net.mutina.uclimb.ForegroundCameraLauncher.java Source code

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Here is the source code for net.mutina.uclimb.ForegroundCameraLauncher.java

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/*
   Licensed to the Apache Software Foundation (ASF) under one
   or more contributor license agreements.  See the NOTICE file
   distributed with this work for additional information
   regarding copyright ownership.  The ASF licenses this file
   to you 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 net.mutina.uclimb;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;

import org.apache.cordova.CameraLauncher;
import org.apache.cordova.ExifHelper;
import org.apache.cordova.api.CordovaInterface;
import org.apache.cordova.api.LOG;
import org.apache.cordova.api.Plugin;
import org.apache.cordova.api.PluginResult;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;

/**
 * This class launches the camera view, allows the user to take a picture, closes the camera view,
 * and returns the captured image.  When the camera view is closed, the screen displayed before 
 * the camera view was shown is redisplayed.
 */
public class ForegroundCameraLauncher extends CameraLauncher {

    private static final String LOG_TAG = "ForegroundCameraLauncher";

    private int mQuality;
    private int targetWidth;
    private int targetHeight;

    private Uri imageUri;
    private File photo;

    public String callbackId;
    private int numPics;

    private static final String _DATA = "_data";

    /**
     * Constructor.
     */
    public ForegroundCameraLauncher() {
    }

    /**
     * Executes the request and returns PluginResult.
     * 
     * @param action        The action to execute.
     * @param args          JSONArry of arguments for the plugin.
     * @param callbackId    The callback id used when calling back into JavaScript.
     * @return              A PluginResult object with a status and message.
     */
    public PluginResult execute(String action, JSONArray args, String callbackId) {
        PluginResult.Status status = PluginResult.Status.OK;
        String result = "";
        this.callbackId = callbackId;

        try {
            if (action.equals("takePicture")) {
                this.targetHeight = 0;
                this.targetWidth = 0;
                this.mQuality = 80;

                JSONObject options = args.optJSONObject(0);
                if (options != null) {
                    this.targetHeight = options.getInt("targetHeight");
                    this.targetWidth = options.getInt("targetWidth");
                    this.mQuality = options.getInt("quality");
                }

                this.takePicture();

                PluginResult r = new PluginResult(PluginResult.Status.NO_RESULT);
                r.setKeepCallback(true);
                return r;
            }
            return new PluginResult(status, result);
        } catch (JSONException e) {
            e.printStackTrace();
            return new PluginResult(PluginResult.Status.JSON_EXCEPTION);
        }
    }

    //--------------------------------------------------------------------------
    // LOCAL METHODS
    //--------------------------------------------------------------------------

    /**
     * Take a picture with the camera.
     * When an image is captured or the camera view is cancelled, the result is returned
     * in CordovaActivity.onActivityResult, which forwards the result to this.onActivityResult.
     * 
     * The image can either be returned as a base64 string or a URI that points to the file.
     * To display base64 string in an img tag, set the source to:
     *      img.src="data:image/jpeg;base64,"+result;
     * or to display URI in an img tag
     *      img.src=result;
     * 
     */
    public void takePicture() {
        // Save the number of images currently on disk for later
        this.numPics = queryImgDB().getCount();

        Intent intent = new Intent(this.ctx.getContext(), CameraActivity.class);
        this.photo = createCaptureFile();
        this.imageUri = Uri.fromFile(photo);
        intent.putExtra(MediaStore.EXTRA_OUTPUT, this.imageUri);

        this.ctx.startActivityForResult((Plugin) this, intent, 1);
    }

    /**
     * Create a file in the applications temporary directory based upon the supplied encoding.
     * 
     * @return a File object pointing to the temporary picture
     */
    private File createCaptureFile() {
        File photo = new File(getTempDirectoryPath(ctx.getContext()), "Pic.jpg");
        return photo;
    }

    /**
     * Called when the camera view exits. 
     * 
     * @param requestCode       The request code originally supplied to startActivityForResult(), 
     *                          allowing you to identify who this result came from.
     * @param resultCode        The integer result code returned by the child activity through its setResult().
     * @param intent            An Intent, which can return result data to the caller (various data can be attached to Intent "extras").
     */
    public void onActivityResult(int requestCode, int resultCode, Intent intent) {

        // If image available
        if (resultCode == Activity.RESULT_OK) {
            try {
                // Create an ExifHelper to save the exif data that is lost during compression
                ExifHelper exif = new ExifHelper();
                exif.createInFile(getTempDirectoryPath(ctx.getContext()) + "/Pic.jpg");
                exif.readExifData();

                // Read in bitmap of captured image
                Bitmap bitmap;
                try {
                    bitmap = android.provider.MediaStore.Images.Media.getBitmap(this.ctx.getContentResolver(),
                            imageUri);
                } catch (FileNotFoundException e) {
                    Uri uri = intent.getData();
                    android.content.ContentResolver resolver = this.ctx.getContentResolver();
                    bitmap = android.graphics.BitmapFactory.decodeStream(resolver.openInputStream(uri));
                }

                bitmap = scaleBitmap(bitmap);

                // Create entry in media store for image
                // (Don't use insertImage() because it uses default compression setting of 50 - no way to change it)
                ContentValues values = new ContentValues();
                values.put(android.provider.MediaStore.Images.Media.MIME_TYPE, "image/jpeg");
                Uri uri = null;
                try {
                    uri = this.ctx.getContentResolver()
                            .insert(android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
                } catch (UnsupportedOperationException e) {
                    LOG.d(LOG_TAG, "Can't write to external media storage.");
                    try {
                        uri = this.ctx.getContentResolver()
                                .insert(android.provider.MediaStore.Images.Media.INTERNAL_CONTENT_URI, values);
                    } catch (UnsupportedOperationException ex) {
                        LOG.d(LOG_TAG, "Can't write to internal media storage.");
                        this.failPicture("Error capturing image - no media storage found.");
                        return;
                    }
                }

                // Add compressed version of captured image to returned media store Uri
                OutputStream os = this.ctx.getContentResolver().openOutputStream(uri);
                bitmap.compress(Bitmap.CompressFormat.JPEG, this.mQuality, os);
                os.close();

                // Restore exif data to file
                exif.createOutFile(getRealPathFromURI(uri, this.ctx));
                exif.writeExifData();

                // Send Uri back to JavaScript for viewing image
                this.success(new PluginResult(PluginResult.Status.OK, uri.toString()), this.callbackId);

                bitmap.recycle();
                bitmap = null;
                System.gc();

                checkForDuplicateImage();
            } catch (IOException e) {
                e.printStackTrace();
                this.failPicture("Error capturing image.");
            }
        }

        // If cancelled
        else if (resultCode == Activity.RESULT_CANCELED) {
            this.failPicture("Camera cancelled.");
        }

        // If something else
        else {
            this.failPicture("Did not complete!");
        }
    }

    /**
     * Scales the bitmap according to the requested size.
     * 
     * @param bitmap        The bitmap to scale.
     * @return Bitmap       A new Bitmap object of the same bitmap after scaling. 
     */
    public Bitmap scaleBitmap(Bitmap bitmap) {
        int newWidth = this.targetWidth;
        int newHeight = this.targetHeight;
        int origWidth = bitmap.getWidth();
        int origHeight = bitmap.getHeight();

        // If no new width or height were specified return the original bitmap
        if (newWidth <= 0 && newHeight <= 0) {
            return bitmap;
        }
        // Only the width was specified
        else if (newWidth > 0 && newHeight <= 0) {
            newHeight = (newWidth * origHeight) / origWidth;
        }
        // only the height was specified
        else if (newWidth <= 0 && newHeight > 0) {
            newWidth = (newHeight * origWidth) / origHeight;
        }
        // If the user specified both a positive width and height
        // (potentially different aspect ratio) then the width or height is
        // scaled so that the image fits while maintaining aspect ratio.
        // Alternatively, the specified width and height could have been
        // kept and Bitmap.SCALE_TO_FIT specified when scaling, but this
        // would result in whitespace in the new image.
        else {
            double newRatio = newWidth / (double) newHeight;
            double origRatio = origWidth / (double) origHeight;

            if (origRatio > newRatio) {
                newHeight = (newWidth * origHeight) / origWidth;
            } else if (origRatio < newRatio) {
                newWidth = (newHeight * origWidth) / origHeight;
            }
        }

        return Bitmap.createScaledBitmap(bitmap, newWidth, newHeight, true);
    }

    /**
     * Creates a cursor that can be used to determine how many images we have.
     * 
     * @return a cursor
     */
    private Cursor queryImgDB() {
        return this.ctx.getContentResolver().query(android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                new String[] { MediaStore.Images.Media._ID }, null, null, null);
    }

    /**
     * Used to find out if we are in a situation where the Camera Intent adds to images
     * to the content store. If we are using a FILE_URI and the number of images in the DB 
     * increases by 2 we have a duplicate, when using a DATA_URL the number is 1.
     */
    private void checkForDuplicateImage() {
        int diff = 2;
        Cursor cursor = queryImgDB();
        int currentNumOfImages = cursor.getCount();

        // delete the duplicate file if the difference is 2 for file URI or 1 for Data URL
        if ((currentNumOfImages - numPics) == diff) {
            cursor.moveToLast();
            int id = Integer.valueOf(cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media._ID))) - 1;
            Uri uri = Uri.parse(MediaStore.Images.Media.EXTERNAL_CONTENT_URI + "/" + id);
            this.ctx.getContentResolver().delete(uri, null, null);
        }
    }

    /**
     * Determine if we can use the SD Card to store the temporary file.  If not then use 
     * the internal cache directory.
     * 
     * @return the absolute path of where to store the file
     */
    private String getTempDirectoryPath(Context ctx) {
        File cache = null;

        // SD Card Mounted
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            cache = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/Android/data/"
                    + ctx.getPackageName() + "/cache/");
        }
        // Use internal storage
        else {
            cache = ctx.getCacheDir();
        }

        // Create the cache directory if it doesn't exist
        if (!cache.exists()) {
            cache.mkdirs();
        }

        return cache.getAbsolutePath();
    }

    /**
     * Queries the media store to find out what the file path is for the Uri we supply
     *
     * @param contentUri the Uri of the audio/image/video
     * @param ctx the current applicaiton context
     * @return the full path to the file
     */
    private String getRealPathFromURI(Uri contentUri, CordovaInterface ctx) {
        String[] proj = { _DATA };
        Cursor cursor = ctx.managedQuery(contentUri, proj, null, null, null);
        int column_index = cursor.getColumnIndexOrThrow(_DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    }
}