add notify method

Author: bruce3x

build.gradle

@@ -5,7 +5,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.2.1'
+        classpath 'com.android.tools.build:gradle:2.2.2'
         classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
 
         // NOTE: Do not place your application dependencies here; they belong

cardstackview/src/main/java/me/brucezz/cardstackview/CardAdapter.java

@@ -1,5 +1,7 @@
 package me.brucezz.cardstackview;
 
+import android.database.DataSetObservable;
+import android.database.DataSetObserver;
 import android.view.View;
 import android.view.ViewGroup;
 
@@ -13,7 +15,7 @@ public abstract class CardAdapter {
     /**
      * 会在 {@link CardStackView} 初始化的时候把所有的 View 都初始化添加进去
      */
-    public abstract View getView(int position, ViewGroup parent);
+    public abstract View getView(View oldView, int position, ViewGroup parent);
 
     /**
      * 获取 View 的数量
@@ -29,4 +31,18 @@ public abstract class CardAdapter {
      * View 最小间隔
      */
     public abstract int getMinCardSpan();
+
+    private final DataSetObservable mObservable = new DataSetObservable();
+
+    public final void notifyDataSetChanged() {
+        mObservable.notifyChanged();
+    }
+
+    public void registerDataSetObserver(DataSetObserver observer) {
+        mObservable.registerObserver(observer);
+    }
+
+    public void unregisterDataSetObserver(DataSetObserver observer) {
+        mObservable.unregisterObserver(observer);
+    }
 }

cardstackview/src/main/java/me/brucezz/cardstackview/CardStackView.java

@@ -2,10 +2,10 @@
 
 import android.animation.ValueAnimator;
 import android.content.Context;
+import android.database.DataSetObserver;
 import android.support.v4.view.GestureDetectorCompat;
 import android.support.v4.widget.ViewDragHelper;
 import android.util.AttributeSet;
-import android.util.Log;
 import android.view.GestureDetector;
 import android.view.MotionEvent;
 import android.view.View;
@@ -21,6 +21,8 @@
 public class CardStackView extends ViewGroup {
     private static final String TAG = "CardStackView";
 
+    private final DataSetObserver mObserver = new CardStackViewDataObserver();
+
     private CardFactory mCardFactory;
     private Options mOptions;
 
@@ -55,7 +57,7 @@ public CardStackView(Context context, AttributeSet attrs, int defStyleAttr) {
 
     private void initViews() {
         for (int i = 0; i < mCardAdapter.getItemCount(); i++) {
-            addView(mCardAdapter.getView(i, this));
+            addView(mCardAdapter.getView(null, i, this));
         }
         mOptions = new Options();
 
@@ -271,8 +273,13 @@ private void updateCardPosition() {
     }
 
     public void setAdapter(CardAdapter adapter) {
+        if (mCardAdapter != null) {
+            mCardAdapter.unregisterDataSetObserver(mObserver);
+        }
+
         this.mCardAdapter = adapter;
         if (mCardAdapter != null && mCardAdapter.getItemCount() > 0) {
+            mCardAdapter.registerDataSetObserver(mObserver);
             initViews();
         }
     }
@@ -307,4 +314,22 @@ public interface onCardClickListener {
          */
         void onClick(View view, int realIndex, int initialIndex);
     }
+
+    private class CardStackViewDataObserver extends DataSetObserver {
+        @Override
+        public void onChanged() {
+            for (int i = 0; i < mCardFactory.size(); i++) {
+                CardHolder holder = mCardFactory.get(i);
+                holder.mView = mCardAdapter.getView(holder.mView, holder.mChildIndex, CardStackView.this);
+            }
+        }
+
+        @Override
+        public void onInvalidated() {
+            for (int i = 0; i < mCardFactory.size(); i++) {
+                CardHolder holder = mCardFactory.get(i);
+                holder.mView.postInvalidate();
+            }
+        }
+    }
 }

sample/src/main/java/me/brucezz/sample/MainActivity.java

@@ -2,6 +2,8 @@
 
 import android.os.Bundle;
 import android.support.v7.app.AppCompatActivity;
+import android.view.Menu;
+import android.view.MenuItem;
 import android.view.View;
 import android.widget.Toast;
 import java.util.Arrays;
@@ -39,4 +41,27 @@ private List<Card> fakeCards() {
         return Arrays.asList(new Card(0xFF2196F3, R.drawable.post, "动态"), new Card(0xFF17B084, R.drawable.task, "任务"),
             new Card(0xFFE85D72, R.drawable.calendar, "日程"), new Card(0xFF00BACF, R.drawable.knowledge, "知识"));
     }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        menu.add(1, 1, 1, "修改数据");
+        menu.add(1, 2, 1, "重置");
+        return super.onCreateOptionsMenu(menu);
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        switch (item.getItemId()) {
+            case 1:
+                for (Card card : mCards) {
+                    card.mTitle += "X";
+                }
+                mCardAdapter.notifyDataSetChanged();
+                break;
+            case 2:
+                recreate();
+                break;
+        }
+        return super.onOptionsItemSelected(item);
+    }
 }

sample/src/main/java/me/brucezz/sample/SimpleCardAdapter.java

@@ -28,19 +28,30 @@ public SimpleCardAdapter(Context context, List<Card> cards) {
     }
 
     @Override
-    public View getView(int position, ViewGroup parent) {
+    public View getView(View oldView, int position, ViewGroup parent) {
         Card card = mCards.get(position);
-        View view = LayoutInflater.from(mContext).inflate(R.layout.item_card, parent, false);
-        CardView cardView = (CardView) view.findViewById(R.id.card);
-        TextView title = (TextView) view.findViewById(R.id.card_title);
-        ImageView image = (ImageView) view.findViewById(R.id.card_image);
 
-        title.setText(card.mTitle);
-        image.setImageResource(card.mImage);
+        ViewHolder holder;
+        View view;
+        if (oldView != null && oldView.getTag() instanceof ViewHolder) {
+            holder = (ViewHolder) oldView.getTag();
+            view = oldView;
+        } else {
+            holder = new ViewHolder();
+            view = LayoutInflater.from(mContext).inflate(R.layout.item_card, parent, false);
+            holder.mCardView = (CardView) view.findViewById(R.id.card);
+            holder.mTextView = (TextView) view.findViewById(R.id.card_title);
+            holder.mImageView = (ImageView) view.findViewById(R.id.card_image);
+        }
+
+        holder.mTextView.setText(card.mTitle);
+        holder.mImageView.setImageResource(card.mImage);
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
             // BugFix: 4.x 版本: CardView 中填充 ImageView 会有白边
-            cardView.setCardBackgroundColor(card.mBgColor);
+            holder.mCardView.setCardBackgroundColor(card.mBgColor);
         }
+        view.setTag(holder);
+
         return view;
     }
 
@@ -58,4 +69,10 @@ public int getCardHeight() {
     public int getMinCardSpan() {
         return mContext.getResources().getDimensionPixelSize(R.dimen.card_span_min);
     }
+
+    private static class ViewHolder {
+        CardView mCardView;
+        TextView mTextView;
+        ImageView mImageView;
+    }
 }