Develop Reference

Use camera but dont want to take photo

I want to use camera in my app but dont want to take photo, actually I am making a app i.e transparent screen, in this I want to show transparent wallpaper i.e I have to start camera for this and i dont want to take images for this
I tried all these codes but have n't got the desirable results. Can anyone suggest what must i do?
used this permission in all cases
<uses-permission android:name="android.permission.CAMERA"/>
Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivity(intent);
Intent intent = new Intent(Intent.ACTION_CAMERA_BUTTON, null);
startActivity(intent);
Intent intent = new Intent(android.provider.MediaStore.INTENT_ACTION_STILL_IMAGE_CAMERA);
startActivity(intent);
Update 1:
I tried this code it showing camera in not correct way, its diverting the preview to right kindly look over this updated code and tell wht amendment i can make over this
public class MainActivity extends Activity {
private Preview mPreview;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
try{
requestWindowFeature(Window.FEATURE_NO_TITLE);
// Create our Preview view and set it as the content of our activity.
mPreview = new Preview(this);
setContentView(mPreview);
}catch(Exception e){
e.printStackTrace();
}
}
******************************************************************************************
public 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.
try{
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}catch(Exception e){
e.printStackTrace();
}
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where
// to draw.
try{
if(mCamera!=null){
mCamera.release();
mCamera=null;
}
mCamera = Camera.open();
Log.i("Camera", "Camera is opened");
mCamera.setPreviewDisplay(holder);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
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.
try{
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}catch(Exception e){
e.printStackTrace();
}
}
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.
try{
Parameters parameters = mCamera.getParameters();
List<Camera.Size> sizes = parameters.getSupportedPreviewSizes();
Camera.Size cs = sizes.get(0);
parameters.setPreviewSize(cs.width, cs.height);
mCamera.setParameters(parameters);
mCamera.startPreview();
}catch(Exception e){
e.printStackTrace();
}
}
}

You need to use surfaceView for this. Here is an example:
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);
}
}
public 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();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where
// to draw.
mCamera = Camera.open();
mCamera.setPreviewDisplay(holder);
}
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 = null;
}
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 = camera.getParameters();
List<Camera.Size> sizes = parameters.getSupportedPreviewSizes();
Camera.Size cs = sizes.get(0);
parameters.setPreviewSize(cs.width, cs.height);
camera.setParameters(parameters);
mCamera.startPreview();
}
}

I used this code and it worked...
<uses-permission android:name="android.permission.CAMERA"/>
public class MainActivity extends Activity {
private Preview mPreview;
/** Called when the activity is first created. */
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
try{
requestWindowFeature(Window.FEATURE_NO_TITLE);
// Create our Preview view and set it as the content of our activity.
mPreview = new Preview(this);
setContentView(mPreview);
}catch(Exception e){
e.printStackTrace();
}
}
}
*****************************************************************************************
public 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.
try {
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
} catch (Exception e) {
e.printStackTrace();
}
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where
// to draw.
try {
if (mCamera != null) {
mCamera.release();
mCamera = null;
}
mCamera = Camera.open();
Log.i("Camera", "Camera is opened");
mCamera.setPreviewDisplay(holder);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
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.
try {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
} catch (Exception e) {
e.printStackTrace();
}
}
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.
try {
Camera.Parameters parameters = mCamera.getParameters();
parameters.set("orientation", "portrait");
mCamera.setDisplayOrientation(90);
List<Camera.Size> sizes = parameters.getSupportedPreviewSizes();
Camera.Size cs = sizes.get(0);
parameters.setPreviewSize(cs.width, cs.height);
mCamera.setParameters(parameters);
mCamera.startPreview();
} catch (Exception e) {
e.printStackTrace();
}
}
}

Surface View Camera Preview

Having a little trouble getting my SurfaceView to show my camera preview. I've looked at some questions on here and Google'd some tuts but I think it may be a small error on my end that I'm just not seeing.
Code
public class RoofPitchActivity extends Activity implements SensorEventListener {
...
private SurfaceView mSurfaceView;
private SurfaceHolder mSurfaceHolder;
private Camera mCamera;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_roof_pitch);
initViews();
}
private void initViews() {
...
Preview preview = new Preview(this);
mCamera = Camera.open();
preview.setCamera(mCamera);
}
...
...
class Preview extends ViewGroup implements SurfaceHolder.Callback {
public Preview(Context context) {
super(context);
mSurfaceView = (SurfaceView) findViewById(R.id.preview);
mSurfaceView = new SurfaceView(context);
addView(mSurfaceView);
mSurfaceHolder = mSurfaceView.getHolder();
mSurfaceHolder.addCallback(this);
}
public void setCamera(Camera camera) {
if (mCamera == camera) {
return;
}
stopPreviewAndFreeCamera();
mCamera = camera;
if (mCamera != null) {
requestLayout();
try {
mCamera.setPreviewDisplay(mSurfaceHolder);
} catch (IOException e) {
e.printStackTrace();
}
mCamera.startPreview();
}
}
private void stopPreviewAndFreeCamera() {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
mCamera.startPreview();
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mSurfaceView.getWidth(), mSurfaceView.getHeight());
requestLayout();
mCamera.setParameters(parameters);
mCamera.startPreview();
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
if (mCamera != null) {
mCamera.stopPreview();
}
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
}
}
}
So when the activity is launched the SurfaceView is black. The camera does not appear to be rendering the preview onto the SurfaceView. I'm sure there's something small I'm missing, or maybe it's just a fundemental misunderstanding of how this works. A fresh set of eyes with a little explanation would be very much appreciated. Thanks

So the answer to my question ended up being device specific. The code was acceptable but my device I'm using to debug is a Nexus 7. This means the camera is front facing and the normal call to the camera does not work. An interesting and funny read about this can be found in this article
Camera.open();
does not work. You must use
Camera.open(0);
So my code ended up with a conditional check for the camera and now it works fine.
Like so
public void setCamera() {
stopPreviewAndFreeCamera();
PackageManager pm = getPackageManager();
boolean backCamera = pm.hasSystemFeature(PackageManager.FEATURE_CAMERA);
boolean frontCamera = pm.hasSystemFeature(PackageManager.FEATURE_CAMERA_FRONT);
if (frontCamera) {
mCamera = Camera.open(0);
} else if (backCamera) {
mCamera = Camera.open();
}
if (mCamera != null) {
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mSurfaceView.getWidth(), mSurfaceView.getHeight());
requestLayout();
try {
mCamera.setParameters(parameters);
mCamera.setPreviewDisplay(mSurfaceHolder);
} catch (IOException e) {
e.printStackTrace();
}
mCamera.startPreview();
}
}

camera preview on lockscreen

I want add a take picture function in lockscreen , and I need to open the preview on screen , but it's fail all the time , logcat say the Error is about "setPreviewWindow - Null ANativeWindow passed to setPreviewWindow" and "startPreview - Preview not started. Preview in progress flag set"
In keyguard_screen_tab_unlock.xml after the digital clock view, put
<FrameLayout
android:id="#+id/mPreview"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
In LockScreen.java constructor:
FrameLayout mFrameLayout = (FrameLayout)findViewById(R.id.mPreview);
SurfacePreview preview = new SurfacePreview(mContext);
preview.setZOrderOnTop(true);
mFrameLayout.addView(preview);
SurfacePreview class :
public class SurfacePreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mSurfaceHolder;
SurfacePreview(Context context) {
super(context);
mSurfaceHolder = this.getHolder();
mSurfaceHolder.addCallback(this);
mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
mCamera = Camera.open(CameraInfo.CAMERA_FACING_BACK);
try {
mCamera.setPreviewDisplay(holder);
} catch (IOException e) {
e.printStackTrace();
}
mCamera.startPreview();
}
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Camera.Parameters parameters = mCamera.getParameters();
mCamera.setParameters(parameters);
mCamera.setDisplayOrientation(90);
}
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.release();
}
}
Anyone kown how to resolve this issue and start prview on LockScreen? Thanks a lot.

How can I make a SurfaceView larger than the screen?

I would like to effectively make a simple digital zoom for the camera preview, so I thought I would simply resize my SurfaceView to be larger than the screen. Other questions (such as 3813049) seem to indicate that this is easy, so I created the sample code below which I expect to let me see only half of the image horizontally (since the SurfaceView is twice as wide as the screen) and have the image only take up half of the screen horizontally. However, running it (when targeted to SDK version 4 on my Thunderbolt with Android 2.2.1) results in being able to see the whole image horizontally while filling the screen horizontally. The SurfaceView appears to behave as intended vertically (when I make it smaller than the screen), but Android won't allow me to make the SurfaceView larger than the screen.
How can I implement a digital zoom? (No, I cannot use Camera.Parameters.setZoom; not only is this not supported by Android 1.6, but different cameras support and implement this differently)
public class MagnifyTestActivity extends Activity implements SurfaceHolder.Callback {
private MagnificationView mPreview;
private SurfaceHolder mHolder;
private Camera mCamera = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPreview = new MagnificationView(this);
setContentView(mPreview);
mHolder = mPreview.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public class MagnificationView extends SurfaceView {
public MagnificationView(Context context) {
super(context);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth()*2;
int height = display.getHeight()/2;
widthMeasureSpec = MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY);
heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
public void surfaceCreated(SurfaceHolder holder) {
mCamera = Camera.open();
try {
mCamera.setPreviewDisplay(holder);
} catch (IOException e) {
e.printStackTrace();
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
mHolder.setFixedSize(w, h);
mCamera.startPreview();
}
}
UPDATE: Based on #Pulkit Sethi's response, it is possible to stretch/magnify the SurfaceView vertically, just not horizontally. To magnify the SurfaceView vertically, simply replace display.getHeight()/2 with display.getHeight()*2 above. Also observe that changing the width doesn't produce any horizontal magnification, either in my code or in Pulkit's.

//Activity class
public class CameraActivity extends Activity implements SurfaceListener {
private static final String TAG = "CameraActivity";
Camera mCamera;
CameraPreview mPreview;
private FrameLayout mCameraPreview;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_camera);
mCamera = getCameraInstance();
mPreview = new CameraPreview(this, mCamera);
mCameraPreview = (FrameLayout) findViewById(R.id.camera_preview);
mCameraPreview.addView(mPreview);
}
#Override
protected void onPause() {
super.onPause();
releaseCamera();
}
private Camera getCameraInstance() {
Camera camera = null;
try {
camera = Camera.open();
} catch (Exception e) {
}
return camera;
}
private void releaseCamera() {
if (null != mCamera) {
mCamera.release();
}
mCamera = null;
}
#Override
public void surfaceCreated() {
//Change these mate
int width = 1000;
int height = 1000;
// Set parent window params
getWindow().setLayout(width, height);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
width, height);
mCameraPreview.setLayoutParams(params);
mCameraPreview.requestLayout();
}
}
// Preview class
public class CameraPreview extends SurfaceView implements
SurfaceHolder.Callback {
private static final String TAG = "CameraPreview";
Context mContext;
Camera mCamera;
SurfaceHolder mHolder;
public interface SurfaceListener{
public void surfaceCreated();
}
SurfaceListener listener;
public CameraPreview(Context context, Camera camera) {
super(context);
mContext = context;
listener = (SurfaceListener)mContext;
mCamera = camera;
mHolder = getHolder();
mHolder.addCallback(this);
// Required prior 3.0 HC
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {
mCamera.setPreviewDisplay(holder);
Parameters params = mCamera.getParameters();
//Change parameters here
mCamera.setParameters(params);
mCamera.startPreview();
listener.surfaceCreated();
} catch (Exception e) {
// TODO: handle exception
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
Log.i(TAG, "Surface changed called");
if (mHolder.getSurface() == null) {
// preview surface does not exist
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e) {
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or
// reformatting changes here
mCamera.setDisplayOrientation(90);
// start preview with new settings
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e) {
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
}
//Layout file
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<FrameLayout
android:id="#+id/camera_preview"
android:layout_width="300dp"
android:layout_height="400dp"
android:layout_centerHorizontal="true"
android:paddingTop="10dp" >
</FrameLayout>
</RelativeLayout>

You can't make your surfaceView bigger than the screen. That being said there are ways around it.
I found you can adjust the size of the canvas in the SurfaceView, which will allow zooming.
public class DrawingThread extends Thread {
private MagnificationView mainPanel;
private SurfaceHolder surfaceHolder;
private boolean run;
public DrawingThread(SurfaceHolder surface, MagnificationView panel){
surfaceHolder = surface;
mainPanel = panel;
}
public SurfaceHolder getSurfaceHolder(){
return surfaceHolder;
}
public void setRunning (boolean run){
this.run = run;
}
public void run(){
Canvas c;
while (run){
c = null;
try {
c = surfaceHolder.lockCanvas(null);
synchronized (surfaceHolder){
mainPanel.OnDraw(c);
}
} finally {
if (c != null){
surfaceHolder.unlockCanvasAndPost(c);
}
}
}
}
}
In the MagnificationView class add a method:
public void OnDraw(Canvas canvas){
if (canvas!=null){
canvas.save();
canvas.scale(scaleX,scaleY);
canvas.restore();
}
}
DrawingThread would be a thread you start in in your Activity. Also in your MagnificationView class override the OnTouchEvent to handle your own pinch-zoom (which will modify scaleX & scaleY.
Hope This solves your issue

What you can do is to get the window and set its height:
getWindow().setLayout(1000, 1000);
This makes your window larger than the screen making your root view and consequently your surfaceview, probably contained inside a Framelayout larger than screen.
This worked for me let me know.
The above would work no matter what. What you would want to do is listen for onSurfaceCreated event for your surface view. Then after you have the started the camera view and you are able to calculate size of your widget holding the preview, you would want to change size of the container widget.
The concept is your container widget (probably FrameLayout) wants to grow larger than screen. The screen itself is restricted by the activity so first set size of your window,
then set size of your framelayout (it would always be shrunk to max size of windows, so set accordingly).
I do all this logic after my onSurfaceCreated is finished I have started the preview. I listen for this event in my activity by implementing a small interface, as my Camera preview is a separate class.
Working on all API level >= 8

Here's my TouchSurfaceView's onMeasure that performs zoom:
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
setMeasuredDimension((int) (width * scaleFactor), (int) (height * scaleFactor));
}
This properly zooms in and out depending on scaleFactor.
I haven't tested this with camera, but it works properly with MediaPlayer (behaving as VideoView).

Android Camera Preview -- How to 'freeze' the camera?

I'm currently trying to build an android application to take pictures and I need to freeze the camera preview on a given event (i.e. picture taken) and restart it only after another event.
What I want, in other words, is for the view to display whatever the camera sees until the freeze event occurs and then to freeze the image (i.e. display whatever was on screen at the time of this event -- as if a picture was taken) until the unfreeze event occurs.
Now, I'm currently using a SurfaceView with a SurfaceHolder.Callback to do this and I tried to use a PreviewCallback to freeze the screen, but unfortunately, I can't find an example or a tutorial and I'm really stuck at this point.
If anyone has a guide or some pointers on how to get this done, I would really appreciate the help...
I'm pasting the relevant parts of my code below:
public class CustomCameraView extends SurfaceView {
Camera camera;
SurfaceHolder previewHolder;
//Callback for the surfaceholder
SurfaceHolder.Callback surfaceHolderListener = new SurfaceHolder.Callback() {
public void surfaceCreated(SurfaceHolder holder) {
camera=Camera.open();
try
{
camera.setPreviewDisplay(previewHolder);
}
catch (Throwable t) {
}
}
public void surfaceChanged(SurfaceHolder surfaceHolder, int format, int w, int h)
{
Parameters params = camera.getParameters();
params.setPictureFormat(PixelFormat.JPEG);
camera.setParameters(params);
camera.startPreview();
}
public void surfaceDestroyed(SurfaceHolder arg0)
{
camera.stopPreview();
camera.release();
}
};
public CustomCameraView(Context ctx)
{
super(ctx);
previewHolder = this.getHolder();
previewHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
previewHolder.addCallback(surfaceHolderListener);
setBackgroundColor(Color.TRANSPARENT);
}
public CustomCameraView(Context context, AttributeSet attrs)
{
super(context, attrs);
}
protected void onDraw (Canvas canvas)
{
}
public void closeCamera()
{
if(camera != null)
camera.release();
}
public void dispatchDraw(Canvas c)
{
super.dispatchDraw(c);
}
}
Thank you very much for your help!
-Billy

Old question, I know, but answering for posterity. You should be able to simply call
camera.stopPreview();
The preview will freeze on whatever you're looking at until you call startPreview() again.