| /* |
| * Copyright (C) 2007 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| 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 { |
| 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); |
| } |
| |
| } |
| |
| // ---------------------------------------------------------------------- |
| |
| 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(); |
| try { |
| mCamera.setPreviewDisplay(holder); |
| } catch (IOException exception) { |
| mCamera.release(); |
| mCamera = null; |
| // TODO: add more exception handling logic here |
| } |
| } |
| |
| 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; |
| } |
| |
| |
| 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(); |
| |
| List<Size> sizes = parameters.getSupportedPreviewSizes(); |
| Size optimalSize = getOptimalPreviewSize(sizes, w, h); |
| parameters.setPreviewSize(optimalSize.width, optimalSize.height); |
| |
| mCamera.setParameters(parameters); |
| mCamera.startPreview(); |
| } |
| |
| } |