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.ViewParent;
  30
  31 public abstract class ReorderableBaseAdapter extends BaseAdapter {
  32         private final WeakHashMap<View, Integer> mPositions = new WeakHashMap<View, Integer>();
  33         private class Reference<T> {
  34                 public Reference(T t) { reference = t; }
  35                 T reference;
  36         }
  37
  38         @Override
  39         public void notifyDataSetChanged() {
  40                 mPositions.clear();
  41                 super.notifyDataSetChanged();
  42         }
  43
  44         @Override
  45         public void notifyDataSetInvalidated() {
  46                 mPositions.clear();
  47                 super.notifyDataSetInvalidated();
  48         }
  49
  50         @Override
  51         protected void bindView(View view, int position) {
  52                 mPositions.put(view, position);
  53         }
  54
  55         @Override
  56         protected void processView(View view, int type) {
  57                 view.setOnDragListener(new View.OnDragListener() {
  58                         @Override
  59                         public boolean onDrag(View dstView, DragEvent event) {
  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
  90                 view.setOnLongClickListener(new View.OnLongClickListener() {
  91                         @Override
  92                         public boolean onLongClick(final View view) {
  93                                 // Force a reset of any states
  94                                 notifyDataSetChanged();
  95
  96                                 // Start the drag on the main loop to allow
  97                                 // the above state reset to settle.
  98                                 view.post(new Runnable() {
  99                                         @Override
 100                                         public void run() {
 101                                                 ClipData data = ClipData.newPlainText("", "");
 102                                                 DragShadowBuilder sb = new View.DragShadowBuilder(view);
 103                                                 view.startDrag(data, sb, new Reference<View>(view), 0);
 104                                         }
 105                                 });
 106
 107                                 return true;
 108                         }
 109                 });
 110         }
 111
 112         protected int getPositionFromView(View view) {
 113                 while(true) {
 114                         Integer position = mPositions.get(view);
 115                         if (position != null)
 116                                 return position;
 117
 118                         ViewParent vp = view.getParent();
 119                         if (vp == null || !(vp instanceof View))
 120                                 break;
 121
 122                         view = (View) vp;
 123                 }
 124
 125                 return -1;
 126         }
 127
 128         public abstract void move(int fromPosition, int toPosition);
 129 }