In this article, the number of taps that user does in a short span of time on a particular view is counted, It can be used for adding different response with different taps. For example one tap on the word will show the meaning of the word while double tap will show its synonyms in a dictionary app. Below is an example in which the number of taps done in textview is shown as a toast.
Step 1: Create an Empty activity in Android Studio. To create one, follow this article- https://www.geeksforgeeks.org/android-how-to-create-start-a-new-project-in-android-studio/. Check if the primary language selected is Kotlin.
Step 2: No change is done in activity_main.xml. Since already a textview is present so the response for the triple tap is added with it.
<? xml version = "1.0" encoding = "utf-8" ?>
android:layout_width = "match_parent"
android:layout_height = "match_parent"
tools:context = ".MainActivity" >
< TextView
android:id = "@+id/tv1"
android:layout_width = "wrap_content"
android:layout_height = "wrap_content"
android:layout_centerInParent = "true"
android:text = "Click Here"
/>
</ RelativeLayout >
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Step 3: In this step add the onTouchListenter with the view. Here in the listener initialize a variable to 0 which will keep the count of taps user has done. Every time user taps in a short span of time the variable value is increased by one. Below is the code for the MainActivity.kt class.
package org.geeksforgeeks.tripletap
import android.os.Bundle
import android.os.Handler
import android.view.MotionEvent
import android.view.View
import android.view.ViewConfiguration
import android.widget.Button
import android.widget.RelativeLayout
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super .onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// Declaring Text View from the Layout file
val tvv = findViewById<TextView>(R.id.tv)
// Implementing onTouchListener on our Text View
tvv.setOnTouchListener(object : View.OnTouchListener {
// Handler to handle the number of clicks
var handler: Handler = Handler()
var numberOfTaps = 0
var lastTapTimeMs: Long = 0
var touchDownMs: Long = 0
override fun onTouch(v: View?, event: MotionEvent): Boolean {
when (event.action) {
MotionEvent.ACTION_DOWN -> touchDownMs = System.currentTimeMillis()
MotionEvent.ACTION_UP -> {
// Handle the numberOfTaps
handler.removeCallbacksAndMessages( null )
if (System.currentTimeMillis() - touchDownMs
> ViewConfiguration.getTapTimeout()) {
//it was not a tap
numberOfTaps = 0
lastTapTimeMs = 0
}
if (numberOfTaps > 0
&& System.currentTimeMillis() - lastTapTimeMs
< ViewConfiguration.getDoubleTapTimeout()
) {
// if the view was clicked once
numberOfTaps += 1
} else {
// if the view was never clicked
numberOfTaps = 1
}
lastTapTimeMs = System.currentTimeMillis()
// Handle Multiple Taps on the View////////////////////////////////
handler.postDelayed(Runnable {
// Toast the number of Taps of current User Event
Toast.makeText(applicationContext, "$numberOfTaps Clicks" ,
Toast.LENGTH_SHORT)
.show()
}, ViewConfiguration.getDoubleTapTimeout().toLong())
/////////////////////////////////////////////////////////////////////
}
}
return true
}
})
}
} |