A SeekBar is an extension of ProgressBar that adds a draggable thumb. The user can touch the thumb and drag left or right to set the current progress level or use the arrow keys. SeekBar is a useful user interface element in Android that allows the selection of integer values using a natural user interface. An example of SeekBar is your device’s brightness control and volume control. But did you knew a SeekBar could be implemented as an Unlock Slide Bar? Through this article, we want to share with you how one can implement an Unlock Slide Bar using a SeekBar.
Difference Between a SeekBar and a ProgressBar
SeekBar has the same attributes as a ProgressBar. But the only difference is the user determines the progress by moving a slider (thumb) in SeekBar. To add a SeekBar to a layout (XML) file, you can use the <SeekBar> element. Below is an example of the Unlock Slide Bar.
Where can one use it?
- To unlock a screen, unlock an activity, go to an activity (what we discussed in this article).
- Using a similar concept to build Games.
- Confirming a checkout at Payment Gateways.
- For Switching off the Alarms.
A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going to implement this project using the Kotlin language.
Please refer to the following points that define the module for the application that we implemented:
- The application has 2 Activities, MainActivity and MainActivity2, both have respective layout files activity_main and activity_main2.
- The SeekBar is present in the First Activity, i.e., declared in the activity_main file.
- We have programmed the SeekBar in such a way that when the user swipes it till the end, the user is taken to a new activity, i.e., MainActivity2. Else, the SeekBar sets its progress to 0 and displays a Toast message.
- A textView is provided in the First Activity to show the progress of the SeekBar in real-time.
To create a Slide-Bar in Android, we follow the following steps:
Step 1: Create a New Project
To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Kotlin as the programming language.
Step 2: Working with the activity_main.xml file
Now go to the activity_main.xml file which represents the UI of the application. Create a SeekBar and TextView as shown. Below is the code for the activity_main.xml file.
Step 3: Working with the MainActivity.kt file
Go to the MainActivity.kt file, and refer the following code. Below is the code for the MainActivity.kt file. Comments are added inside the code to understand the code in more detail.
Step 4: Create another activity
Create another activity with layout file by right-clicking on the app folder > New > Activity > Empty Activity. And refer to the following code. The only changes made to the activity_main2.xml file, no changes made to the MainActivity2.kt file. Below is the core for both activity_main2.xml and MainActivity2.kt file.