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(function (global) {
"use strict";
// an invertible check on the condition.
// if the constraint is applied, then the check is direct
// if not applied, then the result should be reversed
function check(constraintApplied, condition, message) {
var good = constraintApplied ? condition : !condition;
message =
(constraintApplied ? "with" : "without") +
" constraint: should " +
(constraintApplied ? "" : "not ") +
message +
" = " +
(good ? "OK" : "waiting...");
info(message);
return good;
}
function mkElement(type) {
// This makes an unattached element.
// It's not rendered to save the cycles that costs on b2g emulator
// and it gets dropped (and GC'd) when the test is done.
var e = document.createElement(type);
e.width = 32;
e.height = 24;
document.getElementById("display").appendChild(e);
return e;
}
// Runs checkFunc until it reports success.
// This is kludgy, but you have to wait for media to start flowing, and it
// can't be any old media, it has to include real data, for which we have no
// reliable signals to use as a trigger.
function periodicCheck(checkFunc) {
var resolve;
var done = false;
// This returns a function so that we create 10 closures in the loop, not
// one; and so that the timers don't all start straight away
var waitAndCheck = counter => () => {
if (done) {
return Promise.resolve();
}
return new Promise(r => setTimeout(r, 200 << counter)).then(() => {
if (checkFunc()) {
done = true;
resolve();
}
});
};
var chain = Promise.resolve();
for (var i = 0; i < 10; ++i) {
chain = chain.then(waitAndCheck(i));
}
return new Promise(r => (resolve = r));
}
function isSilence(audioData) {
var silence = true;
for (var i = 0; i < audioData.length; ++i) {
if (audioData[i] !== 128) {
silence = false;
}
}
return silence;
}
function checkAudio(constraintApplied, stream) {
var audio = mkElement("audio");
audio.srcObject = stream;
audio.play();
var context = new AudioContext();
var source = context.createMediaStreamSource(stream);
var analyser = context.createAnalyser();
source.connect(analyser);
analyser.connect(context.destination);
return periodicCheck(() => {
var sampleCount = analyser.frequencyBinCount;
info("got some audio samples: " + sampleCount);
var buffer = new Uint8Array(sampleCount);
analyser.getByteTimeDomainData(buffer);
var silent = check(
constraintApplied,
isSilence(buffer),
"be silence for audio"
);
return sampleCount > 0 && silent;
}).then(() => {
source.disconnect();
analyser.disconnect();
audio.pause();
ok(true, "audio is " + (constraintApplied ? "" : "not ") + "silent");
});
}
function checkVideo(constraintApplied, stream) {
var video = mkElement("video");
video.srcObject = stream;
video.play();
return periodicCheck(() => {
try {
var canvas = mkElement("canvas");
var ctx = canvas.getContext("2d");
// we get an error, this round fails, but that failure is usually just
// transitory.
ctx.drawImage(video, 0, 0);
ctx.getImageData(0, 0, 1, 1);
return check(
constraintApplied,
false,
"throw on getImageData for video"
);
} catch (e) {
return check(
constraintApplied,
e.name === "SecurityError",
"get a security error: " + e.name
);
}
}).then(() => {
video.pause();
ok(true, "video is " + (constraintApplied ? "" : "not ") + "protected");
});
}
global.audioIsSilence = checkAudio;
global.videoIsBlack = checkVideo;
})(this);