Android Jetpack Compose - Implement Different Types of Styles and Customization to Text

Jetpack Compose is a new UI toolkit from Google used to create native Android UI. It speeds up and simplifies UI development using less code, Kotlin APIs, and powerful tools.

Prerequisites:

1. Familiar with Kotlin and OOP Concepts as well
2. Basic understanding of Jetpack Compose
3. Android Studio Canary Version

A sample video is given below to get an idea about what we are going to do in this article.

Step-by-Step Implementation

Step 1: Create a New Project in Android Studio

To create a new project in Android Studio using Jetpack Compose please refer to: How to Create a New Project in Android Studio Canary Version with Jetpack Compose.

Step 2: Let’s first review the build.gradle(module level)

Now go to the module-level build.gradle file & check on dependencies. If any of the dependencies are missing add them from the below snippet. Remember to double-check this file that everything is included. If something is missing just add those blocks from the below snippets.

plugins {
 id 'com.android.application'
 id 'org.jetbrains.kotlin.android'
}

android {
 namespace 'com.example.textvariant'
 compileSdk 33

 defaultConfig {
 applicationId "com.example.textvariant"
 minSdk 21
 targetSdk 33
 versionCode 1
 versionName "1.0"

 testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
 vectorDrawables {
 useSupportLibrary true
 }
 }

 buildTypes {
 release {
 minifyEnabled false
 proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
 }
 }
 compileOptions {
 sourceCompatibility JavaVersion.VERSION_1_8
 targetCompatibility JavaVersion.VERSION_1_8
 }
 kotlinOptions {
 jvmTarget = '1.8'
 }
 buildFeatures {
 compose true
 }
 composeOptions {
 kotlinCompilerExtensionVersion compose_version
 }
 packagingOptions {
 resources {
 excludes += '/META-INF/{AL2.0,LGPL2.1}'
 }
 }
}

dependencies {

 implementation 'androidx.core:core-ktx:1.9.0'
 implementation "androidx.compose.ui:ui:$compose_version"
 implementation "androidx.compose.material:material:$compose_version"
 implementation "androidx.compose.ui:ui-tooling-preview:$compose_version"
 implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.5.1'
 implementation 'androidx.activity:activity-compose:1.6.1'


 implementation 'androidx.appcompat:appcompat:1.5.1'
 testImplementation 'junit:junit:4.13.2'
 androidTestImplementation 'androidx.test.ext:junit:1.1.4'
 androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.0'
 androidTestImplementation "androidx.compose.ui:ui-test-junit4:$compose_version"
 debugImplementation "androidx.compose.ui:ui-tooling:$compose_version"
 debugImplementation "androidx.compose.ui:ui-test-manifest:$compose_version"
 implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.0-RC"
 implementation'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.0'

}

Step 3: Review the build.gradle(project level)

Now go to the project-level build.gradle file & check on the buildscript code block. If any of the requirements are missing then add them from the below snippet.

buildscript {
 ext {
 kotlin_version = '1.0.1-2'
 compose_version = '1.1.0-rc01'
 }
 // Requirements
 repositories {
 google()
 mavenCentral()
 }
 dependencies {
 classpath "org.jetbrains.kotlin:kotlin-android-extensions:$kotlin_version" //dependency
 }
}// Top-level build file where you can add configuration options common to all sub-projects/modules.

plugins {
 id 'com.android.application' version '7.3.0-alpha01' apply false
 id 'com.android.library' version '7.3.0-alpha01' apply false
 id 'org.jetbrains.kotlin.android' version '1.6.0' apply false
}

Step 4: Rename MainActivity.kt to CustomTextActivity.kt

We can put the same code to MainActivity.kt as well, but it's a good idea to create or rename the file to reflect its role. Once you change this we also need to modify the AndroidManifest.xml activity tag to the renamed file since the default is MainActivity. You can refer to the below snippet of AndroidManifest.xml.

Step 5: Importing necessary modules

It's good practice to import only the necessary modules rather than importing all the modules and using only a few. 

Step 6: Implement AppCompatActivity() to class CustomTextActivity

SetContent() block will set the activity component function as the root view of the all activities that we declared. The separate composable functions for each text variant will have their respective logic.

Step 7: Create composable functions for making unique customizations of texts in different styles

Before we go, there are a few things you should be aware of:

• Composable annotations: The @Composable annotation is used to indicate a Composable function. Composable functions can only be invoked from other composable functions. Consider composable functions to be comparable to Lego blocks in that each composable function is constructed up of smaller composable functions.
  • Reacting to state changes is the core behavior of Compose. We use the state composable that is used for holding a state value in this composable for representing the current value scale(for zooming in the image) & translation(for panning across the image). Any composable that reads the value of the counter will be recomposed any time the value changes.
  • Row: The row is composable and places its children horizontally. It is comparable to a LinearLayout in that it is horizontally oriented. Additionally, we add a modifier to the row
  • Column: The column is composable and places its children vertically. It is comparable to a LinearLayout in that it is vertically oriented. Additionally, we add a modifier to the column.
  • Modifier:  Modifiers serve as examples of the decorator pattern and are used to alter the composable to which they are applied. In this case, we use the Modifier to set the Column up to take up the whole available width and height using the Modifier.fillMaxSize() modifier.
  • Surface: It's typically used to modify the backdrop color, and add elevation, clip, or form to its children's composable.
  • Text: Display text on the screen. It allows you to customize its appearance using the style property. 
    • TextStyle: TextStyle allows you to specify styling configuration for a `Text` composable. Types of props TextStyle takes in are given below
      1. color => can change the text color
      2. fontSize => can change the font size of text
      3. fontWeight => can change the font weight of the text
      4. fontStyle => can change font style(eg: Italic)
      5. fontFamily => can change font family(eg:Serif)
      6. textDecoration => can change look of text(eg:underlined text)
      7. shadow => gives shadow to the text
      8. textAlign => alignment of text
      9. textIndent => gives indentation to text
      10. lineHeight => height of text

Step 7: If you want to preview your CustomTextActivity then continue else you can skip it

Significance of @preview and @composable annotations :

• Instead of needing to download the app to an Android device or emulator, Android Studio allows you to preview your composable functions within the IDE itself. This is an excellent feature since it allows you to preview every one of your components—or composable functions—right inside the IDE
  • The composable function cannot accept any parameters, which is the fundamental constraint. You may just include your component within another composable function that doesn't take any arguments and calls your composable function with the necessary parameters
  • Also, don't forget to annotate it with @Preview & @Composable annotations

Step 8: Complete Code Snippet

Output:

As we can see with the help of jetpack compose we can make different customization with their own unique style of formatting.