.IsValid());
if (text_ == text)
return;
text_ = text;
UpdateStyleLengths();
// Clear style ranges as they might break new text graphemes and apply
// the first style to the whole text instead.
colors_.SetValue(colors_.breaks().begin()->second);
baselines_.SetValue(baselines_.breaks().begin()->second);
font_size_overrides_.SetValue(font_size_overrides_.breaks().begin()->second);
weights_.SetValue(weights_.breaks().begin()->second);
for (size_t style = 0; style < TEXT_STYLE_COUNT; ++style)
styles_[style].SetValue(styles_[style].breaks().begin()->second);
cached_bounds_and_offset_valid_ = false;
// Reset selection model. SetText should always followed by SetSelectionModel
// or SetCursorPosition in upper layer.
SetSelectionModel(SelectionModel());
// Invalidate the cached text direction if it depends on the text contents.
if (directionality_mode_ == DIRECTIONALITY_FROM_TEXT)
text_direction_ = base::i18n::UNKNOWN_DIRECTION;
obscured_reveal_index_ = -1;
OnTextAttributeChanged();
}
void RenderText::AppendText(const base::string16& text) {
text_ += text;
UpdateStyleLengths();
cached_bounds_and_offset_valid_ = false;
obscured_reveal_index_ = -1;
OnTextAttributeChanged();
}
void RenderText::SetHorizontalAlignment(HorizontalAlignment alignment) {
if (horizontal_alignment_ != alignment) {
horizontal_alignment_ = alignment;
display_offset_ = Vector2d();
cached_bounds_and_offset_valid_ = false;
}
}
void RenderText::SetVerticalAlignment(VerticalAlignment alignment) {
if (vertical_alignment_ != alignment) {
vertical_alignment_ = alignment;
display_offset_ = Vector2d();
cached_bounds_and_offset_valid_ = false;
}
}
void RenderText::SetFontList(const FontList& font_list) {
font_list_ = font_list;
const int font_style = font_list.GetFontStyle();
weights_.SetValue(font_list.GetFontWeight());
styles_[TEXT_STYLE_ITALIC].SetValue((font_style & Font::ITALIC) != 0);
styles_[TEXT_STYLE_UNDERLINE].SetValue((font_style & Font::UNDERLINE) != 0);
styles_[TEXT_STYLE_HEAVY_UNDERLINE].SetValue(false);
baseline_ = kInvalidBaseline;
cached_bounds_and_offset_valid_ = false;
OnLayoutTextAttributeChanged(false);
}
void RenderText::SetCursorEnabled(bool cursor_enabled) {
cursor_enabled_ = cursor_enabled;
cached_bounds_and_offset_valid_ = false;
}
void RenderText::SetObscured(bool obscured) {
if (obscured != obscured_) {
obscured_ = obscured;
obscured_reveal_index_ = -1;
cached_bounds_and_offset_valid_ = false;
OnTextAttributeChanged();
}
}
void RenderText::SetObscuredRevealIndex(int index) {
if (obscured_reveal_index_ == index)
return;
obscured_reveal_index_ = index;
cached_bounds_and_offset_valid_ = false;
OnTextAttributeChanged();
}
void RenderText::SetMultiline(bool multiline) {
if (multiline != multiline_) {
multiline_ = multiline;
cached_bounds_and_offset_valid_ = false;
lines_.clear();
OnTextAttributeChanged();
}
}
void RenderText::SetMaxLines(size_t max_lines) {
max_lines_ = max_lines;
OnDisplayTextAttributeChanged();
}
size_t RenderText::GetNumLines() {
EnsureLayout();
return lines_.size();
}
void RenderText::SetWordWrapBehavior(WordWrapBehavior behavior) {
if (word_wrap_behavior_ == behavior)
return;
word_wrap_behavior_ = behavior;
if (multiline_) {
cached_bounds_and_offset_valid_ = false;
lines_.clear();
OnTextAttributeChanged();
}
}
void RenderText::SetReplaceNewlineCharsWithSymbols(bool replace) {
if (replace_newline_chars_with_symbols_ == replace)
return;
replace_newline_chars_with_symbols_ = replace;
cached_bounds_and_offset_valid_ = false;
OnTextAttributeChanged();
}
void RenderText::SetMinLineHeight(int line_height) {
if (min_line_height_ == line_height)
return;
min_line_height_ = line_height;
cached_bounds_and_offset_valid_ = false;
lines_.clear();
OnDisplayTextAttributeChanged();
}
void RenderText::SetElideBehavior(ElideBehavior elide_behavior) {
// TODO(skanuj) : Add a test for triggering layout change.
if (elide_behavior_ != elide_behavior) {
elide_behavior_ = elide_behavior;
OnDisplayTextAttributeChanged();
}
}
void RenderText::SetDisplayRect(const Rect& r) {
if (r != display_rect_) {
display_rect_ = r;
baseline_ = kInvalidBaseline;
cached_bounds_and_offset_valid_ = false;
lines_.clear();
if (elide_behavior_ != NO_ELIDE &&
elide_behavior_ != FADE_TAIL) {
OnDisplayTextAttributeChanged();
}
}
}
void RenderText::SetCursorPosition(size_t position) {
size_t cursor = std::min(position, text().length());
if (IsValidCursorIndex(cursor)) {
SetSelectionModel(SelectionModel(
cursor, (cursor == 0) ? CURSOR_FORWARD : CURSOR_BACKWARD));
}
}
void RenderText::MoveCursor(BreakType break_type,
VisualCursorDirection direction,
SelectionBehavior selection_behavior) {
SelectionModel cursor(cursor_position(), selection_model_.caret_affinity());
// Ensure |cursor| is at the "end" of the current selection, since this
// determines which side should grow or shrink. If the prior change to the
// selection wasn't from cursor movement, the selection may be undirected. Or,
// the selection may be collapsing. In these cases, pick the "end" using
// |direction| (e.g. the arrow key) rather than the current selection range.
if ((!has_directed_selection_ || selection_behavior == SELECTION_NONE) &&
!selection().is_empty()) {
SelectionModel selection_start = GetSelectionModelForSelectionStart();
Point start = GetCursorBounds(selection_start, true).origin();
Point end = GetCursorBounds(cursor, true).origin();
// Use the selection start if it is left (when |direction| is CURSOR_LEFT)
// or right (when |direction| is CURSOR_RIGHT) of the selection end.
// Consider only the y-coordinates if the selection start and end are on
// different lines.
const bool cursor_is_leading =
(start.y() > end.y()) ||
((start.y() == end.y()) && (start.x() > end.x()));
const bool cursor_should_be_trailing =
(direction == CURSOR_RIGHT) || (direction == CURSOR_DOWN);
if (cursor_is_leading == cursor_should_be_trailing) {
// In this case, a direction has been chosen that doesn't match
// |selection_model|, so the range must be reversed to place the cursor at
// the other end. Note the affinity won't matter: only the affinity of
// |start| (which points "in" to the selection) determines the movement.
Range range = selection_model_.selection();
selection_model_ = SelectionModel(Range(range.end(), range.start()),
selection_model_.caret_affinity());
cursor = selection_start;
}
}
// Cancelling a selection moves to the edge of the selection.
if (break_type != FIELD_BREAK && break_type != LINE_BREAK &&
!selection().is_empty() && selection_behavior == SELECTION_NONE) {
// Use the nearest word boundary in the proper |direction| for word breaks.
if (break_type == WORD_BREAK)
cursor = GetAdjacentSelectionModel(cursor, break_type, direction);
// Use an adjacent selection model if the cursor is not at a valid position.
if (!IsValidCursorIndex(cursor.caret_pos()))
cursor = GetAdjacentSelectionModel(cursor, CHARACTER_BREAK, direction);
} else {
cursor = GetAdjacentSelectionModel(cursor, break_type, direction);
}
// |cursor| corresponds to the tentative end point of the new selection. The
// selection direction is reversed iff the current selection is non-empty and
// the old selection end point and |cursor| are at the opposite ends of the
// old selection start point.
uint32_t min_end = std::min(selection().end(), cursor.selection().end());
uint32_t max_end = std::max(selection().end(), cursor.selection().end());
uint32_t current_start = selection().start();
bool selection_reversed = !selection().is_empty() &&
min_end <= current_start &&
current_start <= max_end;
// Take |selection_behavior| into account.
switch (selection_behavior) {
case SELECTION_RETAIN:
cursor.set_selection_start(current_start);
break;
case SELECTION_EXTEND:
cursor.set_selection_start(selection_reversed ? selection().end()
: current_start);
break;
case SELECTION_CARET:
if (selection_reversed) {
cursor =
SelectionModel(current_start, selection_model_.caret_affinity());
} else {
cursor.set_selection_start(current_start);
}
break;
case SELECTION_NONE:
// Do nothing.
break;
}
SetSelection(cursor);
has_directed_selection_ = true;
// |cached_cursor_x| keeps the initial x-coordinates where CURSOR_UP or
// CURSOR_DOWN starts. This enables the cursor to keep the same x-coordinates
// even when the cursor passes through empty or short lines. The cached
// x-coordinates should be reset when the cursor moves in a horizontal
// direction.
if (direction != CURSOR_UP && direction != CURSOR_DOWN)
reset_cached_cursor_x();
}
bool RenderText::SetSelection(const SelectionModel& model) {
// Enforce valid selection model components.
size_t text_length = text().length();
Range range(
std::min(model.selection().start(), static_cast<uint32_t>(text_length)),
std::min(model.caret_pos(), text_length));
// The current model only supports caret positions at valid cursor indices.
if (!IsValidCursorIndex(range.start()) || !IsValidCursorIndex(range.end()))
return false;
SelectionModel sel(range, model.caret_affinity());
bool changed = sel != selection_model_;
SetSelectionModel(sel);
return changed;
}
bool RenderText::MoveCursorToPoint(const gfx::Point& point,
bool select,
const gfx::Point& drag_origin) {
reset_cached_cursor_x();
gfx::SelectionModel model = FindCursorPosition(point, drag_origin);
if (select)
model.set_selection_start(selection().start());
return SetSelection(model);
}
bool RenderText::SelectRange(const Range& range) {
uint32_t text_length = static_cast<uint32_t>(text().length());
Range sel(std::min(range.start(), text_length),
std::min(range.end(), text_length));
// Allow selection bounds at valid indicies amid multi-character graphemes.
if (!IsValidLogicalIndex(sel.start()) || !IsValidLogicalIndex(sel.end()))
return false;
LogicalCursorDirection affinity =
(sel.is_reversed() || sel.is_empty()) ? CURSOR_FORWARD : CURSOR_BACKWARD;
SetSelectionModel(SelectionModel(sel, affinity));
return true;
}
bool RenderText::IsPointInSelection(const Point& point) {
if (selection().is_empty())
return false;
SelectionModel cursor = FindCursorPosition(point);
return RangeContainsCaret(
selection(), cursor.caret_pos(), cursor.caret_affinity());
}
void RenderText::ClearSelection() {
SetSelectionModel(
SelectionModel(cursor_position(), selection_model_.caret_affinity()));
}
void RenderText::SelectAll(bool reversed) {
const size_t length = text().length();
const Range all = reversed ? Range(length, 0) : Range(0, length);
const bool success = SelectRange(all);
DCHECK(success);
}
void RenderText::SelectWord() {
SelectRange(ExpandRangeToWordBoundary(selection()));
}
void RenderText::SetCompositionRange(const Range& composition_range) {
CHECK(!composition_range.IsValid() ||
Range(0, text_.length()).Contains(composition_range));
composition_range_.set_end(composition_range.end());
composition_range_.set_start(composition_range.start());
// TODO(oshima|msw): Altering composition underlines shouldn't
// require layout changes. It's currently necessary because
// RenderTextHarfBuzz paints text decorations by run, and
// RenderTextMac applies all styles during layout.
OnLayoutTextAttributeChanged(false);
}
void RenderText::SetColor(SkColor value) {
colors_.SetValue(value);
OnTextColorChanged();
}
void RenderText::ApplyColor(SkColor value, const Range& range) {
colors_.ApplyValue(value, range);
OnTextColorChanged();
}
void RenderText::SetBaselineStyle(BaselineStyle value) {
baselines_.SetValue(value);
}
void RenderText::ApplyBaselineStyle(BaselineStyle value, const Range& range) {
baselines_.ApplyValue(value, range);
}
void RenderText::ApplyFontSizeOverride(int font_size_override,
const Range& range) {
font_size_overrides_.ApplyValue(font_size_override, range);
}
void RenderText::SetStyle(TextStyle style, bool value) {
styles_[style].SetValue(value);
cached_bounds_and_offset_valid_ = false;
// TODO(oshima|msw): Not all style change requires layout changes.
// Consider optimizing based on the type of change.
OnLayoutTextAttributeChanged(false);
}
void RenderText::ApplyStyle(TextStyle style, bool value, const Range& range) {
// Do not change styles mid-grapheme to avoid breaking ligatures.
const size_t start = IsValidCursorIndex(range.start()) ? range.start() :
IndexOfAdjacentGrapheme(range.start(), CURSOR_BACKWARD);
const size_t end = IsValidCursorIndex(range.end()) ? range.end() :
IndexOfAdjacentGrapheme(range.end(), CURSOR_FORWARD);
styles_[style].ApplyValue(value, Range(start, end));
cached_bounds_and_offset_valid_ = false;
// TODO(oshima|msw): Not all style change requires layout changes.
// Consider optimizing based on the type of change.
OnLayoutTextAttributeChanged(false);
}
void RenderText::SetWeight(Font::Weight weight) {
weights_.SetValue(weight);
cached_bounds_and_offset_valid_ = false;
OnLayoutTextAttributeChanged(false);
}
void RenderText::ApplyWeight(Font::Weight weight, const Range& range) {
weights_.ApplyValue(weight, range);
cached_bounds_and_offset_valid_ = false;
OnLayoutTextAttributeChanged(false);
}
bool RenderText::GetStyle(TextStyle style) const {
return (styles_[style].breaks().size() == 1) &&
styles_[style].breaks().front().second;
}
void RenderText::SetDirectionalityMode(DirectionalityMode mode) {
if (mode == directionality_mode_)
return;
directionality_mode_ = mode;
text_direction_ = base::i18n::UNKNOWN_DIRECTION;
cached_bounds_and_offset_valid_ = false;
OnLayoutTextAttributeChanged(false);
}
base::i18n::TextDirection RenderText::GetDisplayTextDirection() {
return GetTextDirection(GetDisplayText());
}
VisualCursorDirection RenderText::GetVisualDirectionOfLogicalEnd() {
return GetDisplayTextDirection() == base::i18n::LEFT_TO_RIGHT ? CURSOR_RIGHT
: CURSOR_LEFT;
}
VisualCursorDirection RenderText::GetVisualDirectionOfLogicalBeginning() {
return GetDisplayTextDirection() == base::i18n::RIGHT_TO_LEFT ? CURSOR_RIGHT
: CURSOR_LEFT;
}
SizeF RenderText::GetStringSizeF() {
return SizeF(GetStringSize());
}
Size RenderText::GetLineSize(const SelectionModel& caret) {
return GetStringSize();
}
float RenderText::TotalLineWidth() {
return GetStringSizeF().width();
}
float RenderText::GetContentWidthF() {
const float string_size = GetStringSizeF().width();
// The cursor is drawn one pixel beyond the int-enclosed text bounds.
return cursor_enabled_ ? std::ceil(string_size) + 1 : string_size;
}
int RenderText::GetContentWidth() {
return ToCeiledInt(GetContentWidthF());
}
int RenderText::GetBaseline() {
if (baseline_ == kInvalidBaseline) {
baseline_ =
DetermineBaselineCenteringText(display_rect().height(), font_list());
}
DCHECK_NE(kInvalidBaseline, baseline_);
return baseline_;
}
void RenderText::Draw(Canvas* canvas) {
EnsureLayout();
if (clip_to_display_rect()) {
Rect clip_rect(display_rect());
clip_rect.Inset(ShadowValue::GetMargin(shadows_));
canvas->Save();
canvas->ClipRect(clip_rect);
}
if (!text().empty() && focused())
DrawSelection(canvas);
if (!text().empty()) {
internal::SkiaTextRenderer renderer(canvas);
DrawVisualText(&renderer);
}
if (clip_to_display_rect())
canvas->Restore();
}
bool RenderText::IsValidLogicalIndex(size_t index) const {
// Check that the index is at a valid code point (not mid-surrgate-pair) and
// that it's not truncated from the display text (its glyph may be shown).
//
// Indices within truncated text are disallowed so users can easily interact
// with the underlying truncated text using the ellipsis as a proxy. This lets
// users select all text, select the truncated text, and transition from the
// last rendered glyph to the end of the text without getting invisible cursor
// positions nor needing unbounded arrow key presses to traverse the ellipsis.
return index == 0 || index == text().length() ||
(index < text().length() &&
(truncate_length_ == 0 || index < truncate_length_) &&
IsValidCodePointIndex(text(), index));
}
Rect RenderText::GetCursorBounds(const SelectionModel& caret,
bool insert_mode) {
EnsureLayout();
size_t caret_pos = caret.caret_pos();
DCHECK(IsValidLogicalIndex(caret_pos));
// In overtype mode, ignore the affinity and always indicate that we will
// overtype the next character.
LogicalCursorDirection caret_affinity =
insert_mode ? caret.caret_affinity() : CURSOR_FORWARD;
float x = 0;
int width = 1;
// Check whether the caret is attached to a boundary. Always return a 1-dip
// width caret at the boundary. Avoid calling IndexOfAdjacentGrapheme(), since
// it is slow and can impact browser startup here.
// In insert mode, index 0 is always a boundary. The end, however, is not at a
// boundary when the string ends in RTL text and there is LTR text around it.
const bool at_boundary =
(insert_mode && caret_pos == 0) ||
caret_pos == (caret_affinity == CURSOR_BACKWARD ? 0 : text().length());
if (at_boundary) {
const bool rtl = GetDisplayTextDirection() == base::i18n::RIGHT_TO_LEFT;
if (rtl == (caret_pos == 0))
x = TotalLineWidth();
} else {
// Find the next grapheme continuing in the current direction. This
// determines the substring range that should be highlighted.
size_t caret_end = IndexOfAdjacentGrapheme(caret_pos, caret_affinity);
if (caret_end < caret_pos)
std::swap(caret_end, caret_pos);
const RangeF xspan = GetCursorSpan(Range(caret_pos, caret_end));
if (insert_mode) {
x = (caret_affinity == CURSOR_BACKWARD) ? xspan.end() : xspan.start();
} else { // overtype mode
x = xspan.GetMin();
// Ceil the start and end of the |xspan| because the cursor x-coordinates
// are always ceiled.
width =
std::ceil(Clamp(xspan.GetMax())) - std::ceil(Clamp(xspan.GetMin()));
}
}
return Rect(ToViewPoint(PointF(x, 0), caret_affinity),
Size(width, GetLineSize(caret).height()));
}
const Rect& RenderText::GetUpdatedCursorBounds() {
UpdateCachedBoundsAndOffset();
return cursor_bounds_;
}
size_t RenderText::IndexOfAdjacentGrapheme(size_t index,
LogicalCursorDirection direction) {
if (index > text().length())
return text().length();
EnsureLayout();
if (direction == CURSOR_FORWARD) {
while (index < text().length()) {
index++;
if (IsValidCursorIndex(index))
return index;
}
return text().length();
}
while (index > 0) {
index--;
if (IsValidCursorIndex(index))
return index;
}
return 0;
}
SelectionModel RenderText::GetSelectionModelForSelectionStart() const {
const Range& sel = selection();
if (sel.is_empty())
return selection_model_;
return SelectionModel(sel.start(),
sel.is_reversed() ? CURSOR_BACKWARD : CURSOR_FORWARD);
}
RectF RenderText::GetStringRect() {
return RectF(PointF(ToViewPoint(PointF(), CURSOR_FORWARD)), GetStringSizeF());
}
const Vector2d& RenderText::GetUpdatedDisplayOffset() {
UpdateCachedBoundsAndOffset();
return display_offset_;
}
void RenderText::SetDisplayOffset(int horizontal_offset) {
const int extra_content = GetContentWidth() - display_rect_.width();
const int cursor_width = cursor_enabled_ ? 1 : 0;
int min_offset = 0;
int max_offset = 0;
if (extra_content > 0) {
switch (GetCurrentHorizontalAlignment()) {
case ALIGN_LEFT:
min_offset = -extra_content;
break;
case ALIGN_RIGHT:
max_offset = extra_content;
break;
case ALIGN_CENTER:
// The extra space reserved for cursor at the end of the text is ignored
// when centering text. So, to calculate the valid range for offset, we
// exclude that extra space, calculate the range, and add it back to the
// range (if cursor is enabled).
min_offset = -(extra_content - cursor_width + 1) / 2 - cursor_width;
max_offset = (extra_content - cursor_width) / 2;
break;
default:
break;
}
}
if (horizontal_offset < min_offset)
horizontal_offset = min_offset;
else if (horizontal_offset > max_offset)
horizontal_offset = max_offset;
cached_bounds_and_offset_valid_ = true;
display_offset_.set_x(horizontal_offset);
cursor_bounds_ = GetCursorBounds(selection_model_, true);
}
Vector2d RenderText::GetLineOffset(size_t line_number) {
EnsureLayout();
Vector2d offset = display_rect().OffsetFromOrigin();
// TODO(ckocagil): Apply the display offset for multiline scrolling.
if (!multiline()) {
DCHECK_EQ(ALIGN_MIDDLE, vertical_alignment_);
offset.Add(GetUpdatedDisplayOffset());
} else {
DCHECK_LT(line_number, lines().size());
offset.Add(Vector2d(0, lines_[line_number].preceding_heights));
}
offset.Add(GetAlignmentOffset(line_number));
return offset;
}
bool RenderText::GetWordLookupDataAtPoint(const Point& point,
DecoratedText* decorated_word,
Point* baseline_point) {
if (obscured())
return false;
EnsureLayout();
const SelectionModel model_at_point = FindCursorPosition(point);
const size_t word_index =
GetNearestWordStartBoundary(model_at_point.caret_pos());
if (word_index >= text().length())
return false;
const Range word_range = ExpandRangeToWordBoundary(Range(word_index));
DCHECK(!word_range.is_reversed());
DCHECK(!word_range.is_empty());
return GetLookupDataForRange(word_range, decorated_word, baseline_point);
}
bool RenderText::GetLookupDataForRange(const Range& range,
DecoratedText* decorated_text,
Point* baseline_point) {
EnsureLayout();
const std::vector<Rect> word_bounds = GetSubstringBounds(range);
if (word_bounds.empty() || !GetDecoratedTextForRange(range, decorated_text)) {
return false;
}
// Retrieve the baseline origin of the left-most glyph.
const auto left_rect = std::min_element(
word_bounds.begin(), word_bounds.end(),
[](const Rect& lhs, const Rect& rhs) { return lhs.x() < rhs.x(); });
const int line_index = GetLineContainingYCoord(left_rect->CenterPoint().y() -
GetLineOffset(0).y());
if (line_index < 0 || line_index >= static_cast<int>(lines().size()))
return false;
*baseline_point =
left_rect->origin() + Vector2d(0, lines()[line_index].baseline);
return true;
}
base::string16 RenderText::GetTextFromRange(const Range& range) const {
if (range.IsValid() && range.GetMin() < text().length())
return text().substr(range.GetMin(), range.length());
return base::string16();
}
bool RenderText::IsNewlineSegment(const internal::LineSegment& segment) const {
DCHECK_LT(segment.char_range.start(), text_.length());
return text_[segment.char_range.start()] == '\n';
}
RenderText::RenderText()
: horizontal_alignment_(base::i18n::IsRTL() ? ALIGN_RIGHT : ALIGN_LEFT),
vertical_alignment_(ALIGN_MIDDLE),
directionality_mode_(DIRECTIONALITY_FROM_TEXT),
text_direction_(base::i18n::UNKNOWN_DIRECTION),
cursor_enabled_(true),
has_directed_selection_(kSelectionIsAlwaysDirected),
selection_color_(kDefaultColor),
selection_background_focused_color_(kDefaultSelectionBackgroundColor),
focused_(false),
composition_range_(Range::InvalidRange()),
colors_(kDefaultColor),
baselines_(NORMAL_BASELINE),
font_size_overrides_(0),
weights_(Font::Weight::NORMAL),
styles_(TEXT_STYLE_COUNT),
composition_and_selection_styles_applied_(false),
obscured_(false),
obscured_reveal_index_(-1),
truncate_length_(0),
elide_behavior_(NO_ELIDE),
text_elided_(false),
min_line_height_(0),
multiline_(false),
max_lines_(0),
word_wrap_behavior_(IGNORE_LONG_WORDS),
replace_newline_chars_with_symbols_(true),
subpixel_rendering_suppressed_(false),
clip_to_display_rect_(true),
baseline_(kInvalidBaseline),
cached_bounds_and_offset_valid_(false),
strike_thickness_factor_(kLineThicknessFactor) {}
bool RenderText::IsHomogeneous() const {
if (colors().breaks().size() > 1 || baselines().breaks().size() > 1 ||
font_size_overrides().breaks().size() > 1 ||
weights().breaks().size() > 1)
return false;
for (size_t style = 0; style < TEXT_STYLE_COUNT; ++style) {
if (styles()[style].breaks().size() > 1)
return false;
}
return true;
}
SelectionModel RenderText::GetAdjacentSelectionModel(
const SelectionModel& current,
BreakType break_type,
VisualCursorDirection direction) {
EnsureLayout();
if (direction == CURSOR_UP || direction == CURSOR_DOWN)
return AdjacentLineSelectionModel(current, direction);
if (break_type == FIELD_BREAK || text().empty())
return EdgeSelectionModel(direction);
if (break_type == LINE_BREAK)
return LineSelectionModel(GetLineContainingCaret(current), direction);
if (break_type == CHARACTER_BREAK)
return AdjacentCharSelectionModel(current, direction);
DCHECK(break_type == WORD_BREAK);
return AdjacentWordSelectionModel(current, direction);
}
SelectionModel RenderText::EdgeSelectionModel(
VisualCursorDirection direction) {
if (direction == GetVisualDirectionOfLogicalEnd())
return SelectionModel(text().length(), CURSOR_FORWARD);
return SelectionModel(0, CURSOR_BACKWARD);
}
SelectionModel RenderText::LineSelectionModel(size_t line_index,
VisualCursorDirection direction) {
DCHECK(direction == CURSOR_LEFT || direction == CURSOR_RIGHT);
const internal::Line& line = lines()[line_index];
if (line.segments.empty()) {
// Only the last line can be empty.
DCHECK_EQ(lines().size() - 1, line_index);
return EdgeSelectionModel(GetVisualDirectionOfLogicalEnd());
}
if (line_index ==
(direction == GetVisualDirectionOfLogicalEnd() ? GetNumLines() - 1 : 0)) {
return EdgeSelectionModel(direction);
}
DCHECK_GT(GetNumLines(), 1U);
size_t max_index = 0;
size_t min_index = text().length();
for (const auto& segment : line.segments) {
min_index = std::min<size_t>(min_index, segment.char_range.GetMin());
max_index = std::max<size_t>(max_index, segment.char_range.GetMax());
}
// Do not select the newline character to preserve the line number of the
// cursor. Note that the newline character is always the last character of the
// line regardless of the text direction, so decrease the |max_index|.
if (!line.segments.empty() && (IsNewlineSegment(line.segments.back()) ||
IsNewlineSegment(line.segments.front()))) {
--max_index;
}
// Cursor affinity should be the opposite of visual direction to preserve the
// line number of the cursor in multiline text.
return direction == GetVisualDirectionOfLogicalEnd()
? SelectionModel(DisplayIndexToTextIndex(max_index),
CURSOR_BACKWARD)
: SelectionModel(DisplayIndexToTextIndex(min_index),
CURSOR_FORWARD);
}
void RenderText::SetSelectionModel(const SelectionModel& model) {
DCHECK_LE(model.selection().GetMax(), text().length());
selection_model_ = model;
cached_bounds_and_offset_valid_ = false;
has_directed_selection_ = kSelectionIsAlwaysDirected;
}
void RenderText::OnTextColorChanged() {
}
void RenderText::UpdateDisplayText(float text_width) {
// TODO(krb): Consider other elision modes for multiline.
if ((multiline_ && (!max_lines_ || elide_behavior() != ELIDE_TAIL)) ||
elide_behavior() == NO_ELIDE || elide_behavior() == FADE_TAIL ||
(text_width > 0 && text_width < display_rect_.width()) ||
layout_text_.empty()) {
text_elided_ = false;
display_text_.clear();
return;
}
if (!multiline_) {
// This doesn't trim styles so ellipsis may get rendered as a different
// style than the preceding text. See crbug.com/327850.
display_text_.assign(Elide(layout_text_, text_width,
static_cast<float>(display_rect_.width()),
elide_behavior_));
} else {
bool was_elided = text_elided_;
text_elided_ = false;
display_text_.clear();
std::unique_ptr<RenderText> render_text(
CreateInstanceOfSameStyle(layout_text_));
render_text->SetMultiline(true);
render_text->SetWordWrapBehavior(word_wrap_behavior_);
render_text->SetDisplayRect(display_rect_);
// Have it arrange words on |lines_|.
render_text->EnsureLayout();
if (render_text->lines_.size() > max_lines_) {
// Find the start index of the line to be elided.
size_t start_of_elision = layout_text_.length();
for (const auto& segment : render_text->lines_[max_lines_ - 1].segments) {
uint32_t segment_start = segment.char_range.GetMin();
start_of_elision = std::min<size_t>(start_of_elision, segment_start);
}
base::string16 text_to_elide = layout_text_.substr(start_of_elision);
display_text_.assign(layout_text_.substr(0, start_of_elision) +
Elide(text_to_elide, 0,
static_cast<float>(display_rect_.width()),
ELIDE_TAIL));
// Have GetLineBreaks() re-calculate.
line_breaks_.SetMax(0);
} else {
// If elision changed, re-calculate.
if (was_elided)
line_breaks_.SetMax(0);
// Initial state above is fine.
return;
}
}
text_elided_ = display_text_ != layout_text_;
if (!text_elided_)
display_text_.clear();
}
const BreakList<size_t>& RenderText::GetLineBreaks() {
if (line_breaks_.max() != 0)
return line_breaks_;
const base::string16& layout_text = GetDisplayText();
const size_t text_length = layout_text.length();
line_breaks_.SetValue(0);
line_breaks_.SetMax(text_length);
base::i18n::BreakIterator iter(layout_text,
base::i18n::BreakIterator::BREAK_LINE);
const bool success = iter.Init();
DCHECK(success);
if (success) {
do {
line_breaks_.ApplyValue(iter.pos(), Range(iter.pos(), text_length));
} while (iter.Advance());
}
return line_breaks_;
}
void RenderText::ApplyCompositionAndSelectionStyles() {
// Save the underline and color breaks to undo the temporary styles later.
DCHECK(!composition_and_selection_styles_applied_);
saved_colors_ = colors_;
saved_underlines_ = styles_[TEXT_STYLE_HEAVY_UNDERLINE];
// Apply an underline to the composition range in |underlines|.
if (composition_range_.IsValid() && !composition_range_.is_empty())
styles_[TEXT_STYLE_HEAVY_UNDERLINE].ApplyValue(true, composition_range_);
// Apply the selected text color to the [un-reversed] selection range.
if (!selection().is_empty() && focused()) {
const Range range(selection().GetMin(), selection().GetMax());
colors_.ApplyValue(selection_color_, range);
}
composition_and_selection_styles_applied_ = true;
}
void RenderText::UndoCompositionAndSelectionStyles() {
// Restore the underline and color breaks to undo the temporary styles.
DCHECK(composition_and_selection_styles_applied_);
colors_ = saved_colors_;
styles_[TEXT_STYLE_HEAVY_UNDERLINE] = saved_underlines_;
composition_and_selection_styles_applied_ = false;
}
Point RenderText::ToViewPoint(const PointF& point,
LogicalCursorDirection caret_affinity) {
const auto float_eq = [](float a, float b) {
return std::fabs(a - b) <= kFloatComparisonEpsilon;
};
const auto float_ge = [](float a, float b) {
return a > b || std::fabs(a - b) <= kFloatComparisonEpsilon;
};
const auto float_gt = [](float a, float b) {
return a - b > kFloatComparisonEpsilon;
};
const size_t num_lines = GetNumLines();
if (num_lines == 1) {
return Point(std::ceil(Clamp(point.x())), std::round(point.y())) +
GetLineOffset(0);
}
float x = point.x();
size_t line;
if (GetDisplayTextDirection() == base::i18n::RIGHT_TO_LEFT) {
// |xspan| returned from |GetCursorSpan| in |GetCursorBounds| starts to grow
// from the last character in RTL. On the other hand, the last character is
// positioned in the last line in RTL. So, traverse from the last line.
for (line = num_lines - 1;
line > 0 && float_ge(x, lines_[line].size.width()); --line) {
x -= lines_[line].size.width();
}
// Increment the |line| when |x| is at the newline character. The line is
// broken by word wrapping if the front edge of the line is not a newline
// character. In that case, the same caret position where the line is broken
// can be on both lines depending on the caret affinity.
if (line < num_lines - 1 &&
(IsNewlineSegment(lines_[line].segments.front()) ||
caret_affinity == CURSOR_FORWARD)) {
if (float_eq(x, 0))
x = lines_[++line].size.width();
// In RTL, the newline character is at the front of the line. Because the
// newline character is not drawn at the front of the line, |x| should be
// decreased by the width of the newline character. Check for a newline
// again because the line may have changed.
if (!lines_[line].segments.empty() &&
IsNewlineSegment(lines_[line].segments.front())) {
x -= lines_[line].segments.front().width();
}
}
} else {
for (line = 0; line < num_lines && float_gt(x, lines_[line].size.width());
++line) {
x -= lines_[line].size.width();
}
if (line == num_lines) {
x = lines_[--line].size.width();
} else if (line < num_lines - 1 && float_eq(lines_[line].size.width(), x) &&
(IsNewlineSegment(lines_[line].segments.back()) ||
caret_affinity == CURSOR_FORWARD)) {
// If |x| is at the edge of the line end, move the cursor to the start of
// the next line.
++line;
x = 0;
}
}
return Point(std::ceil(Clamp(x)), std::round(point.y())) +
GetLineOffset(line);
}
HorizontalAlignment RenderText::GetCurrentHorizontalAlignment() {
if (horizontal_alignment_ != ALIGN_TO_HEAD)
return horizontal_alignment_;
return GetDisplayTextDirection() == base::i18n::RIGHT_TO_LEFT ?
ALIGN_RIGHT : ALIGN_LEFT;
}
Vector2d RenderText::GetAlignmentOffset(size_t line_number) {
// TODO(ckocagil): Enable |lines_| usage on RenderTextMac.
if (MultilineSupported() && multiline_)
DCHECK_LT(line_number, lines_.size());
Vector2d offset;
HorizontalAlignment horizontal_alignment = GetCurrentHorizontalAlignment();
if (horizontal_alignment != ALIGN_LEFT) {
const int width = multiline_ ?
std::ceil(lines_[line_number].size.width()) +
(cursor_enabled_ ? 1 : 0) :
GetContentWidth();
offset.set_x(display_rect().width() - width);
// Put any extra margin pixel on the left to match legacy behavior.
if (horizontal_alignment == ALIGN_CENTER)
offset.set_x((offset.x() + 1) / 2);
}
if (!multiline_)
offset.set_y(GetBaseline() - GetDisplayTextBaseline());
else if (vertical_alignment_ == ALIGN_TOP)
offset.set_y(0);
else if (vertical_alignment_ == ALIGN_MIDDLE)
offset.set_y((display_rect_.height() - GetStringSize().height()) / 2);
else
offset.set_y(display_rect_.height() - GetStringSize().height());
return offset;
}
void RenderText::ApplyFadeEffects(internal::SkiaTextRenderer* renderer) {
const int width = display_rect().width();
if (multiline() || elide_behavior_ != FADE_TAIL || GetContentWidth() <= width)
return;
const int gradient_width = CalculateFadeGradientWidth(font_list(), width);
if (gradient_width == 0)
return;
HorizontalAlignment horizontal_alignment = GetCurrentHorizontalAlignment();
Rect solid_part = display_rect();
Rect left_part;
Rect right_part;
if (horizontal_alignment != ALIGN_LEFT) {
left_part = solid_part;
left_part.Inset(0, 0, solid_part.width() - gradient_width, 0);
solid_part.Inset(gradient_width, 0, 0, 0);
}
if (horizontal_alignment != ALIGN_RIGHT) {
right_part = solid_part;
right_part.Inset(solid_part.width() - gradient_width, 0, 0, 0);
solid_part.Inset(0, 0, gradient_width, 0);
}
// CreateFadeShader() expects at least one part to not be empty.
// See https://crbug.com/706835.
if (left_part.IsEmpty() && right_part.IsEmpty())
return;
Rect text_rect = display_rect();
text_rect.Inset(GetAlignmentOffset(0).x(), 0, 0, 0);
// TODO(msw): Use the actual text colors corresponding to each faded part.
renderer->SetShader(
CreateFadeShader(font_list(), text_rect, left_part, right_part,
SkColorSetA(colors_.breaks().front().second, 0xff)));
}
void RenderText::ApplyTextShadows(internal::SkiaTextRenderer* renderer) {
renderer->SetDrawLooper(CreateShadowDrawLooper(shadows_));
}
base::i18n::TextDirection RenderText::GetTextDirection(
const base::string16& text) {
if (text_direction_ == base::i18n::UNKNOWN_DIRECTION) {
switch (directionality_mode_) {
case DIRECTIONALITY_FROM_TEXT:
// Derive the direction from the display text, which differs from text()
// in the case of obscured (password) textfields.
text_direction_ =
base::i18n::GetFirstStrongCharacterDirection(text);
break;
case DIRECTIONALITY_FROM_UI:
text_direction_ = base::i18n::IsRTL() ? base::i18n::RIGHT_TO_LEFT :
base::i18n::LEFT_TO_RIGHT;
break;
case DIRECTIONALITY_FORCE_LTR:
text_direction_ = base::i18n::LEFT_TO_RIGHT;
break;
case DIRECTIONALITY_FORCE_RTL:
text_direction_ = base::i18n::RIGHT_TO_LEFT;
break;
case DIRECTIONALITY_AS_URL:
// Rendering as a URL implies left-to-right paragraph direction.
// URL Standard specifies that a URL "should be rendered as if it were
// in a left-to-right embedding".
// https://url.spec.whatwg.org/#url-rendering
//
// Consider logical string for domain "ABC.com/hello" (where ABC are
// Hebrew (RTL) characters). The normal Bidi algorithm renders this as
// "com/hello.CBA"; by forcing LTR, it is rendered as "CBA.com/hello".
//
// Note that this only applies a LTR embedding at the top level; it
// doesn't change the Bidi algorithm, so there are still some URLs that
// will render in a confusing order. Consider the logical string
// "abc.COM/HELLO/world", which will render as "abc.OLLEH/MOC/world".
// See https://crbug.com/351639.
//
// Note that the LeftToRightUrls feature flag enables additional
// behaviour for DIRECTIONALITY_AS_URL, but the left-to-right embedding
// behaviour is always enabled, regardless of the flag.
text_direction_ = base::i18n::LEFT_TO_RIGHT;
break;
default:
NOTREACHED();
}
}
return text_direction_;
}
size_t RenderText::TextIndexToGivenTextIndex(const base::string16& given_text,
size_t index) const {
DCHECK(given_text == layout_text() || given_text == display_text());
DCHECK_LE(index, text().length());
ptrdiff_t i = obscured() ? UTF16IndexToOffset(text(), 0, index) : index;
CHECK_GE(i, 0);
// Clamp indices to the length of the given layout or display text.
return std::min<size_t>(given_text.length(), i);
}
void RenderText::UpdateStyleLengths() {
const size_t text_length = text_.length();
colors_.SetMax(text_length);
baselines_.SetMax(text_length);
font_size_overrides_.SetMax(text_length);
weights_.SetMax(text_length);
for (size_t style = 0; style < TEXT_STYLE_COUNT; ++style)
styles_[style].SetMax(text_length);
}
int RenderText::GetLineContainingYCoord(float text_y) {
if (text_y < 0)
return -1;
for (size_t i = 0; i < lines().size(); i++) {
const internal::Line& line = lines()[i];
if (text_y <= line.size.height())
return i;
text_y -= line.size.height();
}
return lines().size();
}
// static
bool RenderText::RangeContainsCaret(const Range& range,
size_t caret_pos,
LogicalCursorDirection caret_affinity) {
// NB: exploits unsigned wraparound (WG14/N1124 section 6.2.5 paragraph 9).
size_t adjacent = (caret_affinity == CURSOR_BACKWARD) ?
caret_pos - 1 : caret_pos + 1;
return range.Contains(Range(caret_pos, adjacent));
}
// static
int RenderText::DetermineBaselineCenteringText(const int display_height,
const FontList& font_list) {
const int font_height = font_list.GetHeight();
// Lower and upper bound of baseline shift as we try to show as much area of
// text as possible. In particular case of |display_height| == |font_height|,
// we do not want to shift the baseline.
const int min_shift = std::min(0, display_height - font_height);
const int max_shift = std::abs(display_height - font_height);
const int baseline = font_list.GetBaseline();
const int cap_height = font_list.GetCapHeight();
const int internal_leading = baseline - cap_height;
// Some platforms don't support getting the cap height, and simply return
// the entire font ascent from GetCapHeight(). Centering the ascent makes
// the font look too low, so if GetCapHeight() returns the ascent, center
// the entire font height instead.
const int space =
display_height - ((internal_leading != 0) ? cap_height : font_height);
const int baseline_shift = space / 2 - internal_leading;
return baseline + std::max(min_shift, std::min(max_shift, baseline_shift));
}
// static
gfx::Rect RenderText::ExpandToBeVerticallySymmetric(
const gfx::Rect& rect,
const gfx::Rect& display_rect) {
// Mirror |rect| accross the horizontal line dividing |display_rect| in half.
gfx::Rect result = rect;
int mid_y = display_rect.CenterPoint().y();
// The top of the mirror rect must be equidistant with the bottom of the
// original rect from the mid-line.
result.set_y(mid_y + (mid_y - rect.bottom()));
// Now make a union with the original rect to ensure we are encompassing both.
result.Union(rect);
return result;
}
void RenderText::OnTextAttributeChanged() {
layout_text_.clear();
display_text_.clear();
text_elided_ = false;
line_breaks_.SetMax(0);
if (obscured_) {
size_t obscured_text_length =
static_cast<size_t>(UTF16IndexToOffset(text_, 0, text_.length()));
layout_text_.assign(obscured_text_length, kPasswordReplacementChar);
if (obscured_reveal_index_ >= 0 &&
obscured_reveal_index_ < static_cast<int>(text_.length())) {
// Gets the index range in |text_| to be revealed.
size_t start = obscured_reveal_index_;
U16_SET_CP_START(text_.data(), 0, start);
size_t end = start;
UChar32 unused_char;
U16_NEXT(text_.data(), end, text_.length(), unused_char);
// Gets the index in |layout_text_| to be replaced.
const size_t cp_start =
static_cast<size_t>(UTF16IndexToOffset(text_, 0, start));
if (layout_text_.length() > cp_start)
layout_text_.replace(cp_start, 1, text_.substr(start, end - start));
}
} else {
layout_text_ = text_;
}
const base::string16& text = layout_text_;
if (truncate_length_ > 0 && truncate_length_ < text.length()) {
// Truncate the text at a valid character break and append an ellipsis.
icu::StringCharacterIterator iter(text.c_str());
// Respect ELIDE_HEAD and ELIDE_MIDDLE preferences during truncation.
if (elide_behavior_ == ELIDE_HEAD) {
iter.setIndex32(
static_cast<int32_t>(text.length() - truncate_length_ + 1));
layout_text_.assign(kEllipsisUTF16 + text.substr(iter.getIndex()));
} else if (elide_behavior_ == ELIDE_MIDDLE) {
iter.setIndex32(static_cast<int32_t>(truncate_length_ / 2));
const size_t ellipsis_start = iter.getIndex();
iter.setIndex32(
static_cast<int32_t>(text.length() - (truncate_length_ / 2)));
const size_t ellipsis_end = iter.getIndex();
DCHECK_LE(ellipsis_start, ellipsis_end);
layout_text_.assign(text.substr(0, ellipsis_start) + kEllipsisUTF16 +
text.substr(ellipsis_end));
} else {
iter.setIndex32(static_cast<int32_t>(truncate_length_ - 1));
layout_text_.assign(text.substr(0, iter.getIndex()) + kEllipsisUTF16);
}
}
static const base::char16 kNewline[] = { '\n', 0 };
static const base::char16 kNewlineSymbol[] = { 0x2424, 0 };
if (!multiline_ && replace_newline_chars_with_symbols_)
base::ReplaceChars(layout_text_, kNewline, kNewlineSymbol, &layout_text_);
OnLayoutTextAttributeChanged(true);
}
base::string16 RenderText::Elide(const base::string16& text,
float text_width,
float available_width,
ElideBehavior behavior) {
if (available_width <= 0 || text.empty())
return base::string16();
if (behavior == ELIDE_EMAIL)
return ElideEmail(text, available_width);
if (text_width > 0 && text_width <= available_width)
return text;
TRACE_EVENT0("ui", "RenderText::Elide");
// Create a RenderText copy with attributes that affect the rendering width.
std::unique_ptr<RenderText> render_text = CreateInstanceOfSameStyle(text);
render_text->UpdateStyleLengths();
if (text_width == 0)
text_width = render_text->GetContentWidthF();
if (text_width <= available_width)
return text;
const base::string16 ellipsis = base::string16(kEllipsisUTF16);
const bool insert_ellipsis = (behavior != TRUNCATE);
const bool elide_in_middle = (behavior == ELIDE_MIDDLE);
const bool elide_at_beginning = (behavior == ELIDE_HEAD);
if (insert_ellipsis) {
render_text->SetText(ellipsis);
const float ellipsis_width = render_text->GetContentWidthF();
if (ellipsis_width > available_width)
return base::string16();
}
StringSlicer slicer(text, ellipsis, elide_in_middle, elide_at_beginning);
// Use binary(-like) search to compute the elided text. In particular, do
// an interpolation search, which is a binary search in which each guess
// is an attempt to smartly calculate the right point rather than blindly
// guessing midway between the endpoints.
size_t lo = 0;
size_t hi = text.length() - 1;
size_t guess = std::string::npos;
// These two widths are not exactly right but they're good enough to provide
// some guidance to the search. For example, |text_width| is actually the
// length of text.length(), not text.length()-1.
float lo_width = 0;
float hi_width = text_width;
const base::i18n::TextDirection text_direction = GetTextDirection(text);
while (lo <= hi) {
// Linearly interpolate between |lo| and |hi|, which correspond to widths
// of |lo_width| and |hi_width| to estimate at what position
// |available_width| would be at. Because |lo_width| and |hi_width| are
// both estimates (may be off by a little because, for example, |lo_width|
// may have been calculated from |lo| minus one, not |lo|), we clamp to the
// the valid range.
// |last_guess| is merely used to verify that we're not repeating guesses.
const size_t last_guess = guess;
guess = lo + static_cast<size_t>(ToRoundedInt((available_width - lo_width) *
(hi - lo) /
(hi_width - lo_width)));
guess = base::ClampToRange(guess, lo, hi);
DCHECK_NE(last_guess, guess);
// Restore colors. They will be truncated to size by SetText.
render_text->colors_ = colors_;
base::string16 new_text =
slicer.CutString(guess, insert_ellipsis && behavior != ELIDE_TAIL);
// This has to be an additional step so that the ellipsis is rendered with
// same style as trailing part of the text.
if (insert_ellipsis && behavior == ELIDE_TAIL) {
// When ellipsis follows text whose directionality is not the same as that
// of the whole text, it will be rendered with the directionality of the
// whole text. Since we want ellipsis to indicate continuation of the
// preceding text, we force the directionality of ellipsis to be same as
// the preceding text using LTR or RTL markers.
base::i18n::TextDirection trailing_text_direction =
base::i18n::GetLastStrongCharacterDirection(new_text);
// Ensures that the |new_text| will always be smaller or equal to the
// original text. There is a corner case when only one character is elided
// and two characters are added back (ellipsis and directional marker).
if (trailing_text_direction != text_direction &&
new_text.length() + 2 > text.length() && guess >= 1) {
new_text = slicer.CutString(guess - 1, false);
}
// Append the ellipsis and the optional directional marker characters.
new_text.append(ellipsis);
if (trailing_text_direction != text_direction) {
if (trailing_text_direction == base::i18n::LEFT_TO_RIGHT)
new_text += base::i18n::kLeftToRightMark;
else
new_text += base::i18n::kRightToLeftMark;
}
}
// The elided text must be smaller in bytes. Otherwise, break-lists are not
// consistent and the characters after the last range are not styled.
DCHECK_LE(new_text.size(), text.size());
render_text->SetText(new_text);
// Restore styles and baselines without breaking multi-character graphemes.
render_text->styles_ = styles_;
for (size_t style = 0; style < TEXT_STYLE_COUNT; ++style)
RestoreBreakList(render_text.get(), &render_text->styles_[style]);
RestoreBreakList(render_text.get(), &render_text->baselines_);
RestoreBreakList(render_text.get(), &render_text->font_size_overrides_);
render_text->weights_ = weights_;
RestoreBreakList(render_text.get(), &render_text->weights_);
// We check the width of the whole desired string at once to ensure we
// handle kerning/ligatures/etc. correctly.
const float guess_width = render_text->GetContentWidthF();
if (guess_width == available_width)
break;
if (guess_width > available_width) {
hi = guess - 1;
hi_width = guess_width;
// Move back on the loop terminating condition when the guess is too wide.
if (hi < lo) {
lo = hi;
lo_width = guess_width;
}
} else {
lo = guess + 1;
lo_width = guess_width;
}
}
return render_text->text();
}
base::string16 RenderText::ElideEmail(const base::string16& email,
float available_width) {
// The returned string will have at least one character besides the ellipsis
// on either side of '@'; if that's impossible, a single ellipsis is returned.
// If possible, only the username is elided. Otherwise, the domain is elided
// in the middle, splitting available width equally with the elided username.
// If the username is short enough that it doesn't need half the available
// width, the elided domain will occupy that extra width.
// Split the email into its local-part (username) and domain-part. The email
// spec allows for @ symbols in the username under some special requirements,
// but not in the domain part, so splitting at the last @ symbol is safe.
const size_t split_index = email.find_last_of('@');
DCHECK_NE(split_index, base::string16::npos);
base::string16 username = email.substr(0, split_index);
base::string16 domain = email.substr(split_index + 1);
DCHECK(!username.empty());
DCHECK(!domain.empty());
// Subtract the @ symbol from the available width as it is mandatory.
const base::string16 kAtSignUTF16 = base::ASCIIToUTF16("@");
available_width -= GetStringWidthF(kAtSignUTF16, font_list());
// Check whether eliding the domain is necessary: if eliding the username
// is sufficient, the domain will not be elided.
const float full_username_width = GetStringWidthF(username, font_list());
const float available_domain_width = available_width -
std::min(full_username_width,
GetStringWidthF(username.substr(0, 1) + kEllipsisUTF16, font_list()));
if (GetStringWidthF(domain, font_list()) > available_domain_width) {
// Elide the domain so that it only takes half of the available width.
// Should the username not need all the width available in its half, the
// domain will occupy the leftover width.
// If |desired_domain_width| is greater than |available_domain_width|: the
// minimal username elision allowed by the specifications will not fit; thus
// |desired_domain_width| must be <= |available_domain_width| at all cost.
const float desired_domain_width =
std::min<float>(available_domain_width,
std::max<float>(available_width - full_username_width,
available_width / 2));
domain = Elide(domain, 0, desired_domain_width, ELIDE_MIDDLE);
// Failing to elide the domain such that at least one character remains
// (other than the ellipsis itself) remains: return a single ellipsis.
if (domain.length() <= 1U)
return base::string16(kEllipsisUTF16);
}
// Fit the username in the remaining width (at this point the elided username
// is guaranteed to fit with at least one character remaining given all the
// precautions taken earlier).
available_width -= GetStringWidthF(domain, font_list());
username = Elide(username, 0, available_width, ELIDE_TAIL);
return username + kAtSignUTF16 + domain;
}
void RenderText::UpdateCachedBoundsAndOffset() {
if (cached_bounds_and_offset_valid_)
return;
// TODO(ckocagil): Add support for scrolling multiline text.
int delta_x = 0;
if (cursor_enabled()) {
// When cursor is enabled, ensure it is visible. For this, set the valid
// flag true and calculate the current cursor bounds using the stale
// |display_offset_|. Then calculate the change in offset needed to move the
// cursor into the visible area.
cached_bounds_and_offset_valid_ = true;
cursor_bounds_ = GetCursorBounds(selection_model_, true);
// TODO(bidi): Show RTL glyphs at the cursor position for ALIGN_LEFT, etc.
if (cursor_bounds_.right() > display_rect_.right())
delta_x = display_rect_.right() - cursor_bounds_.right();
else if (cursor_bounds_.x() < display_rect_.x())
delta_x = display_rect_.x() - cursor_bounds_.x();
}
SetDisplayOffset(display_offset_.x() + delta_x);
}
void RenderText::DrawSelection(Canvas* canvas) {
for (Rect s : GetSubstringBounds(selection())) {
if (symmetric_selection_visual_bounds() && !multiline())
s = ExpandToBeVerticallySymmetric(s, display_rect());
canvas->FillRect(s, selection_background_focused_color_);
}
}
size_t RenderText::GetNearestWordStartBoundary(size_t index) const {
const size_t length = text().length();
if (obscured() || length == 0)
return length;
base::i18n::BreakIterator iter(text(), base::i18n::BreakIterator::BREAK_WORD);
const bool success = iter.Init();
DCHECK(success);
if (!success)
return length;
// First search for the word start boundary in the CURSOR_BACKWARD direction,
// then in the CURSOR_FORWARD direction.
for (int i = static_cast<int>(std::min(index, length - 1)); i >= 0; i--)
if (iter.IsStartOfWord(i))
return i;
for (size_t i = index + 1; i < length; i++)
if (iter.IsStartOfWord(i))
return i;
return length;
}
Range RenderText::ExpandRangeToWordBoundary(const Range& range) const {
const size_t length = text().length();
DCHECK_LE(range.GetMax(), length);
if (obscured())
return range.is_reversed() ? Range(length, 0) : Range(0, length);
base::i18n::BreakIterator iter(text(), base::i18n::BreakIterator::BREAK_WORD);
const bool success = iter.Init();
DCHECK(success);
if (!success)
return range;
size_t range_min = range.GetMin();
if (range_min == length && range_min != 0)
--range_min;
for (; range_min != 0; --range_min)
if (iter.IsStartOfWord(range_min) || iter.IsEndOfWord(range_min))
break;
size_t range_max = range.GetMax();
if (range_min == range_max && range_max != length)
++range_max;
for (; range_max < length; ++range_max)
if (iter.IsEndOfWord(range_max) || iter.IsStartOfWord(range_max))
break;
return range.is_reversed() ? Range(range_max, range_min)
: Range(range_min, range_max);
}
internal::TextRunList* RenderText::GetRunList() {
NOTREACHED();
return nullptr;
}
const internal::TextRunList* RenderText::GetRunList() const {
NOTREACHED();
return nullptr;
}
} // namespace gfx