Annotation-System/hmml_to_html/player.js

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// refsCallback: (optional)
// Will be called when the player enters a marker that has a `data-ref` attribute. The value of `data-ref` will be passed to the function.
// When leaving a marker that a `data-ref` attribute, and entering a marker without one (or not entering a new marker at all), the function will be called with `null`.
function Player(htmlContainer, refsCallback) {
this.container = htmlContainer;
this.markersContainer = this.container.querySelector(".markers_container");
this.videoContainer = this.container.querySelector(".video_container");
this.refsCallback = refsCallback || function() {};
if (!this.videoContainer.getAttribute("data-videoId")) {
console.error("Expected to find data-videoId attribute on", this.videoContainer, "for player initialized on", this.container);
throw new Error("Missing data-videoId attribute.");
}
this.markers = [];
var markerEls = this.markersContainer.querySelectorAll(".marker");
if (markerEls.length == 0) {
console.error("No markers found in", this.markersContainer, "for player initialized on", this.container);
throw new Error("Missing markers.");
}
for (var i = 0; i < markerEls.length; ++i) {
var marker = {
timestamp: parseInt(markerEls[i].getAttribute("data-timestamp"), 10),
ref: markerEls[i].getAttribute("data-ref"),
endTime: (i < markerEls.length - 1 ? parseInt(markerEls[i+1].getAttribute("data-timestamp"), 10) : null),
el: markerEls[i],
fadedProgress: markerEls[i].querySelector(".progress.faded"),
progress: markerEls[i].querySelector(".progress.main"),
hoverx: null
};
marker.el.addEventListener("click", this.onMarkerClick.bind(this, marker));
marker.el.addEventListener("mousemove", this.onMarkerMouseMove.bind(this, marker));
marker.el.addEventListener("mouseleave", this.onMarkerMouseLeave.bind(this, marker));
this.markers.push(marker);
}
this.currentMarker = null;
this.currentMarkerIdx = null;
this.youtubePlayer = null;
this.youtubePlayerReady = false;
this.playing = false;
this.shouldPlay = false;
this.buffering = false;
this.pauseAfterBuffer = false;
this.speed = 1;
this.currentTime = 0;
this.lastFrameTime = 0;
this.scrollTo = -1;
this.scrollPosition = 0;
this.nextFrame = null;
this.looping = false;
this.markersContainer.addEventListener("wheel", function(ev) {
this.scrollTo = -1;
}.bind(this));
Player.initializeYoutube(this.onYoutubeReady.bind(this));
this.updateSize();
this.resume();
}
// Start playing the video from the current position.
// If the player hasn't loaded yet, it will autoplay when ready.
Player.prototype.play = function() {
if (this.youtubePlayerReady) {
if (!this.playing) {
this.youtubePlayer.playVideo();
}
this.pauseAfterBuffer = false;
} else {
this.shouldPlay = true;
}
};
// Pause the video at the current position.
// If the player hasn't loaded yet, it will not autoplay when ready. (This is the default)
Player.prototype.pause = function() {
if (this.youtubePlayerReady) {
if (this.playing) {
this.youtubePlayer.pauseVideo();
} else if (this.buffering) {
this.pauseAfterBuffer = true;
}
} else {
this.shouldPlay = false;
}
};
// Sets the current time. Does not affect play status.
// If the player hasn't loaded yet, it will seek to this time when ready.
Player.prototype.setTime = function(time) {
this.currentTime = time;
if (this.youtubePlayerReady) {
this.currentTime = Math.max(0, Math.min(this.currentTime, this.youtubePlayer.getDuration()));
this.youtubePlayer.seekTo(this.currentTime);
}
this.updateProgress();
};
Player.prototype.jumpToNextMarker = function() {
var targetMarkerIdx = Math.min((this.currentMarkerIdx === null ? 0 : this.currentMarkerIdx + 1), this.markers.length-1);
var targetTime = this.markers[targetMarkerIdx].timestamp;
this.setTime(targetTime);
this.play();
};
Player.prototype.jumpToPrevMarker = function() {
var targetMarkerIdx = Math.max(0, (this.currentMarkerIdx === null ? 0 : this.currentMarkerIdx - 1));
var targetTime = this.markers[targetMarkerIdx].timestamp;
this.setTime(targetTime);
this.play();
};
// Call this after changing the size of the video container in order to update the youtube player.
Player.prototype.updateSize = function() {
var width = this.videoContainer.offsetWidth;
var height = width / 16 * 9;
this.markersContainer.style.height = height;
if (this.youtubePlayerReady) {
this.youtubePlayer.setSize(Math.floor(width), Math.floor(height));
}
}
// Stops the per-frame work that the player does. Call when you want to hide or get rid of the player.
Player.prototype.halt = function() {
this.pause();
this.looping = false;
if (this.nextFrame) {
cancelAnimationFrame(this.nextFrame);
this.nextFrame = null;
}
}
// Resumes the per-frame work that the player does. Call when you want to show the player again after hiding.
Player.prototype.resume = function() {
this.looping = true;
if (!this.nextFrame) {
this.doFrame();
}
}
Player.initializeYoutube = function(callback) {
if (window.APYoutubeAPIReady === undefined) {
window.APYoutubeAPIReady = false;
window.APCallbacks = (callback ? [callback] : []);
window.onYouTubeIframeAPIReady = function() {
window.APYoutubeAPIReady = true;
for (var i = 0; i < APCallbacks.length; ++i) {
APCallbacks[i]();
}
};
var scriptTag = document.createElement("SCRIPT");
scriptTag.setAttribute("type", "text/javascript");
scriptTag.setAttribute("src", "https://www.youtube.com/iframe_api");
document.body.appendChild(scriptTag);
} else if (window.APYoutubeAPIReady === false) {
window.APCallbacks.push(callback);
} else if (window.APYoutubeAPIReady === true) {
callback();
}
}
// END PUBLIC INTERFACE
Player.prototype.onMarkerClick = function(marker, ev) {
var time = marker.timestamp;
if (this.currentMarker == marker && marker.hoverx !== null) {
time += (marker.endTime - marker.timestamp) * marker.hoverx;
}
this.setTime(time);
this.play();
};
Player.prototype.onMarkerMouseMove = function(marker, ev) {
if (this.currentMarker == marker) {
marker.hoverx = (ev.offsetX - marker.el.offsetLeft) / marker.el.offsetWidth;
}
};
Player.prototype.onMarkerMouseLeave = function(marker, ev) {
marker.hoverx = null;
};
Player.prototype.updateProgress = function() {
var prevMarker = this.currentMarker;
this.currentMarker = null;
this.currentMarkerIdx = null;
for (var i = 0; i < this.markers.length; ++i) {
var marker = this.markers[i];
if (marker.timestamp <= this.currentTime && this.currentTime < marker.endTime) {
this.currentMarker = marker;
this.currentMarkerIdx = i;
break;
}
}
if (this.currentMarker) {
var totalWidth = this.currentMarker.el.offsetWidth;
var progress = (this.currentTime - this.currentMarker.timestamp) / (this.currentMarker.endTime - this.currentMarker.timestamp);
if (this.currentMarker.hoverx === null) {
var pixelWidth = progress * totalWidth;
this.currentMarker.fadedProgress.style.width = Math.ceil(pixelWidth) + "px";
this.currentMarker.fadedProgress.style.opacity = pixelWidth - Math.floor(pixelWidth);
this.currentMarker.progress.style.width = Math.floor(pixelWidth) + "px";
} else {
this.currentMarker.fadedProgress.style.opacity = 1;
this.currentMarker.progress.style.width = Math.floor(Math.min(this.currentMarker.hoverx, progress) * totalWidth) + "px";
this.currentMarker.fadedProgress.style.width = Math.floor(Math.max(this.currentMarker.hoverx, progress) * totalWidth) + "px";
}
}
if (this.currentMarker != prevMarker) {
if (prevMarker) {
prevMarker.el.classList.remove("current");
prevMarker.fadedProgress.style.width = "0px";
prevMarker.progress.style.width = "0px";
prevMarker.hoverx = null;
}
if (this.currentMarker) {
this.currentMarker.el.classList.add("current");
this.scrollTo = this.currentMarker.el.offsetTop + this.currentMarker.el.offsetHeight/2.0;
this.scrollPosition = this.markersContainer.scrollTop;
}
if (this.currentMarker && this.currentMarker.ref) {
this.refsCallback(this.currentMarker.ref);
} else if (prevMarker && prevMarker.ref) {
this.refsCallback(null);
}
}
};
Player.prototype.doFrame = function() {
var now = performance.now();
var delta = (now - this.lastFrameTime) / 1000.0;
this.lastFrameTime = now;
if (this.playing) {
this.currentTime += delta * this.speed;
}
this.updateProgress();
if (this.scrollTo >= 0) {
var targetPosition = this.scrollTo - this.markersContainer.offsetHeight/2.0;
targetPosition = Math.max(0, Math.min(targetPosition, this.markersContainer.scrollHeight - this.markersContainer.offsetHeight));
this.scrollPosition += (targetPosition - this.scrollPosition) * 0.1;
if (Math.abs(this.scrollPosition - targetPosition) < 1.0) {
this.markersContainer.scrollTop = targetPosition;
this.scrollTo = -1;
} else {
this.markersContainer.scrollTop = this.scrollPosition;
}
}
this.nextFrame = requestAnimationFrame(this.doFrame.bind(this));
};
Player.prototype.onYoutubePlayerReady = function() {
this.youtubePlayerReady = true;
this.markers[this.markers.length-1].endTime = this.youtubePlayer.getDuration();
this.updateSize();
this.youtubePlayer.setPlaybackQuality("hd1080");
if (this.currentTime > 0) {
this.currentTime = Math.max(0, Math.min(this.currentTime, this.youtubePlayer.getDuration()));
this.youtubePlayer.seekTo(this.currentTime, true);
}
if (this.shouldPlay) {
this.youtubePlayer.playVideo();
}
};
Player.prototype.onYoutubePlayerStateChange = function(ev) {
if (ev.data == YT.PlayerState.PLAYING) {
this.playing = true;
this.currentTime = this.youtubePlayer.getCurrentTime();
} else if (ev.data == YT.PlayerState.PAUSED || ev.data == YT.PlayerState.BUFFERING) {
this.playing = false;
this.currentTime = this.youtubePlayer.getCurrentTime();
this.updateProgress();
} else {
this.playing = false;
}
this.buffering = ev.data == YT.PlayerState.BUFFERING;
if (this.playing && this.pauseAfterBuffer) {
this.pauseAfterBuffering = false;
this.pause();
}
};
Player.prototype.onYoutubePlayerPlaybackRateChange = function(ev) {
this.speed = ev.data;
};
Player.prototype.onYoutubeReady = function() {
var youtubePlayerDiv = document.createElement("DIV");
youtubePlayerDiv.id = "youtube_player_" + Player.youtubePlayerCount++;
this.videoContainer.appendChild(youtubePlayerDiv);
this.youtubePlayer = new YT.Player(youtubePlayerDiv.id, {
videoId: this.videoContainer.getAttribute("data-videoId"),
width: this.videoContainer.offsetWidth,
height: this.videoContainer.offsetWidth / 16 * 9,
events: {
"onReady": this.onYoutubePlayerReady.bind(this),
"onStateChange": this.onYoutubePlayerStateChange.bind(this),
"onPlaybackRateChange": this.onYoutubePlayerPlaybackRateChange.bind(this)
}
});
};
Player.youtubePlayerCount = 0;