sch_test/mxclient/js/util/mxAutoSaveManager.js

214 lines
4.3 KiB
JavaScript

/**
* Copyright (c) 2006-2015, JGraph Ltd
* Copyright (c) 2006-2015, Gaudenz Alder
*/
/**
* Class: mxAutoSaveManager
*
* Manager for automatically saving diagrams. The <save> hook must be
* implemented.
*
* Example:
*
* (code)
* var mgr = new mxAutoSaveManager(editor.graph);
* mgr.save = function()
* {
* mxLog.show();
* mxLog.debug('save');
* };
* (end)
*
* Constructor: mxAutoSaveManager
*
* Constructs a new automatic layout for the given graph.
*
* Arguments:
*
* graph - Reference to the enclosing graph.
*/
function mxAutoSaveManager(graph)
{
// Notifies the manager of a change
this.changeHandler = mxUtils.bind(this, function(sender, evt)
{
if (this.isEnabled())
{
this.graphModelChanged(evt.getProperty('edit').changes);
}
});
this.setGraph(graph);
};
/**
* Extends mxEventSource.
*/
mxAutoSaveManager.prototype = new mxEventSource();
mxAutoSaveManager.prototype.constructor = mxAutoSaveManager;
/**
* Variable: graph
*
* Reference to the enclosing <mxGraph>.
*/
mxAutoSaveManager.prototype.graph = null;
/**
* Variable: autoSaveDelay
*
* Minimum amount of seconds between two consecutive autosaves. Eg. a
* value of 1 (s) means the graph is not stored more than once per second.
* Default is 10.
*/
mxAutoSaveManager.prototype.autoSaveDelay = 10;
/**
* Variable: autoSaveThrottle
*
* Minimum amount of seconds between two consecutive autosaves triggered by
* more than <autoSaveThreshhold> changes within a timespan of less than
* <autoSaveDelay> seconds. Eg. a value of 1 (s) means the graph is not
* stored more than once per second even if there are more than
* <autoSaveThreshold> changes within that timespan. Default is 2.
*/
mxAutoSaveManager.prototype.autoSaveThrottle = 2;
/**
* Variable: autoSaveThreshold
*
* Minimum amount of ignored changes before an autosave. Eg. a value of 2
* means after 2 change of the graph model the autosave will trigger if the
* condition below is true. Default is 5.
*/
mxAutoSaveManager.prototype.autoSaveThreshold = 5;
/**
* Variable: ignoredChanges
*
* Counter for ignored changes in autosave.
*/
mxAutoSaveManager.prototype.ignoredChanges = 0;
/**
* Variable: lastSnapshot
*
* Used for autosaving. See <autosave>.
*/
mxAutoSaveManager.prototype.lastSnapshot = 0;
/**
* Variable: enabled
*
* Specifies if event handling is enabled. Default is true.
*/
mxAutoSaveManager.prototype.enabled = true;
/**
* Variable: changeHandler
*
* Holds the function that handles graph model changes.
*/
mxAutoSaveManager.prototype.changeHandler = null;
/**
* Function: isEnabled
*
* Returns true if events are handled. This implementation
* returns <enabled>.
*/
mxAutoSaveManager.prototype.isEnabled = function()
{
return this.enabled;
};
/**
* Function: setEnabled
*
* Enables or disables event handling. This implementation
* updates <enabled>.
*
* Parameters:
*
* enabled - Boolean that specifies the new enabled state.
*/
mxAutoSaveManager.prototype.setEnabled = function(value)
{
this.enabled = value;
};
/**
* Function: setGraph
*
* Sets the graph that the layouts operate on.
*/
mxAutoSaveManager.prototype.setGraph = function(graph)
{
if (this.graph != null)
{
this.graph.getModel().removeListener(this.changeHandler);
}
this.graph = graph;
if (this.graph != null)
{
this.graph.getModel().addListener(mxEvent.CHANGE, this.changeHandler);
}
};
/**
* Function: save
*
* Empty hook that is called if the graph should be saved.
*/
mxAutoSaveManager.prototype.save = function()
{
// empty
};
/**
* Function: graphModelChanged
*
* Invoked when the graph model has changed.
*/
mxAutoSaveManager.prototype.graphModelChanged = function(changes)
{
var now = new Date().getTime();
var dt = (now - this.lastSnapshot) / 1000;
if (dt > this.autoSaveDelay ||
(this.ignoredChanges >= this.autoSaveThreshold &&
dt > this.autoSaveThrottle))
{
this.save();
this.reset();
}
else
{
// Increments the number of ignored changes
this.ignoredChanges++;
}
};
/**
* Function: reset
*
* Resets all counters.
*/
mxAutoSaveManager.prototype.reset = function()
{
this.lastSnapshot = new Date().getTime();
this.ignoredChanges = 0;
};
/**
* Function: destroy
*
* Removes all handlers from the <graph> and deletes the reference to it.
*/
mxAutoSaveManager.prototype.destroy = function()
{
this.setGraph(null);
};