Re: DataSource modified while TableView is displaying data
Re: DataSource modified while TableView is displaying data
- Subject: Re: DataSource modified while TableView is displaying data
- From: Corbin Dunn <email@hidden>
- Date: Thu, 26 Apr 2012 12:47:22 -0700
On Apr 26, 2012, at 3:23 AM, Jean Suisse <email@hidden> wrote:
> Dear Peter,
>
> Thank you for your reply. Here is the requested code (see below).
> After more investigations, I would like to take back a previous statement, that the tableview was perfectly aware that the number of rows in the DS was changed. This is due to my inexperience in stepping through the code across multiple threads.
>
> Here are the facts :
>
> - Only the controller removes rows from the datasource. Either in response to user actions (canceling tasks) or as a result of a Task completed notification from a running task.
> - Each change in the dataSource is immediately followed by a reloadData message sent to the TableView.
> - Sometimes, randomly, the TableView requests a row index that is out of bounds by one index (e.g. row #5 when the dataSource contains only 5 elements).
>
> I am thinking that a redraw occurs in-between the removal of one element of the table and the reloadData message.
> For now, I did a quick fix for this issue by adding a category with "safeObjectAtIndex"…. But one way to be certain would be to ensure that the two messages (removal + reloadData) are sent without any thread/process switching occurring…
>
> The code for numberOfRowsInTableView : (experimentList is an instance of NSMutableAray)
>
> - (NSInteger)numberOfRowsInTableView:(NSTableView*)tableView
> {
> return self.experimentList ? [self.experimentList count] : 0;
> }
This is fine as long as your experimentList is only ever modified on the main thread.
It sounds like that isn't the case, which is why you have random problems.
corbin
>
> Jean
>
>
> On 26 avr. 2012, at 11:45, Peter Hudson wrote:
>
>>
>> Can you post your code for numberOfRowsInTableView:
>>
>> Peter
>
>
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