[CB-14] CameraLauncher Plugin enhancement for loading big image files to avoid OutOfMemory exceptions

• Type: Improvement
• Status: Closed
• Priority: Critical
• Resolution: Not A Problem
• Affects Version/s: 1.1.0
• Fix Version/s: 1.6.0
• Component/s: cordova-android
• Labels: CameraLauncher OutOfMemory decodeStream

Environment

Android SDK: 2.x & above
JDK: 1.6
Eclipse: Helios

• Assignee: Joey Robert Bowser
• Reporter: Bright Zheng
• Created: 08/Nov/11 07:34
• Updated: 23/Aug/18 07:18
• Resolved: 06/Mar/12 21:18

Description

Currently the CameraLauncher plugin of Phonegap (or Apache Callback) is using Android default API for stream decoding.
It will be very easy to get crash by throwing out the OutOfMemory exceptions while loading bigger image files.

So I add a new method called safeDecodeStream for better stream decoding.

safeDecodeStream method

    /**
     * A safer decodeStream method
     * rather than the one of {@link BitmapFactory}
     * which will be easy to get OutOfMemory Exception
     * while loading a big image file.
     * 
     * @param uri
     * @param width
     * @param height
     * @return
     * @throws FileNotFoundException
     */
    protected Bitmap safeDecodeStream(Uri uri, int width, int height)
    throws FileNotFoundException{
		int scale = 1;
		BitmapFactory.Options options = new BitmapFactory.Options();
		android.content.ContentResolver resolver = this.ctx.getContentResolver();
		
		if(width>0 || height>0){
			// Decode image size without loading all data into memory
			options.inJustDecodeBounds = true;
			BitmapFactory.decodeStream(
					new BufferedInputStream(resolver.openInputStream(uri), 16*1024),
					null,
					options);
			
			int w = options.outWidth;
			int h = options.outHeight;
			while (true) {
				if ((width>0 && w/2 < width)
						|| (height>0 && h/2 < height)){
					break;
				}
				w /= 2;
				h /= 2;
				scale *= 2;
			}
		}

		// Decode with inSampleSize option
		options.inJustDecodeBounds = false;
		options.inSampleSize = scale;
		return BitmapFactory.decodeStream(
				new BufferedInputStream(resolver.openInputStream(uri), 16*1024), 
				null, 
				options);
	}  

And then change all the codes which are invoking the Android decodeStream API directly to this method.
e.g.

usage example

//Updated by Bright for safer decodeStream
//android.content.ContentResolver resolver = this.ctx.getContentResolver();
//bitmap = android.graphics.BitmapFactory.decodeStream(resolver.openInputStream(uri));
bitmap = safeDecodeStream(uri, this.targetWidth, this.targetHeight);