Here's what I created to hold the images that my app is currently displaying. Please note that the "Log" object in use here is my custom wrapper around the final Log class inside Android.
package com.wilson.android.library;
/*
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.
*/
import java.io.IOException;
public class DrawableManager {
private final Map<String, Drawable> drawableMap;
public DrawableManager() {
drawableMap = new HashMap<String, Drawable>();
}
public Drawable fetchDrawable(String urlString) {
if (drawableMap.containsKey(urlString)) {
return drawableMap.get(urlString);
}
Log.d(this.getClass().getSimpleName(), "image url:" + urlString);
try {
InputStream is = fetch(urlString);
Drawable drawable = Drawable.createFromStream(is, "src");
if (drawable != null) {
drawableMap.put(urlString, drawable);
Log.d(this.getClass().getSimpleName(), "got a thumbnail drawable: " + drawable.getBounds() + ", "
+ drawable.getIntrinsicHeight() + "," + drawable.getIntrinsicWidth() + ", "
+ drawable.getMinimumHeight() + "," + drawable.getMinimumWidth());
} else {
Log.w(this.getClass().getSimpleName(), "could not get thumbnail");
}
return drawable;
} catch (MalformedURLException e) {
Log.e(this.getClass().getSimpleName(), "fetchDrawable failed", e);
return null;
} catch (IOException e) {
Log.e(this.getClass().getSimpleName(), "fetchDrawable failed", e);
return null;
}
}
public void fetchDrawableOnThread(final String urlString, final ImageView imageView) {
if (drawableMap.containsKey(urlString)) {
imageView.setImageDrawable(drawableMap.get(urlString));
}
final Handler handler = new Handler() {
@Override
public void handleMessage(Message message) {
imageView.setImageDrawable((Drawable) message.obj);
}
};
Thread thread = new Thread() {
@Override
public void run() {
//TODO : set imageView to a "pending" image
Drawable drawable = fetchDrawable(urlString);
Message message = handler.obtainMessage(1, drawable);
handler.sendMessage(message);
}
};
thread.start();
}
private InputStream fetch(String urlString) throws MalformedURLException, IOException {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet request = new HttpGet(urlString);
HttpResponse response = httpClient.execute(request);
return response.getEntity().getContent();
}
}
Thanks to Code Shogun, whose code I adapted to my situation.
Let your activity implementOnClickListener
as usual:
public class SelectFilterActivity extends Activity implements OnClickListener {
private static final int SWIPE_MIN_DISTANCE = 120;
private static final int SWIPE_MAX_OFF_PATH = 250;
private static final int SWIPE_THRESHOLD_VELOCITY = 200;
private GestureDetector gestureDetector;
View.OnTouchListener gestureListener;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
/* ... */
// Gesture detection
gestureDetector = new GestureDetector(this, new MyGestureDetector());
gestureListener = new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
return gestureDetector.onTouchEvent(event);
}
};
}
class MyGestureDetector extends SimpleOnGestureListener {
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
try {
if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
return false;
// right to left swipe
if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
Toast.makeText(SelectFilterActivity.this, "Left Swipe", Toast.LENGTH_SHORT).show();
} else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
Toast.makeText(SelectFilterActivity.this, "Right Swipe", Toast.LENGTH_SHORT).show();
}
} catch (Exception e) {
// nothing
}
return false;
}
@Override
public boolean onDown(MotionEvent e) {
return true;
}
}
}
Attach your gesture listener to all the views you add to the main layout;
// Do this for each view added to the grid
imageView.setOnClickListener(SelectFilterActivity.this);
imageView.setOnTouchListener(gestureListener);
Watch in awe as your overridden methods are hit, both the onClick(View v)
of the activity and the onFling
of the gesture listener.
public void onClick(View v) {
Filter f = (Filter) v.getTag();
FilterFullscreenActivity.show(this, input, f);
}
The post 'fling' dance is optional but encouraged.
Best Answer
The action overflow menu is only available when there is no hard menu button available on the device. I found this stated in the Framework Topics under User Interface > Action Bar, check out the 3rd bullet here.
There is an action bar library written by Jake Wharton called ActionBarSherlock. Perhaps this is able to supply you with an action overflow menu style even when on older devices (which include a hard menu button), however I have not looked into this.
Edit: ActionBarSherlock 4.0 (currently a release candidate) has functionality built in to force action overflow. If you want to extend the ActionBarCompat example yourself, you could take a look on github to get an idea how Jake implemented it. I would suggest just looking into using his library all together, as it is very well done.
If you choose to use Jake's library, look into setting up the Activity theme as @style/Theme.Sherlock.ForceOverflow to force the overflow menu on older devices.
Edit2: Using
ForceOverflow
theme causes issues (example #1) on devices with hardware menu button. Thus, Jake Wharton is going to removeForceOverflow
in the future versions.