Android ImageView Demonstration

Screenshot after five clicks on the PPS image

Screenshot after five clicks on the PPS image

We put one medium size PPS.png image in the folder \res\drawable-mdpi to suit our emulator. The three sizes of the default icon are in the recommended 3 : 4 : 6 ratio as detailed below.

  • 36 x 36 for small screens (drawable-sdpi\icon.png)
  • 48 x 48 for medium screens (drawable-mdpi\icon.png)
  • 72 x 72 for large screens (drawable-ldpi\icon.png)

Notice in the layout file that the src property setting of the ImageView refers to the image folder as "drawable" without any indication of size/resolution and that the file extension of the filename is omitted:

android:src="@drawable/icon"

The code of MainActivity.pas

namespace org.me.android_images;

interface

uses
  java.util,
  android.app,
  android.content,
  android.os,
  android.util,
  android.view,
  android.widget;

type
  MainActivity = public class(Activity)
  private
    ppsImage : ImageView;
  public
    method onCreate(savedInstanceState: Bundle); override;
    method onClickPPS(v : View);
  end;

implementation

method MainActivity.onCreate(savedInstanceState: Bundle);
begin
  inherited;
  // Set view from the "main" layout resource
  ContentView := R.layout.main;
  // Assign ImageView from layout resource.
  ppsImage := ImageView(findViewById(R.id.pps));  
end;

method MainActivity.onClickPPS(v : View);
begin
  ppsImage.setY(ppsImage.getY + 5);
end;

end.

Layout File

<?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"
    android:background="#ffffff"          
    android:gravity="center_horizontal">
    <ImageView
      android:src="@drawable/icon"
      android:paddingTop="30dp"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content" />
    <ImageView
      android:id="@+id/pps"
      android:src="@drawable/pps"
      android:clickable="true"
      android:onClick="onClickPPS"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content" />
  </LinearLayout>

Strings File

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <string name="app_name">org.me.android_images</string>
</resources>
Programming - a skill for life!

Introduction to Android Apps in Oxygene for Java