Added auto exposure implementations for Android and iOS

Author: BeMacized

packages/camera/camera/CHANGELOG.md

@@ -1,3 +1,11 @@
+## 0.6.4
+
+* Adds auto exposure support for Android and iOS implementations.
+
+## 0.6.3+1
+
+* Fixes flash & torch modes not working on some Android devices.
+
 ## 0.6.3
 
 * Adds torch mode as a flash mode for Android and iOS implementations.

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/Camera.java

@@ -4,6 +4,7 @@
 import androidx.annotation.Nullable;
 import io.flutter.plugin.common.BinaryMessenger;
 import io.flutter.plugin.common.MethodChannel;
+import io.flutter.plugins.camera.types.ExposureMode;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -20,13 +21,23 @@ enum EventType {
     channel = new MethodChannel(messenger, "flutter.io/cameraPlugin/camera" + cameraId);
   }
 
-  void sendCameraInitializedEvent(Integer previewWidth, Integer previewHeight) {
+  void sendCameraInitializedEvent(
+      Integer previewWidth,
+      Integer previewHeight,
+      ExposureMode exposureMode,
+      Boolean exposurePointSupported) {
+    assert (previewWidth != null);
+    assert (previewHeight != null);
+    assert (exposureMode != null);
+    assert (exposurePointSupported != null);
     this.send(
         EventType.INITIALIZED,
         new HashMap<String, Object>() {
           {
-            if (previewWidth != null) put("previewWidth", previewWidth.doubleValue());
-            if (previewHeight != null) put("previewHeight", previewHeight.doubleValue());
+            put("previewWidth", previewWidth.doubleValue());
+            put("previewHeight", previewHeight.doubleValue());
+            put("exposureMode", exposureMode.toString());
+            put("exposurePointSupported", exposurePointSupported);
           }
         });
   }

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/DartMessenger.java

@@ -10,6 +10,7 @@
 import io.flutter.plugin.common.MethodChannel;
 import io.flutter.plugin.common.MethodChannel.Result;
 import io.flutter.plugins.camera.CameraPermissions.PermissionsRegistry;
+import io.flutter.plugins.camera.types.ExposureMode;
 import io.flutter.plugins.camera.types.FlashMode;
 import io.flutter.view.TextureRegistry;
 import java.util.HashMap;
@@ -138,6 +139,73 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull final Result result)
           }
           break;
         }
+      case "setExposureMode":
+        {
+          String modeStr = call.argument("mode");
+          ExposureMode mode = ExposureMode.getValueForString(modeStr);
+          if (mode == null) {
+            result.error("setExposureModeFailed", "Unknown exposure mode " + modeStr, null);
+            return;
+          }
+          try {
+            camera.setExposureMode(result, mode);
+          } catch (Exception e) {
+            handleException(e, result);
+          }
+          break;
+        }
+      case "setExposurePoint":
+        {
+          Boolean reset = call.argument("reset");
+          Double x = null;
+          Double y = null;
+          if (reset == null || !reset) {
+            x = call.argument("x");
+            y = call.argument("y");
+          }
+          try {
+            camera.setExposurePoint(result, x, y);
+          } catch (Exception e) {
+            handleException(e, result);
+          }
+          break;
+        }
+      case "getMinExposureOffset":
+        {
+          try {
+            result.success(camera.getMinExposureOffset());
+          } catch (Exception e) {
+            handleException(e, result);
+          }
+          break;
+        }
+      case "getMaxExposureOffset":
+        {
+          try {
+            result.success(camera.getMaxExposureOffset());
+          } catch (Exception e) {
+            handleException(e, result);
+          }
+          break;
+        }
+      case "getExposureOffsetStepSize":
+        {
+          try {
+            result.success(camera.getExposureOffsetStepSize());
+          } catch (Exception e) {
+            handleException(e, result);
+          }
+          break;
+        }
+      case "setExposureOffset":
+        {
+          try {
+            camera.setExposureOffset(result, call.argument("offset"));
+          } catch (Exception e) {
+            handleException(e, result);
+          }
+          break;
+        }
       case "startImageStream":
         {
           try {

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/MethodCallHandlerImpl.java

@@ -7,7 +7,9 @@ class PictureCaptureRequest {
 
   enum State {
     idle,
-    awaitingPreCapture,
+    focusing,
+    preCapture,
+    waitingPreCaptureReady,
     capturing,
     finished,
     error,

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/PictureCaptureRequest.java

@@ -0,0 +1,25 @@
+package io.flutter.plugins.camera.types;
+
+// Mirrors exposure_mode.dart
+public enum ExposureMode {
+  auto("auto"),
+  locked("locked");
+
+  private final String strValue;
+
+  ExposureMode(String strValue) {
+    this.strValue = strValue;
+  }
+
+  public static ExposureMode getValueForString(String modeStr) {
+    for (ExposureMode value : values()) {
+      if (value.strValue.equals(modeStr)) return value;
+    }
+    return null;
+  }
+
+  @Override
+  public String toString() {
+    return strValue;
+  }
+}

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/types/ExposureMode.java

@@ -2,16 +2,26 @@
 
 // Mirrors flash_mode.dart
 public enum FlashMode {
-  off,
-  auto,
-  always,
-  torch;
+  off("off"),
+  auto("auto"),
+  always("always"),
+  torch("torch");
+
+  private final String strValue;
+
+  FlashMode(String strValue) {
+    this.strValue = strValue;
+  }
 
   public static FlashMode getValueForString(String modeStr) {
-    try {
-      return valueOf(modeStr);
-    } catch (IllegalArgumentException | NullPointerException e) {
-      return null;
+    for (FlashMode value : values()) {
+      if (value.strValue.equals(modeStr)) return value;
     }
+    return null;
+  }
+
+  @Override
+  public String toString() {
+    return strValue;
   }
 }

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/types/FlashMode.java

@@ -58,14 +58,16 @@ public void sendCameraErrorEvent_includesErrorDescriptions() {
 
   @Test
   public void sendCameraInitializedEvent_includesPreviewSize() {
-    dartMessenger.sendCameraInitializedEvent(0, 0);
+    dartMessenger.sendCameraInitializedEvent(0, 0, ExposureMode.auto, true);
 
     List<ByteBuffer> sentMessages = fakeBinaryMessenger.getMessages();
     assertEquals(1, sentMessages.size());
     MethodCall call = decodeSentMessage(sentMessages.get(0));
     assertEquals("initialized", call.method);
     assertEquals(0, (double) call.argument("previewWidth"), 0);
     assertEquals(0, (double) call.argument("previewHeight"), 0);
+    assertEquals("ExposureMode auto", call.argument("exposureMode"), "auto");
+    assertEquals("exposurePointSupported", call.argument("exposurePointSupported"), true);
   }
 
   @Test

packages/camera/camera/android/src/test/java/io/flutter/plugins/camera/DartMessengerTest.java

@@ -20,11 +20,15 @@ public void state_is_idle_by_default() {
   @Test
   public void setState_sets_state() {
     PictureCaptureRequest req = new PictureCaptureRequest(null);
-    req.setState(PictureCaptureRequest.State.awaitingPreCapture);
+    req.setState(PictureCaptureRequest.State.focusing);
+    assertEquals("State is focusing", req.getState(), PictureCaptureRequest.State.focusing);
+    req.setState(PictureCaptureRequest.State.preCapture);
+    assertEquals("State is preCapture", req.getState(), PictureCaptureRequest.State.preCapture);
+    req.setState(PictureCaptureRequest.State.waitingPreCaptureReady);
     assertEquals(
-        "State is awaitingPreCapture",
+        "State is waitingPreCaptureReady",
         req.getState(),
-        PictureCaptureRequest.State.awaitingPreCapture);
+        PictureCaptureRequest.State.waitingPreCaptureReady);
     req.setState(PictureCaptureRequest.State.capturing);
     assertEquals(
         "State is awaitingPreCapture", req.getState(), PictureCaptureRequest.State.capturing);
@@ -49,7 +53,7 @@ public void isFinished_is_true_When_state_is_finished_or_error() {
     // Test false states
     req.setState(PictureCaptureRequest.State.idle);
     assertFalse(req.isFinished());
-    req.setState(PictureCaptureRequest.State.awaitingPreCapture);
+    req.setState(PictureCaptureRequest.State.preCapture);
     assertFalse(req.isFinished());
     req.setState(PictureCaptureRequest.State.capturing);
     assertFalse(req.isFinished());

packages/camera/camera/android/src/test/java/io/flutter/plugins/camera/PictureCaptureRequestTest.java

@@ -0,0 +1,33 @@
+package io.flutter.plugins.camera.types;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class ExposureModeTest {
+
+  @Test
+  public void getValueForString_returns_correct_values() {
+    assertEquals(
+        "Returns ExposureMode.auto for 'auto'",
+        ExposureMode.getValueForString("auto"),
+        ExposureMode.auto);
+    assertEquals(
+        "Returns ExposureMode.locked for 'locked'",
+        ExposureMode.getValueForString("locked"),
+        ExposureMode.locked);
+  }
+
+  @Test
+  public void getValueForString_returns_null_for_nonexistant_value() {
+    assertEquals(
+        "Returns null for 'nonexistant'", ExposureMode.getValueForString("nonexistant"), null);
+  }
+
+  @Test
+  public void toString_returns_correct_value() {
+    assertEquals("Returns 'auto' for ExposureMode.auto", ExposureMode.auto.toString(), "auto");
+    assertEquals(
+        "Returns 'locked' for ExposureMode.locked", ExposureMode.locked.toString(), "locked");
+  }
+}