homeclaw/web-ui/audiomass/state.js

(function ( PKAE ) {
	'use strict';
	
	function PKState ( _depth, app ) {
		if (!_depth) _depth = 1;

		var q = this;

		var _id = 1;
		var _fireEvent = app.fireEvent;
		var _listenFor = app.listenFor;

		var undo_state_list = [];
		var redo_state_list = [];

		function currentStateFor ( state ) {
			var current = {
				data: app.engine.wavesurfer.backend.buffer
			};
			if (state.type === 'mult' && app.multitrack)
				current.mt = app.multitrack.getState ();
			if (state.type === 'mrk' && app.mrk)
				current.markers = app.mrk.ser (state.ctx);
			return current;
		}

		function updateStateData ( state, current ) {
			state.data = current.data;
			if (current.mt) state.mt = current.mt;
			if (current.markers) state.markers = current.markers;
		}

		q.getLastUndoState = function () {
			return (undo_state_list [ undo_state_list.length - 1]);
		};

		q.pushUndoState = function ( state ) {
			if (!state) return (false);

			if (!state.id) state.id = ++_id;
			if (undo_state_list.length >= _depth) undo_state_list.shift ();

			if (undo_state_list.length > 0)
			{
				if (undo_state_list[undo_state_list.length - 1].id !== state.id - 1)
					undo_state_list = [];
			}
			if (redo_state_list.length > 0)
			{
				if (redo_state_list[0].id !== state.id + 1)
					redo_state_list = [];
			}

			undo_state_list.push ( state );

			_fireEvent ( 'StatePush', undo_state_list.length );
			_fireEvent ( 'DidStateChange', undo_state_list, redo_state_list);
			
			return (true);
		};

		q.popUndoState = function () {
			var last_state =undo_state_list.pop ();

			if (last_state) {	
				if (redo_state_list.length > 0)
				{
					if (redo_state_list[0].id !== last_state.id + 1)
						redo_state_list = [];
				}

				var current = currentStateFor ( last_state );

				_fireEvent ( 'StateDidPop', last_state, 1 );

				updateStateData ( last_state, current );
				redo_state_list.unshift (last_state);

				_fireEvent ( 'DidStateChange', undo_state_list, redo_state_list);
			}

			return (last_state);
		};
		
		q.shiftRedoState = function () {
			var last_state = redo_state_list.shift ();
			
			if (last_state) {
				if (undo_state_list.length > 0)
				{
					if (undo_state_list[undo_state_list.length - 1].id !== last_state.id - 1)
						undo_state_list = [];
				}

				var current = currentStateFor ( last_state );

				_fireEvent ( 'StateDidPop', last_state, 0 );

				updateStateData ( last_state, current );
				undo_state_list.push (last_state);

				_fireEvent ( 'DidStateChange', undo_state_list, redo_state_list);
			}
			
			return (last_state);
		};
		
		q.clearAllState = function () {
			undo_state_list = [];
			redo_state_list = [];

			_fireEvent ( 'StateClearAll' );
			_fireEvent ( 'DidStateChange', [], []);
		};

		_listenFor ('StateRequestPush', function ( _state ) {
			q.pushUndoState ( _state );
		});
		_listenFor ('StateRequestUndo', function () {
			q.popUndoState ();
		});
		_listenFor ('StateRequestRedo', function () {
			q.shiftRedoState ();
		});
		_listenFor ('StateRequestClearAll', function () {
			q.clearAllState ();
		});
		_listenFor ('StateRequestLastState', function () {
			_fireEvent ('StateDidLastState', q.getLastUndoState ());
		});
		// -
	};
	
	PKAE._deps.state = PKState;
	
})( PKAudioEditor );