void PDFRenderTask::execute()
{
// don't execute the prerender task if the page is out of date
if (is_page_out_of_date())
{
return;
}
PDFRenderer *renderer = doc_ctrl->get_renderer();
// estimate whether the page has been cached
// it is necessary here although there is same estimation
// in main thread, because the same page might be constructed
// in other tasks.
if (page == 0)
{
page = doc_ctrl->get_page(page_number);
if (page == 0)
{
page = renderer->gen_page(page_number, page_render_attr);
}
}
//assert(page);
if (page == 0)
{
ERRORPRINTF("Cannot Create New Page");
return;
}
// set the reference id, this operation is thread-safe now
// NOTE: this function must be called before setting render attributes
// because the main thread would update the ref id if the render attributes
// changes.
page->set_ref_id(ref_id);
// if it is ZOOM_AUTO_CROP mode, it means it is necessary to get the content
// area of the page
double real_zoom = page_render_attr.get_real_zoom_value();
if (real_zoom == PLUGIN_ZOOM_TO_CROP_BY_PAGE ||
real_zoom == PLUGIN_ZOOM_TO_CROP_BY_WIDTH)
{
RenderArea content_area;
if (!page->get_content_area(renderer, content_area))
{
ERRORPRINTF("Cannot get content area of page:%d", page_number);
return;
}
PDFRenderAttributes origin_attr = page_render_attr;
renderer->calc_real_zoom(page_number, origin_attr, page_render_attr);
real_zoom = page_render_attr.get_real_zoom_value();
}
// if the page is cached and the bitmap has been rendered
// calculate the delta value. Becuase the old bitmap would
// be destroyed and new one is going to be rendered in the following
// step
int page_len = static_cast<int>(page->length());
page_len = static_cast<int>(PDFPage::try_calc_length(real_zoom,
doc_ctrl->get_page_crop_width(page_number),
doc_ctrl->get_page_crop_height(page_number))) -
page_len;
PDFPage::RenderStatus cur_status = page->get_render_status();
if (!(page->get_render_attr() == page_render_attr))
{
// if the render attributes change, re-render the page
// DO NOT update the render setting here, because it might
// change the length of page
// DO NOT change the status of page at this moment
cur_status = PDFPage::RENDER_STOP;
}
bool render_done = true;
// render bitmap
if (cur_status != PDFPage::RENDER_DONE)
{
TRACE("Task, Render Page:%d, Ref ID:%d, Current Task:%p\n\n", page_number, ref_id, this);
// update the page cache to make sure there is enough memory
// if page_len < 0, it means the page is going to shrink, the memory
// must be enough
// TODO. Add the page number as one parameter for making enough memory
// The pages with lower priorites would be released.
if (page_len > 0 &&
!PDFLibrary::instance().make_enough_memory(doc_ctrl,
page_number,
page_len))
{
WARNPRINTF("Cannot make enough memory to implement rendering");
// notify uds that it is out of memory that the page rendering
// is aborted
renderer->handle_page_ready(render_result, page, TASK_RENDER_OOM);
return;
}
// update the render status
page->set_render_status(cur_status);
// only set the render attributes
page->set_render_attr(page_render_attr);
render_done = page->render_splash_map(renderer
, static_cast<void*>(this));
// render the text page when the render is done
if (render_done)
{
page->render_text(renderer);
}
}
if (render_done)
{
// set the render status at last
page->set_render_status(PDFPage::RENDER_DONE);
if (render_result != 0)
{
// set the page into render result
render_result->set_page(page);
}
// notify uds that the page is ready
renderer->handle_page_ready(render_result, page, TASK_RENDER_DONE);
}
else
{
if (render_result != 0 && is_aborted())
{
// if the task is aborted, set the render result to "Discard"
render_result->set_discard(true);
}
else
{
renderer->handle_page_ready(render_result, page, TASK_RENDER_OOM);
}
}
}
