How can a Vue component click a button or check a checkbox to change tooltip text and button color using a function?

How can a Vue component click a button or check a checkbox to change tooltip text and button color using a function? In the following code, these actions are being handled by the handle() function, but the tooltip text and button color are not being updated.

Any help would be greatly appreciated.

The Vue component:

<template>
  <div class="text-center">
    <b-button v-bind:v-b-tooltip.hover.right=tooltipText  v-bind:variant=color  @click="handler(state)">

        

    </b-button>  
  </div>
</template>

<script>

import EventBus from '../eventBus.js'
export default {

    props: ['username', 'checkbox1'],

    data() {
      return {
         tooltipText: null,
         color: null,
         user: null, 
         state: null,
         user: this.username
     }      
},

methods: {


    handler(bool) {

        if (!this.state == null){
        this.state = !this.state
        }

        if (!this.bool){

        EventBus.$emit('handleUser', this.user)

        this.color = 'outline-sucess'

        this.state = false

        this.tooltipText = 'block'

        return

        } else {

        EventBus.$emit('handleUser', this.user)

        this.color = 'outline-danger'

        this.tooltipText = 'unblock'

        this.state = true

        return

        }

    },

},

created() {
    this.handler(this.checkbox1);
  },


  watch: {
    checkbox1() {
        this.handler(this.checkbox1)
    }
 },

} 

</script>
<style scoped>

.active {
    color: red;
}
</style>