third_party/WebKit/Source/platform/exported/WebFont.cpp

// Copyright 2016 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 "public/platform/WebFont.h"

#include "platform/fonts/Font.h"
#include "platform/fonts/FontCache.h"
#include "platform/fonts/FontDescription.h"
#include "platform/graphics/GraphicsContext.h"
#include "platform/graphics/paint/DrawingRecorder.h"
#include "platform/graphics/paint/SkPictureBuilder.h"
#include "platform/text/TextRun.h"
#include "public/platform/WebFloatPoint.h"
#include "public/platform/WebFloatRect.h"
#include "public/platform/WebFontDescription.h"
#include "public/platform/WebRect.h"
#include "public/platform/WebTextRun.h"

namespace blink {

WebFont* WebFont::create(const WebFontDescription& description) {
  return new WebFont(description);
}

class WebFont::Impl final {
 public:
  explicit Impl(const WebFontDescription& description) : m_font(description) {
    m_font.update(nullptr);
  }

  const Font& getFont() const { return m_font; }

 private:
  Font m_font;
};

WebFont::WebFont(const WebFontDescription& description)
    : m_private(new Impl(description)) {}

WebFont::~WebFont() {}

WebFontDescription WebFont::getFontDescription() const {
  return WebFontDescription(m_private->getFont().getFontDescription());
}

static inline const SimpleFontData* getFontData(const Font& font) {
  const SimpleFontData* fontData = font.primaryFont();
  DCHECK(fontData);
  return fontData;
}

int WebFont::ascent() const {
  const SimpleFontData* fontData = getFontData(m_private->getFont());
  return fontData ? fontData->getFontMetrics().ascent() : 0;
}

int WebFont::descent() const {
  const SimpleFontData* fontData = getFontData(m_private->getFont());
  return fontData ? fontData->getFontMetrics().descent() : 0;
}

int WebFont::height() const {
  const SimpleFontData* fontData = getFontData(m_private->getFont());
  return fontData ? fontData->getFontMetrics().height() : 0;
}

int WebFont::lineSpacing() const {
  const SimpleFontData* fontData = getFontData(m_private->getFont());
  return fontData ? fontData->getFontMetrics().lineSpacing() : 0;
}

float WebFont::xHeight() const {
  const SimpleFontData* fontData = m_private->getFont().primaryFont();
  DCHECK(fontData);
  return fontData ? fontData->getFontMetrics().xHeight() : 0;
}

void WebFont::drawText(WebCanvas* canvas,
                       const WebTextRun& run,
                       const WebFloatPoint& leftBaseline,
                       WebColor color,
                       const WebRect& clip) const {
  FontCachePurgePreventer fontCachePurgePreventer;
  FloatRect textClipRect(clip);
  TextRun textRun(run);
  TextRunPaintInfo runInfo(textRun);
  runInfo.bounds = textClipRect;

  IntRect intRect(clip);
  SkPictureBuilder pictureBuilder(intRect);
  GraphicsContext& context = pictureBuilder.context();

  {
    DrawingRecorder drawingRecorder(context, pictureBuilder,
                                    DisplayItem::kWebFont, intRect);
    context.save();
    context.setFillColor(color);
    context.clip(textClipRect);
    context.drawText(m_private->getFont(), runInfo, leftBaseline);
    context.restore();
  }

  pictureBuilder.endRecording()->playback(canvas);
}

int WebFont::calculateWidth(const WebTextRun& run) const {
  return m_private->getFont().width(run, 0);
}

int WebFont::offsetForPosition(const WebTextRun& run, float position) const {
  return m_private->getFont().offsetForPosition(run, position, true);
}

WebFloatRect WebFont::selectionRectForText(const WebTextRun& run,
                                           const WebFloatPoint& leftBaseline,
                                           int height,
                                           int from,
                                           int to) const {
  return m_private->getFont().selectionRectForText(run, leftBaseline, height,
                                                   from, to);
}

}  // namespace blink