Friday, August 5, 2016

Android ClickableSpan example

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/coordinator_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ece5ec"
    >
    <TextView
        android:id="@+id/tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_margin="25dp"
        android:textSize="40sp"
        android:gravity="center"
        />
</android.support.design.widget.CoordinatorLayout>
MainActivity.java

package com.cfsuman.me.androidcodesnippets;

import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.support.design.widget.CoordinatorLayout;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import android.text.method.LinkMovementMethod;
import android.text.style.ClickableSpan;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;


public class MainActivity extends AppCompatActivity {
    private Context mContext;
    private Activity mActivity;

    private CoordinatorLayout mCLayout;
    private TextView mTextView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Get the application context
        mContext = getApplicationContext();
        mActivity = MainActivity.this;

        // Get the widget reference from XML layout
        mCLayout = (CoordinatorLayout) findViewById(R.id.coordinator_layout);
        mTextView = (TextView) findViewById(R.id.tv);

        // Initialize a new String variable
        String text = "Test text to show ClickableSpan example." +
                " Click to display @Red, @Green, @Blue background.";

        // Initialize a new SpannableStringBuilder instance
        SpannableStringBuilder ssBuilder = new SpannableStringBuilder(text);

        // Initialize a new ClickableSpan to display red background
        ClickableSpan redClickableSpan = new ClickableSpan() {
            @Override
            public void onClick(View view) {
                // Do something
                Toast.makeText(mContext, "@Red", Toast.LENGTH_SHORT).show();
                mCLayout.setBackgroundColor(Color.RED);
            }
        };

        // Initialize a new ClickableSpan to display green background
        ClickableSpan greenClickableSpan = new ClickableSpan() {
            @Override
            public void onClick(View view) {
                // Do something
                Toast.makeText(mContext, "@Green", Toast.LENGTH_SHORT).show();
                mCLayout.setBackgroundColor(Color.GREEN);
            }
        };

        // Initialize a new ClickableSpan to display blue background
        ClickableSpan blueClickableSpan = new ClickableSpan() {
            @Override
            public void onClick(View view) {
                // Do something
                Toast.makeText(mContext, "@Blue", Toast.LENGTH_SHORT).show();
                mCLayout.setBackgroundColor(Color.BLUE);
            }
        };

        // Apply the clickable text to the span
        ssBuilder.setSpan(
                redClickableSpan, // Span to add
                text.indexOf("@Red"), // Start of the span (inclusive)
                text.indexOf("@Red") + String.valueOf("@Red").length(), // End of the span (exclusive)
                Spanned.SPAN_EXCLUSIVE_EXCLUSIVE // Do not extend the span when text add later
        );

        // Apply the clickable text to the span
        ssBuilder.setSpan(
                greenClickableSpan,
                text.indexOf("@Green"),
                text.indexOf("@Green") + String.valueOf("@Green").length(),
                Spanned.SPAN_EXCLUSIVE_EXCLUSIVE
        );

        // Apply the clickable text to the span
        ssBuilder.setSpan(
                blueClickableSpan,
                text.indexOf("@Blue"),
                text.indexOf("@Blue") + String.valueOf("@Blue").length(),
                Spanned.SPAN_EXCLUSIVE_EXCLUSIVE
        );

        // Display the spannable text to TextView
        mTextView.setText(ssBuilder);

        // Specify the TextView movement method
        mTextView.setMovementMethod(LinkMovementMethod.getInstance());
    }
}