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function bindCallback(obj, callback, arg1, arg2, arg3)
{
return function(arg) {
if (arg == undefined)
callback.apply(obj, [arg1, arg2, arg3]);
else
callback.apply(obj, [arg, arg1, arg2, arg3]);
};
}
// Usage:
// var helper = new JoinHelper;
//
// helper.run(function() { /* do something that eventually calls helper.done(); */ });
// helper.run(function() { /* do something that eventually calls helper.done(); */ });
// ...
// helper.join(joinCallback);
//
var JoinHelper = function()
{
this.pendingOperations = [];
this.pendingOperationCount = 0;
this.joinCallback = null;
this.run = function(operation)
{
this.pendingOperationCount++;
operation();
};
// Call this when an operation is done.
this.done = function()
{
this.pendingOperationCount--;
if (this.pendingOperationCount == 0 && this.joinCallback)
this.joinCallback();
};
// This eventually calls the joinCallback when helper.done() is called as many times as helper.run() is called.
this.join = function(joinCallback)
{
if (this.pendingOperationCount == 0)
joinCallback();
else
this.joinCallback = joinCallback;
};
};
// Remove everything in the given directory.
function removeAllInDirectory(directory, successCallback, errorCallback) {
var RemoveAllInDirectoryHelper = function(successCallback, errorCallback) {
this.entriesCount = 0;
this.done = false;
this.reader = null;
this.successCallback = successCallback;
this.errorCallback = errorCallback;
this.entryRemovedCallback = bindCallback(this, function(entry)
{
if (--this.entriesCount == 0 && this.successCallback && this.done) {
this.successCallback();
this.successCallback = null;
}
});
this.entriesCallback = bindCallback(this, function(entries)
{
for (var i = 0; i < entries.length; ++i) {
this.entriesCount++;
if (entries[i].isDirectory)
entries[i].removeRecursively(this.entryRemovedCallback, this.errorCallback);
else
entries[i].remove(this.entryRemovedCallback, this.errorCallback);
}
if (entries.length)
this.reader.readEntries(this.entriesCallback, this.errorCallback);
else if (this.entriesCount > 0)
this.done = true;
else if (this.successCallback)
this.successCallback();
});
this.removeAllInDirectory = function(directory)
{
this.reader = directory.createReader();
this.reader.readEntries(this.entriesCallback, this.errorCallback);
};
};
var helper = new RemoveAllInDirectoryHelper(successCallback, errorCallback);
helper.removeAllInDirectory(directory);
}
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