Refactor common code from across Android apps into module

1 files changed, 383 insertions, 0 deletions

diff --git a/android-core/src/main/java/com/google/zxing/client/android/camera/CameraConfigurationUtils.java b/android-core/src/main/java/com/google/zxing/client/android/camera/CameraConfigurationUtils.java
new file mode 100644
index 000000000..4fd44f6cf
--- /dev/null
+++ b/android-core/src/main/java/com/google/zxing/client/android/camera/CameraConfigurationUtils.java
@@ -0,0 +1,383 @@
+/*
+ * Copyright (C) 2014 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.client.android.camera;
+
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.hardware.Camera;
+import android.util.Log;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * Utility methods for configuring the Android camera.
+ *
+ * @author Sean Owen
+ */
+public final class CameraConfigurationUtils {
+
+  private static final String TAG = "CameraConfiguration";
+
+  private static final int MIN_PREVIEW_PIXELS = 480 * 320; // normal screen
+  private static final float MAX_EXPOSURE_COMPENSATION = 1.5f;
+  private static final float MIN_EXPOSURE_COMPENSATION = 0.0f;
+  private static final double MAX_ASPECT_DISTORTION = 0.15;
+  private static final int MIN_FPS = 10;
+  private static final int AREA_PER_1000 = 400;
+
+  private CameraConfigurationUtils() {
+  }
+
+  public static void setFocus(Camera.Parameters parameters,
+                              boolean autoFocus,
+                              boolean disableContinuous,
+                              boolean safeMode) {
+    List<String> supportedFocusModes = parameters.getSupportedFocusModes();
+    String focusMode = null;
+    if (autoFocus) {
+      if (safeMode || disableContinuous) {
+        focusMode = CameraConfigurationUtils.findSettableValue("focus mode",
+                                                               supportedFocusModes,
+                                                               Camera.Parameters.FOCUS_MODE_AUTO);
+      } else {
+        focusMode = CameraConfigurationUtils.findSettableValue("focus mode",
+                                                               supportedFocusModes,
+                                                               Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE,
+                                                               Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO,
+                                                               Camera.Parameters.FOCUS_MODE_AUTO);
+      }
+    }
+    // Maybe selected auto-focus but not available, so fall through here:
+    if (!safeMode && focusMode == null) {
+      focusMode = CameraConfigurationUtils.findSettableValue("focus mode",
+                                                             supportedFocusModes,
+                                                             Camera.Parameters.FOCUS_MODE_MACRO,
+                                                             Camera.Parameters.FOCUS_MODE_EDOF);
+    }
+    if (focusMode != null) {
+      if (focusMode.equals(parameters.getFocusMode())) {
+        Log.i(TAG, "Focus mode already set to " + focusMode);
+      } else {
+        parameters.setFocusMode(focusMode);
+      }
+    }
+  }
+
+  public static void setTorch(Camera.Parameters parameters, boolean on) {
+    List<String> supportedFlashModes = parameters.getSupportedFlashModes();
+    String flashMode;
+    if (on) {
+      flashMode = CameraConfigurationUtils.findSettableValue("flash mode",
+                                                             supportedFlashModes,
+                                                             Camera.Parameters.FLASH_MODE_TORCH,
+                                                             Camera.Parameters.FLASH_MODE_ON);
+    } else {
+      flashMode = CameraConfigurationUtils.findSettableValue("flash mode",
+                                                             supportedFlashModes,
+                                                             Camera.Parameters.FLASH_MODE_OFF);
+    }
+    if (flashMode != null) {
+      if (flashMode.equals(parameters.getFlashMode())) {
+        Log.i(TAG, "Flash mode already set to " + flashMode);
+      } else {
+        Log.i(TAG, "Setting flash mode to " + flashMode);
+        parameters.setFlashMode(flashMode);
+      }
+    }
+  }
+
+  public static void setBestExposure(Camera.Parameters parameters, boolean lightOn) {
+    int minExposure = parameters.getMinExposureCompensation();
+    int maxExposure = parameters.getMaxExposureCompensation();
+    float step = parameters.getExposureCompensationStep();
+    if ((minExposure != 0 || maxExposure != 0) && step > 0.0f) {
+      // Set low when light is on
+      float targetCompensation = lightOn ? MIN_EXPOSURE_COMPENSATION : MAX_EXPOSURE_COMPENSATION;
+      int compensationSteps = Math.round(targetCompensation / step);
+      float actualCompensation = step * compensationSteps;
+      // Clamp value:
+      compensationSteps = Math.max(Math.min(compensationSteps, maxExposure), minExposure);
+      if (parameters.getExposureCompensation() == compensationSteps) {
+        Log.i(TAG, "Exposure compensation already set to " + compensationSteps + " / " + actualCompensation);
+      } else {
+        Log.i(TAG, "Setting exposure compensation to " + compensationSteps + " / " + actualCompensation);
+        parameters.setExposureCompensation(compensationSteps);
+      }
+    } else {
+      Log.i(TAG, "Camera does not support exposure compensation");
+    }
+  }
+
+  public static void setBestPreviewFPS(Camera.Parameters parameters) {
+    setBestPreviewFPS(parameters, MIN_FPS);
+  }
+
+  public static void setBestPreviewFPS(Camera.Parameters parameters, int minFPS) {
+    List<int[]> supportedPreviewFpsRanges = parameters.getSupportedPreviewFpsRange();
+    Log.i(TAG, "Supported FPS ranges: " + toString(supportedPreviewFpsRanges));
+    if (supportedPreviewFpsRanges != null && !supportedPreviewFpsRanges.isEmpty()) {
+      int[] minimumSuitableFpsRange = null;
+      for (int[] fpsRange : supportedPreviewFpsRanges) {
+        int fpsMax = fpsRange[Camera.Parameters.PREVIEW_FPS_MAX_INDEX];
+        if (fpsMax >= minFPS * 1000 &&
+            (minimumSuitableFpsRange == null ||
+             fpsMax > minimumSuitableFpsRange[Camera.Parameters.PREVIEW_FPS_MAX_INDEX])) {
+          minimumSuitableFpsRange = fpsRange;
+        }
+      }
+      if (minimumSuitableFpsRange == null) {
+        Log.i(TAG, "No suitable FPS range?");
+      } else {
+        int[] currentFpsRange = new int[2];
+        parameters.getPreviewFpsRange(currentFpsRange);
+        if (Arrays.equals(currentFpsRange, minimumSuitableFpsRange)) {
+          Log.i(TAG, "FPS range already set to " + Arrays.toString(minimumSuitableFpsRange));
+        } else {
+          Log.i(TAG, "Setting FPS range to " + Arrays.toString(minimumSuitableFpsRange));
+          parameters.setPreviewFpsRange(minimumSuitableFpsRange[Camera.Parameters.PREVIEW_FPS_MIN_INDEX],
+                                        minimumSuitableFpsRange[Camera.Parameters.PREVIEW_FPS_MAX_INDEX]);
+        }
+      }
+    }
+  }
+
+  public static void setFocusArea(Camera.Parameters parameters) {
+    if (parameters.getMaxNumFocusAreas() > 0) {
+      Log.i(TAG, "Old focus areas: " + toString(parameters.getFocusAreas()));
+      List<Camera.Area> middleArea = buildMiddleArea(AREA_PER_1000);
+      Log.i(TAG, "Setting focus area to : " + toString(middleArea));
+      parameters.setFocusAreas(middleArea);
+    } else {
+      Log.i(TAG, "Device does not support focus areas");
+    }
+  }
+
+  public static void setMetering(Camera.Parameters parameters) {
+    if (parameters.getMaxNumMeteringAreas() > 0) {
+      Log.i(TAG, "Old metering areas: " + parameters.getMeteringAreas());
+      List<Camera.Area> middleArea = buildMiddleArea(AREA_PER_1000);
+      Log.i(TAG, "Setting metering area to : " + toString(middleArea));
+      parameters.setMeteringAreas(middleArea);
+    } else {
+      Log.i(TAG, "Device does not support metering areas");
+    }
+  }
+
+  private static List<Camera.Area> buildMiddleArea(int areaPer1000) {
+    return Collections.singletonList(
+        new Camera.Area(new Rect(-areaPer1000, -areaPer1000, areaPer1000, areaPer1000), 1));
+  }
+
+  public static void setVideoStabilization(Camera.Parameters parameters) {
+    if (parameters.isVideoStabilizationSupported()) {
+      if (parameters.getVideoStabilization()) {
+        Log.i(TAG, "Video stabilization already enabled");
+      } else {
+        Log.i(TAG, "Enabling video stabilization...");
+        parameters.setVideoStabilization(true);
+      }
+    } else {
+      Log.i(TAG, "This device does not support video stabilization");
+    }
+  }
+
+  public static void setBarcodeSceneMode(Camera.Parameters parameters) {
+    if (Camera.Parameters.SCENE_MODE_BARCODE.equals(parameters.getSceneMode())) {
+      Log.i(TAG, "Barcode scene mode already set");
+      return;
+    }
+    String sceneMode = findSettableValue("scene mode",
+                                         parameters.getSupportedSceneModes(),
+                                         Camera.Parameters.SCENE_MODE_BARCODE);
+    if (sceneMode != null) {
+      parameters.setSceneMode(sceneMode);
+    }
+  }
+
+  public static void setMaxZoom(Camera.Parameters parameters) {
+    int maxZoom = parameters.getMaxZoom();
+    Log.i(TAG, "Setting zoom to max of " + maxZoom);
+    setZoom(parameters, maxZoom);
+  }
+
+  public static void setZoom(Camera.Parameters parameters, int zoom) {
+    if (parameters.isZoomSupported()) {
+      if (parameters.getZoom() == zoom) {
+        Log.i(TAG, "Zoom is already set to " + zoom);
+      } else {
+        Log.i(TAG, "Setting zoom to " + zoom);
+        parameters.setZoom(zoom);
+      }
+    } else {
+      Log.i(TAG, "Zoom is not supported");
+    }
+  }
+
+  public static void setInvertColor(Camera.Parameters parameters) {
+    if (Camera.Parameters.EFFECT_NEGATIVE.equals(parameters.getColorEffect())) {
+      Log.i(TAG, "Negative effect already set");
+      return;
+    }
+    String colorMode =
+        CameraConfigurationUtils.findSettableValue("color effect",
+                                                   parameters.getSupportedColorEffects(),
+                                                   Camera.Parameters.EFFECT_NEGATIVE);
+    if (colorMode != null) {
+      parameters.setColorEffect(colorMode);
+    }
+  }
+
+  public static Point findBestPreviewSizeValue(Camera.Parameters parameters, Point screenResolution) {
+
+    List<Camera.Size> rawSupportedSizes = parameters.getSupportedPreviewSizes();
+    if (rawSupportedSizes == null) {
+      Log.w(TAG, "Device returned no supported preview sizes; using default");
+      Camera.Size defaultSize = parameters.getPreviewSize();
+      if (defaultSize == null) {
+        throw new IllegalStateException("Parameters contained no preview size!");
+      }
+      return new Point(defaultSize.width, defaultSize.height);
+    }
+
+    // Sort by size, descending
+    List<Camera.Size> supportedPreviewSizes = new ArrayList<>(rawSupportedSizes);
+    Collections.sort(supportedPreviewSizes, new Comparator<Camera.Size>() {
+      @Override
+      public int compare(Camera.Size a, Camera.Size b) {
+        int aPixels = a.height * a.width;
+        int bPixels = b.height * b.width;
+        if (bPixels < aPixels) {
+          return -1;
+        }
+        if (bPixels > aPixels) {
+          return 1;
+        }
+        return 0;
+      }
+    });
+
+    if (Log.isLoggable(TAG, Log.INFO)) {
+      StringBuilder previewSizesString = new StringBuilder();
+      for (Camera.Size supportedPreviewSize : supportedPreviewSizes) {
+        previewSizesString.append(supportedPreviewSize.width).append('x')
+            .append(supportedPreviewSize.height).append(' ');
+      }
+      Log.i(TAG, "Supported preview sizes: " + previewSizesString);
+    }
+
+    double screenAspectRatio = (double) screenResolution.x / (double) screenResolution.y;
+
+    // Remove sizes that are unsuitable
+    Iterator<Camera.Size> it = supportedPreviewSizes.iterator();
+    while (it.hasNext()) {
+      Camera.Size supportedPreviewSize = it.next();
+      int realWidth = supportedPreviewSize.width;
+      int realHeight = supportedPreviewSize.height;
+      if (realWidth * realHeight < MIN_PREVIEW_PIXELS) {
+        it.remove();
+        continue;
+      }
+
+      boolean isCandidatePortrait = realWidth < realHeight;
+      int maybeFlippedWidth = isCandidatePortrait ? realHeight : realWidth;
+      int maybeFlippedHeight = isCandidatePortrait ? realWidth : realHeight;
+      double aspectRatio = (double) maybeFlippedWidth / (double) maybeFlippedHeight;
+      double distortion = Math.abs(aspectRatio - screenAspectRatio);
+      if (distortion > MAX_ASPECT_DISTORTION) {
+        it.remove();
+        continue;
+      }
+
+      if (maybeFlippedWidth == screenResolution.x && maybeFlippedHeight == screenResolution.y) {
+        Point exactPoint = new Point(realWidth, realHeight);
+        Log.i(TAG, "Found preview size exactly matching screen size: " + exactPoint);
+        return exactPoint;
+      }
+    }
+
+    // If no exact match, use largest preview size. This was not a great idea on older devices because
+    // of the additional computation needed. We're likely to get here on newer Android 4+ devices, where
+    // the CPU is much more powerful.
+    if (!supportedPreviewSizes.isEmpty()) {
+      Camera.Size largestPreview = supportedPreviewSizes.get(0);
+      Point largestSize = new Point(largestPreview.width, largestPreview.height);
+      Log.i(TAG, "Using largest suitable preview size: " + largestSize);
+      return largestSize;
+    }
+
+    // If there is nothing at all suitable, return current preview size
+    Camera.Size defaultPreview = parameters.getPreviewSize();
+    if (defaultPreview == null) {
+      throw new IllegalStateException("Parameters contained no preview size!");
+    }
+    Point defaultSize = new Point(defaultPreview.width, defaultPreview.height);
+    Log.i(TAG, "No suitable preview sizes, using default: " + defaultSize);
+    return defaultSize;
+  }
+
+  private static String findSettableValue(String name,
+                                          Collection<String> supportedValues,
+                                          String... desiredValues) {
+    Log.i(TAG, "Requesting " + name + " value from among: " + Arrays.toString(desiredValues));
+    Log.i(TAG, "Supported " + name + " values: " + supportedValues);
+    if (supportedValues != null) {
+      for (String desiredValue : desiredValues) {
+        if (supportedValues.contains(desiredValue)) {
+          Log.i(TAG, "Can set " + name + " to: " + desiredValue);
+          return desiredValue;
+        }
+      }
+    }
+    Log.i(TAG, "No supported values match");
+    return null;
+  }
+
+  private static String toString(Collection<int[]> arrays) {
+    if (arrays == null || arrays.isEmpty()) {
+      return "[]";
+    }
+    StringBuilder buffer = new StringBuilder();
+    buffer.append('[');
+    Iterator<int[]> it = arrays.iterator();
+    while (it.hasNext()) {
+      buffer.append(Arrays.toString(it.next()));
+      if (it.hasNext()) {
+        buffer.append(", ");
+      }
+    }
+    buffer.append(']');
+    return buffer.toString();
+  }
+
+  private static String toString(Iterable<Camera.Area> areas) {
+    if (areas == null) {
+      return null;
+    }
+    StringBuilder result = new StringBuilder();
+    for (Camera.Area area : areas) {
+      result.append(area.rect).append(':').append(area.weight).append(' ');
+    }
+    return result.toString();
+  }
+
+}