Image Compression Plugin

This plugin provides functionality to compress images selected for upload directly on the device, significantly reducing bandwidth usage and upload times.

Setup and Configuration

1. Enable Plugin: Ensure ImageCompressionPlugin is listed in the plugins.enabled property in app/src/main/assets/swv.properties.

   # In swv.properties
   plugins.enabled=ImageCompressionPlugin,...
   

2. Configure Quality: The default compression quality is 80 (out of 100). To change this, you currently modify the static initializer block in app/src/main/java/mgks/os/swv/plugins/ImageCompressionPlugin.java.

   // In ImageCompressionPlugin.java
   static {
       Map<String, Object> config = new HashMap<>();
       config.put("quality", 75); // Change default quality here
       PluginManager.registerPlugin(new ImageCompressionPlugin(), config);
   }
   

Usage

The plugin is designed to be used from JavaScript, typically after a user has selected an image file for upload and you have its base64 representation.

Compressing an Image from JavaScript

The plugin injects a window.ImageCompressor object into your web page.

// Assume 'originalBase64' is the base64 string of the image you want to compress
// (e.g., from a FileReader result)

if (window.ImageCompressor) {
  // The compress function takes the original base64 string and a callback
  window.ImageCompressor.compress(originalBase64, function(compressedBase64) {
    if (compressedBase64) {
      console.log('Compression successful!');
      console.log('Original size:', originalBase64.length);
      console.log('Compressed size:', compressedBase64.length);
      
      // Now you can upload the 'compressedBase64' string to your server
      uploadImage(compressedBase64);

    } else {
      console.error('Compression failed.');
    }
  });
}

This workflow allows you to seamlessly compress images on the client-side before they are transmitted, saving data for both the user and your server.