cpdf_progressiverenderer.cpp

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// Copyright 2016 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
#include "core/fpdfapi/render/cpdf_progressiverenderer.h"
 
#include "core/fpdfapi/page/cpdf_image.h"
#include "core/fpdfapi/page/cpdf_imageobject.h"
#include "core/fpdfapi/page/cpdf_pageimagecache.h"
#include "core/fpdfapi/page/cpdf_pageobject.h"
#include "core/fpdfapi/page/cpdf_pageobjectholder.h"
#include "core/fpdfapi/render/cpdf_renderoptions.h"
#include "core/fpdfapi/render/cpdf_renderstatus.h"
#include "core/fxcrt/pauseindicator_iface.h"
#include "core/fxge/cfx_renderdevice.h"
 
CPDF_ProgressiveRenderer::CPDF_ProgressiveRenderer(
    CPDF_RenderContext* pContext,
    CFX_RenderDevice* pDevice,
    const CPDF_RenderOptions* pOptions)
    : m_pContext(pContext), m_pDevice(pDevice), m_pOptions(pOptions) {}
 
CPDF_ProgressiveRenderer::~CPDF_ProgressiveRenderer() {
  if (m_pRenderStatus) {
    m_pRenderStatus.reset();  // Release first.
    m_pDevice->RestoreState(false);
  }
}
 
void CPDF_ProgressiveRenderer::Start(PauseIndicatorIface* pPause) {
  if (!m_pContext || !m_pDevice || m_Status != kReady) {
    m_Status = kFailed;
    return;
  }
  m_Status = kToBeContinued;
  Continue(pPause);
}
 
void CPDF_ProgressiveRenderer::Continue(PauseIndicatorIface* pPause) {
  while (m_Status == kToBeContinued) {
    if (!m_pCurrentLayer) {
      if (m_LayerIndex >= m_pContext->CountLayers()) {
        m_Status = kDone;
        return;
      }
      m_pCurrentLayer = m_pContext->GetLayer(m_LayerIndex);
      m_LastObjectRendered = m_pCurrentLayer->GetObjectHolder()->end();
      m_pRenderStatus =
          std::make_unique<CPDF_RenderStatus>(m_pContext, m_pDevice);
      if (m_pOptions)
        m_pRenderStatus->SetOptions(*m_pOptions);
      m_pRenderStatus->SetTransparency(
          m_pCurrentLayer->GetObjectHolder()->GetTransparency());
      m_pRenderStatus->Initialize(nullptr, nullptr);
      m_pDevice->SaveState();
      m_ClipRect = m_pCurrentLayer->GetMatrix().GetInverse().TransformRect(
          CFX_FloatRect(m_pDevice->GetClipBox()));
    }
    CPDF_PageObjectHolder::const_iterator iter;
    CPDF_PageObjectHolder::const_iterator iterEnd =
        m_pCurrentLayer->GetObjectHolder()->end();
    if (m_LastObjectRendered != iterEnd) {
      iter = m_LastObjectRendered;
      ++iter;
    } else {
      iter = m_pCurrentLayer->GetObjectHolder()->begin();
    }
    int nObjsToGo = kStepLimit;
    bool is_mask = false;
    while (iter != iterEnd) {
      CPDF_PageObject* pCurObj = iter->get();
      if (pCurObj && pCurObj->GetRect().left <= m_ClipRect.right &&
          pCurObj->GetRect().right >= m_ClipRect.left &&
          pCurObj->GetRect().bottom <= m_ClipRect.top &&
          pCurObj->GetRect().top >= m_ClipRect.bottom) {
        if (m_pOptions->GetOptions().bBreakForMasks && pCurObj->IsImage() &&
            pCurObj->AsImage()->GetImage()->IsMask()) {
          if (m_pDevice->GetDeviceType() == DeviceType::kPrinter) {
            m_LastObjectRendered = iter;
            m_pRenderStatus->ProcessClipPath(pCurObj->clip_path(),
                                             m_pCurrentLayer->GetMatrix());
            return;
          }
          is_mask = true;
        }
        if (m_pRenderStatus->ContinueSingleObject(
                pCurObj, m_pCurrentLayer->GetMatrix(), pPause)) {
          return;
        }
        if (pCurObj->IsImage() && m_pRenderStatus->GetRenderOptions()
                                      .GetOptions()
                                      .bLimitedImageCache) {
          m_pContext->GetPageCache()->CacheOptimization(
              m_pRenderStatus->GetRenderOptions().GetCacheSizeLimit());
        }
        if (pCurObj->IsForm() || pCurObj->IsShading())
          nObjsToGo = 0;
        else
          --nObjsToGo;
      }
      m_LastObjectRendered = iter;
      if (nObjsToGo == 0) {
        if (pPause && pPause->NeedToPauseNow())
          return;
        nObjsToGo = kStepLimit;
      }
      ++iter;
      if (is_mask && iter != iterEnd)
        return;
    }
    if (m_pCurrentLayer->GetObjectHolder()->GetParseState() ==
        CPDF_PageObjectHolder::ParseState::kParsed) {
      m_pRenderStatus.reset();
      m_pDevice->RestoreState(false);
      m_pCurrentLayer = nullptr;
      m_LayerIndex++;
      if (is_mask || (pPause && pPause->NeedToPauseNow()))
        return;
    } else if (is_mask) {
      return;
    } else {
      m_pCurrentLayer->GetObjectHolder()->ContinueParse(pPause);
      if (m_pCurrentLayer->GetObjectHolder()->GetParseState() !=
          CPDF_PageObjectHolder::ParseState::kParsed) {
        return;
      }
    }
  }
}