bind.cc

#include "webview.h"

#include <chrono>
#include <string>
#include <thread>

constexpr const auto html =
    R"html(<button id="increment">Tap me</button>
<div>You tapped <span id="count">0</span> time(s).</div>
<button id="compute">Compute</button>
<div>Result of computation: <span id="compute-result">0</span></div>
<script>
  const [incrementElement, countElement, computeElement, computeResultElement] =
    document.querySelectorAll("#increment, #count, #compute, #compute-result");
  document.addEventListener("DOMContentLoaded", () => {
    incrementElement.addEventListener("click", () => {
      window.increment().then(result => {
        countElement.textContent = result.count;
      });
    });
    computeElement.addEventListener("click", () => {
      computeElement.disabled = true;
      window.compute(6, 7).then(result => {
        computeResultElement.textContent = result;
        computeElement.disabled = false;
      });
    });
  });
</script>)html";

#ifdef _WIN32
int WINAPI WinMain(HINSTANCE /*hInst*/, HINSTANCE /*hPrevInst*/,
                   LPSTR /*lpCmdLine*/, int /*nCmdShow*/) {
#else
int main() {
#endif
  unsigned int count = 0;
  webview::webview w(false, nullptr);
  w.set_title("Bind Example");
  w.set_size(480, 320, WEBVIEW_HINT_NONE);

  // A binding that increments a value and immediately returns the new value.
  w.bind("increment", [&](const std::string & /*req*/) -> std::string {
    auto count_string = std::to_string(++count);
    return "{\"count\": " + count_string + "}";
  });

  // An binding that creates a new thread and returns the result at a later time.
  w.bind(
      "compute",
      [&](const std::string &seq, const std::string &req, void * /*arg*/) {
        // Create a thread and forget about it for the sake of simplicity.
        std::thread([&, seq, req] {
          // Simulate load.
          std::this_thread::sleep_for(std::chrono::seconds(1));
          // json_parse() is an implementation detail and is only used here
          // to provide a working example.
          auto left = std::stoll(webview::detail::json_parse(req, "", 0));
          auto right = std::stoll(webview::detail::json_parse(req, "", 1));
          auto result = std::to_string(left * right);
          w.resolve(seq, 0, result);
        }).detach();
      },
      nullptr);

  w.set_html(html);
  w.run();

  return 0;
}