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Overview

RiveSMITrigger represents a trigger input in a Rive state machine. Triggers are one-time events that can cause state transitions when fired. Unlike boolean and number inputs which maintain state, triggers are momentary - they fire once and automatically reset. Inherits from RiveSMIInput.

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Methods

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fire

- (void)fire;
Fires the trigger, causing any associated state transitions to occur. The trigger automatically resets after being fired.

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Usage Example

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Basic Usage

// Get a trigger input from the state machine
RiveSMITrigger* clickTrigger = (RiveSMITrigger*)[stateMachine inputFromName:@"click"];

// Fire the trigger
[clickTrigger fire];

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Button Interaction

// Connect a button tap to a Rive trigger
- (IBAction)buttonTapped:(UIButton*)sender {
    RiveSMITrigger* buttonTrigger = (RiveSMITrigger*)[stateMachine inputFromName:@"onButtonTap"];
    [buttonTrigger fire];
}

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Multiple Triggers

// Initialize Rive view and get state machine
RiveStateMachineInstance* stateMachine = [riveView stateMachine:@"State Machine 1"];

// Get trigger inputs
RiveSMITrigger* startTrigger = (RiveSMITrigger*)[stateMachine inputFromName:@"start"];
RiveSMITrigger* stopTrigger = (RiveSMITrigger*)[stateMachine inputFromName:@"stop"];
RiveSMITrigger* resetTrigger = (RiveSMITrigger*)[stateMachine inputFromName:@"reset"];

// Fire triggers based on events
[startTrigger fire];  // Start animation

// Later...
[stopTrigger fire];   // Stop animation

// Later...
[resetTrigger fire];  // Reset to initial state

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Gesture Recognition

// Fire trigger on swipe gesture
- (void)handleSwipeGesture:(UISwipeGestureRecognizer*)gesture {
    RiveSMITrigger* swipeTrigger;
    
    if (gesture.direction == UISwipeGestureRecognizerDirectionLeft) {
        swipeTrigger = (RiveSMITrigger*)[stateMachine inputFromName:@"swipeLeft"];
    } else if (gesture.direction == UISwipeGestureRecognizerDirectionRight) {
        swipeTrigger = (RiveSMITrigger*)[stateMachine inputFromName:@"swipeRight"];
    }
    
    [swipeTrigger fire];
}

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Game Events

// Fire triggers based on game events
RiveSMITrigger* collectCoin = (RiveSMITrigger*)[stateMachine inputFromName:@"collectCoin"];
RiveSMITrigger* levelComplete = (RiveSMITrigger*)[stateMachine inputFromName:@"levelComplete"];
RiveSMITrigger* gameOver = (RiveSMITrigger*)[stateMachine inputFromName:@"gameOver"];

// When player collects a coin
[collectCoin fire];

// When level is completed
[levelComplete fire];

// When game ends
[gameOver fire];

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Type Checking

You can verify an input is a trigger before casting: 
RiveSMIInput* input = [stateMachine inputFromName:@"myInput"];

if ([input isTrigger]) {
    RiveSMITrigger* trigger = (RiveSMITrigger*)input;
    [trigger fire];
}

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Trigger vs Boolean

Use triggers for one-time events and booleans for persistent state: 
// Trigger - fires once
RiveSMITrigger* explosionTrigger = (RiveSMITrigger*)[stateMachine inputFromName:@"explode"];
[explosionTrigger fire];  // Plays explosion animation once

// Boolean - maintains state
RiveSMIBool* isExploded = (RiveSMIBool*)[stateMachine inputFromName:@"isExploded"];
[isExploded setValue:true];  // Keeps object in exploded state

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See Also