/// <summary>
/// Captures page screenshot.
/// </summary>
/// <param name="webview">The WebView control.</param>
/// <param name="settings">The capture settings or null.</param>
/// <param name="targetStream">A stream to save the captured image to.</param>
/// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
/// <returns>The task object representing the asynchronous operation.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="webview"/> or <paramref name="targetStream"/> is null.
/// </exception>
/// <exception cref="DevToolsProtocolException">
/// An error occurred while trying to execute a DevTools Protocol method.
/// </exception>
/// <exception cref="InvalidOperationException">Other error occurred.</exception>
public static async Task CaptureScreenshotAsync(this IChromiumWebView webview, PageCaptureSettings settings, Stream targetStream, CancellationToken cancellationToken)
{
if (webview is null)
throw new ArgumentNullException(nameof(webview));
if (targetStream is null)
throw new ArgumentNullException(nameof(targetStream));
CefDictionaryValue args;
if (settings is null)
{
args = null;
}
else
{
args = new CefDictionaryValue();
if (settings.Format == ImageCompressionFormat.Jpeg)
{
args.SetString("format", "jpeg");
if (settings.Quality.HasValue)
args.SetInt("quality", settings.Quality.Value);
}
if (!settings.FromSurface)
args.SetBool("fromSurface", false);
if (settings.Viewport != null)
{
PageViewport viewport = settings.Viewport;
var viewportDict = new CefDictionaryValue();
viewportDict.SetDouble("x", viewport.X);
viewportDict.SetDouble("y", viewport.Y);
viewportDict.SetDouble("width", viewport.Width);
viewportDict.SetDouble("height", viewport.Height);
viewportDict.SetDouble("scale", viewport.Scale);
args.SetDictionary("clip", viewportDict);
}
if (settings.CaptureBeyondViewport)
args.SetBool("captureBeyondViewport", true);
}
byte[] rv = (byte[])await ExecuteDevToolsMethodInternalAsync(webview, "Page.captureScreenshot", args, null, cancellationToken).ConfigureAwait(false);
if (rv != null && rv.Length > 11 && rv[rv.Length - 1] == '}' && rv[rv.Length - 2] == '"'
&& "{\"data\":\"".Equals(Encoding.ASCII.GetString(rv, 0, 9), StringComparison.Ordinal))
{
using (var input = new MemoryStream(rv, 9, rv.Length - 11))
using (var base64Transform = new FromBase64Transform(FromBase64TransformMode.IgnoreWhiteSpaces))
using (var cryptoStream = new CryptoStream(input, base64Transform, CryptoStreamMode.Read))
{
await cryptoStream.CopyToAsync(targetStream, 4096, cancellationToken).ConfigureAwait(false);
await targetStream.FlushAsync(cancellationToken).ConfigureAwait(false);
}
}
else
{
throw new InvalidOperationException();
}
}
/// <summary>
/// Enables touch on platforms which do not support them.
/// </summary>
/// <param name="webview">The WebView control.</param>
/// <param name="enabled">True whether the touch event emulation should be enabled.</param>
/// <param name="maxTouchPoints">Maximum touch points supported. Defaults to one.</param>
/// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
/// <returns>The task object representing the asynchronous operation.</returns>
public static async Task SetTouchEmulationEnabledAsync(this IChromiumWebView webview, bool enabled, int? maxTouchPoints, CancellationToken cancellationToken)
{
if (webview is null)
throw new ArgumentNullException(nameof(webview));
var args = new CefDictionaryValue();
args.SetBool("enabled", enabled);
if (maxTouchPoints is not null)
{
if (maxTouchPoints.Value < 1 || maxTouchPoints.Value > 16)
throw new ArgumentOutOfRangeException(nameof(maxTouchPoints), "Touch points must be between 1 and 16.");
args.SetInt("maxTouchPoints", maxTouchPoints.Value);
}
ThrowIfNotEmptyResponse(await ExecuteDevToolsMethodInternalAsync(webview, "Emulation.setTouchEmulationEnabled", args, cancellationToken).ConfigureAwait(false));
}