指定したURLを開くImageView Widget

activity_sample.xml

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

    <com.example.app.widget.LinkImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:contentDescription="@null"
        android:src="@drawable/logo"
        app:href="@string/url" />

</LinearLayout>

attrs.xml

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

    <attr name="href" format="string" />

    <declare-styleable name="LinkImageView">
        <attr name="href" />
    </declare-styleable>

</resources>

LinkImageView.java

package com.example.app.widget;

import com.example.app.R;
import android.content.Context;
import android.content.Intent;
import android.content.res.TypedArray;
import android.net.Uri;
import android.util.AttributeSet;
import android.view.View;
import android.widget.ImageView;

public class LinkImageView extends ImageView implements View.OnClickListener {

    private String url;

    public LinkImageView(Context context) {
        this(context, null);
    }

    public LinkImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public LinkImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        TypedArray a = context.obtainStyledAttributes(attrs,
                R.styleable.LinkImageView);

        url = a.getString(R.styleable.LinkImageView_href);

        a.recycle();

        this.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        Context context = getContext();

        Uri uri = Uri.parse(url);
        Intent intent = new Intent(Intent.ACTION_VIEW, uri);
        context.startActivity(intent);
    }

}