feat: Add GitHub Actions workflow for model export and enhance DeepLabV3 Android demo with improved segmentation visualization and inference time display.

Author: kirklandsign

dl3/android/DeepLabV3Demo/app/src/main/java/org/pytorch/executorchexamples/dl3/MainActivity.java

@@ -33,7 +33,11 @@
 import androidx.core.content.ContextCompat;
 
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
 import java.util.ArrayList;
 import org.pytorch.executorch.EValue;
 import org.pytorch.executorch.Module;
@@ -42,13 +46,19 @@
 public class MainActivity extends Activity implements Runnable {
   private ImageView mImageView;
   private Button mButtonXnnpack;
+  private Button mDownloadModelButton;
   private ProgressBar mProgressBar;
   private android.widget.TextView mInferenceTimeText;
+  private android.widget.TextView mModelStatusText;
   private Bitmap mBitmap = null;
   private Module mModule = null;
   private String mImagename = "corgi.jpeg";
   private long mInferenceTime = 0;
 
+  // Model download configuration
+  private static final String MODEL_URL = "https://example.com/dl3_xnnpack_fp32.pte"; // TODO: Replace with actual URL
+  private static final String MODEL_PATH = "/data/local/tmp/dl3_xnnpack_fp32.pte";
+
   private final ArrayList<String> mImageFiles = new ArrayList<>();
 
   private int mCurrentImageIndex = 0;
@@ -221,15 +231,21 @@ protected void onCreate(Bundle savedInstanceState) {
     // Initialize all views first!
     mImageView = findViewById(R.id.imageView);
     mButtonXnnpack = findViewById(R.id.xnnpackButton);
+    mDownloadModelButton = findViewById(R.id.downloadModelButton);
     mProgressBar = findViewById(R.id.progressBar);
     mInferenceTimeText = findViewById(R.id.inferenceTimeText);
+    mModelStatusText = findViewById(R.id.modelStatusText);
 
     populateImagePathFromAssets();
     showImage();
 
-    mModule = Module.load("/data/local/tmp/dl3_xnnpack_fp32.pte");
+    // Check if model exists and load it, otherwise show download button
+    loadModelOrShowDownloadButton();
     mImageView.setImageBitmap(mBitmap);
 
+    // Download button click handler
+    mDownloadModelButton.setOnClickListener(v -> downloadModel());
+
     final Button buttonNext = findViewById(R.id.nextButton);
     buttonNext.setOnClickListener(
         new View.OnClickListener() {
@@ -372,4 +388,75 @@ private int blendColors(int background, int foreground, float alpha) {
     int b = (int) (bgB * (1 - alpha) + fgB * alpha);
     return 0xFF000000 | (r << 16) | (g << 8) | b;
   }
+
+  private void loadModelOrShowDownloadButton() {
+    File modelFile = new File(MODEL_PATH);
+    if (modelFile.exists()) {
+      try {
+        mModule = Module.load(MODEL_PATH);
+        mButtonXnnpack.setEnabled(true);
+        mDownloadModelButton.setVisibility(View.GONE);
+        mModelStatusText.setText("Model loaded");
+        mModelStatusText.setVisibility(View.VISIBLE);
+      } catch (Exception e) {
+        Log.e("MainActivity", "Failed to load model", e);
+        showUIMessage(this, "Failed to load model: " + e.getMessage());
+        mButtonXnnpack.setEnabled(false);
+        mDownloadModelButton.setVisibility(View.VISIBLE);
+        mModelStatusText.setText("Model load failed");
+        mModelStatusText.setVisibility(View.VISIBLE);
+      }
+    } else {
+      mButtonXnnpack.setEnabled(false);
+      mDownloadModelButton.setVisibility(View.VISIBLE);
+      mModelStatusText.setText("Model not found");
+      mModelStatusText.setVisibility(View.VISIBLE);
+    }
+  }
+
+  private void downloadModel() {
+    mDownloadModelButton.setEnabled(false);
+    mDownloadModelButton.setText(R.string.downloading);
+    mProgressBar.setVisibility(View.VISIBLE);
+    mModelStatusText.setText("Downloading...");
+
+    new Thread(() -> {
+      try {
+        URL url = new URL(MODEL_URL);
+        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+        connection.setRequestMethod("GET");
+        connection.connect();
+
+        if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
+          throw new IOException("Server returned HTTP " + connection.getResponseCode());
+        }
+
+        File outputFile = new File(MODEL_PATH);
+        try (InputStream input = connection.getInputStream();
+             FileOutputStream output = new FileOutputStream(outputFile)) {
+          byte[] buffer = new byte[4096];
+          int bytesRead;
+          while ((bytesRead = input.read(buffer)) != -1) {
+            output.write(buffer, 0, bytesRead);
+          }
+        }
+
+        runOnUiThread(() -> {
+          mDownloadModelButton.setText(R.string.download_model);
+          mProgressBar.setVisibility(View.INVISIBLE);
+          loadModelOrShowDownloadButton();
+          showUIMessage(this, "Model downloaded successfully!");
+        });
+      } catch (Exception e) {
+        Log.e("MainActivity", "Failed to download model", e);
+        runOnUiThread(() -> {
+          mDownloadModelButton.setEnabled(true);
+          mDownloadModelButton.setText(R.string.download_model);
+          mProgressBar.setVisibility(View.INVISIBLE);
+          mModelStatusText.setText("Download failed");
+          showUIMessage(this, "Download failed: " + e.getMessage());
+        });
+      }
+    }).start();
+  }
 }