Avoid crashing when FlutterImageView is resized to zero dimension (#27946)

Author: eggfly

shell/platform/android/io/flutter/embedding/android/FlutterImageView.java

@@ -20,9 +20,11 @@
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
+import io.flutter.Log;
 import io.flutter.embedding.engine.renderer.FlutterRenderer;
 import io.flutter.embedding.engine.renderer.RenderSurface;
 import java.nio.ByteBuffer;
+import java.util.Locale;
 
 /**
  * Paints a Flutter UI provided by an {@link android.media.ImageReader} onto a {@link
@@ -38,11 +40,17 @@
  */
 @TargetApi(19)
 public class FlutterImageView extends View implements RenderSurface {
+  private static final String TAG = "FlutterImageView";
+
   @NonNull private ImageReader imageReader;
   @Nullable private Image currentImage;
   @Nullable private Bitmap currentBitmap;
   @Nullable private FlutterRenderer flutterRenderer;
 
+  public ImageReader getImageReader() {
+    return imageReader;
+  }
+
   public enum SurfaceKind {
     /** Displays the background canvas. */
     background,
@@ -86,9 +94,21 @@ private void init() {
     setAlpha(0.0f);
   }
 
+  private static void logW(String format, Object... args) {
+    Log.w(TAG, String.format(Locale.US, format, args));
+  }
+
   @TargetApi(19)
   @NonNull
   private static ImageReader createImageReader(int width, int height) {
+    if (width <= 0) {
+      logW("ImageReader width must be greater than 0, but given width=%d, set width=1", width);
+      width = 1;
+    }
+    if (height <= 0) {
+      logW("ImageReader height must be greater than 0, but given height=%d, set height=1", height);
+      height = 1;
+    }
     if (android.os.Build.VERSION.SDK_INT >= 29) {
       return ImageReader.newInstance(
           width,

shell/platform/android/test/io/flutter/embedding/android/FlutterViewTest.java

@@ -734,6 +734,31 @@ public void flutterImageView_detachFromRendererClosesPreviousImage() {
     verify(mockImage, times(3)).close();
   }
 
+  @Test
+  public void flutterImageView_workaroundWithOnePixelWhenResizeWithZero() {
+    final ImageReader mockReader = mock(ImageReader.class);
+    when(mockReader.getMaxImages()).thenReturn(2);
+
+    final FlutterImageView imageView =
+        spy(
+            new FlutterImageView(
+                RuntimeEnvironment.application,
+                mockReader,
+                FlutterImageView.SurfaceKind.background));
+
+    final FlutterJNI jni = mock(FlutterJNI.class);
+    imageView.attachToRenderer(new FlutterRenderer(jni));
+
+    final Image mockImage = mock(Image.class);
+    when(mockReader.acquireLatestImage()).thenReturn(mockImage);
+
+    final int incorrectWidth = 0;
+    final int incorrectHeight = -100;
+    imageView.resizeIfNeeded(incorrectWidth, incorrectHeight);
+    assertEquals(1, imageView.getImageReader().getWidth());
+    assertEquals(1, imageView.getImageReader().getHeight());
+  }
+
   @Test
   public void flutterSurfaceView_GathersTransparentRegion() {
     final Region mockRegion = mock(Region.class);