In this article, we will learn how to create android ImageSwitcher programmatically in Kotlin. We will go through various steps that explains how to create ImageSwitcher and add it in kotlin file, use different attributes to customise it etc. in any android application. For example, how to set text in ImageSwitcher programmatically, how to set id of ImageSwitcher, how to capitalise text of ImageSwitcher dynamically etc. We will get answer to all such questions in this post.
Learn to use Different Attributes of ImageSwitcher in XML File to Customize it.
Output
Getting Started
We can define android ImageSwitcher widget as below –
ImageSwitcher is a widget that are used to flip between different images with some animations on it.
Now, how do we use ImageSwitcher in android application ?
Creating New Project
Follow steps below to create any android project in Kotlin –
Step | Description |
---|---|
1. | Open Android Studio (Ignore if already done). |
2. | Go to File => New => New Project. This will open a new window. Then, under Phone and Tablet section, select Empty Activity. Then, click Next. |
3. | In next screen, select project name as DynamicImageSwitcher. Then, fill other required details. |
4. | Then, clicking on Finish button creates new project. |
Newbie in Android ?
Some very important concepts (Recommended to learn before you move ahead)
Before we move ahead, we need to setup for viewBinding to access ImageSwitcher in Kotlin file without using findViewById() method.
Setup ViewBinding
Add viewBinding true in app/build.gradle file.
android { // OTHER CODE... buildFeatures { viewBinding true } }
Now, set content in activity using view binding.
Open MainActivity.kt file and write below code in it.
class MainActivity : AppCompatActivity() { private lateinit var binding: ActivityMainBinding override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) binding = ActivityMainBinding.inflate(layoutInflater) val view = binding.root setContentView(view) } }
Now, we can access view in Kotlin file without using findViewById() method.
Since we have a new project, we will modify the xml and class file to use ImageSwitcher programmatically in kotlin. Please follow the steps below.
1. Download Drawable Resources
We need drawable images for this tutorial. So, we can click here to download all the images required> for this tutorial.
2. Modify Values Folder
Open res/values/strings.xml file. Add below code into it.
<resources> <string name="app_name">DynamicImageSwitcher</string> <string name="next">Next</string> </resources>
Other values folders have not been changed. So, we are not going to mention it here.
3. Modify Layout Folder
Open res/layout/activity_main.xml file. Add below code into it.
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <Button android:id="@+id/btnNext" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_marginTop="40dp" android:text="@string/next"/> <LinearLayout android:id="@+id/rootContainer" android:layout_width="match_parent" android:layout_height="wrap_content" android:gravity="center" android:orientation="vertical"> </LinearLayout> </LinearLayout>
Note that LinearLayout has id rootContainer. In Kotlin file, we will create ImageSwitcher Dynamically and add it into this LinearLayout having id rootContainer.
4. Create Android ImageSwitcher programmatically in Kotlin
Open src/main/java/com.tutorialwing.dynamicimageswitcher/MainActivity.kt file. Then, add below code into it.
package com.tutorialwing.dynamicimageswitcher import androidx.appcompat.app.AppCompatActivity import android.os.Bundle import android.view.animation.AnimationUtils import android.widget.FrameLayout import android.widget.ImageSwitcher import android.widget.ImageView import android.widget.LinearLayout import com.tutorialwing.dynamicimageswitcher.databinding.ActivityMainBinding class MainActivity : AppCompatActivity() { private lateinit var binding: ActivityMainBinding private var nameList = intArrayOf( R.drawable.chinchilla, R.drawable.cod, R.drawable.crane, R.drawable.crocodile, R.drawable.deer, R.drawable.dog, R.drawable.dolphin, R.drawable.dove, R.drawable.eel, R.drawable.elephant, R.drawable.emu, R.drawable.fly ) private var index = 0 override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) binding = ActivityMainBinding.inflate(layoutInflater) val view = binding.root setContentView(view) setupImageSwitcher() } private fun setupImageSwitcher() { val imageSwitcher = ImageSwitcher(this) val layoutParams = LinearLayout.LayoutParams(900, 900) layoutParams.setMargins(20, 20, 20, 20) imageSwitcher.layoutParams = layoutParams imageSwitcher.setFactory { val imageView = ImageView(applicationContext) imageView.scaleType = ImageView.ScaleType.FIT_CENTER imageView.layoutParams = FrameLayout.LayoutParams( FrameLayout.LayoutParams.WRAP_CONTENT, FrameLayout.LayoutParams.WRAP_CONTENT ) imageView } imageSwitcher.setImageResource(nameList[index]) val inAnim = AnimationUtils.loadAnimation(this, android.R.anim.slide_in_left) imageSwitcher.inAnimation = inAnim val out = AnimationUtils.loadAnimation(this, android.R.anim.slide_out_right) imageSwitcher.outAnimation = out val linearLayout = findViewById<LinearLayout>(R.id.rootContainer) linearLayout?.addView(imageSwitcher) binding.btnNext.setOnClickListener { index = if (++index < nameList.size) index else 0 imageSwitcher.setImageResource(nameList[index]) } } }
We have created imageSwitcher programmatically in kotlin file (i.e. in MainActivity.kt file). Then, we have set layout params, margins etc. in it. Then, we have set factory of imageSwitcher to provide views between which imageSwitcher will flip. Then, we will set animation to apply when image disappears/appears from/on the screen. After that, we have added this imageSwitcher in linearLayout having id rootContainer. At last, we have accessed button and set click listener to show next image in the imageSwitcher.
Finally, when you run the application, you will get output as shown above.
Now, Let’s check how to use different attributes of ImageSwitcher to customize it dynamically –
Set Id of ImageSwitcher
Follow steps below to set id of ImageSwitcher programmatically –
- Create ids.xml file in res/values folder. Then, add below code into it –
<?xml version="1.0" encoding="utf-8"?> <resources> <item type="id" name="imageSwitcher_ID" /> </resources>
-
Now, we can set id of ImageSwitcher dynamically, in MainActivity.kt file, as –
imageSwitcher.id = R.id.imageSwitcher_ID // ImageSwitcher
Here, we have set id of ImageSwitcher using property access syntax – imageSwitcher.id
Learn to Set ID of ImageSwitcher Using XML Attribute
Set Width and Height of ImageSwitcher
We use layoutParams to set width and height of any View programmatically. In this article, we have added ImageSwitcher in LinearLayout. So, we will define LayoutParams as below –
imageSwitcher.layoutParams = LinearLayout.LayoutParams( ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT )
Here, we have set width and height as WRAP_CONTENT. Some of possible values for width and height are –
- WRAP_CONTENT: Sets value of width or height depending on text inside it.
- MATCH_PARENT: Sets value of width of height depending on width or height of parent layout . i.e. width or height of ImageSwitcher will be same as width or height of parent layout.
- Fixed Value: Sets width or height as per value provided.
Learn to Set Width or Height of ImageSwitcher Using XML Attribute
Set Padding of ImageSwitcher
Follow steps below to set padding of ImageSwitcher Dynamically –
- If there is no dimens.xml file, create dimens.xml file in res/values folder. Then, add below code in it –
<?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="text_padding">16dp</dimen> </resources>
- Now, we can set padding of ImageSwitcher dynamically, in MainActivity.kt file, as –
val padding = resources.getDimension(R.dimen.text_padding).toInt() imageSwitcher.setPadding(padding, padding, padding, padding)
Here, we have accessed dimension defined in dimens.xml using getDimension() method. Then, set padding of ImageSwitcher using setPadding() method.
Learn to Set Padding of ImageSwitcher Using XML Attribute
Set Margin of ImageSwitcher
Follow steps below to set margin of ImageSwitcher Dynamically –
- If there is no dimens.xml file, create dimens.xml file in res/values folder. Then, add below code in it –
<?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="text_margin">16dp</dimen> </resources>
- Now, we can set margin of ImageSwitcher dynamically, in MainActivity.kt file, as –
val margin = resources.getDimension(R.dimen.text_margin).toInt() val layoutParams = LinearLayout.LayoutParams( ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT ) layoutParams.setMargins(margin, margin, margin, margin) imageSwitcher.layoutParams = layoutParams
Here, we have accessed dimension defined in dimens.xml using getDimension() method. Then, we have defined layoutParams, set margin to layoutParams. After that, set layoutParams to ImageSwitcher.
Learn to Set Margin of ImageSwitcher Using XML Attribute
Set Background of ImageSwitcher
Follow steps below to set background of ImageSwitcher programmatically –
- If there is no colors.xml file, create colors.xml file in res/values folder. Then, add below code in it –
<?xml version="1.0" encoding="utf-8"?> <resources> <color name="purple_200">#FFBB86FC</color> </resources>
- Now, we can set background of ImageSwitcher dynamically, in MainActivity.kt file, as –
val color = ContextCompat.getColor(this, R.color.purple_200) imageSwitcher.setBackgroundColor(color)
Here, we used setBackgroundColor() method to set background color in imageSwitcher.
Learn to Set Background of ImageSwitcher Using XML Attribute
Set Visibility of ImageSwitcher
We can set visibility of ImageSwitcher programmatically as –
imageSwitcher.visibility = View.VISIBLE
Here, we have set visibility of ImageSwitcher using imageSwitcher.visibility attribute. Visibility can be of three types – gone, visible and invisible.
Learn to Set Visibility of ImageSwitcher Using XML Attribute
That’s end of tutorial on ImageSwitcher Programmatically in Kotlin With Example.
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