GlobalOverlayService

I went through about 10 other implementations of the global floating overlays and none of them were as modular as I would have liked. So, this is my implementation.

Goals:

1. Minimal setup.
2. Looks "good enough".

Here's a quick demo video showing this library in action:

Main Features

1. Minimal setup
2. Looks "good enough"
3. Easy, readable implementation
4. Overlay view dragging
5. Simple onClick and onRemove listeners
6. Close view by dragging to an "X" view at the bottom of the screen
7. Simple demo

Simple Usage

1. Set this project as a dependency. In your app module's build.gradle, add the following lines:

    repositories {
        maven {
            url "https://jitpack.io"
        }
    }
   
    dependencies {
        compile 'com.github.danialgoodwin:android-global-overlay:v0.9'
    }
   

2. Create an instance of GlobalOverlay and call addOverlayView(View). Example working code:

    public class MySimpleOverlayService extends Service {
   
        private GlobalOverlay mGlobalOverlay;
   
        @Override
        public void onCreate() {
            super.onCreate();
            mGlobalOverlay = new GlobalOverlay(this);
   
            ImageView view = new ImageView(this);
            view.setImageResource(R.mipmap.ic_launcher);
            mGlobalOverlay.addOverlayView(view, new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    toast("onClick");
                    stopSelf(); // Stop service not needed.
                }
            });
        }
   
        private void toast(String message) {
            Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
        }
   
    }
   

3. In AndroidManifest.xml, add your Service and the required Android permission:

    <manifest ...>
   
        <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
   
        <application ...>
            ...
            <service android:name=".MySimpleOverlayService"
                android:exported="false"
                android:enabled="true" />
        </application>
    </manifest>
   

4. Call startService() whenever you want to show the global overlay. For example, in my MainActivity.java:

    private void startOverlay() {
        startService(new Intent(this, MySimpleOverlayService.class));
    }
   

Done. Most cases won't need to do any more than that. Though there are a few more methods to support other use cases.

The library class GlobalOverlay has a few more features available:

• In the above sample, where the OnClickListener is passed in as an argument, there's an overloaded method that also allows an OnLongClickListener and OnOverlayRemoveListener. (Note: OnLongClickListener isn't implemented yet.)
• Change what the "remove view" looks by using the overloaded constructor GlobalOverlay(Context, View).
• You can remove the overlay without destroying the Service by calling removeOverlayView(View) with the same view you used in addOverlayView(View).
• The OnRemoveOverlayListener.onRemoveOverlay provides an argument that takes into account whether or not the user is the one to remove the overlay. (I'm using this info for analytics)

Limitations

• Currently, the OnLongClickListener isn't implemented. (Mainly, because I didn't need it, but I provide a starting point in the source code. ;) )
• The minSdkVersion is 15. There's nothing fancy about the library, so I'm sure it will work for lower APIs, but I haven't checked.

Possible Gotchas

• When the user manually removes the overlay (by dragging to the removeView), you would have to manually stop the service is it's not needed anymore.
• Currently, only one floating overlay view is allowed at a time.

Contributing

Have fun. Pull requests welcomed. This was a very simple library to create and is simple to modify and extend.

Want ideas?

• How about fully implementing the OnLongClickListener?
• Allowing library implementer to setup by just providing the resDrawableId, rather than the full View.
• Better default UX for overlay view
• Better default UX for remove view
• Allowing library implementer to stylize components rather than replacing them. Perhaps defaulting to match theme.

AOSP code style preferred.

Modifying the drag style

The current implementation is set in addOverlayView(), which calls newSimpleOnTouchListener(). So, you can either tweak that or just provide a different way for getting the required OnTouchListener.

API Design considerations

The first version of this library extended Service. Since v0.9, the main library has been changed to be a regular object that was more versatile with only a few more lines for the API implementer. For a while, the old GlobalOverlayService will remain in the repo.

License

The MIT License (MIT)

Copyright (c) 2015 Danial Goodwin

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.