fix async image logic

This was done completely wrong. The view will recycle the individual
view at will, so you can't keep a map of them like we had. instead,
use a SoftReference cache of the drawables so that we can display
them quickly when possible

1 files changed, 26 insertions, 10 deletions

diff --git a/src/org/linaro/connect/JSONImageListAdapter.java b/src/org/linaro/connect/JSONImageListAdapter.java
index ab02307..8c2715d 100644
--- a/src/org/linaro/connect/JSONImageListAdapter.java
+++ b/src/org/linaro/connect/JSONImageListAdapter.java
@@ -1,11 +1,13 @@
 package org.linaro.connect;
 
+import java.lang.ref.SoftReference;
 import java.util.HashMap;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
 
 import android.content.Context;
 import android.graphics.drawable.Drawable;
+import android.os.Handler;
 import android.util.Log;
 import android.view.View;
 import android.view.ViewGroup;
@@ -15,16 +17,18 @@ import android.widget.ImageView;
 
 public class JSONImageListAdapter extends ArrayAdapter<JSONImageItem> {
 
+	private final Handler mHandler;
 	private final BlockingQueue<JSONImageItem> mItemQueue;
-	private final HashMap<JSONImageItem, ImageView> mItemMap;
+	private final HashMap<JSONImageItem,SoftReference<Drawable>> mCache;
 
 	private boolean mWorking = true;
 
 	public JSONImageListAdapter(Context ctx) {
 		super(ctx, 0, 0);
 
-		mItemMap = new HashMap<JSONImageItem, ImageView>();
+		mCache = new HashMap<JSONImageItem,SoftReference<Drawable>>();
 		mItemQueue = new LinkedBlockingQueue<JSONImageItem>();
+		mHandler = new Handler();
 		new Thread(mDownloader).start();
 	}
 
@@ -41,10 +45,19 @@ public class JSONImageListAdapter extends ArrayAdapter<JSONImageItem> {
 			imageView = (ImageView) convertView;
 		}
 
-		imageView.setImageResource(R.drawable.image_loading);
-
 		JSONImageItem jso = getItem(position);
-		mItemMap.put(jso, imageView);
+		SoftReference<Drawable> ref = mCache.get(jso);
+		if( ref != null ) {
+			Drawable d = ref.get();
+			if( d == null ) { //we've been garbage collected, read from cache
+				d = jso.getThumnail();
+				mCache.put(jso, new SoftReference<Drawable>(d));
+			}
+
+			imageView.setImageDrawable(d);
+		} else {
+			imageView.setImageResource(R.drawable.image_loading);
+		}
 		return imageView;
 	}
 
@@ -60,16 +73,19 @@ public class JSONImageListAdapter extends ArrayAdapter<JSONImageItem> {
 
 	private void downloadAndDisplay(JSONImageItem jsi) {
 		final Drawable d = jsi.getThumnail();
-		final ImageView iv = mItemMap.get(jsi);
-		if( d != null && iv != null )
-			iv.post(new Runnable() {
+		if ( d != null ) {
+			mCache.put(jsi, new SoftReference<Drawable>(d));
+			mHandler.post(new Runnable() {
 				@Override
 				public void run() {
-					iv.setImageDrawable(d);
+					notifyDataSetChanged();
 				}
 			});
-		else
+		}
+		else {
 			Log.e(LinaroConnect.TAG, "null jso or view in image list");
+			mItemQueue.add(jsi); //try again for later
+		}
 	}
 
 	private final Runnable mDownloader = new Runnable() {