Android TextView Justify Text

Viewed 546980

How do you get the text of a TextView to be Justified (with text flush on the left- and right- hand sides)?

I found a possible solution here, but it does not work (even if you change vertical-center to center_vertical, etc).

20 Answers

Very Simple We can do that in the xml file

<TextView 
android:justificationMode="inter_word"
/>

Here's how I did it, I think the most elegant way I could. With this solution, the only things you need to do in your layouts are:

  • add an additional xmlns declaration
  • change your TextViews source text namespace from android to your new namespace
  • replace your TextViews with x.y.z.JustifiedTextView

Here's the code. Works perfectly fine on my phones (Galaxy Nexus Android 4.0.2, Galaxy Teos Android 2.1). Feel free, of course, to replace my package name with yours.

/assets/justified_textview.css:

body {
    font-size: 1.0em;
    color: rgb(180,180,180);
    text-align: justify;
}

@media screen and (-webkit-device-pixel-ratio: 1.5) {
    /* CSS for high-density screens */
    body {
        font-size: 1.05em;
    }
}

@media screen and (-webkit-device-pixel-ratio: 2.0) {
    /* CSS for extra high-density screens */
    body {
        font-size: 1.1em;
    }
}

/res/values/attrs.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="JustifiedTextView">
        <attr name="text" format="reference" />
    </declare-styleable>
</resources>

/res/layout/test.xml:

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:myapp="http://schemas.android.com/apk/res/net.bicou.myapp"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <net.bicou.myapp.widget.JustifiedTextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            myapp:text="@string/surv1_1" />

    </LinearLayout>
</ScrollView>

/src/net/bicou/myapp/widget/JustifiedTextView.java:

package net.bicou.myapp.widget;

import net.bicou.myapp.R;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Color;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.View;
import android.webkit.WebView;

public class JustifiedTextView extends WebView {
    public JustifiedTextView(final Context context) {
        this(context, null, 0);
    }

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

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

        if (attrs != null) {
            final TypedValue tv = new TypedValue();
            final TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.JustifiedTextView, defStyle, 0);
            if (ta != null) {
                ta.getValue(R.styleable.JustifiedTextView_text, tv);

                if (tv.resourceId > 0) {
                    final String text = context.getString(tv.resourceId).replace("\n", "<br />");
                    loadDataWithBaseURL("file:///android_asset/",
                            "<html><head>" +
                                    "<link rel=\"stylesheet\" type=\"text/css\" href=\"justified_textview.css\" />" +
                                    "</head><body>" + text + "</body></html>",

                                    "text/html", "UTF8", null);
                    setTransparentBackground();
                }
            }
        }
    }

    public void setTransparentBackground() {
        try {
            setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        } catch (final NoSuchMethodError e) {
        }

        setBackgroundColor(Color.TRANSPARENT);
        setBackgroundDrawable(null);
        setBackgroundResource(0);
    }
}

We need to set the rendering to software in order to get transparent background on Android 3+. Hence the try-catch for older versions of Android.

Hope this helps!

PS: please not that it might be useful to add this to your whole activity on Android 3+ in order to get the expected behavior:
android:hardwareAccelerated="false"

see here in the github

Just import the two files "TextJustifyUtils.java" and "TextViewEx.java" in your project.

public class TextJustifyUtils {
    // Please use run(...) instead
    public static void justify(TextView textView) {
        Paint paint = new Paint();

        String[] blocks;
        float spaceOffset = 0;
        float textWrapWidth = 0;

        int spacesToSpread;
        float wrappedEdgeSpace;
        String block;
        String[] lineAsWords;
        String wrappedLine;
        String smb = "";
        Object[] wrappedObj;

        // Pull widget properties
        paint.setColor(textView.getCurrentTextColor());
        paint.setTypeface(textView.getTypeface());
        paint.setTextSize(textView.getTextSize());

        textWrapWidth = textView.getWidth();
        spaceOffset = paint.measureText(" ");
        blocks = textView.getText().toString().split("((?<=\n)|(?=\n))");

        if (textWrapWidth < 20) {
            return;
        }

        for (int i = 0; i < blocks.length; i++) {
            block = blocks[i];

            if (block.length() == 0) {
                continue;
            } else if (block.equals("\n")) {
                smb += block;
                continue;
            }

            block = block.trim();

            if (block.length() == 0)
                continue;

            wrappedObj = TextJustifyUtils.createWrappedLine(block, paint,
                    spaceOffset, textWrapWidth);
            wrappedLine = ((String) wrappedObj[0]);
            wrappedEdgeSpace = (Float) wrappedObj[1];
            lineAsWords = wrappedLine.split(" ");
            spacesToSpread = (int) (wrappedEdgeSpace != Float.MIN_VALUE ? wrappedEdgeSpace
                    / spaceOffset
                    : 0);

            for (String word : lineAsWords) {
                smb += word + " ";

                if (--spacesToSpread > 0) {
                    smb += " ";
                }
            }

            smb = smb.trim();

            if (blocks[i].length() > 0) {
                blocks[i] = blocks[i].substring(wrappedLine.length());

                if (blocks[i].length() > 0) {
                    smb += "\n";
                }

                i--;
            }
        }

        textView.setGravity(Gravity.LEFT);
        textView.setText(smb);
    }

    protected static Object[] createWrappedLine(String block, Paint paint,
            float spaceOffset, float maxWidth) {
        float cacheWidth = maxWidth;
        float origMaxWidth = maxWidth;

        String line = "";

        for (String word : block.split("\\s")) {
            cacheWidth = paint.measureText(word);
            maxWidth -= cacheWidth;

            if (maxWidth <= 0) {
                return new Object[] { line, maxWidth + cacheWidth + spaceOffset };
            }

            line += word + " ";
            maxWidth -= spaceOffset;

        }

        if (paint.measureText(block) <= origMaxWidth) {
            return new Object[] { block, Float.MIN_VALUE };
        }

        return new Object[] { line, maxWidth };
    }

    final static String SYSTEM_NEWLINE = "\n";
    final static float COMPLEXITY = 5.12f; // Reducing this will increase
                                            // efficiency but will decrease
                                            // effectiveness
    final static Paint p = new Paint();

    public static void run(final TextView tv, float origWidth) {
        String s = tv.getText().toString();
        p.setTypeface(tv.getTypeface());
        String[] splits = s.split(SYSTEM_NEWLINE);
        float width = origWidth - 5;
        for (int x = 0; x < splits.length; x++)
            if (p.measureText(splits[x]) > width) {
                splits[x] = wrap(splits[x], width, p);
                String[] microSplits = splits[x].split(SYSTEM_NEWLINE);
                for (int y = 0; y < microSplits.length - 1; y++)
                    microSplits[y] = justify(removeLast(microSplits[y], " "),
                            width, p);
                StringBuilder smb_internal = new StringBuilder();
                for (int z = 0; z < microSplits.length; z++)
                    smb_internal.append(microSplits[z]
                            + ((z + 1 < microSplits.length) ? SYSTEM_NEWLINE
                                    : ""));
                splits[x] = smb_internal.toString();
            }
        final StringBuilder smb = new StringBuilder();
        for (String cleaned : splits)
            smb.append(cleaned + SYSTEM_NEWLINE);
        tv.setGravity(Gravity.LEFT);
        tv.setText(smb);
    }

    private static String wrap(String s, float width, Paint p) {
        String[] str = s.split("\\s"); // regex
        StringBuilder smb = new StringBuilder(); // save memory
        smb.append(SYSTEM_NEWLINE);
        for (int x = 0; x < str.length; x++) {
            float length = p.measureText(str[x]);
            String[] pieces = smb.toString().split(SYSTEM_NEWLINE);
            try {
                if (p.measureText(pieces[pieces.length - 1]) + length > width)
                    smb.append(SYSTEM_NEWLINE);
            } catch (Exception e) {
            }
            smb.append(str[x] + " ");
        }
        return smb.toString().replaceFirst(SYSTEM_NEWLINE, "");
    }

    private static String removeLast(String s, String g) {
        if (s.contains(g)) {
            int index = s.lastIndexOf(g);
            int indexEnd = index + g.length();
            if (index == 0)
                return s.substring(1);
            else if (index == s.length() - 1)
                return s.substring(0, index);
            else
                return s.substring(0, index) + s.substring(indexEnd);
        }
        return s;
    }

    private static String justifyOperation(String s, float width, Paint p) {
        float holder = (float) (COMPLEXITY * Math.random());
        while (s.contains(Float.toString(holder)))
            holder = (float) (COMPLEXITY * Math.random());
        String holder_string = Float.toString(holder);
        float lessThan = width;
        int timeOut = 100;
        int current = 0;
        while (p.measureText(s) < lessThan && current < timeOut) {
            s = s.replaceFirst(" ([^" + holder_string + "])", " "
                    + holder_string + "$1");
            lessThan = p.measureText(holder_string) + lessThan
                    - p.measureText(" ");
            current++;
        }
        String cleaned = s.replaceAll(holder_string, " ");
        return cleaned;
    }

    private static String justify(String s, float width, Paint p) {
        while (p.measureText(s) < width) {
            s = justifyOperation(s, width, p);
        }
        return s;
    }
}

and

public class TextViewEx extends TextView {
    private Paint paint = new Paint();

    private String[] blocks;
    private float spaceOffset = 0;
    private float horizontalOffset = 0;
    private float verticalOffset = 0;
    private float horizontalFontOffset = 0;
    private float dirtyRegionWidth = 0;
    private boolean wrapEnabled = false;
    int left, top, right, bottom = 0;
    private Align _align = Align.LEFT;
    private float strecthOffset;
    private float wrappedEdgeSpace;
    private String block;
    private String wrappedLine;
    private String[] lineAsWords;
    private Object[] wrappedObj;

    private Bitmap cache = null;
    private boolean cacheEnabled = false;

    public TextViewEx(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        // set a minimum of left and right padding so that the texts are not too
        // close to the side screen
        // this.setPadding(10, 0, 10, 0);
    }

    public TextViewEx(Context context, AttributeSet attrs) {
        super(context, attrs);
        // this.setPadding(10, 0, 10, 0);
    }

    public TextViewEx(Context context) {
        super(context);
        // this.setPadding(10, 0, 10, 0);
    }

    @Override
    public void setPadding(int left, int top, int right, int bottom) {
        // TODO Auto-generated method stub
        super.setPadding(left + 10, top, right + 10, bottom);
    }

    @Override
    public void setDrawingCacheEnabled(boolean cacheEnabled) {
        this.cacheEnabled = cacheEnabled;
    }

    public void setText(String st, boolean wrap) {
        wrapEnabled = wrap;
        super.setText(st);
    }

    public void setTextAlign(Align align) {
        _align = align;
    }

    @SuppressLint("NewApi")
    @Override
    protected void onDraw(Canvas canvas) {
        // If wrap is disabled then,
        // request original onDraw
        if (!wrapEnabled) {
            super.onDraw(canvas);
            return;
        }

        // Active canas needs to be set
        // based on cacheEnabled
        Canvas activeCanvas = null;

        // Set the active canvas based on
        // whether cache is enabled
        if (cacheEnabled) {

            if (cache != null) {
                // Draw to the OS provided canvas
                // if the cache is not empty
                canvas.drawBitmap(cache, 0, 0, paint);
                return;
            } else {
                // Create a bitmap and set the activeCanvas
                // to the one derived from the bitmap
                cache = Bitmap.createBitmap(getWidth(), getHeight(),
                        Config.ARGB_4444);
                activeCanvas = new Canvas(cache);
            }
        } else {
            // Active canvas is the OS
            // provided canvas
            activeCanvas = canvas;
        }

        // Pull widget properties
        paint.setColor(getCurrentTextColor());
        paint.setTypeface(getTypeface());
        paint.setTextSize(getTextSize());
        paint.setTextAlign(_align);
        paint.setFlags(Paint.ANTI_ALIAS_FLAG);

        // minus out the paddings pixel
        dirtyRegionWidth = getWidth() - getPaddingLeft() - getPaddingRight();
        int maxLines = Integer.MAX_VALUE;
        int currentapiVersion = android.os.Build.VERSION.SDK_INT;
        if (currentapiVersion >= android.os.Build.VERSION_CODES.JELLY_BEAN) {
            maxLines = getMaxLines();
        }
        int lines = 1;
        blocks = getText().toString().split("((?<=\n)|(?=\n))");
        verticalOffset = horizontalFontOffset = getLineHeight() - 0.5f; // Temp
                                                                        // fix
        spaceOffset = paint.measureText(" ");

        for (int i = 0; i < blocks.length && lines <= maxLines; i++) {
            block = blocks[i];
            horizontalOffset = 0;

            if (block.length() == 0) {
                continue;
            } else if (block.equals("\n")) {
                verticalOffset += horizontalFontOffset;
                continue;
            }

            block = block.trim();

            if (block.length() == 0) {
                continue;
            }

            wrappedObj = TextJustifyUtils.createWrappedLine(block, paint,
                    spaceOffset, dirtyRegionWidth);

            wrappedLine = ((String) wrappedObj[0]);
            wrappedEdgeSpace = (Float) wrappedObj[1];
            lineAsWords = wrappedLine.split(" ");
            strecthOffset = wrappedEdgeSpace != Float.MIN_VALUE ? wrappedEdgeSpace
                    / (lineAsWords.length - 1)
                    : 0;

            for (int j = 0; j < lineAsWords.length; j++) {
                String word = lineAsWords[j];
                if (lines == maxLines && j == lineAsWords.length - 1) {
                    activeCanvas.drawText("...", horizontalOffset,
                            verticalOffset, paint);

                } else if (j == 0) {
                    // if it is the first word of the line, text will be drawn
                    // starting from right edge of textview
                    if (_align == Align.RIGHT) {
                        activeCanvas.drawText(word, getWidth()
                                - (getPaddingRight()), verticalOffset, paint);
                        // add in the paddings to the horizontalOffset
                        horizontalOffset += getWidth() - (getPaddingRight());
                    } else {
                        activeCanvas.drawText(word, getPaddingLeft(),
                                verticalOffset, paint);
                        horizontalOffset += getPaddingLeft();
                    }

                } else {
                    activeCanvas.drawText(word, horizontalOffset,
                            verticalOffset, paint);
                }
                if (_align == Align.RIGHT)
                    horizontalOffset -= paint.measureText(word) + spaceOffset
                            + strecthOffset;
                else
                    horizontalOffset += paint.measureText(word) + spaceOffset
                            + strecthOffset;
            }

            lines++;

            if (blocks[i].length() > 0) {
                blocks[i] = blocks[i].substring(wrappedLine.length());
                verticalOffset += blocks[i].length() > 0 ? horizontalFontOffset
                        : 0;
                i--;
            }
        }

        if (cacheEnabled) {
            // Draw the cache onto the OS provided
            // canvas.
            canvas.drawBitmap(cache, 0, 0, paint);
        }
    }
}

Now, if you use normal textView like:

<TextView
                android:id="@+id/original"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/lorum_ipsum" />

Simply use

<yourpackagename.TextViewEx
                android:id="@+id/changed"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/lorum_ipsum" />

Define a variable and set justify to be true,

TextViewEx changed = (TextViewEx) findViewById(R.id.changed);
changed.setText(getResources().getString(R.string.lorum_ipsum),true);

You can use justificationMode as inter_word in xml. You have to remember that this attribute is available for api level 26 and higher. For that you can assign targetApi as o. The full code is given bellow

<com.google.android.material.textview.MaterialTextView
            ...
            android:justificationMode="inter_word"
            tools:targetApi="o" />

Please try this code for below 8.0

<TextView 
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_gravity="center_horizontal"
  android:gravity="center|start"/>
Related