video-quality-selector.js

/**
 * Video.js Resolution Selector
 *
 * This plugin for Video.js adds a resolution selector option
 * to the toolbar. Usage:
 *
 * <video>
 * 	<source data-res="480" src="..." />
 * 	<source data-res="240" src="..." />
 * </video>
 */

(function( _V_ ) {
	
	/***********************************************************************************
	 * Define some helper functions
	 ***********************************************************************************/
	var methods = {
		
		/**
		 * In a future version, this can be made more intelligent,
		 * but for now, we'll just add a "p" at the end if we are passed
		 * numbers.
		 *
		 * @param	(string)	res	The resolution to make a label for
		 *
		 * @returns	(string)	The label text string
		 */
		res_label : function( res ) {
			
			return ( /^\d+$/.test( res ) ) ? res + 'p' : res;
		}
	};
	
	/***********************************************************************************
	 * Setup our resolution menu items
	 ***********************************************************************************/
	_V_.ResolutionMenuItem = _V_.MenuItem.extend({
		
		// Call variable to prevent the resolution change from being called twice
		call_count : 0,
		
		/** @constructor */
		init : function( player, options ){
			
			var touchstart = false;
			
			// Modify options for parent MenuItem class's init.
			options.label = methods.res_label( options.res );
			options.selected = ( options.res.toString() === player.getCurrentRes().toString() );
			
			// Call the parent constructor
			_V_.MenuItem.call( this, player, options );
			
			// Store the resolution as a property
			this.resolution = options.res;
			
			// Register our click and tap handlers
			this.on( ['click', 'tap'], this.onClick );
			
			// Toggle the selected class whenever the resolution changes
			player.on( 'changeRes', _V_.bind( this, function() {
				
				if ( this.resolution == player.getCurrentRes() ) {
					
					this.selected( true );
					
				} else {
					
					this.selected( false );
				}
				
				// Reset the call count
				this.call_count = 0;
			}));
		}
	});
	
	// Handle clicks on the menu items
	_V_.ResolutionMenuItem.prototype.onClick = function() {
		
		// Check if this has already been called
		if ( this.call_count > 0 ) { return; }
		
		// Call the player.changeRes method
		this.player().changeRes( this.resolution );
		
		// Increment the call counter
		this.call_count++;
	};
	
	/***********************************************************************************
	 * Setup our resolution menu title item
	 ***********************************************************************************/
	_V_.ResolutionTitleMenuItem = _V_.MenuItem.extend({
		
		init : function( player, options ) {
			
			// Call the parent constructor
			_V_.MenuItem.call( this, player, options );
			
			// No click handler for the menu title
			this.off( 'click' );
		}
	});
	
	/***********************************************************************************
	 * Define our resolution selector button
	 ***********************************************************************************/
	_V_.ResolutionSelector = _V_.MenuButton.extend({
		
		/** @constructor */
		init : function( player, options ) {
			
			// Add our list of available resolutions to the player object
			player.availableRes = options.available_res;
			
			// Call the parent constructor
			_V_.MenuButton.call( this, player, options );
			
			// Set the button text based on the option provided
			this.el().firstChild.firstChild.innerHTML = options.buttonText;
		}
	});
	
	// Set class for resolution selector button
	_V_.ResolutionSelector.prototype.className = 'vjs-res-button';
	
	// Create a menu item for each available resolution
	_V_.ResolutionSelector.prototype.createItems = function() {
		
		var player = this.player(),
			items = [],
			current_res;
		
		// Add the menu title item
		items.push( new _V_.ResolutionTitleMenuItem( player, {
			
			el : _V_.Component.prototype.createEl( 'li', {
				
				className	: 'vjs-menu-title vjs-res-menu-title',
				innerHTML	: player.localize( 'Quality' )
			})
		}));
		
		// Add an item for each available resolution
		for ( current_res in player.availableRes ) {
			
			// Don't add an item for the length attribute
			if ( 'length' == current_res ) { continue; }
			
			items.push( new _V_.ResolutionMenuItem( player, {
				res : current_res
			}));
		}
		
		// Sort the available resolutions in descending order
		items.sort(function( a, b ) {
			
			if ( typeof a.resolution == 'undefined' ) {
				
				return -1;
				
			} else {
				
				return parseInt( b.resolution ) - parseInt( a.resolution );
			}
		});
		
		return items;
	};
	
	/***********************************************************************************
	 * Register the plugin with videojs, main plugin function
	 ***********************************************************************************/
	_V_.plugin( 'resolutionSelector', function( options ) {
		
		// Only enable the plugin on HTML5 videos
		if ( ! this.el().firstChild.canPlayType  ) { return; }	
		
		/*******************************************************************
		 * Setup variables, parse settings
		 *******************************************************************/
		var player = this,
			sources	= player.options().sources,
			i = sources.length,
			j,
			found_type,
			
			// Override default options with those provided
			settings = _V_.util.mergeOptions({
				
				default_res	: '',		// (string)	The resolution that should be selected by default ( '480' or  '480,1080,240' )
				force_types	: false		// (array)	List of media types. If passed, we need to have source for each type in each resolution or that resolution will not be an option
				
			}, options || {} ),
			
			available_res = { length : 0 },
			current_res,
			resolutionSelector,
			
			// Split default resolutions if set and valid, otherwise default to an empty array
			default_resolutions = ( settings.default_res && typeof settings.default_res == 'string' ) ? settings.default_res.split( ',' ) : [];
		
		// Get all of the available resoloutions
		while ( i > 0 ) {
			
			i--;
			
			// Skip sources that don't have data-res attributes
			if ( ! sources[i]['data-res'] ) { continue; }
			
			current_res = sources[i]['data-res'];
			
			if ( typeof available_res[current_res] !== 'object' ) {
				
				available_res[current_res] = [];
				available_res.length++;
			}
			
			available_res[current_res].unshift( sources[i] );
		}
		
		// Check for forced types
		if ( settings.force_types ) {
			
			// Loop through all available resoultions
			for ( current_res in available_res ) {
				
				// Don't count the length property as a resolution
				if ( 'length' == current_res ) { continue; }
				
				i = settings.force_types.length;
				found_types = 0;
				
				// Loop through all required types
				while ( i > 0 ) {
					
					i--;
					
					j = available_res[current_res].length;
					
					// Loop through all available sources in current resolution
					while ( j > 0 ) {
						
						j--;
						
						// Check if the current source matches the current type we're checking
						if ( settings.force_types[i] === available_res[current_res][j].type ) {
							
							found_types++;
							break;
						}
					}
				}
				
				// If we didn't find sources for all of the required types in the current res, remove it
				if ( found_types < settings.force_types.length ) {
					
					delete available_res[current_res];
					available_res.length--;
				}
			}
		}
		
		// Make sure we have at least 2 available resolutions before we add the button
		if ( available_res.length < 2 ) { return; }
		
		// Loop through the choosen default resolutions if there were any
		for ( i = 0; i < default_resolutions.length; i++ ) {
			
			// Set the video to start out with the first available default res
			if ( available_res[default_resolutions[i]] ) {
				
				player.src( available_res[default_resolutions[i]] );
				player.currentRes = default_resolutions[i];
				break;
			}
		}
		
		/*******************************************************************
		 * Add methods to player object
		 *******************************************************************/
		
		// Make sure we have player.localize() if it's not defined by Video.js
		if ( typeof player.localize !== 'function' ) {
			
			player.localize = function( string ) {
				
				return string;
			};
		}
		
		// Helper function to get the current resolution
		player.getCurrentRes = function() {
			
			if ( typeof player.currentRes !== 'undefined' ) {
				
				return player.currentRes;
				
			} else {
				
				try {
					
					return res = player.options().sources[0]['data-res'];
					
				} catch(e) {
					
					return '';
				}
			}
		};
		
		// Define the change res method
		player.changeRes = function( target_resolution ) {
			
			var video_el = player.el().firstChild,
				is_paused = player.paused(),
				current_time = player.currentTime(),
				button_nodes,
				button_node_count;
			
			// Do nothing if we aren't changing resolutions or if the resolution isn't defined
			if ( player.getCurrentRes() == target_resolution
				|| ! player.availableRes
				|| ! player.availableRes[target_resolution] ) { return; }
			
			// Make sure the loadedmetadata event will fire
			if ( 'none' == video_el.preload ) { video_el.preload = 'metadata'; }
			
			// Change the source and make sure we don't start the video over		
			player.src( player.availableRes[target_resolution] ).one( 'loadedmetadata', function() {
				
				player.currentTime( current_time );
				
				// If the video was paused, don't show the poster image again
				player.addClass( 'vjs-has-started' );
				
				if ( ! is_paused ) { player.play(); }
			});
			
			// Save the newly selected resolution in our player options property
			player.currentRes = target_resolution;
			
			// Make sure the button has been added to the control bar
			if ( player.controlBar.resolutionSelector ) {
				
				button_nodes = player.controlBar.resolutionSelector.el().firstChild.children;
				button_node_count = button_nodes.length;
				
				// Update the button text
				while ( button_node_count > 0 ) {
					
					button_node_count--;
					
					if ( 'vjs-control-text' == button_nodes[button_node_count].className ) {
						
						button_nodes[button_node_count].innerHTML = methods.res_label( target_resolution );
						break;
					}
				}
			}
			
			// Update the classes to reflect the currently selected resolution
			player.trigger( 'changeRes' );
		};
		
		/*******************************************************************
		 * Add the resolution selector button
		 *******************************************************************/
		
		// Get the starting resolution
		current_res = player.getCurrentRes();
		
		if ( current_res ) { current_res = methods.res_label( current_res ); }
		
		// Add the resolution selector button
		resolutionSelector = new _V_.ResolutionSelector( player, {
			buttonText		: player.localize( current_res || 'Quality' ),
			available_res	: available_res
		});
		
		// Add the button to the control bar object and the DOM
		player.controlBar.resolutionSelector = player.controlBar.addChild( resolutionSelector );
	});

})( videojs );