From a2e3dedbe4e09c4299143110bf938956c74ffe6c Mon Sep 17 00:00:00 2001
From: Tim Redfern <tim@eclectronics.org>
Date: Mon, 9 Sep 2013 12:38:17 +0100
Subject: integrated working example

---
 src/com/example/rotorm/Preview.java | 160 ++++++++++++++++++++++++++++++++++++
 1 file changed, 160 insertions(+)
 create mode 100644 src/com/example/rotorm/Preview.java

(limited to 'src/com/example/rotorm/Preview.java')

diff --git a/src/com/example/rotorm/Preview.java b/src/com/example/rotorm/Preview.java
new file mode 100644
index 0000000..5fdea5a
--- /dev/null
+++ b/src/com/example/rotorm/Preview.java
@@ -0,0 +1,160 @@
+package com.example.rotorm;
+
+import java.io.IOException;
+import java.util.List;
+
+import android.content.Context;
+import android.hardware.Camera;
+import android.hardware.Camera.Size;
+import android.util.Log;
+import android.view.SurfaceHolder;
+import android.view.SurfaceView;
+import android.view.View;
+import android.view.ViewGroup;
+
+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, SurfaceView sv) {
+        super(context);
+
+        mSurfaceView = sv;
+//        addView(mSurfaceView);
+       
+        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();
+
+    		// get Camera parameters
+    		Camera.Parameters params = mCamera.getParameters();
+
+    		List<String> focusModes = params.getSupportedFocusModes();
+    		if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
+    			// set the focus mode
+    			params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
+    			// set Camera parameters
+    			mCamera.setParameters(params);
+    		}
+    	}
+    }
+
+    @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.
+        try {
+            if (mCamera != null) {
+                mCamera.setPreviewDisplay(holder);
+            }
+        } catch (IOException exception) {
+            Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
+        }
+    }
+
+    public void surfaceDestroyed(SurfaceHolder holder) {
+        // Surface will be destroyed when we return, so stop the preview.
+        if (mCamera != null) {
+            mCamera.stopPreview();
+        }
+    }
+
+
+    private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
+        final double ASPECT_TOLERANCE = 0.1;
+        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) {
+    	if(mCamera != null) {
+    		Camera.Parameters parameters = mCamera.getParameters();
+    		parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
+    		requestLayout();
+
+    		mCamera.setParameters(parameters);
+    		mCamera.startPreview();
+    	}
+    }
+
+}
-- 
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