Added UI for config (config itself is missing though)

New way to directly call settings activity of backend (if set), see second sample

AndroidManifest.xml

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-	package="org.microg.nlp">
+<manifest package="org.microg.nlp"
+	xmlns:android="http://schemas.android.com/apk/res/android">
 
-	<uses-sdk android:minSdkVersion="9" />
+	<uses-sdk android:minSdkVersion="14" />
 
 	<application
 		android:icon="@drawable/nlp_app_icon"
@@ -64,7 +64,7 @@
 
 		<activity
 			android:name="org.microg.nlp.ui.LocationBackendConfig"
-			android:theme="@android:style/Theme.DeviceDefault.Light">
+			android:theme="@android:style/Theme.Holo.Light">
 			<intent-filter>
 				<action android:name="android.intent.action.MAIN" />
 				<category android:name="android.intent.category.LAUNCHER" />

README.md

@@ -4,3 +4,5 @@ The next generation NetworkLocationProvider, based on plugins
 `sample` contains a sample plugin.
 
 To be build with Android Build System using `make UnifiedNlp`
+
+Some components: Copyright (C) 2013 The Android Open Source Project

api/src/org/microg/nlp/api/NlpApiConstants.java

@@ -2,4 +2,5 @@ package org.microg.nlp.api;
 
 public class NlpApiConstants {
 	public static final String ACTION_LOCATION_BACKEND = "org.microg.nlp.LOCATION_BACKEND";
+	public static final String METADATA_BACKEND_SETTINGS_ACTIVITY = "org.microg.nlp.BACKEND_SETTINGS_ACTIVITY";
 }

res/layout/backend_list_entry.xml

@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+	android:orientation="horizontal"
+	android:layout_width="match_parent"
+	android:layout_height="wrap_content"
+	android:gravity="center_vertical"
+	android:padding="16dp">
+
+	<ImageView
+		android:id="@android:id/icon"
+		android:layout_width="48dp"
+		android:layout_height="48dp" />
+
+	<LinearLayout
+		android:orientation="vertical"
+		android:layout_width="0dip"
+		android:layout_weight="1"
+		android:paddingLeft="8dp"
+		android:paddingRight="8dp"
+		android:layout_height="wrap_content">
+
+		<!-- simple name -->
+		<TextView
+			android:id="@android:id/text1"
+			style="?android:textAppearanceMedium"
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content" />
+
+		<!-- service info -->
+		<TextView
+			android:id="@android:id/text2"
+			style="?android:textAppearanceSmall"
+			android:visibility="gone"
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content" />
+
+	</LinearLayout>
+
+	<ImageView
+		android:id="@android:id/button1"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:focusable="false"
+		android:clickable="false"
+		android:background="?android:selectableItemBackground"
+		android:src="@drawable/ic_menu_moreoverflow_normal_holo_light" />
+</LinearLayout>

res/layout/pluginselection.xml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+	android:orientation="vertical"
+	android:layout_width="match_parent"
+	android:layout_height="match_parent">
+
+	<org.microg.nlp.ui.DynamicListView
+		android:id="@android:id/list"
+		android:layout_width="match_parent"
+		android:layout_height="wrap_content" />
+
+	<TextView
+		android:id="@android:id/button1"
+		android:duplicateParentState="true"
+		android:layout_width="wrap_content"
+		android:layout_height="?android:listPreferredItemHeight"
+		android:layout_gravity="center"
+		android:paddingRight="20dp"
+		android:drawableLeft="@drawable/ic_action_add"
+		android:drawablePadding="8dp"
+		android:gravity="center_vertical"
+		android:textColor="#c333"
+		android:textAppearance="?android:textAppearanceMedium"
+		android:textStyle="bold"
+		android:textAllCaps="true"
+		android:text="@string/add_plugin" />
+</LinearLayout>

res/values/strings.xml

@@ -1,4 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
 	<string name="nlp_app_name">NLP Controller</string>
+	<string name="add_plugin">Add plugin</string>
 </resources>

sample/AndroidManifest.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-	package="org.microg.nlp.api.sample">
+<manifest package="org.microg.nlp.api.sample"
+	xmlns:android="http://schemas.android.com/apk/res/android">
 
 	<uses-sdk android:minSdkVersion="19" />
 	<application
@@ -8,10 +8,27 @@
 		android:label="@string/app_name">
 		<service
 			android:name=".SampleBackendService"
-			android:exported="true">
+			android:exported="true"
+			android:label="NLPV2-Sample">
 			<intent-filter>
 				<action android:name="org.microg.nlp.LOCATION_BACKEND" />
 			</intent-filter>
 		</service>
+		<service
+			android:name=".SecondSampleService"
+			android:exported="true"
+			android:label="NLPV2-Second">
+			<intent-filter>
+				<action android:name="org.microg.nlp.LOCATION_BACKEND" />
+			</intent-filter>
+			<meta-data
+				android:name="org.microg.nlp.BACKEND_SETTINGS_ACTIVITY"
+				android:value="org.microg.nlp.api.sample.SecondSettings" />
+		</service>
+
+		<activity
+			android:name=".SecondSettings"
+			android:exported="true"
+			android:label="Second Settings Activity" />
 	</application>
 </manifest>

sample/src/org/microg/nlp/api/sample/SecondSampleService.java

@@ -0,0 +1,15 @@
+package org.microg.nlp.api.sample;
+
+import android.location.Location;
+import org.microg.nlp.api.LocationBackendService;
+
+public class SecondSampleService extends LocationBackendService {
+	@Override
+	protected Location update() {
+		Location location = new Location("second-sample");
+		location.setLatitude(13);
+		location.setLongitude(13);
+		location.setAccuracy(100);
+		return location;
+	}
+}

sample/src/org/microg/nlp/api/sample/SecondSettings.java

@@ -0,0 +1,10 @@
+package org.microg.nlp.api.sample;
+
+import android.app.Activity;
+import android.os.Bundle;
+
+public class SecondSettings extends Activity {
+	public void onCreate(Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+	}
+}

src/org/microg/nlp/geocode/GeocodeService.java

@@ -1,8 +1,5 @@
 package org.microg.nlp.geocode;
 
-import android.app.Service;
-import android.content.Intent;
-import android.os.IBinder;
 import org.microg.nlp.ProviderService;
 
 public abstract class GeocodeService extends ProviderService {

src/org/microg/nlp/ui/DynamicListView.java

@@ -0,0 +1,611 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed 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.
+ */
+
+package org.microg.nlp.ui;
+
+import android.animation.*;
+import android.content.Context;
+import android.content.pm.ServiceInfo;
+import android.graphics.*;
+import android.graphics.drawable.BitmapDrawable;
+import android.util.AttributeSet;
+import android.util.DisplayMetrics;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.ViewTreeObserver;
+import android.widget.*;
+
+import java.util.HashMap;
+import java.util.List;
+
+/**
+ * The dynamic listview is an extension of listview that supports cell dragging
+ * and swapping.
+ * <p/>
+ * This layout is in charge of positioning the hover cell in the correct location
+ * on the screen in response to user touch events. It uses the position of the
+ * hover cell to determine when two cells should be swapped. If two cells should
+ * be swapped, all the corresponding data set and layout changes are handled here.
+ * <p/>
+ * If no cell is selected, all the touch events are passed down to the listview
+ * and behave normally. If one of the items in the listview experiences a
+ * long press event, the contents of its current visible state are captured as
+ * a bitmap and its visibility is set to INVISIBLE. A hover cell is then created and
+ * added to this layout as an overlaying BitmapDrawable above the listview. Once the
+ * hover cell is translated some distance to signify an item swap, a data set change
+ * accompanied by animation takes place. When the user releases the hover cell,
+ * it animates into its corresponding position in the listview.
+ * <p/>
+ * When the hover cell is either above or below the bounds of the listview, this
+ * listview also scrolls on its own so as to reveal additional content.
+ */
+public class DynamicListView extends ListView {
+
+	/**
+	 * This TypeEvaluator is used to animate the BitmapDrawable back to its
+	 * final location when the user lifts his finger by modifying the
+	 * BitmapDrawable's bounds.
+	 */
+	private final static TypeEvaluator<Rect> sBoundEvaluator = new TypeEvaluator<Rect>() {
+		public Rect evaluate(float fraction, Rect startValue, Rect endValue) {
+			return new Rect(interpolate(startValue.left, endValue.left, fraction),
+					interpolate(startValue.top, endValue.top, fraction),
+					interpolate(startValue.right, endValue.right, fraction),
+					interpolate(startValue.bottom, endValue.bottom, fraction));
+		}
+
+		public int interpolate(int start, int end, float fraction) {
+			return (int) (start + fraction * (end - start));
+		}
+	};
+	private final int SMOOTH_SCROLL_AMOUNT_AT_EDGE = 15;
+	private final int MOVE_DURATION = 150;
+	private final int LINE_THICKNESS = 15;
+	private final int INVALID_ID = -1;
+	private long mBelowItemId = INVALID_ID;
+	private long mMobileItemId = INVALID_ID;
+	private long mAboveItemId = INVALID_ID;
+	private final int INVALID_POINTER_ID = -1;
+	private int mActivePointerId = INVALID_POINTER_ID;
+	public List<ServiceInfo> mList;
+	private int mLastEventY = -1;
+	private int mDownY = -1;
+	private int mDownX = -1;
+	private int mTotalOffset = 0;
+	private boolean mCellIsMobile = false;
+	private boolean mIsMobileScrolling = false;
+	private int mSmoothScrollAmountAtEdge = 0;
+	private BitmapDrawable mHoverCell;
+	/**
+	 * Listens for long clicks on any items in the listview. When a cell has
+	 * been selected, the hover cell is created and set up.
+	 */
+	private AdapterView.OnItemLongClickListener mOnItemLongClickListener =
+			new AdapterView.OnItemLongClickListener() {
+				public boolean onItemLongClick(AdapterView<?> arg0, View arg1, int pos, long id) {
+					mTotalOffset = 0;
+
+					int position = pointToPosition(mDownX, mDownY);
+					int itemNum = position - getFirstVisiblePosition();
+
+					View selectedView = getChildAt(itemNum);
+					mMobileItemId = getAdapter().getItemId(position);
+					mHoverCell = getAndAddHoverView(selectedView);
+					selectedView.setVisibility(INVISIBLE);
+
+					mCellIsMobile = true;
+
+					updateNeighborViewsForID(mMobileItemId);
+
+					return true;
+				}
+			};
+	private Rect mHoverCellCurrentBounds;
+	private Rect mHoverCellOriginalBounds;
+	private boolean mIsWaitingForScrollFinish = false;
+	private int mScrollState = OnScrollListener.SCROLL_STATE_IDLE;
+
+	public DynamicListView(Context context) {
+		super(context);
+		init(context);
+	}
+
+	public DynamicListView(Context context, AttributeSet attrs, int defStyle) {
+		super(context, attrs, defStyle);
+		init(context);
+	}
+
+	public DynamicListView(Context context, AttributeSet attrs) {
+		super(context, attrs);
+		init(context);
+	}
+
+	public void init(Context context) {
+		setOnItemLongClickListener(mOnItemLongClickListener);
+		setOnScrollListener(mScrollListener);
+		DisplayMetrics metrics = context.getResources().getDisplayMetrics();
+		mSmoothScrollAmountAtEdge = (int) (SMOOTH_SCROLL_AMOUNT_AT_EDGE / metrics.density);
+	}
+
+	/**
+	 * Creates the hover cell with the appropriate bitmap and of appropriate
+	 * size. The hover cell's BitmapDrawable is drawn on top of the bitmap every
+	 * single time an invalidate call is made.
+	 */
+	private BitmapDrawable getAndAddHoverView(View v) {
+
+		int w = v.getWidth();
+		int h = v.getHeight();
+		int top = v.getTop();
+		int left = v.getLeft();
+
+		Bitmap b = getBitmapWithBorder(v);
+
+		BitmapDrawable drawable = new BitmapDrawable(getResources(), b);
+
+		mHoverCellOriginalBounds = new Rect(left, top, left + w, top + h);
+		mHoverCellCurrentBounds = new Rect(mHoverCellOriginalBounds);
+
+		drawable.setBounds(mHoverCellCurrentBounds);
+
+		return drawable;
+	}
+
+	/**
+	 * Draws a black border over the screenshot of the view passed in.
+	 */
+	private Bitmap getBitmapWithBorder(View v) {
+		Bitmap bitmap = getBitmapFromView(v);
+		Canvas can = new Canvas(bitmap);
+
+		Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
+
+		Paint paint = new Paint();
+		paint.setStyle(Paint.Style.STROKE);
+		paint.setStrokeWidth(LINE_THICKNESS);
+		paint.setColor(Color.BLACK);
+
+		can.drawBitmap(bitmap, 0, 0, null);
+		can.drawRect(rect, paint);
+
+		return bitmap;
+	}
+
+	/**
+	 * Returns a bitmap showing a screenshot of the view passed in.
+	 */
+	private Bitmap getBitmapFromView(View v) {
+		Bitmap bitmap = Bitmap.createBitmap(v.getWidth(), v.getHeight(), Bitmap.Config.ARGB_8888);
+		Canvas canvas = new Canvas(bitmap);
+		v.draw(canvas);
+		return bitmap;
+	}
+
+	/**
+	 * Stores a reference to the views above and below the item currently
+	 * corresponding to the hover cell. It is important to note that if this
+	 * item is either at the top or bottom of the list, mAboveItemId or mBelowItemId
+	 * may be invalid.
+	 */
+	private void updateNeighborViewsForID(long itemID) {
+		int position = getPositionForID(itemID);
+		StableArrayAdapter adapter = ((StableArrayAdapter) getAdapter());
+		mAboveItemId = adapter.getItemId(position - 1);
+		mBelowItemId = adapter.getItemId(position + 1);
+	}
+
+	/**
+	 * Retrieves the view in the list corresponding to itemID
+	 */
+	public View getViewForID(long itemID) {
+		int firstVisiblePosition = getFirstVisiblePosition();
+		StableArrayAdapter adapter = ((StableArrayAdapter) getAdapter());
+		for (int i = 0; i < getChildCount(); i++) {
+			View v = getChildAt(i);
+			int position = firstVisiblePosition + i;
+			long id = adapter.getItemId(position);
+			if (id == itemID) {
+				return v;
+			}
+		}
+		return null;
+	}
+
+	/**
+	 * Retrieves the position in the list corresponding to itemID
+	 */
+	public int getPositionForID(long itemID) {
+		View v = getViewForID(itemID);
+		if (v == null) {
+			return -1;
+		} else {
+			return getPositionForView(v);
+		}
+	}
+
+	/**
+	 * dispatchDraw gets invoked when all the child views are about to be drawn.
+	 * By overriding this method, the hover cell (BitmapDrawable) can be drawn
+	 * over the listview's items whenever the listview is redrawn.
+	 */
+	@Override
+	protected void dispatchDraw(Canvas canvas) {
+		super.dispatchDraw(canvas);
+		if (mHoverCell != null) {
+			mHoverCell.draw(canvas);
+		}
+	}
+
+	@Override
+	public boolean onTouchEvent(MotionEvent event) {
+
+		switch (event.getAction() & MotionEvent.ACTION_MASK) {
+			case MotionEvent.ACTION_DOWN:
+				mDownX = (int) event.getX();
+				mDownY = (int) event.getY();
+				mActivePointerId = event.getPointerId(0);
+				break;
+			case MotionEvent.ACTION_MOVE:
+				if (mActivePointerId == INVALID_POINTER_ID) {
+					break;
+				}
+
+				int pointerIndex = event.findPointerIndex(mActivePointerId);
+
+				mLastEventY = (int) event.getY(pointerIndex);
+				int deltaY = mLastEventY - mDownY;
+
+				if (mCellIsMobile) {
+					mHoverCellCurrentBounds.offsetTo(mHoverCellOriginalBounds.left,
+							mHoverCellOriginalBounds.top + deltaY + mTotalOffset);
+					mHoverCell.setBounds(mHoverCellCurrentBounds);
+					invalidate();
+
+					handleCellSwitch();
+
+					mIsMobileScrolling = false;
+					handleMobileCellScroll();
+
+					return false;
+				}
+				break;
+			case MotionEvent.ACTION_UP:
+				touchEventsEnded();
+				break;
+			case MotionEvent.ACTION_CANCEL:
+				touchEventsCancelled();
+				break;
+			case MotionEvent.ACTION_POINTER_UP:
+			    /* If a multitouch event took place and the original touch dictating
+		         * the movement of the hover cell has ended, then the dragging event
+                 * ends and the hover cell is animated to its corresponding position
+                 * in the listview. */
+				pointerIndex = (event.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >>
+						MotionEvent.ACTION_POINTER_INDEX_SHIFT;
+				final int pointerId = event.getPointerId(pointerIndex);
+				if (pointerId == mActivePointerId) {
+					touchEventsEnded();
+				}
+				break;
+			default:
+				break;
+		}
+
+		return super.onTouchEvent(event);
+	}
+
+	/**
+	 * This method determines whether the hover cell has been shifted far enough
+	 * to invoke a cell swap. If so, then the respective cell swap candidate is
+	 * determined and the data set is changed. Upon posting a notification of the
+	 * data set change, a layout is invoked to place the cells in the right place.
+	 * Using a ViewTreeObserver and a corresponding OnPreDrawListener, we can
+	 * offset the cell being swapped to where it previously was and then animate it to
+	 * its new position.
+	 */
+	private void handleCellSwitch() {
+		final int deltaY = mLastEventY - mDownY;
+		int deltaYTotal = mHoverCellOriginalBounds.top + mTotalOffset + deltaY;
+
+		View belowView = getViewForID(mBelowItemId);
+		View mobileView = getViewForID(mMobileItemId);
+		View aboveView = getViewForID(mAboveItemId);
+
+		boolean isBelow = (belowView != null) && (deltaYTotal > belowView.getTop());
+		boolean isAbove = (aboveView != null) && (deltaYTotal < aboveView.getTop());
+
+		if (isBelow || isAbove) {
+
+			final long switchItemID = isBelow ? mBelowItemId : mAboveItemId;
+			View switchView = isBelow ? belowView : aboveView;
+			final int originalItem = getPositionForView(mobileView);
+
+			if (switchView == null) {
+				updateNeighborViewsForID(mMobileItemId);
+				return;
+			}
+
+			swapElements(mList, originalItem, getPositionForView(switchView));
+
+			((BaseAdapter) getAdapter()).notifyDataSetChanged();
+
+			mDownY = mLastEventY;
+
+			final int switchViewStartTop = switchView.getTop();
+
+			mobileView.setVisibility(View.VISIBLE);
+			switchView.setVisibility(View.INVISIBLE);
+
+			updateNeighborViewsForID(mMobileItemId);
+
+			final ViewTreeObserver observer = getViewTreeObserver();
+			observer.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
+				public boolean onPreDraw() {
+					observer.removeOnPreDrawListener(this);
+
+					View switchView = getViewForID(switchItemID);
+
+					mTotalOffset += deltaY;
+
+					int switchViewNewTop = switchView.getTop();
+					int delta = switchViewStartTop - switchViewNewTop;
+
+					switchView.setTranslationY(delta);
+
+					ObjectAnimator animator = ObjectAnimator.ofFloat(switchView,
+							View.TRANSLATION_Y, 0);
+					animator.setDuration(MOVE_DURATION);
+					animator.start();
+
+					return true;
+				}
+			});
+		}
+	}
+
+	private void swapElements(List arrayList, int indexOne, int indexTwo) {
+		Object temp = arrayList.get(indexOne);
+		arrayList.set(indexOne, arrayList.get(indexTwo));
+		arrayList.set(indexTwo, temp);
+	}
+
+	/**
+	 * Resets all the appropriate fields to a default state while also animating
+	 * the hover cell back to its correct location.
+	 */
+	private void touchEventsEnded() {
+		final View mobileView = getViewForID(mMobileItemId);
+		if (mCellIsMobile || mIsWaitingForScrollFinish) {
+			mCellIsMobile = false;
+			mIsWaitingForScrollFinish = false;
+			mIsMobileScrolling = false;
+			mActivePointerId = INVALID_POINTER_ID;
+
+			// If the autoscroller has not completed scrolling, we need to wait for it to
+			// finish in order to determine the final location of where the hover cell
+			// should be animated to.
+			if (mScrollState != OnScrollListener.SCROLL_STATE_IDLE) {
+				mIsWaitingForScrollFinish = true;
+				return;
+			}
+
+			mHoverCellCurrentBounds.offsetTo(mHoverCellOriginalBounds.left, mobileView.getTop());
+
+			ObjectAnimator hoverViewAnimator = ObjectAnimator.ofObject(mHoverCell, "bounds",
+					sBoundEvaluator, mHoverCellCurrentBounds);
+			hoverViewAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
+				@Override
+				public void onAnimationUpdate(ValueAnimator valueAnimator) {
+					invalidate();
+				}
+			});
+			hoverViewAnimator.addListener(new AnimatorListenerAdapter() {
+				@Override
+				public void onAnimationStart(Animator animation) {
+					setEnabled(false);
+				}
+
+				@Override
+				public void onAnimationEnd(Animator animation) {
+					mAboveItemId = INVALID_ID;
+					mMobileItemId = INVALID_ID;
+					mBelowItemId = INVALID_ID;
+					mobileView.setVisibility(VISIBLE);
+					mHoverCell = null;
+					setEnabled(true);
+					invalidate();
+				}
+			});
+			hoverViewAnimator.start();
+		} else {
+			touchEventsCancelled();
+		}
+	}
+
+	/**
+	 * Resets all the appropriate fields to a default state.
+	 */
+	private void touchEventsCancelled() {
+		View mobileView = getViewForID(mMobileItemId);
+		if (mCellIsMobile) {
+			mAboveItemId = INVALID_ID;
+			mMobileItemId = INVALID_ID;
+			mBelowItemId = INVALID_ID;
+			mobileView.setVisibility(VISIBLE);
+			mHoverCell = null;
+			invalidate();
+		}
+		mCellIsMobile = false;
+		mIsMobileScrolling = false;
+		mActivePointerId = INVALID_POINTER_ID;
+	}
+
+	/**
+	 * Determines whether this listview is in a scrolling state invoked
+	 * by the fact that the hover cell is out of the bounds of the listview;
+	 */
+	private void handleMobileCellScroll() {
+		mIsMobileScrolling = handleMobileCellScroll(mHoverCellCurrentBounds);
+	}
+
+	/**
+	 * This method is in charge of determining if the hover cell is above
+	 * or below the bounds of the listview. If so, the listview does an appropriate
+	 * upward or downward smooth scroll so as to reveal new items.
+	 */
+	public boolean handleMobileCellScroll(Rect r) {
+		int offset = computeVerticalScrollOffset();
+		int height = getHeight();
+		int extent = computeVerticalScrollExtent();
+		int range = computeVerticalScrollRange();
+		int hoverViewTop = r.top;
+		int hoverHeight = r.height();
+
+		if (hoverViewTop <= 0 && offset > 0) {
+			smoothScrollBy(-mSmoothScrollAmountAtEdge, 0);
+			return true;
+		}
+
+		if (hoverViewTop + hoverHeight >= height && (offset + extent) < range) {
+			smoothScrollBy(mSmoothScrollAmountAtEdge, 0);
+			return true;
+		}
+
+		return false;
+	}
+
+	public void setList(List<ServiceInfo> list) {
+		this.mList = list;
+	}	/**
+	 * This scroll listener is added to the listview in order to handle cell swapping
+	 * when the cell is either at the top or bottom edge of the listview. If the hover
+	 * cell is at either edge of the listview, the listview will begin scrolling. As
+	 * scrolling takes place, the listview continuously checks if new cells became visible
+	 * and determines whether they are potential candidates for a cell swap.
+	 */
+	private AbsListView.OnScrollListener mScrollListener = new AbsListView.OnScrollListener() {
+
+		private int mPreviousFirstVisibleItem = -1;
+		private int mPreviousVisibleItemCount = -1;
+		private int mCurrentFirstVisibleItem;
+		private int mCurrentVisibleItemCount;
+		private int mCurrentScrollState;
+
+		public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
+		                     int totalItemCount) {
+			mCurrentFirstVisibleItem = firstVisibleItem;
+			mCurrentVisibleItemCount = visibleItemCount;
+
+			mPreviousFirstVisibleItem = (mPreviousFirstVisibleItem == -1) ? mCurrentFirstVisibleItem
+					: mPreviousFirstVisibleItem;
+			mPreviousVisibleItemCount = (mPreviousVisibleItemCount == -1) ? mCurrentVisibleItemCount
+					: mPreviousVisibleItemCount;
+
+			checkAndHandleFirstVisibleCellChange();
+			checkAndHandleLastVisibleCellChange();
+
+			mPreviousFirstVisibleItem = mCurrentFirstVisibleItem;
+			mPreviousVisibleItemCount = mCurrentVisibleItemCount;
+		}
+
+		@Override
+		public void onScrollStateChanged(AbsListView view, int scrollState) {
+			mCurrentScrollState = scrollState;
+			mScrollState = scrollState;
+			isScrollCompleted();
+		}
+
+		/**
+		 * This method is in charge of invoking 1 of 2 actions. Firstly, if the listview
+		 * is in a state of scrolling invoked by the hover cell being outside the bounds
+		 * of the listview, then this scrolling event is continued. Secondly, if the hover
+		 * cell has already been released, this invokes the animation for the hover cell
+		 * to return to its correct position after the listview has entered an idle scroll
+		 * state.
+		 */
+		private void isScrollCompleted() {
+			if (mCurrentVisibleItemCount > 0 && mCurrentScrollState == SCROLL_STATE_IDLE) {
+				if (mCellIsMobile && mIsMobileScrolling) {
+					handleMobileCellScroll();
+				} else if (mIsWaitingForScrollFinish) {
+					touchEventsEnded();
+				}
+			}
+		}
+
+		/**
+		 * Determines if the listview scrolled up enough to reveal a new cell at the
+		 * top of the list. If so, then the appropriate parameters are updated.
+		 */
+		public void checkAndHandleFirstVisibleCellChange() {
+			if (mCurrentFirstVisibleItem != mPreviousFirstVisibleItem) {
+				if (mCellIsMobile && mMobileItemId != INVALID_ID) {
+					updateNeighborViewsForID(mMobileItemId);
+					handleCellSwitch();
+				}
+			}
+		}
+
+		/**
+		 * Determines if the listview scrolled down enough to reveal a new cell at the
+		 * bottom of the list. If so, then the appropriate parameters are updated.
+		 */
+		public void checkAndHandleLastVisibleCellChange() {
+			int currentLastVisibleItem = mCurrentFirstVisibleItem + mCurrentVisibleItemCount;
+			int previousLastVisibleItem = mPreviousFirstVisibleItem + mPreviousVisibleItemCount;
+			if (currentLastVisibleItem != previousLastVisibleItem) {
+				if (mCellIsMobile && mMobileItemId != INVALID_ID) {
+					updateNeighborViewsForID(mMobileItemId);
+					handleCellSwitch();
+				}
+			}
+		}
+	};
+
+	public static class StableArrayAdapter extends ArrayAdapter<ServiceInfo> {
+
+		final int INVALID_ID = -1;
+
+		HashMap<ServiceInfo, Integer> mIdMap = new HashMap<ServiceInfo, Integer>();
+
+		public StableArrayAdapter(Context context, int rootViewResourceId, int textViewResourceId, List<ServiceInfo> objects) {
+			super(context, rootViewResourceId, textViewResourceId, objects);
+			init(objects);
+		}
+
+		private void init(List<ServiceInfo> objects) {
+			for (int i = 0; i < objects.size(); ++i) {
+				mIdMap.put(objects.get(i), i);
+			}
+		}
+
+		@Override
+		public long getItemId(int position) {
+			if (position < 0 || position >= mIdMap.size()) {
+				return INVALID_ID;
+			}
+			ServiceInfo item = getItem(position);
+			return mIdMap.get(item);
+		}
+
+		@Override
+		public boolean hasStableIds() {
+			return true;
+		}
+	}
+
+
+}

src/org/microg/nlp/ui/LocationBackendConfig.java

@@ -1,84 +1,210 @@
 package org.microg.nlp.ui;
 
-import android.app.ListActivity;
+import android.app.Activity;
 import android.content.Intent;
+import android.content.pm.ComponentInfo;
+import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
+import android.content.pm.ServiceInfo;
 import android.graphics.drawable.Drawable;
 import android.os.Bundle;
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.Menu;
+import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.*;
+import android.widget.AdapterView;
+import android.widget.ImageView;
+import android.widget.PopupMenu;
+import android.widget.TextView;
+import org.microg.nlp.R;
 import org.microg.nlp.api.NlpApiConstants;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
-public class LocationBackendConfig extends ListActivity {
+public class LocationBackendConfig extends Activity {
+	private static final String TAG = LocationBackendConfig.class.getName();
 
-	private List<String> activeBackends;
+	private List<ServiceInfo> activeBackends;
+	private Map<ServiceInfo, KnownBackend> knownBackends;
+	private List<ServiceInfo> unusedBackends;
 	private Adapter adapter;
+	private DynamicListView listView;
+	private View addButton;
+	private PopupMenu popUp;
 
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
-		activeBackends = new ArrayList<String>();
-		List<KnownBackend> backends = new ArrayList<KnownBackend>();
+		setContentView(R.layout.pluginselection);
+		listView = (DynamicListView) findViewById(android.R.id.list);
+		listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
+			@Override
+			public void onItemClick(AdapterView<?> view, View view2, int i, long l) {
+				Log.d(TAG, "onItemClick: " + l);
+			}
+		});
+		addButton = findViewById(android.R.id.button1);
+		addButton.setOnClickListener(new View.OnClickListener() {
+			@Override
+			public void onClick(View view) {
+				showAddPluginPopup(view);
+			}
+		});
+
+		updateBackends();
+	}
+
+	private void updateBackends() {
+		activeBackends = new ArrayList<ServiceInfo>();
+		knownBackends = new HashMap<ServiceInfo, KnownBackend>();
+		unusedBackends = new ArrayList<ServiceInfo>();
 		Intent intent = new Intent(NlpApiConstants.ACTION_LOCATION_BACKEND);
-		List<ResolveInfo> resolveInfos = getPackageManager().queryIntentServices(intent, 0);
+		List<ResolveInfo> resolveInfos = getPackageManager().queryIntentServices(intent, PackageManager.GET_META_DATA);
 		for (ResolveInfo info : resolveInfos) {
-			String packageName = info.serviceInfo.packageName;
-			String simpleName = String.valueOf(info.serviceInfo.loadLabel(getPackageManager()));
-			Drawable icon = info.serviceInfo.loadIcon(getPackageManager());
-			backends.add(new KnownBackend(packageName, simpleName, icon));
+			ServiceInfo serviceInfo = info.serviceInfo;
+			String simpleName = String.valueOf(serviceInfo.loadLabel(getPackageManager()));
+			Drawable icon = serviceInfo.loadIcon(getPackageManager());
+			knownBackends.put(serviceInfo, new KnownBackend(serviceInfo, simpleName, icon));
 		}
-		adapter = new Adapter(backends);
-		setListAdapter(adapter);
+		updateAddButton();
 	}
 
-	@Override
-	protected void onListItemClick(ListView l, View v, int position, long id) {
-		super.onListItemClick(l, v, position, id);
-		KnownBackend backend = adapter.getItem(position);
-		if (activeBackends.contains(backend.packageName)) {
-			activeBackends.remove(backend.packageName);
+	private void updateAddButton() {
+		if (activeBackends.size() == knownBackends.size()) {
+			if (activeBackends.isEmpty()) {
+				// No backend installed
+				// TODO: notify user about that
+			}
+			addButton.setVisibility(View.GONE);
 		} else {
-			activeBackends.add(backend.packageName);
+			addButton.setVisibility(View.VISIBLE);
 		}
-		adapter.notifyDataSetChanged();
 	}
 
-	private class Adapter extends ArrayAdapter<KnownBackend> {
-		public Adapter(List<KnownBackend> backends) {
-			super(LocationBackendConfig.this, android.R.layout.select_dialog_multichoice, android.R.id.text1, backends);
+	private void resetAdapter() {
+		List<ServiceInfo> backends = activeBackends;
+		adapter = new Adapter(backends);
+		listView.setList(backends);
+		listView.setAdapter(adapter);
+	}
+
+	private void updateUnusedBackends() {
+		unusedBackends.clear();
+		for (KnownBackend backend : knownBackends.values()) {
+			if (!activeBackends.contains(backend.serviceInfo)) {
+				unusedBackends.add(backend.serviceInfo);
+			}
+		}
+	}
+
+	private void showAddPluginPopup(View anchorView) {
+		updateUnusedBackends();
+
+		if (popUp != null) {
+			popUp.dismiss();
+		}
+		popUp = new PopupMenu(this, anchorView);
+
+		for (int i = 0; i < unusedBackends.size(); i++) {
+			KnownBackend backend = knownBackends.get(unusedBackends.get(i));
+			String label = backend.simpleName;
+			if (TextUtils.isEmpty(label)) {
+				label = backend.serviceInfo.name;
+			}
+			popUp.getMenu().add(Menu.NONE, i, Menu.NONE, label);
+		}
+		popUp.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
+			@Override
+			public boolean onMenuItemClick(MenuItem menuItem) {
+				popUp.dismiss();
+				popUp = null;
+
+				activeBackends.add(unusedBackends.get(menuItem.getItemId()));
+				updateAddButton();
+				resetAdapter();
+				return true;
+			}
+		});
+		popUp.show();
+	}
+
+	private Intent createSettingsIntent(ComponentInfo componentInfo) {
+		Intent settingsIntent = new Intent(Intent.ACTION_VIEW);
+		settingsIntent.setPackage(componentInfo.packageName);
+		settingsIntent.setClassName(componentInfo.packageName,
+				componentInfo.metaData.getString(NlpApiConstants.METADATA_BACKEND_SETTINGS_ACTIVITY));
+		return settingsIntent;
+	}
+
+	private void showSettingsPopup(View anchorView, final KnownBackend backend) {
+		if (popUp != null) {
+			popUp.dismiss();
+		}
+		popUp = new PopupMenu(this, anchorView);
+		popUp.getMenu().add(Menu.NONE, 0, Menu.NONE, "Remove");  // TODO label
+		if (backend.serviceInfo.metaData != null &&
+				backend.serviceInfo.metaData.getString(NlpApiConstants.METADATA_BACKEND_SETTINGS_ACTIVITY) != null) {
+			if (getPackageManager().resolveActivity(createSettingsIntent(backend.serviceInfo), 0) != null) {
+				popUp.getMenu().add(Menu.NONE, 1, Menu.NONE, "Settings"); // TODO label
+			}
+		}
+		popUp.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
+			@Override
+			public boolean onMenuItemClick(MenuItem item) {
+				popUp.dismiss();
+				popUp = null;
+
+				if (item.getItemId() == 0) {
+					activeBackends.remove(backend.serviceInfo);
+					updateAddButton();
+					resetAdapter();
+				} else if (item.getItemId() == 1) {
+					startActivity(createSettingsIntent(backend.serviceInfo));
+				}
+				return true;
+			}
+		});
+		popUp.show();
+	}
+
+	private class Adapter extends DynamicListView.StableArrayAdapter {
+		public Adapter(List<ServiceInfo> backends) {
+			super(LocationBackendConfig.this, R.layout.backend_list_entry, android.R.id.text2, backends);
 		}
 
 		@Override
 		public View getView(int position, View convertView, ViewGroup parent) {
-			// User super class to create the View
 			View v = super.getView(position, convertView, parent);
-			CheckedTextView tv = (CheckedTextView) v.findViewById(android.R.id.text1);
-
-			// Put the image on the TextView
-			tv.setCompoundDrawablesWithIntrinsicBounds(getItem(position).icon, null,
-					null, null);
-
-			// Add margin between image and text (support various screen densities)
-			int dp10 = (int) (10 * getContext().getResources().getDisplayMetrics().density + 0.5f);
-			tv.setCompoundDrawablePadding(dp10);
-
-			tv.setChecked(activeBackends.contains(getItem(position).packageName));
-
+			final KnownBackend backend = knownBackends.get(getItem(position));
+			ImageView icon = (ImageView) v.findViewById(android.R.id.icon);
+			icon.setImageDrawable(backend.icon);
+			TextView title = (TextView) v.findViewById(android.R.id.text1);
+			title.setText(backend.simpleName);
+			TextView subtitle = (TextView) v.findViewById(android.R.id.text2);
+			subtitle.setText(backend.serviceInfo.name);
+			View overflow = v.findViewById(android.R.id.button1);
+			overflow.setOnClickListener(new View.OnClickListener() {
+				@Override
+				public void onClick(View view) {
+					showSettingsPopup(view, backend);
+				}
+			});
 			return v;
 		}
 	}
 
 	private class KnownBackend {
-		private String packageName;
+		private ServiceInfo serviceInfo;
 		private String simpleName;
 		private Drawable icon;
 
-		public KnownBackend(String packageName, String simpleName, Drawable icon) {
-			this.packageName = packageName;
+		private KnownBackend(ServiceInfo serviceInfo, String simpleName, Drawable icon) {
+			this.serviceInfo = serviceInfo;
 			this.simpleName = simpleName;
 			this.icon = icon;
 		}