Question

I’m using mt4j library in a quite big project, in which scenes are pushed and poped regularly ; mt4j uses Processing library to deal with images.

We use the loadImage() method to load images, but I don’t know how to delete these images from memory when a scene is poped ; we have actually memory problems, because the memory used increases during the application running time..

Do you have some idea ?

Thanks
Jérémy

EDIT :

I just wrote an ImageManager class :

package managers;

import java.util.HashMap;
import java.util.Map;

import org.mt4j.MTApplication;

import processing.core.PImage;




public class ImageManager {

private static ImageManager mImageManager = null;

protected MTApplication mApp;
protected Map< String, PImage > mImages;

protected PImage mTempImg;

private ImageManager( MTApplication app ) {
    mApp = app;
    mImages = new HashMap< String, PImage >();
}

public static synchronized ImageManager getInstance( MTApplication app ) {
    if( mImageManager == null ) {
        mImageManager = new ImageManager( app );
    }

    return mImageManager;
}

/**
 * Load or retrieve img in memory
 * 
 * @param path Path to the image
 * @return <PImage> the image
 */
public PImage getImage( String path ) {
    // Search for image
    if( mImages.containsKey( path ) ) {
        System.out.println( "ImageManager::getImage : image found !" );
        mTempImg = mImages.get( path );
    } 
    else {
        System.out.println( "ImageManager::getImage : image not found, loading" );
        mTempImg = mApp.loadImage( path );
        mImages.put( path, mTempImg );
    }

    return mTempImg;
}
}

Here is my problem : I thought that it would help me with memory problems, but I still see memory increase every time I load an image. An exemple of use :

ImageManager imgManager = ImageManager.getInstance( (MTApplication) app );
            PImage image = imgManager.getImage( getPathToIcons() + imagesNames[i] );
            //PImage image = app.loadImage(getPathToIcons() + imagesNames[i]);
            mSceneImages.add( image );

Any idea ? Thanks

EDIT 2 : In fact, this method is working great 🙂 Problem solved !

Answer 1

EDIT : finally I’ve tryed to delete images at a time, but it doesn’t clean memory… It’s like there still is some other references that I can’t find… Any idea to be sure of memory cleaning ?

My solution to the problem : ImageManager class

package managers;

import java.util.HashMap;
import java.util.Map;

import org.mt4j.MTApplication;

import processing.core.PImage;




public class ImageManager {

private static ImageManager mImageManager = null;

protected MTApplication mApp;
protected Map< String, PImage > mImages;

protected PImage mTempImg;

private ImageManager( MTApplication app ) {
    mApp = app;
    mImages = new HashMap< String, PImage >();
}

public static synchronized ImageManager getInstance( MTApplication app ) {
    if( mImageManager == null ) {
        mImageManager = new ImageManager( app );
    }

    return mImageManager;
}

/**
 * Load or retrieve img in memory
 * 
 * @param path Path to the image
 * @return <PImage> the image
 */
public PImage getImage( String path ) {
    // Search for image
    if( mImages.containsKey( path ) ) {
        System.out.println( "ImageManager::getImage : image found !" );
        mTempImg = mImages.get( path );
    } 
    else {
        System.out.println( "ImageManager::getImage : image not found, loading" );
        mTempImg = mApp.loadImage( path );
        mImages.put( path, mTempImg );
    }

    return mTempImg;
}
}