Pileus Git - ~andy/freeotp/blob - src/org/fedorahosted/freeotp/adapters/ReorderableBaseAdapter.java

   1 /*
   2  * FreeOTP
   3  *
   4  * Authors: Nathaniel McCallum <npmccallum@redhat.com>
   5  *
   6  * Copyright (C) 2013  Nathaniel McCallum, Red Hat
   7  *
   8  * Licensed under the Apache License, Version 2.0 (the "License");
   9  * you may not use this file except in compliance with the License.
  10  * You may obtain a copy of the License at
  11  *
  12  *     http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing, software
  15  * distributed under the License is distributed on an "AS IS" BASIS,
  16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  17  * See the License for the specific language governing permissions and
  18  * limitations under the License.
  19  */
  20
  21 package org.fedorahosted.freeotp.adapters;
  22
  23 import java.util.WeakHashMap;
  24
  25 import android.content.ClipData;
  26 import android.view.DragEvent;
  27 import android.view.View;
  28 import android.view.View.DragShadowBuilder;
  29 import android.view.View.OnDragListener;
  30 import android.view.View.OnLongClickListener;
  31 import android.view.ViewParent;
  32
  33 public abstract class ReorderableBaseAdapter extends BaseAdapter implements OnLongClickListener, OnDragListener {
  34         private final WeakHashMap<View, Integer> mPositions = new WeakHashMap<View, Integer>();
  35         private class Reference<T> {
  36                 public Reference(T t) { reference = t; }
  37                 T reference;
  38         }
  39
  40         @Override
  41         public void notifyDataSetChanged() {
  42                 mPositions.clear();
  43                 super.notifyDataSetChanged();
  44         }
  45
  46         @Override
  47         public void notifyDataSetInvalidated() {
  48                 mPositions.clear();
  49                 super.notifyDataSetInvalidated();
  50         }
  51
  52         @Override
  53         protected void bindView(View view, int position) {
  54                 mPositions.put(view, position);
  55         }
  56
  57         @Override
  58         public boolean onDrag(View dstView, DragEvent event) {
  59                 @SuppressWarnings("unchecked")
  60                 Reference<View> ref = (Reference<View>) event.getLocalState();
  61                 final View srcView = ref.reference;
  62
  63                 switch (event.getAction()) {
  64                 case DragEvent.ACTION_DRAG_ENTERED:
  65                         srcView.setVisibility(View.VISIBLE);
  66                         dstView.setVisibility(View.INVISIBLE);
  67
  68                         Integer src = mPositions.get(srcView);
  69                         Integer dst = mPositions.get(dstView);
  70                         if (src != null && dst != null)
  71                                 move(src, dst);
  72
  73                         ref.reference = dstView;
  74                         break;
  75
  76                 case DragEvent.ACTION_DRAG_ENDED:
  77                     srcView.post(new Runnable() {
  78                                 @Override
  79                                 public void run() {
  80                                         srcView.setVisibility(View.VISIBLE);
  81                                 }
  82                         });
  83                         break;
  84                 }
  85
  86                 return true;
  87         }
  88
  89         @Override
  90         public boolean onLongClick(final View view) {
  91                 // Force a reset of any states
  92                 notifyDataSetChanged();
  93
  94                 // Start the drag on the main loop to allow
  95                 // the above state reset to settle.
  96                 view.post(new Runnable() {
  97                         @Override
  98                         public void run() {
  99                                 ClipData data = ClipData.newPlainText("", "");
 100                                 DragShadowBuilder sb = new View.DragShadowBuilder(view);
 101                                 view.startDrag(data, sb, new Reference<View>(view), 0);
 102                         }
 103                 });
 104
 105                 return true;
 106         }
 107
 108         @Override
 109         protected void processView(View view, int type) {
 110                 view.setOnDragListener(this);
 111                 view.setOnLongClickListener(this);
 112         }
 113
 114         protected int getPositionFromView(View view) {
 115                 while(true) {
 116                         Integer position = mPositions.get(view);
 117                         if (position != null)
 118                                 return position;
 119
 120                         ViewParent vp = view.getParent();
 121                         if (vp == null || !(vp instanceof View))
 122                                 break;
 123
 124                         view = (View) vp;
 125                 }
 126
 127                 return -1;
 128         }
 129
 130         public abstract void move(int fromPosition, int toPosition);
 131 }