How to disable sorting in NSTableVIew? - objective-c

I have a an NSTableView when ever I click on a specific header column the data in the table get reversed or sort upside down. I have checked NSTableView as well as NSTableColumn but couldn't find any method that disables this. I would be obliged if anyone can help in disabling this sorting on clicking on the header of a particular column.

Sorting of the NSTableView is done by its sortDescriptors, see here.
An NSTableColumn uses its sortDescriptorPrototype (see here) to generate the sort descriptor of the NSTableView, depending on how many times you clicked the column header, etc.
If you use dataSource to manage the data, then the sort descriptor is communicated via the delegate method tableView:sortDescriptorsDidChange:, see here. You just need to ignore the change message to stop sorting.
If you use Cocoa bindings to manage the data, the sort descriptor is generated by the table column and set to the NSArrayController. To stop it, just open the inspector of the binding of the table column, select value, and uncheck "Creates Sort Descriptor."

Related

disable the reordering of rows in a NSTableView

I need to disable the reordering of rows in a NSTableView so that when I open the application data of the NSTableView are in the same order in which I created them.
In Inspector, check the bindings of the sorted table column, select value and check that the option "Creates Sort Descriptor" in unchecked.

Changing visibility of NSPopUpButton's items based on keypress

I've got an application here that needs to read in a bunch of data from an external file and display it as a NSPopUpButton in a Cocoa user interface. The catch here is that the data that is being read in needs to have a flag that states if it is considered "hidden" or not.
If the data is hidden, it needs to be added to the NSPopUpButton as an NSMenuItem, but the hidden flag needs to be set to YES so it does not normally appear in the NSPopUpButton menu. If the user holds down a "magic key" on their keyboard (usually ALT, in this case) then those hidden objects need to be unhidden. If the user lets go of the ALT key, then they need to be automatically re-hidden, except for the one that may have been selected -- which would become hidden if another NSMenuItem were chosen.
I'm kind of having a heck of a time figuring this out, actually.
I was wondering if there is a straight forward way of doing this using NSArrayController and an NSPopUpButton, but thus far I have not been able to find anything resembling a solution -- not when it comes to managing the hidden property of the NSMenuItem objects.
Does anyone know how this can be achieved using Cocoa Bindings?
You can wire the popup to an array controller and alter the filter predicate. From an MVC design standpoint, you wouldn't use an attribute like "hidden", which is a view characteristic, but maybe "advanced". Normally, set a filter predicate on your array controller to "advanced = no". Then when the user holds your preferred modifier, remove the predicate. The popup will update automatically. The array controller should be bound to an array property on another object (in your data model). The popup should be bound to arrangedObjects on the array controller.

Using Custom Cell for Mac Application

Does anyone have any info on this? I'm new to cocoa, all tutorials seem to be for iPhone which uses a different view controller. Anyone willing to provide a step by step for adding labels to a custom cell? (I'm pulling from Core Data)
EDIT: It's important to note I'm using Core Data here. Many tutorials use arrays.. I don't understand why you would use that??
I'll award an answer quickly!
Zach
I'm not sure if this is going to help you, but your problem seems unrelated to your use of CoreData.
If I've understood your problem correctly, here are some steps:
Populate your NSTableView
Using CoreData, what you can do is put an NSArrayController object in your XIB document, set its mode to Entity and choose the Entity you want to display in your TableView (all of this from the first tab of the inspector on your array controller object).
Then, bind your NSTableView Content to the arrangedObjects of the array controller. You might also bind the selectionIndexes and use some sort descriptors on the array controller to order your data, as CoreData will give you a set rather than an array.
Click on your table view as many times as necessary as to select the table column in which you want your custom cell to appear, and set its Value binding to arrangedObjects too.
Set your custom cell
Finally, click on the cell of this table column and in the "Identity" of the inspector, change the class name of the cell to the class name of your custom cell.
I'll let you read the appropriate documentation to implement your custom cell according to what you want to achieve.
With the different bindings I've described, the objectValue of your cell should be the object from your array controller at the same index of the row your cell will appear on.
Please note that I've not tested again all of these steps but answered from memory... there might be details I've missed but you should have the main steps here.

Populate NSForm with NSComboBoxes

So I have a task of reading from an xml file which contains a description of what form fields and comboboxes should exist in a dialog. I started by using NSForm and addentry to add the form fields, but then found out NSMatrix may be required to add combobox cells dynamically.
So my questions are:
1) Since NSForm inherits from NSMatrix can I add combobox cells to NSForm after I add the text fields.
2) If I have to use NSMatrix, does anyone have any good sample code they can point me to or write which adds a text field, and combobox to it at runtime and then resizes the NSMatrix to fit its contents. A lot of books just describe what NSMatrix is, and show how to populare it using interface builder.
NSForm does not allow custom cell types (text field only) and NSMatrix takes only one cell type (you cannot have an NSMatrix that has a mix of NSTextFieldCell and NSComboBoxCell).
If you really need to create a variable number of rows of field + combo box, you're going to have to manage the creation, layout, and destruction of these manually.
Alternatively, you might consider using collection views.
Update - If you're targeting 10.7 and up and need better control than collection views offer, consider using view-based table views.

NSTableView. How to override autoscroll behavior?

I've got an NSTableView that displays (via bindings) data from an NSTreeController. The application frequently appends/changes data to/in the bound array.
The problem is that if the user has selected a row in the table, but has scrolled so that the selected data is no longer visible, when the application updates the array it causes the display to auto-scroll so that the selected line is once again on screen. This is pretty
frustrating to users, especially since new data can arrive at any time.
Is there any way of disabling this feature?
You may have to subclass NSTableView and override -scrollRowToVisible:, temporarily bracketing the call to super. This may also require a custom BOOL ivar in your subclass to keep track of whether you want to scroll.
I would start by setting a breakpoint there to see when exactly the autoscroll is triggered. This should help to find the proper moments to toggle the ivar.
Are you using an NSTreeController with an NSOutlineView or an NSArrayController with an NSTableView? Using an NSTreeController with an NSTableView doesn't make a lot of sense to me?
If you're using an NSTableView you should probably be using an NSArrayController to manage its data and this rearranging of the rows is a feature of the NSArrayController. Try turning off the Auto Rearrange Content option on your controller within IB.
When it's on, the array controller will rearrange its objects on addition, removal and changes to objects that would affect the sort ordering (if any) and cause any table views or outline views to reload their data.
I don't know of a similar feature for NSTreeController mainly because I don't use it since it's never worked well for me. I, sadly, recommend to just use the datasource methods for the NSOutlineView and supply your data the old-fashioned way. In my experience, NSTreeController is only well suited for the most trivial tasks.