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Android - TextView
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  Spannable TextView

A spannable TextView can be used in Android to highlight a particular portion of text with a different color, style, size, and/or click event in a single TextView widget.

Consider that you have defined a TextView as follows:

TextView textview=findViewById(R.id.textview);

Then you can apply different highlighting to it as shown below:

  • **Spannable color:** In order to set a different color to some portion of text, a `ForegroundColorSpan` can be used, as shown in the following example: 
    Spannable spannable = new SpannableString(firstWord+lastWord);
spannable.setSpan(new ForegroundColorSpan(firstWordColor), 0, firstWord.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan(new ForegroundColorSpan(lastWordColor), firstWord.length(), firstWord.length()+lastWord.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textview.setText( spannable );

    Output created by the code above: Example text highlighted by color (opens new window)

  • Spannable font: In order to set a different font size to some portion of text, a RelativeSizeSpan can be used, as shown in the following example:

    Spannable spannable = new SpannableString(firstWord+lastWord);
spannable.setSpan(new RelativeSizeSpan(1.1f),0, firstWord.length(),  Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); // set size
spannable.setSpan(new RelativeSizeSpan(0.8f), firstWord.length(), firstWord.length() + lastWord.length(),  Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); // set size
textview.setText( spannable );

    Output created by the code above: Example text highlighted by larger font size (opens new window)

  • Spannable typeface: In order to set a different font typeface to some portion of text, a custom TypefaceSpan can be used, as shown in the following example:

    Spannable spannable = new SpannableString(firstWord+lastWord);
spannable.setSpan( new CustomTypefaceSpan("SFUIText-Bold.otf",fontBold), 0, firstWord.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan( new CustomTypefaceSpan("SFUIText-Regular.otf",fontRegular), firstWord.length(), firstWord.length() + lastWord.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
text.setText( spannable );

    However, in order to make the above code working, the class CustomTypefaceSpan has to be derived from the class TypefaceSpan. This can be done as follows:

    public class CustomTypefaceSpan extends TypefaceSpan {
    private final Typeface newType;

    public CustomTypefaceSpan(String family, Typeface type) {
        super(family);
        newType = type;
    }

    @Override
    public void updateDrawState(TextPaint ds) {
        applyCustomTypeFace(ds, newType);
    }

    @Override
    public void updateMeasureState(TextPaint paint) {
        applyCustomTypeFace(paint, newType);
    }

    private static void applyCustomTypeFace(Paint paint, Typeface tf) {
        int oldStyle;
        Typeface old = paint.getTypeface();
        if (old == null) {
            oldStyle = 0;
        } else {
            oldStyle = old.getStyle();
        }
        int fake = oldStyle & ~tf.getStyle();
        if ((fake & Typeface.BOLD) != 0) {
            paint.setFakeBoldText(true);
        }

        if ((fake & Typeface.ITALIC) != 0) {
            paint.setTextSkewX(-0.25f);
        }

        paint.setTypeface(tf);
    }
}
    •   TextView with image

    Android allows programmers to place images at all four corners of a TextView. For example, if you are creating a field with a TextView and at same time you want to show that the field is editable, then developers will usually place an edit icon near that field. Android provides us an interesting option called compound drawable for a TextView:

    <TextView
        android:id="@+id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:drawablePadding="4dp"
        android:drawableRight="@drawable/edit"
        android:text="Hello world"
        android:textSize="18dp" />

    You can set the drawable to any side of your TextView as follows:

    android:drawableLeft="@drawable/edit"
android:drawableRight="@drawable/edit"
android:drawableTop="@drawable/edit"
android:drawableBottom="@drawable/edit"

    Setting the drawable can also be achieved programmatically in the following way:

    yourTextView.setCompoundDrawables(leftDrawable, rightDrawable, topDrawable, bottomDrawable);

    Setting any of the parameters handed over to setCompoundDrawables() to null will remove the icon from the corresponding side of the TextView.
      Strikethrough TextView

    Strikethrough the entire text

    String sampleText = "This is a test strike";
textView.setPaintFlags(tv.getPaintFlags()| Paint.STRIKE_THRU_TEXT_FLAG);
textView.setText(sampleText);

    Output: This is a test strike

    Strikethrough only parts of the text

    String sampleText = "This is a test strike";
SpannableStringBuilder spanBuilder = new SpannableStringBuilder(sampleText);
StrikethroughSpan strikethroughSpan = new StrikethroughSpan();
spanBuilder.setSpan(
        strikethroughSpan, // Span to add
        0, // Start
        4, // End of the span (exclusive)
        Spanned.SPAN_EXCLUSIVE_EXCLUSIVE // Text changes will not reflect in the strike changing
);
textView.setText(spanBuilder);

    Output: This is a test strike
      Make RelativeSizeSpan align to top

    In order to make a RelativeSizeSpan align to the top, a custom class can be derived from the class SuperscriptSpan. In the following example, the derived class is named TopAlignSuperscriptSpan:

    activity_main.xml:

    <TextView
    android:id="@+id/txtView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="50dp"
    android:textSize="26sp" />

    MainActivity.java:

    TextView txtView = (TextView) findViewById(R.id.txtView);

SpannableString spannableString = new SpannableString("RM123.456");
spannableString.setSpan( new TopAlignSuperscriptSpan( (float)0.35 ), 0, 2, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE );
txtView.setText(spannableString);

    TopAlignSuperscriptSpan.java:

    private class TopAlignSuperscriptSpan extends SuperscriptSpan {
    //divide superscript by this number
    protected int fontScale = 2;

    //shift value, 0 to 1.0
    protected float shiftPercentage = 0;

    //doesn't shift
    TopAlignSuperscriptSpan() {}

    //sets the shift percentage
    TopAlignSuperscriptSpan( float shiftPercentage ) {
        if( shiftPercentage > 0.0 && shiftPercentage < 1.0 )
            this.shiftPercentage = shiftPercentage;
    }

    @Override
    public void updateDrawState( TextPaint tp ) {
        //original ascent
        float ascent = tp.ascent();

        //scale down the font
        tp.setTextSize( tp.getTextSize() / fontScale );

        //get the new font ascent
        float newAscent = tp.getFontMetrics().ascent;

        //move baseline to top of old font, then move down size of new font
        //adjust for errors with shift percentage
        tp.baselineShift += ( ascent - ascent * shiftPercentage )
                - (newAscent - newAscent * shiftPercentage );
    }

    @Override
    public void updateMeasureState( TextPaint tp ) {
        updateDrawState( tp );
    }
}

    Reference screenshot:

    Screenshot showing the result of the above code (opens new window)
      Pinchzoom on TextView

    activity_main.xml:

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

    <TextView
        android:id="@+id/mytv"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="This is my sample text for pinch zoom demo, you can zoom in and out using pinch zoom, thanks" />

</RelativeLayout>

    MainActivity.java:

    import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.TextView;

public class MyTextViewPinchZoomClass extends Activity implements OnTouchListener {

    final static float STEP = 200;
    TextView mytv;
    float mRatio = 1.0f;
    int mBaseDist;
    float mBaseRatio;
    float fontsize = 13;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mytv = (TextView) findViewById(R.id.mytv);
        mytv.setTextSize(mRatio + 13);
    }

    public boolean onTouchEvent(MotionEvent event) {
        if (event.getPointerCount() == 2) {
            int action = event.getAction();
            int pureaction = action & MotionEvent.ACTION_MASK;
            if (pureaction == MotionEvent.ACTION_POINTER_DOWN) {
                mBaseDist = getDistance(event);
                mBaseRatio = mRatio;
            } else {
                float delta = (getDistance(event) - mBaseDist) / STEP;
                float multi = (float) Math.pow(2, delta);
                mRatio = Math.min(1024.0f, Math.max(0.1f, mBaseRatio * multi));
                mytv.setTextSize(mRatio + 13);
            }
        }
        return true;
    }

    int getDistance(MotionEvent event) {
        int dx = (int) (event.getX(0) - event.getX(1));
        int dy = (int) (event.getY(0) - event.getY(1));
        return (int) (Math.sqrt(dx * dx + dy * dy));
    }

    public boolean onTouch(View v, MotionEvent event) {
        return false;
    }
}
      Textview with different Textsize

    You can archive different Textsizes inside a Textview with a Span

    TextView textView = (TextView) findViewById(R.id.textView);
Spannable span = new SpannableString(textView.getText());
span.setSpan(new RelativeSizeSpan(0.8f), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(span)
      TextView customization 
    public class CustomTextView extends TextView {

    private float strokeWidth;
    private Integer strokeColor;
    private Paint.Join strokeJoin;
    private float strokeMiter;


    public CustomTextView(Context context) {
        super(context);
        init(null);
    }

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

    public CustomTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(attrs);
    }

    public void init(AttributeSet attrs) {

        if (attrs != null) {
            TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.CustomTextView);

            if (a.hasValue(R.styleable.CustomTextView_strokeColor)) {
                float strokeWidth = a.getDimensionPixelSize(R.styleable.CustomTextView_strokeWidth, 1);
                int strokeColor = a.getColor(R.styleable.CustomTextView_strokeColor, 0xff000000);
                float strokeMiter = a.getDimensionPixelSize(R.styleable.CustomTextView_strokeMiter, 10);
                Paint.Join strokeJoin = null;
                switch (a.getInt(R.styleable.CustomTextView_strokeJoinStyle, 0)) {
                    case (0):
                        strokeJoin = Paint.Join.MITER;
                        break;
                    case (1):
                        strokeJoin = Paint.Join.BEVEL;
                        break;
                    case (2):
                        strokeJoin = Paint.Join.ROUND;
                        break;
                }
                this.setStroke(strokeWidth, strokeColor, strokeJoin, strokeMiter);
            }
        }
    }

    public void setStroke(float width, int color, Paint.Join join, float miter) {
        strokeWidth = width;
        strokeColor = color;
        strokeJoin = join;
        strokeMiter = miter;
    }

    @Override
    public void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        int restoreColor = this.getCurrentTextColor();
        if (strokeColor != null) {
            TextPaint paint = this.getPaint();
            paint.setStyle(Paint.Style.STROKE);
            paint.setStrokeJoin(strokeJoin);
            paint.setStrokeMiter(strokeMiter);
            this.setTextColor(strokeColor);
            paint.setStrokeWidth(strokeWidth);
            super.onDraw(canvas);
            paint.setStyle(Paint.Style.FILL);
            this.setTextColor(restoreColor);
        }
    }
}

    Usage:

    public class MainActivity extends Activity {

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

        CustomTextView customTextView = (CustomTextView) findViewById(R.id.pager_title);
    }
}

    Layout:

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@mipmap/background">


    <pk.sohail.gallerytest.activity.CustomTextView
        android:id="@+id/pager_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:gravity="center"
        android:text="@string/txt_title_photo_gallery"
        android:textColor="@color/white"
        android:textSize="30dp"
        android:textStyle="bold"
        app:outerShadowRadius="10dp"
        app:strokeColor="@color/title_text_color"
        app:strokeJoinStyle="miter"
        app:strokeWidth="2dp" />

</RelativeLayout>

    attars:

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

    <declare-styleable name="CustomTextView">

        <attr name="outerShadowRadius" format="dimension" />
        <attr name="strokeWidth" format="dimension" />
        <attr name="strokeMiter" format="dimension" />
        <attr name="strokeColor" format="color" />
        <attr name="strokeJoinStyle">
            <enum name="miter" value="0" />
            <enum name="bevel" value="1" />
            <enum name="round" value="2" />
        </attr>
    </declare-styleable>

</resources>

    Programmatically usage:

    CustomTextView mtxt_name = (CustomTextView) findViewById(R.id.pager_title); 
//then use 
setStroke(float width, int color, Paint.Join join, float miter);
//method before setting 
setText("Sample Text");
      Theme and Style customization

    MainActivity.java:

    public class MainActivity extends AppCompatActivity {

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

    activity_main.xml:

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:custom="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <com.customthemeattributedemo.customview.CustomTextView
        style="?mediumTextStyle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="20dp"
        android:text="@string/message_hello"
        custom:font_family="@string/bold_font" />

    <com.customthemeattributedemo.customview.CustomTextView
        style="?largeTextStyle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="20dp"
        android:text="@string/message_hello"
        custom:font_family="@string/bold_font" />
</LinearLayout>

    CustomTextView.java:

    public class CustomTextView extends TextView {

    private static final String TAG = "TextViewPlus";
    private Context mContext;

    public CustomTextView(Context context) {
        super(context);
        mContext = context;
    }

    public CustomTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        setCustomFont(context, attrs);
    }

    public CustomTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        mContext = context;
        setCustomFont(context, attrs);
    }

    private void setCustomFont(Context ctx, AttributeSet attrs) {
        TypedArray customFontNameTypedArray = ctx.obtainStyledAttributes(attrs, R.styleable.CustomTextView);
        String customFont = customFontNameTypedArray.getString(R.styleable.CustomTextView_font_family);
        Typeface typeface = null;
        typeface = Typeface.createFromAsset(ctx.getAssets(), customFont);
        setTypeface(typeface);
        customFontNameTypedArray.recycle();
    }
}

    attrs.xml:

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

    <attr name="mediumTextStyle" format="reference" />
    <attr name="largeTextStyle" format="reference" />

    <declare-styleable name="CustomTextView">

        <attr name="font_family" format="string" />
        <!--- Your other attributes -->

    </declare-styleable>
</resources>

    strings.xml:

    <resources>
    <string name="app_name">Custom Style Theme Attribute Demo</string>
    <string name="message_hello">Hello Hiren!</string>

    <string name="bold_font">bold.ttf</string>
</resources>

    styles.xml:

    <resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>

        <item name="mediumTextStyle">@style/textMedium</item>
        <item name="largeTextStyle">@style/textLarge</item>
    </style>


    <style name="textMedium" parent="textParentStyle">
        <item name="android:textAppearance">@android:style/TextAppearance.Medium</item>
    </style>

    <style name="textLarge" parent="textParentStyle">
        <item name="android:textAppearance">@android:style/TextAppearance.Large</item>
    </style>

    <style name="textParentStyle">
        <item name="android:textColor">@android:color/white</item>
        <item name="android:background">@color/colorPrimary</item>
        <item name="android:padding">5dp</item>
    </style>

</resources>
      Single TextView with two different colors

    Colored text can be created by passing the text and a font color name to the following function:

    private String getColoredSpanned(String text, String color) {
    String input = "<font color=" + color + ">" + text + "</font>";
    return input;
}

    The colored text can then be set to a TextView (or even to a Button, EditText, etc.) by using the example code below.

    First, define a TextView as follows:

    TextView txtView = (TextView)findViewById(R.id.txtView);

    Then, create differently colored text and assign it to strings:

    String name = getColoredSpanned("Hiren", "#800000");
String surName = getColoredSpanned("Patel","#000080");

    Finally, set the two differently colored strings to the TextView:

    txtView.setText(Html.fromHtml(name+" "+surName));

    Reference screenshot:

    Screenshot showing the result of the above code (opens new window)

    Syntax

    • TextView (Context context)
    • (TextView)findViewById(int id)
    • void setText (int resid)
    • void setText (CharSequence text)//You can use String as an argument

    Remarks

    Try to use it in xml design or programmatically.

    		 

    Read Article
    https://develop.horje.com/learn/1434/reference

     

    Horje