NS_IMETHODIMP
nsSimplePageSequenceFrame::PrePrintNextPage(nsITimerCallback* aCallback, bool* aDone)
{
nsIFrame* currentPage = GetCurrentPageFrame();
if (!currentPage) {
*aDone = true;
return NS_ERROR_FAILURE;
}
DetermineWhetherToPrintPage();
// Nothing to do if the current page doesn't get printed OR rendering to
// preview. For preview, the `CallPrintCallback` is called from within the
// HTMLCanvasElement::HandlePrintCallback.
if (!mPrintThisPage || !PresContext()->IsRootPaginatedDocument()) {
*aDone = true;
return NS_OK;
}
// If the canvasList is null, then generate it and start the render
// process for all the canvas.
if (!mCurrentCanvasListSetup) {
mCurrentCanvasListSetup = true;
GetPrintCanvasElementsInFrame(currentPage, &mCurrentCanvasList);
if (mCurrentCanvasList.Length() != 0) {
nsresult rv = NS_OK;
// Begin printing of the document
nsDeviceContext *dc = PresContext()->DeviceContext();
PR_PL(("\n"));
PR_PL(("***************** BeginPage *****************\n"));
rv = dc->BeginPage();
NS_ENSURE_SUCCESS(rv, rv);
mCalledBeginPage = true;
nsRefPtr<gfxContext> renderingContext = dc->CreateRenderingContext();
NS_ENSURE_TRUE(renderingContext, NS_ERROR_OUT_OF_MEMORY);
nsRefPtr<gfxASurface> renderingSurface =
renderingContext->CurrentSurface();
NS_ENSURE_TRUE(renderingSurface, NS_ERROR_OUT_OF_MEMORY);
for (int32_t i = mCurrentCanvasList.Length() - 1; i >= 0 ; i--) {
HTMLCanvasElement* canvas = mCurrentCanvasList[i];
nsIntSize size = canvas->GetSize();
nsRefPtr<gfxASurface> printSurface = renderingSurface->
CreateSimilarSurface(
gfxContentType::COLOR_ALPHA,
size
);
if (!printSurface) {
continue;
}
nsICanvasRenderingContextInternal* ctx = canvas->GetContextAtIndex(0);
if (!ctx) {
continue;
}
// Initialize the context with the new printSurface.
ctx->InitializeWithSurface(nullptr, printSurface, size.width, size.height);
// Start the rendering process.
nsWeakFrame weakFrame = this;
canvas->DispatchPrintCallback(aCallback);
NS_ENSURE_STATE(weakFrame.IsAlive());
}
}
}
uint32_t doneCounter = 0;
for (int32_t i = mCurrentCanvasList.Length() - 1; i >= 0 ; i--) {
HTMLCanvasElement* canvas = mCurrentCanvasList[i];
if (canvas->IsPrintCallbackDone()) {
doneCounter++;
}
}
// If all canvas have finished rendering, return true, otherwise false.
*aDone = doneCounter == mCurrentCanvasList.Length();
return NS_OK;
}
