Android 複数画面 1 Activity で画面遷移

1画面 1Activity は設計も実装も楽なんですけど、なんせ Activity 間の遷移は時間がかかります。一瞬待たされるよね？ setContentView() を使って画面遷移を実現すると、待たされることはなくなります。

では、コード。

R.layout.main -> R.layout.first -> R.layout.second -> finish




という画面遷移になっています。

package yanzm.products.screentransition.lib;

import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {

  static final private String prefName = "MY_PREF";
  private int mScreenId = R.layout.main;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    SharedPreferences prefs = getSharedPreferences(prefName, Context.MODE_PRIVATE);
    int screenId = prefs.getInt("screenId", R.layout.main);

    setScreenContent(screenId);
  }

  @Override
  public void onDestroy() {
    super.onDestroy();
    SharedPreferences prefs = getSharedPreferences(prefName, Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = prefs.edit();
    editor.putInt("screenId", mScreenId);
    editor.commit();
  }

  private void setScreenContent(int screenId) {
    mScreenId = screenId;
    setContentView(screenId);
  
    switch (screenId) {
    case R.layout.first: {
      setFirstScreenContent();
      break;
    }
    case R.layout.second: {
      setSecondScreenContent();
      break;
    }
    case R.layout.main: {
      setMainScreenContent();
      break;
    }
    }
  }

  private void setMainScreenContent() {
    Button backButton = (Button) findViewById(R.id.back);
    backButton.setVisibility(View.INVISIBLE);

    Button nextButton = (Button) findViewById(R.id.next);
    nextButton.setOnClickListener(new OnClickListener() {
      public void onClick(View v) {
        setScreenContent(R.layout.first);
      }
    });
  }

  private void setFirstScreenContent() {
    Button backButton = (Button) findViewById(R.id.back);
    backButton.setOnClickListener(new OnClickListener() {
      public void onClick(View v) {
        setScreenContent(R.layout.main);
      }
    });

    Button nextButton = (Button) findViewById(R.id.next);
    nextButton.setOnClickListener(new OnClickListener() {
      public void onClick(View v) {
        setScreenContent(R.layout.second);
      }
    });
  }

  private void setSecondScreenContent() {
    Button backButton = (Button) findViewById(R.id.back);
    backButton.setOnClickListener(new OnClickListener() {
      public void onClick(View v) {
        setScreenContent(R.layout.first);
      }
    });

    Button nextButton = (Button) findViewById(R.id.next);
    nextButton.setOnClickListener(new OnClickListener() {
      public void onClick(View v) {
        finish();
      }
    });
  }
}

R.layout.main

<?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/content"
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:layout_weight="1"
        android:text="This is main contents"
        />
    <include layout="@layout/back_next" />
</LinearLayout>

R.layout.first

<?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"
    >
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1">
        <TextView  
           android:id="@+id/content"
           android:layout_width="wrap_content" 
           android:layout_height="wrap_content" 
           android:text="this is first contents"
           />
       <ImageView
           android:layout_width="wrap_content" 
           android:layout_height="wrap_content" 
           android:src="@drawable/icon"
           />
    </LinearLayout>
    <include layout="@layout/back_next" />
</LinearLayout>

R.layout.second

<?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"
    >
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1">
        <TextView  
           android:id="@+id/content"
           android:layout_width="wrap_content" 
           android:layout_height="wrap_content" 
           android:text="this is second contents"
           />
       <ImageView
           android:layout_width="wrap_content" 
           android:layout_height="wrap_content" 
           android:src="@drawable/icon"
           />
       <ImageView
           android:layout_width="wrap_content" 
           android:layout_height="wrap_content" 
           android:src="@drawable/icon"
           />
    </LinearLayout>
    <include layout="@layout/back_next" />
</LinearLayout>

R.layout.back_next

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    >
    <Button
        android:id="@+id/back"
        android:layout_width="0dip"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="Back"
        />
    <Button
        android:id="@+id/next"
        android:layout_width="0dip"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="Next"
        />
</LinearLayout>