├── .gitignore
├── LICENSE
├── README.md
└── src
    └── com
        └── larphoid
            └── overscrolllistview
                └── OverscrollListview.java


/.gitignore:
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 1 | # built application files
 2 | *.apk
 3 | *.ap_
 4 | 
 5 | # files for the dex VM
 6 | *.dex
 7 | 
 8 | # Java class files
 9 | *.class
10 | 
11 | # generated files
12 | bin/
13 | gen/
14 | 
15 | # Local configuration file (sdk path, etc)
16 | local.properties
17 | 
18 | # Eclipse project files
19 | .classpath
20 | .project
21 | 


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/LICENSE:
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 1 | Overscroll-ListView
 2 | Copyright (C) 2013 Larphoid Apps.
 3 | 
 4 | This program is free software: you can redistribute it and/or modify
 5 | it under the terms of the GNU General Public License as published by
 6 | the Free Software Foundation, either version 3 of the License, or
 7 | (at your option) any later version.
 8 | 
 9 | This program is distributed in the hope that it will be useful,
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 | GNU General Public License for more details.
13 | 


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/README.md:
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 1 | android-Overscroll-ListView
 2 | ===========================
 3 | 
 4 | An 'Overscrollable' ListView with 'Bounce' effect for android !
 5 | 
 6 | Usage:
 7 | ======
 8 | The bounce effect can be turned on / off with listview.setBounce(true / false).
 9 | 
10 | The animation delay can be set via the delay variable, which is in milliseconds. Default = 10. The higher the value, the slower the animation.
11 | 
12 | The bounce length can be set with listview.setElasticity(float), see source file for help.
13 | 
14 | The break speed can be set with listview.setBreakspeed(float), see source file for help.
15 | 
16 | In xml, instead of creating a ListView, create a com.larphoid.overscrollinglistview.OverscrollListview
17 | 
18 | Ofcourse you can put the OverscrollListview.java in your current package and change com.larphoid.overscrollinglistview to your current package name.
19 | 
20 | When assigning the listview to a variable somewhere in your app, ofcourse you have to make it a OverscrollListview.
21 | 
22 | IMPORTANT: whenever you populate your listview, when you'r finished populating, don't forget to call listview.initializeValues().
23 | 
24 | CHANGES:
25 | after populating the listview it is not necesary anymore to set the first visible item to something other than the header or footer view (for example like this: listview.setSelectionFromTop(listview.nHeaders, listview.divHeight)), this is now done in initializeValues().
26 | 
27 | Thats it, enjoy !
28 | 
29 | Example:
30 | ========
31 | The following is an example of how to include Overscrollable in your project.
32 | ```Java
33 | package com.example.tutorial;
34 | 
35 | 
36 | import android.os.Bundle;
37 | import android.app.Activity;
38 | import android.widget.ArrayAdapter;
39 | import com.larphoid.overscrolllistview.OverscrollListview;
40 | 
41 | public class MainActivity extends Activity {
42 | 
43 | 	@Override
44 | 	protected void onCreate(Bundle savedInstanceState) {
45 | 		super.onCreate(savedInstanceState);
46 | 		setContentView(R.layout.activity_main);
47 | 
48 | 		OverscrollListview listView = (OverscrollListview)findViewById(R.id.list);
49 | 
50 | 		// Defined Array values to show in ListView
51 | 		String[] values = new String[] { 
52 | 				"List item 1", 
53 | 				"List item 2",
54 | 				"List item 3",
55 | 				"List item 4", 
56 | 				"List item 5", 
57 | 				"List item 6", 
58 | 				"List item 7", 
59 | 				"List item 8" 
60 | 		};
61 | 		ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
62 | 				android.R.layout.simple_list_item_1, android.R.id.text1, values);
63 | 		listView.setAdapter(adapter); 
64 | 	}
65 | }
66 | 
67 | ```
68 | 
69 | ```XML
70 | <!-- activity_main.xml -->
71 | <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
72 |     android:layout_width="match_parent"
73 |     android:layout_height="match_parent"
74 |     android:orientation="vertical" >
75 | 
76 |     <com.larphoid.overscrolllistview.OverscrollListview
77 |         android:id="@+id/list"
78 |         android:layout_width="match_parent"
79 |         android:layout_height="wrap_content" >
80 |     </com.larphoid.overscrolllistview.OverscrollListview>
81 | 
82 | </LinearLayout>
83 | ```
84 | 
85 | Be sure to include the 'com.larphoid.overscrolllistview' package in your Android
86 | Project src file and you're all set.
87 | 
88 | 
89 | LICENSE
90 | =======
91 | 
92 | This projected is licensed under the terms of the LGPL license.
93 | 


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/src/com/larphoid/overscrolllistview/OverscrollListview.java:
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  1 | package com.larphoid.overscrolllistview;
  2 | 
  3 | import android.content.Context;
  4 | import android.os.Handler;
  5 | import android.util.AttributeSet;
  6 | import android.view.Display;
  7 | import android.view.GestureDetector;
  8 | import android.view.MotionEvent;
  9 | import android.view.View;
 10 | import android.view.WindowManager;
 11 | import android.view.GestureDetector.OnGestureListener;
 12 | import android.widget.AbsListView;
 13 | import android.widget.Adapter;
 14 | import android.widget.AdapterView;
 15 | import android.widget.ListView;
 16 | import android.widget.AbsListView.OnScrollListener;
 17 | 
 18 | /** @author Larphoid Apps. */
 19 | public class OverscrollListView extends ListView implements OnScrollListener, View.OnTouchListener, android.widget.AdapterView.OnItemSelectedListener {
 20 | 
 21 | 	protected static float BREAKSPEED = 4f, ELASTICITY = 0.67f;
 22 | 
 23 | 	public int nHeaders = 1, nFooters = 1, divHeight = 0, delay = 10;
 24 | 	private int firstVis, visibleCnt, lastVis, totalItems, scrollstate;
 25 | 	private boolean bounce = true, rebound = false, recalcV = false, trackballEvent = false;
 26 | 	private long flingTimestamp;
 27 | 	private float velocity;
 28 | 	private View measure;
 29 | 	private GestureDetector gesture;
 30 | 	private Handler mHandler = new Handler();
 31 | 
 32 | 	public OverscrollListView(Context context) {
 33 | 		super(context);
 34 | 		initialize(context);
 35 | 	}
 36 | 
 37 | 	public OverscrollListView(Context context, AttributeSet attrs) {
 38 | 		super(context, attrs);
 39 | 		initialize(context);
 40 | 	}
 41 | 
 42 | 	public OverscrollListView(Context context, AttributeSet attrs, int defStyle) {
 43 | 		super(context, attrs, defStyle);
 44 | 		initialize(context);
 45 | 	}
 46 | 
 47 | 	@Override
 48 | 	public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
 49 | 		firstVis = firstVisibleItem;
 50 | 		visibleCnt = visibleItemCount;
 51 | 		totalItems = totalItemCount;
 52 | 		lastVis = firstVisibleItem + visibleItemCount;
 53 | 	}
 54 | 
 55 | 	@Override
 56 | 	public void onScrollStateChanged(AbsListView view, int scrollState) {
 57 | 		scrollstate = scrollState;
 58 | 		if ( scrollState != OnScrollListener.SCROLL_STATE_TOUCH_SCROLL ) {
 59 | 			rebound = true;
 60 | 			mHandler.postDelayed(checkListviewTopAndBottom, delay);
 61 | 		}
 62 | 	}
 63 | 
 64 | 	@Override
 65 | 	public void onItemSelected(AdapterView<?> av, View v, int position, long id) {
 66 | 		rebound = true;
 67 | 		mHandler.postDelayed(checkListviewTopAndBottom, delay);
 68 | 	}
 69 | 
 70 | 	@Override
 71 | 	public void onNothingSelected(AdapterView<?> av) {
 72 | 		rebound = true;
 73 | 		mHandler.postDelayed(checkListviewTopAndBottom, delay);
 74 | 	}
 75 | 
 76 | 	@Override
 77 | 	public boolean onTrackballEvent(MotionEvent event) {
 78 | 		trackballEvent = true;
 79 | 		rebound = true;
 80 | 		mHandler.postDelayed(checkListviewTopAndBottom, delay);
 81 | 		return super.onTrackballEvent(event);
 82 | 	}
 83 | 
 84 | 	@Override
 85 | 	public boolean onTouch(View v, MotionEvent event) {
 86 | 		gesture.onTouchEvent(event);
 87 | 		return false;
 88 | 	}
 89 | 
 90 | 	private class gestureListener implements OnGestureListener {
 91 | 		@Override
 92 | 		public boolean onDown(MotionEvent e) {
 93 | 			rebound = false;
 94 | 			recalcV = false;
 95 | 			velocity = 0f;
 96 | 			return false;
 97 | 		}
 98 | 
 99 | 		@Override
100 | 		public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
101 | 			rebound = true;
102 | 			recalcV = true;
103 | 			velocity = velocityY / 25f;
104 | 			flingTimestamp = System.currentTimeMillis();
105 | 			return false;
106 | 		}
107 | 
108 | 		@Override
109 | 		public void onLongPress(MotionEvent e) {
110 | 		}
111 | 
112 | 		@Override
113 | 		public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
114 | 			return false;
115 | 		}
116 | 
117 | 		@Override
118 | 		public void onShowPress(MotionEvent e) {
119 | 		}
120 | 
121 | 		@Override
122 | 		public boolean onSingleTapUp(MotionEvent e) {
123 | 			rebound = true;
124 | 			recalcV = false;
125 | 			velocity = 0f;
126 | 			return false;
127 | 		}
128 | 	};
129 | 
130 | 	private void initialize(Context context) {
131 | 		final Display display = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
132 | 		final View v = new View(context);
133 | 		v.setMinimumHeight(Math.max(display.getWidth(), display.getHeight()));
134 | 		addHeaderView(v, null, false);
135 | 		addFooterView(v, null, false);
136 | 
137 | 		gesture = new GestureDetector(new gestureListener());
138 | 		gesture.setIsLongpressEnabled(false);
139 | 		flingTimestamp = System.currentTimeMillis();
140 | 		setHeaderDividersEnabled(false);
141 | 		setFooterDividersEnabled(false);
142 | 		setOnTouchListener(this);
143 | 		setOnScrollListener(this);
144 | 		setOnItemSelectedListener(this);
145 | 	}
146 | 
147 | 	/** This should be called after you finish populating the listview ! This includes any calls to {@link Adapter#notifyDataSetChanged()} and obviously every time you re-populate the listview. */
148 | 	public void initializeValues() {
149 | 		nHeaders = getHeaderViewsCount();
150 | 		nFooters = getFooterViewsCount();
151 | 		divHeight = getDividerHeight();
152 | 		firstVis = 0;
153 | 		visibleCnt = 0;
154 | 		lastVis = 0;
155 | 		totalItems = 0;
156 | 		scrollstate = 0;
157 | 		rebound = true;
158 | 		setSelectionFromTop(nHeaders, divHeight);
159 | 		smoothScrollBy(0, 0);
160 | 		mHandler.postDelayed(checkListviewTopAndBottom, delay);
161 | 	}
162 | 
163 | 	/**
164 | 	 * Turns the bouncing animation on or off.
165 | 	 * 
166 | 	 * @param bouncing
167 | 	 *            {@code true } for bouncing effect (this is also the default), {@code false} to turn it off.
168 | 	 */
169 | 	public void setBounce(boolean bouncing) {
170 | 		bounce = bouncing;
171 | 	}
172 | 
173 | 	/**
174 | 	 * Sets how fast the animation will be. Higher value means faster animation. Must be >= 1.05. Together with Elasticity <= 0.75 it will not bounce forever.
175 | 	 * 
176 | 	 * @param breakspead
177 | 	 *            Default is 4.0
178 | 	 */
179 | 	public void setBreakspeed(final float breakspeed) {
180 | 		if ( Math.abs(breakspeed) >= 1.05f ) {
181 | 			BREAKSPEED = Math.abs(breakspeed);
182 | 		}
183 | 	}
184 | 
185 | 	/**
186 | 	 * Sets how much it will keep bouncing. Lower value means less bouncing. Must be <= 0.75. Together with Breakspeed >= 1.05 it will not bounce forever.
187 | 	 * 
188 | 	 * @param elasticity
189 | 	 *            Default is 0.67
190 | 	 */
191 | 	public void setElasticity(final float elasticity) {
192 | 		if ( Math.abs(elasticity) <= 0.75f ) {
193 | 			ELASTICITY = Math.abs(elasticity);
194 | 		}
195 | 	}
196 | 
197 | 	public Runnable checkListviewTopAndBottom = new Runnable() {
198 | 		@Override
199 | 		public void run() {
200 | 
201 | 			mHandler.removeCallbacks(checkListviewTopAndBottom);
202 | 
203 | 			if ( trackballEvent && firstVis < nHeaders && lastVis >= totalItems ) {
204 | 				trackballEvent = false;
205 | 				rebound = false;
206 | 				return;
207 | 			}
208 | 
209 | 			if ( rebound ) {
210 | 
211 | 				if ( firstVis < nHeaders ) {
212 | 
213 | 					// hack to avoid strange behaviour when there aren't enough items to fill the entire listview
214 | 					if ( lastVis >= totalItems ) {
215 | 						smoothScrollBy(0, 0);
216 | 						rebound = false;
217 | 						recalcV = false;
218 | 						velocity = 0f;
219 | 					}
220 | 
221 | 					if ( recalcV ) {
222 | 						recalcV = false;
223 | 						velocity /= (1f + ((System.currentTimeMillis() - flingTimestamp) / 1000f));
224 | 					}
225 | 					if ( firstVis == nHeaders ) {
226 | 						recalcV = false;
227 | 					}
228 | 					if ( visibleCnt > nHeaders ) {
229 | 						measure = getChildAt(nHeaders);
230 | 						if ( measure.getTop() + velocity < divHeight ) {
231 | 							velocity *= -ELASTICITY;
232 | 							if ( !bounce || Math.abs(velocity) < BREAKSPEED ) {
233 | 								rebound = false;
234 | 								recalcV = false;
235 | 								velocity = 0f;
236 | 							} else {
237 | 								setSelectionFromTop(nHeaders, divHeight + 1);
238 | 							}
239 | 						}
240 | 					} else {
241 | 						if ( velocity > 0f ) velocity = -velocity;
242 | 					}
243 | 					if ( rebound ) {
244 | 						smoothScrollBy((int) -velocity, 0);
245 | 						if ( velocity > BREAKSPEED ) {
246 | 							velocity *= ELASTICITY;
247 | 							if ( velocity < BREAKSPEED ) {
248 | 								rebound = false;
249 | 								recalcV = false;
250 | 								velocity = 0f;
251 | 							}
252 | 						} else velocity -= BREAKSPEED;
253 | 					}
254 | 
255 | 				} else if ( lastVis >= totalItems ) {
256 | 
257 | 					if ( recalcV ) {
258 | 						recalcV = false;
259 | 						velocity /= (1f + ((System.currentTimeMillis() - flingTimestamp) / 1000f));
260 | 					}
261 | 					if ( lastVis == totalItems - nHeaders - nFooters ) {
262 | 						rebound = false;
263 | 						recalcV = false;
264 | 						velocity = 0f;
265 | 					} else {
266 | 						if ( visibleCnt > (nHeaders + nFooters) ) {
267 | 							measure = getChildAt(visibleCnt - nHeaders - nFooters);
268 | 							if ( measure.getBottom() + velocity > getHeight() - divHeight ) {
269 | 								velocity *= -ELASTICITY;
270 | 								if ( !bounce || Math.abs(velocity) < BREAKSPEED ) {
271 | 									rebound = false;
272 | 									recalcV = false;
273 | 									velocity = 0f;
274 | 								} else {
275 | 									setSelectionFromTop(lastVis - nHeaders - nFooters, getHeight() - divHeight - measure.getHeight() - 1);
276 | 								}
277 | 							}
278 | 						} else {
279 | 							if ( velocity < 0f ) velocity = -velocity;
280 | 						}
281 | 					}
282 | 					if ( rebound ) {
283 | 						smoothScrollBy((int) -velocity, 0);
284 | 						if ( velocity < -BREAKSPEED ) {
285 | 							velocity *= ELASTICITY;
286 | 							if ( velocity > -BREAKSPEED / ELASTICITY ) {
287 | 								rebound = false;
288 | 								recalcV = false;
289 | 								velocity = 0f;
290 | 							}
291 | 						} else velocity += BREAKSPEED;
292 | 					}
293 | 
294 | 				} else if ( scrollstate == OnScrollListener.SCROLL_STATE_IDLE ) {
295 | 
296 | 					rebound = false;
297 | 					recalcV = false;
298 | 					velocity = 0f;
299 | 				}
300 | 				mHandler.postDelayed(checkListviewTopAndBottom, delay);
301 | 				return;
302 | 			}
303 | 
304 | 			if ( scrollstate != OnScrollListener.SCROLL_STATE_IDLE ) return;
305 | 
306 | 			if ( totalItems == (nHeaders + nFooters) || firstVis < nHeaders ) {
307 | 				setSelectionFromTop(nHeaders, divHeight);
308 | 				smoothScrollBy(0, 0);
309 | 			} else if ( lastVis == totalItems ) {
310 | 				int offset = getHeight() - divHeight;
311 | 				measure = getChildAt(visibleCnt - nHeaders - nFooters);
312 | 				if ( measure != null ) offset -= measure.getHeight();
313 | 				setSelectionFromTop(lastVis - nHeaders - nFooters, offset);
314 | 				smoothScrollBy(0, 0);
315 | 			}
316 | 		}
317 | 	};
318 | }
319 | 


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