WKInterfaceTable, WKInterfaceButton and action methods

Question

I'm experimenting with WatchKit and I'm trying to accomplish something that may be obvious but I can't seem to figure out how.

I have a single watch interface that contains a table with several rows of the same row controller, each containing two buttons. The action methods for the buttons are contained in the appropriate row controller class. The background image of the button changes each time it is tapped. That all works. However, I also need to call a function in the interface controller and change some variables that exist in the interface controller, each time the button is tapped.

Is this possible? I also understand that I can't call didSelectRowAtIndex at the same time as my button action.

Thanks!

score 1 · Accepted Answer · answered Feb 13 '15 at 23:44

You will need to wire your InterfaceController to your buttons and then call the appropriate method. It is best to decouple it via a delegate or using a selector, but you can just past your interface controller if needed.

This assumes you wired your WKInterfaceTable object to the property table in your interface controller.

//In your interface controller
- (void)loadTableData
{
    NSInteger numRows = <CALC_NUM_ROWS>;

    [self.table setNumberOfRows:num withRowType:@"<MY_ROW_TYPE>"];

    for (int i = 0; i < num; i++)
    {
        MyRowController *row = [self.table rowControllerAtIndex:i];

        //Here is where you want to wire your interface controller to your row
        //You will need to add this method to your row class
        [row addSelectionTarget:self action:@selector(myMethodToCall)];

    }
}

- (void) myMethodToCall
{ 
   //Do something in your interface controller when a button is selection
}


//Now in your MyRowController
-(void)addSelectionTarget:(id)target action:(SEL)action
{ 
    //You will need to add properties for these.
    self.selectionTarget = target;
    self.selectionAction = action;
}

//Call this when you want to call back to your interface controller
- (void)fireSelectionAction
{
    [self.selectionTarget performSelector:self.selectionAction];

    //Or to do it without warnings on ARC
    IMP imp = [self.selectionTarget methodForSelector:self.selectionAction];
    void (*func)(id, SEL) = (void *)imp;
    func(self.selectionTarget, self.selectionAction);

}

Thanks so much for the detailed response. I'm fairly new to iOS dev and I've only worked with Swift. Any clues on how to translate this to Swift would be greatly appreciated! — Papaya4APPLE, Feb 14 '15 at 00:25
How do you know the button that was tapped in the row? There's no row index being passed; and there's no tag associated with the control. — Daniel, May 18 '15 at 18:23

score 0 · Answer 2 · answered Aug 13 '15 at 17:13

In your interface controller (NOT the row controller; it must be a WKInterfaceController subclass), implement the following method:

- (void)table:(WKInterfaceTable *)table didSelectRowAtIndex:(NSInteger)rowIndex
{
    NSLog(@"You tapped the row at index %d", rowIndex);
}

WKInterfaceTable, WKInterfaceButton and action methods

2 Answers2