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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.example.android.apis.view;
     18 
     19 import com.example.android.apis.R;
     20 
     21 import android.content.ClipData;
     22 import android.content.Context;
     23 import android.content.res.TypedArray;
     24 import android.graphics.*;
     25 import android.os.SystemClock;
     26 import android.text.TextPaint;
     27 import android.util.AttributeSet;
     28 import android.util.Log;
     29 import android.view.DragEvent;
     30 import android.view.View;
     31 import android.widget.TextView;
     32 
     33 public class DraggableDot extends View {
     34     static final String TAG = "DraggableDot";
     35 
     36     private boolean mDragInProgress;
     37     private boolean mHovering;
     38     private boolean mAcceptsDrag;
     39     TextView mReportView;
     40 
     41     private Paint mPaint;
     42     private TextPaint mLegendPaint;
     43     private Paint mGlow;
     44     private static final int NUM_GLOW_STEPS = 10;
     45     private static final int GREEN_STEP = 0x0000FF00 / NUM_GLOW_STEPS;
     46     private static final int WHITE_STEP = 0x00FFFFFF / NUM_GLOW_STEPS;
     47     private static final int ALPHA_STEP = 0xFF000000 / NUM_GLOW_STEPS;
     48 
     49     int mRadius;
     50     int mAnrType;
     51     CharSequence mLegend;
     52 
     53     static final int ANR_NONE = 0;
     54     static final int ANR_SHADOW = 1;
     55     static final int ANR_DROP = 2;
     56 
     57     void sleepSixSeconds() {
     58         // hang forever; good for producing ANRs
     59         long start = SystemClock.uptimeMillis();
     60         do {
     61             try { Thread.sleep(1000); } catch (InterruptedException e) {}
     62         } while (SystemClock.uptimeMillis() < start + 6000);
     63     }
     64 
     65     // Shadow builder that can ANR if desired
     66     class ANRShadowBuilder extends DragShadowBuilder {
     67         boolean mDoAnr;
     68 
     69         public ANRShadowBuilder(View view, boolean doAnr) {
     70             super(view);
     71             mDoAnr = doAnr;
     72         }
     73 
     74         @Override
     75         public void onDrawShadow(Canvas canvas) {
     76             if (mDoAnr) {
     77                 sleepSixSeconds();
     78             }
     79             super.onDrawShadow(canvas);
     80         }
     81     }
     82 
     83     public DraggableDot(Context context, AttributeSet attrs) {
     84         super(context, attrs);
     85 
     86         setFocusable(true);
     87         setClickable(true);
     88 
     89         mLegend = "";
     90 
     91         mPaint = new Paint();
     92         mPaint.setAntiAlias(true);
     93         mPaint.setStrokeWidth(6);
     94         mPaint.setColor(0xFFD00000);
     95 
     96         mLegendPaint = new TextPaint();
     97         mLegendPaint.setAntiAlias(true);
     98         mLegendPaint.setTextAlign(Paint.Align.CENTER);
     99         mLegendPaint.setColor(0xFFF0F0FF);
    100 
    101         mGlow = new Paint();
    102         mGlow.setAntiAlias(true);
    103         mGlow.setStrokeWidth(1);
    104         mGlow.setStyle(Paint.Style.STROKE);
    105 
    106         // look up any layout-defined attributes
    107         TypedArray a = context.obtainStyledAttributes(attrs,
    108                 R.styleable.DraggableDot);
    109 
    110         final int N = a.getIndexCount();
    111         for (int i = 0; i < N; i++) {
    112             int attr = a.getIndex(i);
    113             switch (attr) {
    114             case R.styleable.DraggableDot_radius: {
    115                 mRadius = a.getDimensionPixelSize(attr, 0);
    116             } break;
    117 
    118             case R.styleable.DraggableDot_legend: {
    119                 mLegend = a.getText(attr);
    120             } break;
    121 
    122             case R.styleable.DraggableDot_anr: {
    123                 mAnrType = a.getInt(attr, 0);
    124             } break;
    125             }
    126         }
    127 
    128         Log.i(TAG, "DraggableDot @ " + this + " : radius=" + mRadius + " legend='" + mLegend
    129                 + "' anr=" + mAnrType);
    130 
    131         setOnLongClickListener(new View.OnLongClickListener() {
    132             public boolean onLongClick(View v) {
    133                 ClipData data = ClipData.newPlainText("dot", "Dot : " + v.toString());
    134                 v.startDrag(data, new ANRShadowBuilder(v, mAnrType == ANR_SHADOW),
    135                         (Object)v, 0);
    136                 return true;
    137             }
    138         });
    139     }
    140 
    141     void setReportView(TextView view) {
    142         mReportView = view;
    143     }
    144 
    145     @Override
    146     protected void onDraw(Canvas canvas) {
    147         float wf = getWidth();
    148         float hf = getHeight();
    149         final float cx = wf/2;
    150         final float cy = hf/2;
    151         wf -= getPaddingLeft() + getPaddingRight();
    152         hf -= getPaddingTop() + getPaddingBottom();
    153         float rad = (wf < hf) ? wf/2 : hf/2;
    154         canvas.drawCircle(cx, cy, rad, mPaint);
    155 
    156         if (mLegend != null && mLegend.length() > 0) {
    157             canvas.drawText(mLegend, 0, mLegend.length(),
    158                     cx, cy + mLegendPaint.getFontSpacing()/2,
    159                     mLegendPaint);
    160         }
    161 
    162         // if we're in the middle of a drag, light up as a potential target
    163         if (mDragInProgress && mAcceptsDrag) {
    164             for (int i = NUM_GLOW_STEPS; i > 0; i--) {
    165                 int color = (mHovering) ? WHITE_STEP : GREEN_STEP;
    166                 color = i*(color | ALPHA_STEP);
    167                 mGlow.setColor(color);
    168                 canvas.drawCircle(cx, cy, rad, mGlow);
    169                 rad -= 0.5f;
    170                 canvas.drawCircle(cx, cy, rad, mGlow);
    171                 rad -= 0.5f;
    172             }
    173         }
    174     }
    175 
    176     @Override
    177     protected void onMeasure(int widthSpec, int heightSpec) {
    178         int totalDiameter = 2*mRadius + getPaddingLeft() + getPaddingRight();
    179         setMeasuredDimension(totalDiameter, totalDiameter);
    180     }
    181 
    182     /**
    183      * Drag and drop
    184      */
    185     @Override
    186     public boolean onDragEvent(DragEvent event) {
    187         boolean result = false;
    188         switch (event.getAction()) {
    189         case DragEvent.ACTION_DRAG_STARTED: {
    190             // claim to accept any dragged content
    191             Log.i(TAG, "Drag started, event=" + event);
    192             // cache whether we accept the drag to return for LOCATION events
    193             mDragInProgress = true;
    194             mAcceptsDrag = result = true;
    195             // Redraw in the new visual state if we are a potential drop target
    196             if (mAcceptsDrag) {
    197                 invalidate();
    198             }
    199         } break;
    200 
    201         case DragEvent.ACTION_DRAG_ENDED: {
    202             Log.i(TAG, "Drag ended.");
    203             if (mAcceptsDrag) {
    204                 invalidate();
    205             }
    206             mDragInProgress = false;
    207             mHovering = false;
    208         } break;
    209 
    210         case DragEvent.ACTION_DRAG_LOCATION: {
    211             // we returned true to DRAG_STARTED, so return true here
    212             Log.i(TAG, "... seeing drag locations ...");
    213             result = mAcceptsDrag;
    214         } break;
    215 
    216         case DragEvent.ACTION_DROP: {
    217             Log.i(TAG, "Got a drop! dot=" + this + " event=" + event);
    218             if (mAnrType == ANR_DROP) {
    219                 sleepSixSeconds();
    220             }
    221             processDrop(event);
    222             result = true;
    223         } break;
    224 
    225         case DragEvent.ACTION_DRAG_ENTERED: {
    226             Log.i(TAG, "Entered dot @ " + this);
    227             mHovering = true;
    228             invalidate();
    229         } break;
    230 
    231         case DragEvent.ACTION_DRAG_EXITED: {
    232             Log.i(TAG, "Exited dot @ " + this);
    233             mHovering = false;
    234             invalidate();
    235         } break;
    236 
    237         default:
    238             Log.i(TAG, "other drag event: " + event);
    239             result = mAcceptsDrag;
    240             break;
    241         }
    242 
    243         return result;
    244     }
    245 
    246     private void processDrop(DragEvent event) {
    247         final ClipData data = event.getClipData();
    248         final int N = data.getItemCount();
    249         for (int i = 0; i < N; i++) {
    250             ClipData.Item item = data.getItemAt(i);
    251             Log.i(TAG, "Dropped item " + i + " : " + item);
    252             if (mReportView != null) {
    253                 String text = item.coerceToText(getContext()).toString();
    254                 if (event.getLocalState() == (Object) this) {
    255                     text += " : Dropped on self!";
    256                 }
    257                 mReportView.setText(text);
    258             }
    259         }
    260     }
    261 }