Since preview size will not match preview size in Android 4+ with soft nav bar, prefer large preview that is roughly the right aspect ratio

git-svn-id: https://zxing.googlecode.com/svn/trunk@2828 59b500cc-1b3d-0410-9834-0bbf25fbcc57

android/AndroidManifest.xml

@@ -16,8 +16,8 @@
  -->
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="com.google.zxing.client.android"
-          android:versionName="4.4 beta 1"
-          android:versionCode="89"
+          android:versionName="4.4 beta 2"
+          android:versionCode="90"
           android:installLocation="auto">
 
   <uses-permission android:name="android.permission.CAMERA"/>

android/assets/html-en/whatsnew.html

@@ -9,9 +9,10 @@
 <p>New in version 4.4:</p>
 <ul>
   <li>Android 2.3.3 is required now.</li>
-  <li>The Holo theme is enabled on Android 3 and Android 4 devices</li>
+  <li>The Holo theme is enabled on Android 3 and Android 4 devices.</li>
   <li>The barcode scanning rectangle has been enlarged slightly on some devices.</li>
-  <li>Minor fixes.</li>
+  <li>The chosen preview size has changed on some Android 4 devices, 
+      in order to accommodate the space taken by the soft navigation bar.</li>
 </ul>
 </body>
 </html>

android/src/com/google/zxing/client/android/camera/CameraConfigurationManager.java

@@ -31,6 +31,7 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
+import java.util.Iterator;
 import java.util.List;
 
 /**
@@ -44,10 +45,10 @@ final class CameraConfigurationManager {
   // This is bigger than the size of a small screen, which is still supported. The routine
   // below will still select the default (presumably 320x240) size for these. This prevents
   // accidental selection of very low resolution on some devices.
-  private static final int MIN_PREVIEW_PIXELS = 470 * 320; // normal screen
-  private static final int MAX_PREVIEW_PIXELS = 1280 * 800;
+  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 final Context context;
   private Point screenResolution;
@@ -114,7 +115,7 @@ final class CameraConfigurationManager {
     if (!safeMode && focusMode == null) {
       focusMode = findSettableValue(parameters.getSupportedFocusModes(),
                                     Camera.Parameters.FOCUS_MODE_MACRO,
-                                    "edof"); // Camera.Parameters.FOCUS_MODE_EDOF in 2.2+
+                                    Camera.Parameters.FOCUS_MODE_EDOF);
     }
     if (focusMode != null) {
       parameters.setFocusMode(focusMode);
@@ -239,41 +240,51 @@ final class CameraConfigurationManager {
       Log.i(TAG, "Supported preview sizes: " + previewSizesString);
     }
 
-    Point bestSize = null;
-    float screenAspectRatio = (float) screenResolution.x / (float) screenResolution.y;
+    double screenAspectRatio = (double) screenResolution.x / (double) screenResolution.y;
 
-    float diff = Float.POSITIVE_INFINITY;
-    for (Camera.Size supportedPreviewSize : supportedPreviewSizes) {
+    // 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;
-      int pixels = realWidth * realHeight;
-      if (pixels < MIN_PREVIEW_PIXELS || pixels > MAX_PREVIEW_PIXELS) {
+      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;
       }
-      float aspectRatio = (float) maybeFlippedWidth / (float) maybeFlippedHeight;
-      float newDiff = Math.abs(aspectRatio - screenAspectRatio);
-      if (newDiff < diff) {
-        bestSize = new Point(realWidth, realHeight);
-        diff = newDiff;
-      }
     }
 
-    if (bestSize == null) {
-      Camera.Size defaultSize = parameters.getPreviewSize();
-      bestSize = new Point(defaultSize.width, defaultSize.height);
-      Log.i(TAG, "No suitable preview sizes, using default: " + bestSize);
+    // 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;
     }
 
-    Log.i(TAG, "Found best approximate preview size: " + bestSize);
-    return bestSize;
+    // If there is nothing at all suitable, return current preview size
+    Camera.Size defaultPreview = parameters.getPreviewSize();
+    Point defaultSize = new Point(defaultPreview.width, defaultPreview.height);
+    Log.i(TAG, "No suitable preview sizes, using default: " + defaultSize);
+    return defaultSize;
   }
 
   private static String findSettableValue(Collection<String> supportedValues,