Change track selection range for NSTextField (cocoa)
Does anyone know how I can track changes in values NSTextField.currentEditor.selectedRange
for NSTextField
?
There is this wonderful thing NSTextViewDidChangeSelectionNotification
, it does exactly what I need, but only works for NSTextView
.
I tried to play with KVC / KVO but I didn't get what I wanted. I am guessing that I did something wrong.
I will try to explain what I need to achieve.
I have NSTextField
, below I have a label where I want to put the values from the NSTextField.currentEditor.selectedRange
text above. In real time, i.e. I want to constantly update the content of my label with selection length and starting position from NSTextField.currentEditor.selectedRange
when selecting a region of text.
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NSTextField
uses the current window's margin editor to actually edit the text, and this NSTextView
. To subscribe to NSTextViewDidChangeSelectionNotification
this text view, you need to figure out when your field is receiving keyboard focus and then request it currentEditor
.
Unfortunately it controlTextDidBeginEditing:
never seems to be called, but you can override becomeFirstResponder
to get the same effect (be sure to call super).
I can't seem to find a good place to unsubscribe as the textbox only has keyboard focus for a second and then loses it when the NSTextView field editor is created and activated.
So in the end what I am doing is subscribing to a notification with an object nil
when the view is created, unsubscribing in the dealloc and checking to see if notification.object == self.currentEditor
the notification handler is present and ignoring all others.
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You can implement -windowWillReturnFieldEditor:toObject:
in your dedet NSWindow
and return a different field editor for the controls you need, perhaps with appropriate notifications NSTextView
configured just for that field editor. Or, of course, you can return your own subclass NSTextView
, although this is probably not needed here.
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