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      1 /*
      2  * Copyright (C) 2011 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.android.browser.view;
     18 
     19 import android.database.DataSetObserver;
     20 import android.graphics.Canvas;
     21 import android.view.MotionEvent;
     22 import android.view.View;
     23 import android.widget.Adapter;
     24 
     25 import java.util.ArrayList;
     26 
     27 /**
     28  * common code for pie views
     29  */
     30 public abstract class BasePieView implements PieMenu.PieView {
     31 
     32     protected Adapter mAdapter;
     33     private DataSetObserver mObserver;
     34     protected ArrayList<View> mViews;
     35 
     36     protected OnLayoutListener mListener;
     37 
     38     protected int mCurrent;
     39     protected int mChildWidth;
     40     protected int mChildHeight;
     41     protected int mWidth;
     42     protected int mHeight;
     43     protected int mLeft;
     44     protected int mTop;
     45 
     46     public BasePieView() {
     47     }
     48 
     49     public void setLayoutListener(OnLayoutListener l) {
     50         mListener = l;
     51     }
     52 
     53     public void setAdapter(Adapter adapter) {
     54         mAdapter = adapter;
     55         if (adapter == null) {
     56             if (mAdapter != null) {
     57                 mAdapter.unregisterDataSetObserver(mObserver);
     58             }
     59             mViews = null;
     60             mCurrent = -1;
     61         } else {
     62             mObserver = new DataSetObserver() {
     63                 @Override
     64                 public void onChanged() {
     65                     buildViews();
     66                 }
     67 
     68                 @Override
     69                 public void onInvalidated() {
     70                     mViews.clear();
     71                 }
     72             };
     73             mAdapter.registerDataSetObserver(mObserver);
     74             setCurrent(0);
     75         }
     76     }
     77 
     78     public void setCurrent(int ix) {
     79         mCurrent = ix;
     80     }
     81 
     82     public Adapter getAdapter() {
     83         return mAdapter;
     84     }
     85 
     86     protected void buildViews() {
     87         if (mAdapter != null) {
     88             final int n = mAdapter.getCount();
     89             if (mViews == null) {
     90                 mViews = new ArrayList<View>(n);
     91             } else {
     92                 mViews.clear();
     93             }
     94             mChildWidth = 0;
     95             mChildHeight = 0;
     96             for (int i = 0; i < n; i++) {
     97                 View view = mAdapter.getView(i, null, null);
     98                 view.measure(View.MeasureSpec.UNSPECIFIED,
     99                         View.MeasureSpec.UNSPECIFIED);
    100                 mChildWidth = Math.max(mChildWidth, view.getMeasuredWidth());
    101                 mChildHeight = Math.max(mChildHeight, view.getMeasuredHeight());
    102                 mViews.add(view);
    103             }
    104         }
    105     }
    106 
    107     /**
    108      * this will be called before the first draw call
    109      * needs to set top, left, width, height
    110      */
    111     @Override
    112     public void layout(int anchorX, int anchorY, boolean left, float angle) {
    113         if (mListener != null) {
    114             mListener.onLayout(anchorX, anchorY, left);
    115         }
    116     }
    117 
    118 
    119     @Override
    120     public abstract void draw(Canvas canvas);
    121 
    122     protected void drawView(View view, Canvas canvas) {
    123         final int state = canvas.save();
    124         canvas.translate(view.getLeft(), view.getTop());
    125         view.draw(canvas);
    126         canvas.restoreToCount(state);
    127     }
    128 
    129     protected abstract int findChildAt(int y);
    130 
    131     @Override
    132     public boolean onTouchEvent(MotionEvent evt) {
    133         int action = evt.getActionMasked();
    134         int evtx = (int) evt.getX();
    135         int evty = (int) evt.getY();
    136         if ((evtx < mLeft) || (evtx >= mLeft + mWidth)
    137                 || (evty < mTop) || (evty >= mTop + mHeight)) {
    138             return false;
    139         }
    140         switch (action) {
    141             case MotionEvent.ACTION_MOVE:
    142                 View v = mViews.get(mCurrent);
    143                 setCurrent(Math.max(0, Math.min(mViews.size() -1,
    144                         findChildAt(evty))));
    145                 View v1 = mViews.get(mCurrent);
    146                 if (v != v1) {
    147                     v.setPressed(false);
    148                     v1.setPressed(true);
    149                 }
    150                 break;
    151             case MotionEvent.ACTION_UP:
    152                 mViews.get(mCurrent).performClick();
    153                 mViews.get(mCurrent).setPressed(false);
    154                 break;
    155             default:
    156                 break;
    157         }
    158         return true;
    159     }
    160 
    161 }
    162