my solution is more like building a square mask and then to place it over the preview surface.
You will need 3 things mainly, first a square frame component. I've made a custom component:
package com.example.squaredviewer;
import android.content.Context;
import android.util.AttributeSet;
import android.view.Display;
import android.view.WindowManager;
import android.widget.RelativeLayout;
/**
* Created by yadirhb on 14-08-2015.
*/
public class SquaredFrame extends RelativeLayout{
public SquaredFrame(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int size = Math.min(getMeasuredWidth(), getMeasuredHeight());
setMeasuredDimension(size, size);
}
}
Depending of the Android API version for the which you're developing, you will maybe need to add another constructor overload. For Kitkat this is just fine.
The second step is to build the layout:
<?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"
android:orientation="horizontal"
android:visibility="visible">
<RelativeLayout
android:id="@+id/camera_preview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="false"
android:layout_alignParentTop="false"
android:layout_centerInParent="true"
android:background="#ffffff">
</RelativeLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:background="#131008">
</LinearLayout>
<com.example.squaredviewer.SquaredFrame
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"></com.example.squaredviewer.SquaredFrame>
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:background="#131008" />
</LinearLayout>
</RelativeLayout>
Notice that the RelativeLayout "camera_preview" is the one used to render the preview, it is centered and has a LinearLayout which contains the squared component. This is actually the "mask" and it covers the camera preview.
Notice also that except the SquaredFrame, which is transparent, the others two are background coloured with black.
Now the surface view, for the camera preview in which the surface is sized acording the aspect ratio.
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private final String TAG = "PIC-FRAME";
private SurfaceHolder mHolder;
private Camera mCamera;
private Display display;
public CameraPreview(Activity context, Camera camera) {
super(context);
mCamera = camera;
display = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
setKeepScreenOn(true);
}
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
this.getHolder().removeCallback(this);
}
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.
if (mHolder.getSurface() == null) {
// preview surface does not exist
return;
}
try {
// stop preview before making changes
mCamera.stopPreview();
// set preview size and make any resize, rotate or
// reformatting changes here
// Now that the size is known, set up the camera parameters and begin
// the preview.
Camera.Parameters parameters = mCamera.getParameters();
// You need to choose the most appropriate previewSize for your app
Camera.Size previewSize = parametes.getSupportedPreviewSizes().get(0);
parameters.setPreviewSize(previewSize.width, previewSize.height);
// start preview with new settings
mCamera.setParameters(parameters);
// Set the holder size based on the aspect ratio
int size = Math.min(display.getWidth(), display.getHeight());
double ratio = (double) previewSize.width / previewSize.height;
mHolder.setFixedSize((int)(size * ratio), size);
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e) {
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
}
}
Now everything must be tied in the activity class
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_picture_taker);
mDecorView = getWindow().getDecorView();
//mCamera = a camera instance;
// Create our Preview view and set it as the content of our activity.
mPreview = new CameraPreview(this, mCamera);
//Layout where camera preview is shown.
RelativeLayout preview = (RelativeLayout) findViewById(R.id.camera_preview);
//FrameLayout stack controllers inside and superpose them.
preview.addView(mPreview, 0);
// TODO
}
A little long, but I hope it be helpful for more than one. :-)
