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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.gecko.util;
import androidx.annotation.Nullable;
import org.mozilla.gecko.annotation.RobocopTarget;
import org.mozilla.gecko.annotation.WrapForJNI;
import org.mozilla.geckoview.GeckoResult;
/**
* Callback interface for Gecko requests.
*
* <p>For each instance of EventCallback, exactly one of sendResponse, sendError, or sendCancel must
* be called to prevent observer leaks. If more than one send* method is called, or if a single send
* method is called multiple times, an {@link IllegalStateException} will be thrown.
*/
@RobocopTarget
@WrapForJNI(calledFrom = "gecko")
public interface EventCallback {
/**
* Sends a success response with the given data.
*
* @param response The response data to send to Gecko. Can be any of the types accepted by
* JSONObject#put(String, Object).
*/
void sendSuccess(Object response);
/**
* Sends an error response with the given data.
*
* @param response The response data to send to Gecko. Can be any of the types accepted by
* JSONObject#put(String, Object).
*/
void sendError(Object response);
/**
* Resolve this Event callback with the result from the {@link GeckoResult}.
*
* @param response the result that will be used for this callback.
*/
default <T> void resolveTo(final @Nullable GeckoResult<T> response) {
if (response == null) {
sendSuccess(null);
return;
}
response.accept(
this::sendSuccess,
throwable -> {
// Don't propagate Errors, just crash
if (!(throwable instanceof Exception)) {
throw new GeckoResult.UncaughtException(throwable);
}
sendError(throwable.getMessage());
});
}
}