Java Android App Development Course, Image Processing - Glide Library

Image processing is an essential part of Android app development. In particular, the Glide library plays a significant role in efficiently loading and displaying images of various resolutions. In this tutorial, we will learn how to load and cache images using the Glide library.

1. Overview of the Glide Library

Glide is an image loading and caching library developed by Google, capable of fetching images from complex URLs or loading images from the local file system. Glide provides powerful capabilities to handle edge cases and various image formats, making it very useful in image processing applications.

2. Setting Up Glide

To use Glide, you first need to add the library to your Gradle file. Open the build.gradle file of your project in Android Studio and add the following dependencies.

dependencies {
    implementation 'com.github.bumptech.glide:glide:4.12.0'
    annotationProcessor 'com.github.bumptech.glide:compiler:4.12.0'
}

After adding the above content, synchronize the Gradle file to include the Glide library in your project.

3. Basic Usage of Glide

The usage of Glide is very simple. By default, you can load an image into an ImageView like this.

import com.bumptech.glide.Glide;

ImageView imageView = findViewById(R.id.imageView);
Glide.with(this)
     .load("https://example.com/image.jpg")
     .into(imageView);

In the above code, Glide.with(this) retrieves the context of the current activity, and the .load() method is used to fetch the image. Finally, the .into() method is used to set the image into the ImageView.

4. Image Loading Options in Glide

Glide offers various image loading options. Here are some common options used frequently.

4.1. Resizing Images

You can resize the image to your desired dimensions while loading. The example below shows how to load an image resized to 100×100 pixels.

Glide.with(this)
     .load("https://example.com/image.jpg")
     .override(100, 100)
     .into(imageView);

4.2. Setting Placeholder and Error Images

You can set a placeholder image to display while the image is loading or an error image to show in case of a loading failure.

Glide.with(this)
     .load("https://example.com/image.jpg")
     .placeholder(R.drawable.placeholder)
     .error(R.drawable.error)
     .into(imageView);

4.3. Creating Circular Images

If you want to create a circular image using Glide, refer to the following example.

import com.bumptech.glide.load.resource.bitmap.CircleCrop;

Glide.with(this)
     .load("https://example.com/profile.jpg")
     .transform(new CircleCrop())
     .into(imageView);

5. Caching Mechanism of Glide

Glide automatically performs caching when loading images. It uses both memory and disk caching to optimize performance.

5.1. Memory Cache

Memory cache helps the application quickly access images within the range of memory. This reduces the response time while loading images.

5.2. Disk Cache

Disk cache allows images to be saved on the device’s storage media, enabling faster loading for subsequent identical requests. This helps reduce data usage and improve performance.

6. Advanced Features of Glide

In addition to basic image loading, Glide provides various advanced features. Here are a few of them.

6.1. GIF Support

Glide allows you to easily load GIF images. The code below demonstrates how to set a GIF image in an ImageView.

Glide.with(this)
     .asGif()
     .load("https://example.com/animation.gif")
     .into(imageView);

6.2. Implementing a Progress Bar

You can display a progress bar while the image is loading using Glide. The RequestListener of Glide can be used to handle loading states.

Glide.with(this)
     .load("https://example.com/image.jpg")
     .listener(new RequestListener() {
         @Override
         public boolean onLoadFailed(@Nullable GlideException e, Object model, Target target, boolean isFirstResource) {
             // Handle load failure
             return false;
         }

         @Override
         public boolean onResourceReady(Drawable resource, Object model, Target target, DataSource dataSource, boolean isFirstResource) {
             // Handle successful image load
             return false;
         }
     })
     .into(imageView);

6.3. Parameter Tuning

Glide provides capabilities to manage images more precisely using additional parameters. For example, you can preprocess each image before loading them.

Glide.with(this)
     .load("https://example.com/image.jpg")
     .apply(RequestOptions.bitmapTransform(new BlurTransformation(25, 3)))
     .into(imageView);

Conclusion

Glide is an excellent tool that makes image processing simple and efficient in Android applications. By utilizing memory and disk cache options, you can improve the overall performance of your app, while supporting various image formats and transformation features. We hope you learned how to use Glide through this tutorial and can apply it to your apps.

Additionally, you can find the documentation for Glide here.

Java Android App Development Course, Image Processing – Glide Library