Using Reflection to call method : View « UI « Android

1. Android
2. UI
3. View

Using Reflection to call method

    


/***
  Copyright (c) 2008-2009 CommonsWare, LLC
  
  Licensed under the Apache License, Version 2.0 (the "License"); you may
  not use this file except in compliance with the License. You may obtain
  a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
 */

package app.test;

import java.lang.reflect.Method;
import java.util.Date;
import java.util.HashMap;

import android.app.Activity;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.TextView;

public class Test extends Activity {
  private static final String LOG_KEY = "Tagger";
  private static Method _setTag = null;
  private static Method _getTag = null;

  static {
    int sdk = new Integer(Build.VERSION.SDK).intValue();

    if (sdk >= 4) {
      try {
        _setTag = View.class.getMethod("setTag", new Class[] {
            Integer.TYPE, Object.class });
        _getTag = View.class.getMethod("getTag",
            new Class[] { Integer.TYPE });
      } catch (Throwable t) {
        Log.e(LOG_KEY, "Could not initialize 1.6 accessors", t);
      }
    }
  };

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    TextView view = (TextView) findViewById(R.id.test);
    setTag(view, R.id.test, new Date());
    view.setText(getTag(view, R.id.test).toString());
  }

  public void setTag(View v, int key, Object value) {
    if (_setTag != null) {
      try {
        _setTag.invoke(v, key, value);
      } catch (Throwable t) {
        Log.e(LOG_KEY, "Could not use 1.6 setTag()", t);
      }
    } else {
      HashMap<Integer, Object> meta = (HashMap<Integer, Object>) v
          .getTag();

      if (meta == null) {
        meta = new HashMap<Integer, Object>();
        v.setTag(meta);
      }

      meta.put(key, value);
    }
  }

  public Object getTag(View v, int key) {
    Object result = null;

    if (_getTag != null) {
      try {
        result = _getTag.invoke(v, key);
      } catch (Throwable t) {
        Log.e(LOG_KEY, "Could not use 1.6 getTag()", t);
      }
    } else {
      HashMap<Integer, Object> meta = (HashMap<Integer, Object>) v
          .getTag();

      if (meta == null) {
        meta = new HashMap<Integer, Object>();
        v.setTag(meta);
      }

      result = meta.get(key);
    }

    return (result);
  }
}

//main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView android:id="@+id/test"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    />
</LinearLayout>

   
    
    
    
  

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