Merge change I1558a070 into eclair-mr2

* changes:
  Fix the camera preview demo.

samples/ApiDemos/src/com/example/android/apis/graphics/CameraPreview.java

@@ -19,24 +19,27 @@ package com.example.android.apis.graphics;
 import android.app.Activity;
 import android.content.Context;
 import android.hardware.Camera;
+import android.hardware.Camera.Size;
 import android.os.Bundle;
 import android.view.SurfaceHolder;
 import android.view.SurfaceView;
 import android.view.Window;
+
 import java.io.IOException;
+import java.util.List;
 
 // ----------------------------------------------------------------------
 
-public class CameraPreview extends Activity {    
+public class CameraPreview extends Activity {
     private Preview mPreview;
-    
+
     @Override
 	protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        
+
         // Hide the window title.
         requestWindowFeature(Window.FEATURE_NO_TITLE);
-    
+
         // Create our Preview view and set it as the content of our activity.
         mPreview = new Preview(this);
         setContentView(mPreview);
@@ -49,10 +52,10 @@ public class CameraPreview extends Activity {
 class Preview extends SurfaceView implements SurfaceHolder.Callback {
     SurfaceHolder mHolder;
     Camera mCamera;
-    
+
     Preview(Context context) {
         super(context);
-        
+
         // Install a SurfaceHolder.Callback so we get notified when the
         // underlying surface is created and destroyed.
         mHolder = getHolder();
@@ -82,11 +85,49 @@ class Preview extends SurfaceView implements SurfaceHolder.Callback {
         mCamera = null;
     }
 
+
+    private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
+        final double ASPECT_TOLERANCE = 0.05;
+        double targetRatio = (double) w / h;
+        if (sizes == null) return null;
+
+        Size optimalSize = null;
+        double minDiff = Double.MAX_VALUE;
+
+        int targetHeight = h;
+
+        // Try to find an size match aspect ratio and size
+        for (Size size : sizes) {
+            double ratio = (double) size.width / size.height;
+            if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
+            if (Math.abs(size.height - targetHeight) < minDiff) {
+                optimalSize = size;
+                minDiff = Math.abs(size.height - targetHeight);
+            }
+        }
+
+        // Cannot find the one match the aspect ratio, ignore the requirement
+        if (optimalSize == null) {
+            minDiff = Double.MAX_VALUE;
+            for (Size size : sizes) {
+                if (Math.abs(size.height - targetHeight) < minDiff) {
+                    optimalSize = size;
+                    minDiff = Math.abs(size.height - targetHeight);
+                }
+            }
+        }
+        return optimalSize;
+    }
+
     public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
         // Now that the size is known, set up the camera parameters and begin
         // the preview.
         Camera.Parameters parameters = mCamera.getParameters();
-        parameters.setPreviewSize(w, h);
+
+        List<Size> sizes = parameters.getSupportedPreviewSizes();
+        Size optimalSize = getOptimalPreviewSize(sizes, w, h);
+        parameters.setPreviewSize(optimalSize.width, optimalSize.height);
+
         mCamera.setParameters(parameters);
         mCamera.startPreview();
     }