feat: add webContents.getPrintersAsync() (#31023)

This deprecates the synchronous and blocking `webContents.getPrinters()`
function and introduces `webContents.getPrintersAsync()`, which is
asynchronous and non-blocking.

Signed-off-by: Darshan Sen <darshan.sen@postman.com>
This commit is contained in:
Darshan Sen 2021-10-25 23:46:58 +05:30 committed by GitHub
parent b936f5e14a
commit 8f51d3e1bf
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GPG key ID: 4AEE18F83AFDEB23
5 changed files with 70 additions and 4 deletions

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@ -10,7 +10,11 @@
#include "shell/common/node_includes.h"
#if BUILDFLAG(ENABLE_PRINTING)
#include "base/task/task_traits.h"
#include "base/task/thread_pool.h"
#include "printing/backend/print_backend.h"
#include "shell/common/gin_helper/promise.h"
#include "shell/common/process_util.h"
#endif
namespace gin {
@ -39,13 +43,16 @@ namespace electron {
namespace api {
#if BUILDFLAG(ENABLE_PRINTING)
printing::PrinterList GetPrinterList() {
printing::PrinterList GetPrinterList(v8::Isolate* isolate) {
EmitWarning(node::Environment::GetCurrent(isolate),
"Deprecation Warning: getPrinters() is deprecated. "
"Use the asynchronous and non-blocking version, "
"getPrintersAsync(), instead.",
"electron");
printing::PrinterList printers;
auto print_backend = printing::PrintBackend::CreateInstance(
g_browser_process->GetApplicationLocale());
{
// TODO(deepak1556): Deprecate this api in favor of an
// async version and post a non blocing task call.
base::ThreadRestrictions::ScopedAllowIO allow_io;
printing::mojom::ResultCode code =
print_backend->EnumeratePrinters(&printers);
@ -54,6 +61,32 @@ printing::PrinterList GetPrinterList() {
}
return printers;
}
v8::Local<v8::Promise> GetPrinterListAsync(v8::Isolate* isolate) {
gin_helper::Promise<printing::PrinterList> promise(isolate);
v8::Local<v8::Promise> handle = promise.GetHandle();
base::ThreadPool::PostTaskAndReplyWithResult(
FROM_HERE, {base::TaskPriority::USER_VISIBLE, base::MayBlock()},
base::BindOnce([]() {
printing::PrinterList printers;
auto print_backend = printing::PrintBackend::CreateInstance(
g_browser_process->GetApplicationLocale());
printing::mojom::ResultCode code =
print_backend->EnumeratePrinters(&printers);
if (code != printing::mojom::ResultCode::kSuccess)
LOG(INFO) << "Failed to enumerate printers";
return printers;
}),
base::BindOnce(
[](gin_helper::Promise<printing::PrinterList> promise,
const printing::PrinterList& printers) {
promise.Resolve(printers);
},
std::move(promise)));
return handle;
}
#endif
} // namespace api
@ -64,6 +97,7 @@ namespace {
#if BUILDFLAG(ENABLE_PRINTING)
using electron::api::GetPrinterList;
using electron::api::GetPrinterListAsync;
#endif
void Initialize(v8::Local<v8::Object> exports,
@ -74,6 +108,8 @@ void Initialize(v8::Local<v8::Object> exports,
gin_helper::Dictionary dict(isolate, exports);
#if BUILDFLAG(ENABLE_PRINTING)
dict.SetMethod("getPrinterList", base::BindRepeating(&GetPrinterList));
dict.SetMethod("getPrinterListAsync",
base::BindRepeating(&GetPrinterListAsync));
#endif
}