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am 83c50ca7: Merge "Update ApiDemos CameraPreview activity to properly center the preview in cases where the camera hardware doesn\'t support a preview size with the same aspect ratio as the device display." into gingerbread

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Merge commit '83c50ca740fabe25189601db90dc1f65ed4d2061' into gingerbread-plus-aosp

* commit '83c50ca740fabe25189601db90dc1f65ed4d2061':
  Update ApiDemos CameraPreview activity to properly center the preview in cases where the camera hardware doesn't support a preview size with the same aspect ratio as the device display.
This commit is contained in:
Roman Nurik
2010-10-25 13:55:34 -07:00
committed by Android Git Automerger
parent ccbd8955c0 83c50ca740
commit affd0f8ec3
1 changed files with 104 additions and 19 deletions
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123
samples/ApiDemos/src/com/example/android/apis/graphics/CameraPreview.java
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@@ -21,9 +21,13 @@ import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.Size;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import java.io.IOException;
import java.util.List;
@@ -32,62 +36,145 @@ import java.util.List;
public class CameraPreview extends Activity {
private Preview mPreview;
Camera mCamera;
@Override
protected void onCreate(Bundle savedInstanceState) {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Hide the window title.
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
// Create our Preview view and set it as the content of our activity.
// Create a RelativeLayout container that will hold a SurfaceView,
// and set it as the content of our activity.
mPreview = new Preview(this);
setContentView(mPreview);
}
@Override
protected void onResume() {
super.onResume();
mCamera = Camera.open();
mPreview.setCamera(mCamera);
}
@Override
protected void onPause() {
super.onPause();
// Because the Camera object is a shared resource, it's very
// important to release it when the activity is paused.
if (mCamera != null) {
mPreview.setCamera(null);
mCamera.release();
mCamera = null;
}
}
}
// ----------------------------------------------------------------------
class Preview extends SurfaceView implements SurfaceHolder.Callback {
/**
* A simple wrapper around a Camera and a SurfaceView that renders a centered preview of the Camera
* to the surface. We need to center the SurfaceView because not all devices have cameras that
* support preview sizes at the same aspect ratio as the device's display.
*/
class Preview extends ViewGroup implements SurfaceHolder.Callback {
private final String TAG = "Preview";
SurfaceView mSurfaceView;
SurfaceHolder mHolder;
Size mPreviewSize;
List<Size> mSupportedPreviewSizes;
Camera mCamera;
Preview(Context context) {
super(context);
mSurfaceView = new SurfaceView(context);
addView(mSurfaceView);
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void setCamera(Camera camera) {
mCamera = camera;
if (mCamera != null) {
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
requestLayout();
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// We purposely disregard child measurements because act as a
// wrapper to a SurfaceView that centers the camera preview instead
// of stretching it.
final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
setMeasuredDimension(width, height);
if (mSupportedPreviewSizes != null) {
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
}
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (changed && getChildCount() > 0) {
final View child = getChildAt(0);
final int width = r - l;
final int height = b - t;
int previewWidth = width;
int previewHeight = height;
if (mPreviewSize != null) {
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
}
// Center the child SurfaceView within the parent.
if (width * previewHeight > height * previewWidth) {
final int scaledChildWidth = previewWidth * height / previewHeight;
child.layout((width - scaledChildWidth) / 2, 0,
(width + scaledChildWidth) / 2, height);
} else {
final int scaledChildHeight = previewHeight * width / previewWidth;
child.layout(0, (height - scaledChildHeight) / 2,
width, (height + scaledChildHeight) / 2);
}
}
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where
// to draw.
mCamera = Camera.open();
try {
mCamera.setPreviewDisplay(holder);
if (mCamera != null) {
mCamera.setPreviewDisplay(holder);
}
} catch (IOException exception) {
mCamera.release();
mCamera = null;
// TODO: add more exception handling logic here
Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
// Because the CameraDevice object is not a shared resource, it's very
// important to release it when the activity is paused.
mCamera.stopPreview();
mCamera.release();
mCamera = null;
if (mCamera != null) {
mCamera.stopPreview();
}
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.05;
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) w / h;
if (sizes == null) return null;
@@ -123,10 +210,8 @@ class Preview extends SurfaceView implements SurfaceHolder.Callback {
// Now that the size is known, set up the camera parameters and begin
// the preview.
Camera.Parameters parameters = mCamera.getParameters();
List<Size> sizes = parameters.getSupportedPreviewSizes();
Size optimalSize = getOptimalPreviewSize(sizes, w, h);
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
requestLayout();
mCamera.setParameters(parameters);
mCamera.startPreview();