chromium/src/third_party/blink/renderer/core/paint/text_painter.cc

// Copyright 2014 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 "third_party/blink/renderer/core/paint/text_painter.h"

#include "third_party/blink/renderer/core/css/css_property_names.h"
#include "third_party/blink/renderer/core/frame/settings.h"
#include "third_party/blink/renderer/core/layout/api/line_layout_api_shim.h"
#include "third_party/blink/renderer/core/layout/api/line_layout_item.h"
#include "third_party/blink/renderer/core/layout/layout_object.h"
#include "third_party/blink/renderer/core/layout/layout_text_combine.h"
#include "third_party/blink/renderer/core/paint/applied_decoration_painter.h"
#include "third_party/blink/renderer/core/paint/box_painter.h"
#include "third_party/blink/renderer/core/paint/highlight_painting_utils.h"
#include "third_party/blink/renderer/core/paint/paint_info.h"
#include "third_party/blink/renderer/core/style/computed_style.h"
#include "third_party/blink/renderer/core/style/shadow_list.h"
#include "third_party/blink/renderer/platform/fonts/font.h"
#include "third_party/blink/renderer/platform/fonts/text_run_paint_info.h"
#include "third_party/blink/renderer/platform/graphics/graphics_context.h"
#include "third_party/blink/renderer/platform/graphics/graphics_context_state_saver.h"
#include "third_party/blink/renderer/platform/text/text_run.h"
#include "third_party/blink/renderer/platform/wtf/assertions.h"
#include "third_party/blink/renderer/platform/wtf/text/character_names.h"

namespace blink {

void TextPainter::Paint(unsigned start_offset,
                        unsigned end_offset,
                        unsigned length,
                        const TextPaintStyle& text_style,
                        DOMNodeId node_id) {
  GraphicsContextStateSaver state_saver(graphics_context_, false);
  UpdateGraphicsContext(text_style, state_saver);
  if (combined_text_) {
    graphics_context_.Save();
    combined_text_->TransformToInlineCoordinates(graphics_context_,
                                                 text_frame_rect_);
    PaintInternal<kPaintText>(start_offset, end_offset, length, node_id);
    graphics_context_.Restore();
  } else {
    PaintInternal<kPaintText>(start_offset, end_offset, length, node_id);
  }

  if (!emphasis_mark_.IsEmpty()) {
    if (text_style.emphasis_mark_color != text_style.fill_color)
      graphics_context_.SetFillColor(text_style.emphasis_mark_color);

    if (combined_text_) {
      PaintEmphasisMarkForCombinedText();
    } else {
      PaintInternal<kPaintEmphasisMark>(start_offset, end_offset, length,
                                        node_id);
    }
  }
}

template <TextPainter::PaintInternalStep step>
void TextPainter::PaintInternalRun(TextRunPaintInfo& text_run_paint_info,
                                   unsigned from,
                                   unsigned to,
                                   DOMNodeId node_id) {
  DCHECK(from <= text_run_paint_info.run.length());
  DCHECK(to <= text_run_paint_info.run.length());

  text_run_paint_info.from = from;
  text_run_paint_info.to = to;

  if (step == kPaintEmphasisMark) {
    graphics_context_.DrawEmphasisMarks(
        font_, text_run_paint_info, emphasis_mark_,
        FloatPoint(text_origin_) + IntSize(0, emphasis_mark_offset_));
  } else {
    DCHECK(step == kPaintText);
    graphics_context_.DrawText(font_, text_run_paint_info,
                               FloatPoint(text_origin_), node_id);
  }
}

template <TextPainter::PaintInternalStep Step>
void TextPainter::PaintInternal(unsigned start_offset,
                                unsigned end_offset,
                                unsigned truncation_point,
                                DOMNodeId node_id) {
  TextRunPaintInfo text_run_paint_info(run_);
  if (start_offset <= end_offset) {
    PaintInternalRun<Step>(text_run_paint_info, start_offset, end_offset,
                           node_id);
  } else {
    if (end_offset > 0) {
      PaintInternalRun<Step>(text_run_paint_info, ellipsis_offset_, end_offset,
                             node_id);
    }
    if (start_offset < truncation_point) {
      PaintInternalRun<Step>(text_run_paint_info, start_offset,
                             truncation_point, node_id);
    }
  }
}

void TextPainter::ClipDecorationsStripe(float upper,
                                        float stripe_width,
                                        float dilation) {
  TextRunPaintInfo text_run_paint_info(run_);
  if (!run_.length())
    return;

  Vector<Font::TextIntercept> text_intercepts;
  font_.GetTextIntercepts(
      text_run_paint_info, graphics_context_.DeviceScaleFactor(),
      graphics_context_.FillFlags(),
      std::make_tuple(upper, upper + stripe_width), text_intercepts);

  DecorationsStripeIntercepts(upper, stripe_width, dilation, text_intercepts);
}

void TextPainter::PaintEmphasisMarkForCombinedText() {
  const SimpleFontData* font_data = font_.PrimaryFont();
  DCHECK(font_data);
  if (!font_data)
    return;

  DCHECK(combined_text_);
  TextRun placeholder_text_run(&kIdeographicFullStopCharacter, 1);
  FloatPoint emphasis_mark_text_origin(
      text_frame_rect_.X().ToFloat(), text_frame_rect_.Y().ToFloat() +
                                          font_data->GetFontMetrics().Ascent() +
                                          emphasis_mark_offset_);
  TextRunPaintInfo text_run_paint_info(placeholder_text_run);
  graphics_context_.ConcatCTM(Rotation(text_frame_rect_, kClockwise));
  graphics_context_.DrawEmphasisMarks(combined_text_->OriginalFont(),
                                      text_run_paint_info, emphasis_mark_,
                                      emphasis_mark_text_origin);
  graphics_context_.ConcatCTM(Rotation(text_frame_rect_, kCounterclockwise));
}

}  // namespace blink