Load resources from XML

This example show how to load resources from xml.

Create /res/values/arrays.xml to define drawable and int, used to load drawable and background color in our ImageViews.

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <array name="resicon">
        <item>@android:drawable/ic_dialog_alert</item>
        <item>@android:drawable/ic_menu_camera</item>
        <item>@android:drawable/ic_menu_compass</item>
        <item>@android:drawable/ic_menu_directions</item>
        <item>@android:drawable/ic_menu_gallery</item>
    </array>
    <array name="rescolor">
        <item>#FF101010</item>
        <item>#FF202020</item>
        <item>#FF303030</item>
        <item>#FF404040</item>
        <item>#FF505050</item>
    </array>

</resources>

package com.example.androidxmlresources;

import android.support.v7.app.ActionBarActivity;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.content.res.TypedArray;
import android.os.Bundle;

public class MainActivity extends ActionBarActivity {

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  
  TypedArray arrayResources = getResources().obtainTypedArray(R.array.resicon);
  TypedArray arrayColors = getResources().obtainTypedArray(R.array.rescolor);

  LinearLayout layout = new LinearLayout(this);
  LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
    LinearLayout.LayoutParams.MATCH_PARENT, 
    LinearLayout.LayoutParams.WRAP_CONTENT);
  layout.setOrientation(LinearLayout.VERTICAL);
  layout.setLayoutParams(params);
  
  TextView textView = new TextView(this);
  textView.setText("android-er.blogspot.com");
  layout.addView(textView);
  
  for(int i=0; i<arrayResources.length(); i++){
   ImageView imageView = new ImageView(this);
   imageView.setImageDrawable(arrayResources.getDrawable(i));
   imageView.setBackgroundColor(arrayColors.getColor(i, 0xFF000000));
   layout.addView(imageView);
  }
  setContentView(layout);
  
  arrayResources.recycle();
  arrayColors.recycle();
 }

}

Include custom view in XML

The exercise show how to refer custom view in XML.

Create custom view extending View in separated file, MyView.java.

package com.example.androidpaint;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.View;

public class MyView extends View {
 
 Bitmap myBitmap;
 int minWidth, minHeight;

 public MyView(Context context) {
  super(context);
  init();
 }

 public MyView(Context context, AttributeSet attrs) {
  super(context, attrs);
  init();
 }

 public MyView(Context context, AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
  init();
 }
 
 private void init(){
  myBitmap = BitmapFactory.decodeResource(
    getResources(), R.drawable.ic_launcher);
  minWidth = myBitmap.getWidth();
  minHeight = myBitmap.getHeight();
 }

 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  canvas.drawBitmap(myBitmap, 0, 0, null);
 }

 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  super.onMeasure(widthMeasureSpec, heightMeasureSpec);
  setMeasuredDimension(minWidth, minHeight);
 }
 
}

Include <com.example.androidpaint.MyView> in layout XML. where com.example.androidpaint is our package.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold" />
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="button"/>
    
    <com.example.androidpaint.MyView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
    <com.example.androidpaint.MyView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="another button"/>

</LinearLayout>