Text view is most commonly used control across applications.
It is used to display texts. In android, not only text, you can also display
html text in text view. Texts in Text views can be modified and formatted
easily.
There are two ways how you can add text view into a layout,
1. Through
designer, by drag and drop onto layout or just edit xml file and type it
manually.
2. Add
text view on the fly through code.
What all you can do with text view? Well, here is the list
of few important things.
1. Change
font type – use built-in font types (limited) or refer to external font file. To
use external font file, add font file (.ttf) into assets folder and import into text view using TypeFace object.
ex: Typeface newtypeface =
Typeface.createFromAsset(getAssets(), "Amazone BT.ttf");
2. Change
font style – bold, normal, italic (anyone at a time, multiple style only through text as html).
3. Change
font size – using a float value and unit to use.When no unit is specified, android defaults to pixels. Preferred units are dp/dip and sp. (pixels are not preferred in
android as it varies across devices).
4. Change
text color – you can change text color and text background color. Text color
attribute accepts only hexadecimal values when assigned in layout file. If you
are adding color from code, it’s better to use Color class of android or manually create your color using
hexadecimal values and add it. Text background accepts both color values and
images.
5. Text
appearances – create your own style and refer it or use android built-in text
appearances.
6. Modify
text dynamically through code.
7. Bind
events and act accordingly. Ex: click event, touch event, focus event etc...
Text appearance defines how your text should look to user. There
are few ways how you can modify your text.
1. Styled
and formatted in layout file.
2. If
needs are simple, android’s built-in styles can be used.
3. If
you want to make some really attractive formatting and re-use it, then define the style by yourself
in style.xml file and refer it
either in layout file or through code using resource id. Ex: R.style.yourstyle
Here is an example of how you can use text view in android.
TextViewDemoActivity.java
package com.coffeewithtechie.textviewdemo;
import android.app.Activity;
import android.graphics.Color;
import android.graphics.Typeface;
import android.os.Bundle;
import android.text.Html;
import android.util.TypedValue;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
import android.widget.TextView;
public class TextViewDemoActivity extends Activity {
TextView
tv4;
TextView
tv5;
TextView
tv6;
/** Called when
the activity is first created. */
@Override
public void
onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv4 =
(TextView)findViewById(R.id.textView4);
Typeface newtypeface
= Typeface.createFromAsset(getAssets(), "Amazone BT.ttf"); // font
file referred from assests folder
tv4 .setTypeface(newtypeface);
tv5 =
(TextView)findViewById(R.id.textView5);
tv5 .setText(Html.fromHtml("
this is html
string
"));
// html text,
only basic html tags works, styles doesn't work
tv6 =
(TextView)findViewById(R.id.textView6);
//
tv6.setOnClickListener(new OnClickListener() {
//
// @Override
// public
void onClick(View v) {
// //
TODO Auto-generated method stub
// String
text = tv6.getText().toString(); // get textview text value
// text
= "you clicked me!";
// tv6.setText(text);
// modify text dynamically
// }
// });
tv6.setOnTouchListener(new OnTouchListener() {
@Override
public
boolean onTouch(View v, MotionEvent event) {
String
text =
tv6.getText().toString(); // get textview text value
text
= "you touched me! at x:"+ event.getX()+" y:"+
event.getY()+" positions";
tv6.setText(text);
// modify text dynamically
return
true;
}
});
//dynamic
textview
TextView
tvDynamic = new TextView(this);
tvDynamic.setLayoutParams(new
LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
tvDynamic.setText("Dynamic text view, styled from code");
tvDynamic.setTextColor(Color.MAGENTA);
tvDynamic.setTextSize(TypedValue.COMPLEX_UNIT_MM, 5f); // font size in
millimeter
LinearLayout
layoutparent = (LinearLayout)findViewById(R.id.layoutparent);
layoutparent.addView(tvDynamic); //adding newly created text view to
layout
tvDynamic.setTextAppearance(this, R.style.CustomTextViewStyle);
}
}
Main.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:id="@+id/layoutparent"
android:orientation="vertical" >
<TextView android:background="#aaaaaa"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello" />
<TextView
android:background="@drawable/backgroun"
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="styled in xml"
android:textColor="#887722"
android:textSize="30dp"
android:textStyle="italic"
android:typeface="serif"
/>
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Styled with built in android styles"
android:textAppearance="@android:style/TextAppearance.Widget.TextView.PopupMenu"
/>
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Styled with custom styles"
android:textAppearance="@style/CustomTextViewStyle"
/>
<TextView
android:id="@+id/textView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Text with font type from external source"
android:textSize="25dp"
/>
<TextView
android:id="@+id/textView5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/textView6"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Touch me!"
/>
</LinearLayout>
Values/styles.xml
create a style.xml file under values folder and the below code
xml version="1.0"
encoding="utf-8"?>
<resources>
<style name="CustomTextViewStyle">
<item name="android:textColor">#ff0000<item>
<item name="android:textSize">26sp<item>
<item name="android:textStyle">bold<item>
style>
resources>
This is how it looks when executed.
 |
| output - before touch event |
Text modifies dynamically after touching “Touch me!” text view.
 |
| output - after executing touch event |
