Managing an Android page, such as managing a page on an iPhone

I would like to add something to this VERY useful site, so this is not a question, but rather my solution to this problem. I would also like to add that this solution was backed by support for the form from this site and many others, so it is a joint effort of many other developers. I say thank you to them!

QUESTION: "How can you recreate the horizontal scrolling aspects of iPhone applications and the associated page controls in the Android environment?"

This arose because I wanted to display the steps in the recipe, the method associated with it for each step, and the necessary ingredients in one scroll. I also wanted the page control to appear to the user where they were on the steps, and allows them to go to any specific step.

This part of my application displays the steps in the recipe. Each step is displayed on the page and consists of three components. Step ID (i.e. STEP 1, STEP 2), method and ingredients needed for the step.

Below the recipe section, a page control is displayed showing which page is active and can be used to go to specific pages. You will notice that the page control has image buttons, and two images have simple circles, one for an unselected page (page.png) and one for a selected page (page_selected.png)

When an action is created, the steps for the selected recipe are extracted from the data and the scroller section created by adding a view for each step in the recipe. When you scroll the scroller, the view switches to the next or previous page, and the pager display refreshes to indicate which page you are on.

The first 3 xml layouts (res / layout)

recipe.xml

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

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

 <!--Scroller section-->

   <HorizontalScrollView
       android:id="@+id/scroll_view"
        android:layout_width="match_parent"
        android:layout_height="320dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="100dp" >

            <LinearLayout
                android:id="@+id/methodScrollView"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="horizontal" >
            </LinearLayout>

    </HorizontalScrollView>

<!-- pager section --> 

    <LinearLayout
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="20dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="430dp"
        android:gravity="center"
        android:orientation="horizontal" >

    </LinearLayout>

</RelativeLayout>

recipesscroll.xml (the view that will be added to the scroller section for each step of the recipe. Note that the scroller section has onTouchlistner in recipeViewController.java to handle page scrolling)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/recipeScroll"
    android:layout_width="320dp"
    android:layout_height="320dp"
    android:gravity="center_vertical" >

   <TextView
    android:id="@+id/method"
    style="@style/scrollMethod"
    android:layout_width="wrap_content"
    android:layout_height="200dp"
    android:layout_alignParentTop="true"
    android:text="Method" />

   <TextView
    android:id="@+id/ingredients"
    style="@style/scrollIngredients"
    android:layout_width="wrap_content"
    android:layout_height="120dp"
    android:layout_alignParentTop="true"
    android:text="Ingredients" />

   <TextView
    android:id="@+id/methodStep"
    style="@style/scrollStep"
    android:layout_width="wrap_content"
    android:layout_height="20dp"
    android:layout_alignParentTop="true"
    android:text="Step" />

</RelativeLayout>

recipiespager.xml(, . , onClick recipeViewController.java, , )

<?xml version="1.0" encoding="utf-8"?>
<Button xmlns:android="http://schemas.android.com/apk/res/android"
            style="@style/pageButton"
            android:layout_marginLeft="10dp"
            android:layout_width="16dp"
            android:layout_height="16dp"
            android:onClick="selectPage">

</Button>

recipeViewController.java

//my package name change this to yours
package com.infactdata.spinAdinner;

import java.util.ArrayList;

//DataModel is the model for my data change this to yours or ignore 
because it is just away of holding the data that will populate the views
import com.infactdata.plist.DataModel;

import android.content.res.Resources;
import android.graphics.Typeface;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.HorizontalScrollView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;

public class RecipeViewController extends RootViewController {
    private DataModel currentData;
    HorizontalScrollView h_scroll;
    int numberOfPages = 0;
    int thePage;
    int otherPage;

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

        //first of the xml files
        setContentView(R.layout.recipe);

        //reference to my global variables
        GlobalClass global = (GlobalClass)getApplicationContext();

        //because I wanted a particular type face
        Typeface face=Typeface.createFromAsset(getAssets(), "fonts/trebucit.ttf");

        //VERY IMPORTANT because we need to use this to add the content to the scroll
        and pager sections   
        LayoutInflater inflater = getLayoutInflater();

        //current data held a dataModel
        currentData = global.getCurrent();  

        currentName.setText(currentData.getName());

        String imageFile = currentData.getImage();
        Resources r = getResources();

        int res = r.getIdentifier(imageFile, "drawable", "com.infactdata.spinAdinner");
        image.setImageResource(res);

        //recources that change the pager indicators to different images
        thePage = r.getIdentifier("page_selected", "drawable","com.infactdata.spinAdinner");
        otherPage = r.getIdentifier("page", "drawable", "com.infactdata.spinAdinner");

        //Get the method(ArrayList) out of the currentData(DataModel). This is the array of 
        data that will fill the added view with different content (ie. the specific
        instructions for the recipe step. This could be your own data array.   

        ArrayList<String[]> method = new ArrayList<String[]>();
        method = currentData.getMethod(0);
        numberOfPages = method.size();

        //now to build the views by adding the content and then adding the text for that 
        content that reflects the instructions for the step in the recipe  

        for( int i = 0; i < method.size(); i++){

            String[] methodStep = method.get(i);

            //find the scroll view
            LinearLayout scroll = (LinearLayout) findViewById(R.id.methodScrollView);

            //find the recipe scroller. the second xml file 
            RelativeLayout step = (RelativeLayout)findViewById(R.id.recipeScroll);

            //add the recipe step (step) to the scrollview (scroll)
            step = (RelativeLayout)inflater.inflate(R.layout.recipescroll, scroll, false);

            //add the instructions for this step in the recipe
            TextView stage = (TextView)step.findViewById(R.id.methodStep);
            stage.setText(methodStep[0].toString());
            stage.setTypeface(face);

            TextView methodText = (TextView)step.findViewById(R.id.method);
            methodText.setText(methodStep[1].toString());
            methodText.setTypeface(face);

            TextView ingredients = (TextView)step.findViewById(R.id.ingredients);
            ingredients.setText(methodStep[2].toString());
            ingredients.setTypeface(face);

            //create method step and add to scroll
            scroll.addView(step);

            //pager setup is a duplicate of the above
            //find the pager
            LinearLayout pager = (LinearLayout) findViewById(R.id.pager);

           //find the pager button. the third xml file
           Button page = (Button)inflater.inflate(R.layout.recipespager, pager, false);

           //give each button it own ID. This will be used to test which button should  be highlighted and used to move to a specific page. This is because the ID is equal to the page number (0 based of course) 
           page.setId(i);

           //because this is a fresh construction we will be on page 0 so highlight that button   
          if (i == 0){
              page.setBackgroundResource(thePage);
           }

           //create page control and add to pager
           pager.addView(page);
       }

      //create the onTouch controls 

      h_scroll = (HorizontalScrollView) findViewById(R.id.scroll_view);
      h_scroll.setOnTouchListener(scrolling);

 }

 private OnTouchListener scrolling = new OnTouchListener(){
     public boolean onTouch(View v, MotionEvent event) {
         if (event.getAction() == MotionEvent.ACTION_UP || event.getAction() == 
         MotionEvent.ACTION_CANCEL ){
             int scrollX = h_scroll.getScrollX();
             int itemWidth = h_scroll.getMeasuredWidth();
             int activePage = ((scrollX + itemWidth / 2) / itemWidth);
             int scrollTo = activePage * itemWidth;
             h_scroll.smoothScrollTo(scrollTo, 0);


             //page control display the active page button
             Log.v("MyDebug","Active page = "+activePage);
             for(int i = 0; i < numberOfPages; i++){
                Button aPage = (Button) findViewById(i);
                if(i == activePage){
                    aPage.setBackgroundResource(thePage);
                }else{
                    aPage.setBackgroundResource(otherPage);
                }
             }

             return true;
         } else {
             return false;
         }
     }

 };


 //this is the onClick handler for the page buttons and moves the scroller to the page 
 associated with the button. That is through the button ID, which matches the page 
 number (0 based of course

 public void selectPage(View v) {
     int newPage = v.getId();
     int itemWidth = h_scroll.getMeasuredWidth();
     int scrollTo = newPage * itemWidth;
     h_scroll.smoothScrollTo(scrollTo, 0);

   //page control display
     Log.v("MyDebug","Active page = "+newPage);
     for(int i = 0; i < numberOfPages; i++){
        Button aPage = (Button) findViewById(i);
        if(i == newPage){
            aPage.setBackgroundResource(thePage);
        }else{
            aPage.setBackgroundResource(otherPage);
        }
     }
  }

  public void finishActivity(View v){
      //perform back action
      finish();
  }

  public void nextActivity(View v){
      //move to next activity
  }
}

, . , , , , - . THANKS stackoverflow!!!!