Justify text in an Android app using a WebView but presenting a TextView-like interface?

I'm looking for a simple way to forget that I'm using a WebView to have justified text in my TextView. Has someone made a custom view for this? I'm well aware that I can do something like this:

 WebView view = new WebView(this);    
         view.loadData("my html with text justification","text/html","utf-8");

But it gets ugly when you want to set the size, the color or other common properties of the TextView. There must be a more convenient way of doing it.


Solution 1:

It was getting on my nerves, I admit it. I like the TextViews to look like TextViews in the code, and even if I'm using a WebView as the means of achieving the text-align:justified formatting, I don't want to look at it that way.

I created a custom view (ugly, probably bad) that implements the methods that I commonly use from the TextView and modifies the content of the WebView in order to reflect those changes. Wether it's useful for someone else or a potential hazard I really don't know, for me it works, I've used it in several projects and haven't run into any issues. The only minor inconvenience is that I assume it as a bigger toll memory-wise but nothing to worry about if it's just one or two (correct me if I'm wrong).

The result is the following:

enter image description here

And the code for setting it programmatically is as simple as this:

 JustifiedTextView J = new JustifiedTextView();
                   J.setText("insert your text here");

Of course it'd be stupid to leave it like that so I also added the methods for changing the font-size and the font-color which are basically all I use TextViews for. Meaning I can do something like this:

 JustifiedTextView J = new JustifiedTextView();
                   J.setText("insert your text here");
                   J.setTextColor(Color.RED);
                   J.setTextSize(30);

And obtain the following result (images are cropped):

enter image description here

But, this is not to show us how it looks, it's to share how you've done it!

I know, I know. Here's the full code. It also addresses Problems when setting transparent background and loading UTF-8 strings into the view. See the comments in reloadData() for details.

public class JustifiedTextView extends WebView{
    private String core      = "<html><body style='text-align:justify;color:rgba(%s);font-size:%dpx;margin: 0px 0px 0px 0px;'>%s</body></html>";
    private String textColor = "0,0,0,255";
    private String text      = "";
    private int textSize     = 12;
    private int backgroundColor=Color.TRANSPARENT;

    public JustifiedTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.setWebChromeClient(new WebChromeClient(){});
    }

    public void setText(String s){
        this.text = s;
        reloadData();
    }

    @SuppressLint("NewApi")
    private void reloadData(){

        // loadData(...) has a bug showing utf-8 correctly. That's why we need to set it first.
        this.getSettings().setDefaultTextEncodingName("utf-8");

        this.loadData(String.format(core,textColor,textSize,text), "text/html","utf-8");

        // set WebView's background color *after* data was loaded.
        super.setBackgroundColor(backgroundColor);

        // Hardware rendering breaks background color to work as expected.
        // Need to use software renderer in that case.
        if(android.os.Build.VERSION.SDK_INT >= 11)
            this.setLayerType(WebView.LAYER_TYPE_SOFTWARE, null);
    }

    public void setTextColor(int hex){
        String h = Integer.toHexString(hex);
        int a = Integer.parseInt(h.substring(0, 2),16);
        int r = Integer.parseInt(h.substring(2, 4),16);
        int g = Integer.parseInt(h.substring(4, 6),16);
        int b = Integer.parseInt(h.substring(6, 8),16);
        textColor = String.format("%d,%d,%d,%d", r, g, b, a); 
        reloadData();
    }

    public void setBackgroundColor(int hex){
        backgroundColor = hex;
        reloadData();
    }

    public void setTextSize(int textSize){
        this.textSize = textSize;
        reloadData();
    }
}

Solution 2:

In just three steps, you can justify your web view text.

1)

// Justify tag
String justifyTag = "<html><body style='text-align:justify;'>%s</body></html>";

2)

// Concatenate your string with the tag to Justify it
String dataString = String.format(Locale.US, justifyTag, "my html with text justification");

3)

// Load the data in the web view
webView.loadDataWithBaseURL("", dataString, "text/html", "UTF-8", "");

Solution 3:

Without webview solution is : https://github.com/merterhk/JustifiedTextView

import java.util.ArrayList;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.text.TextPaint;
import android.view.View;

public class JustifiedTextView extends View {
        String text;
        ArrayList<Line> linesCollection = new ArrayList<Line>();
        TextPaint textPaint;
        Typeface font;
        int textColor;
        float textSize = 42f, lineHeight = 57f, wordSpacing = 15f, lineSpacing = 15f;
        float onBirim, w, h;
        float leftPadding, rightPadding;

        public JustifiedTextView(Context context, String text) {
                super(context);
                this.text = text;
                init();
        }

        private void init() {
                textPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG);
                textColor = Color.BLACK;
        }

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
                super.onMeasure(widthMeasureSpec, heightMeasureSpec);

                if (font != null) {
                        font = Typeface.createFromAsset(getContext().getAssets(), "font/Trykker-Regular.ttf");
                        textPaint.setTypeface(font);
                }
                textPaint.setColor(textColor);

                int minw = getPaddingLeft() + getPaddingRight() + getSuggestedMinimumWidth();
                w = resolveSizeAndState(minw, widthMeasureSpec, 1);
                h = MeasureSpec.getSize(widthMeasureSpec);

                onBirim = 0.009259259f * w;
                lineHeight = textSize + lineSpacing;
                leftPadding = 3 * onBirim + getPaddingLeft();
                rightPadding = 3 * onBirim + getPaddingRight();

                textPaint.setTextSize(textSize);

                wordSpacing = 15f;
                Line lineBuffer = new Line();
                this.linesCollection.clear();
                String[] lines = text.split("\n");
                for (String line : lines) {
                        String[] words = line.split(" ");
                        lineBuffer = new Line();
                        float lineWidth = leftPadding + rightPadding;
                        float totalWordWidth = 0;
                        for (String word : words) {
                                float ww = textPaint.measureText(word) + wordSpacing;
                                if (lineWidth + ww + (lineBuffer.getWords().size() * wordSpacing) > w) {// is
                                        lineBuffer.addWord(word);
                                        totalWordWidth += textPaint.measureText(word);
                                        lineBuffer.setSpacing((w - totalWordWidth - leftPadding - rightPadding) / (lineBuffer.getWords().size() - 1));
                                        this.linesCollection.add(lineBuffer);
                                        lineBuffer = new Line();
                                        totalWordWidth = 0;
                                        lineWidth = leftPadding + rightPadding;
                                } else {
                                        lineBuffer.setSpacing(wordSpacing);
                                        lineBuffer.addWord(word);
                                        totalWordWidth += textPaint.measureText(word);
                                        lineWidth += ww;
                                }
                        }
                        this.linesCollection.add(lineBuffer);
                }
                setMeasuredDimension((int) w, (int) ((this.linesCollection.size() + 1) * lineHeight + (10 * onBirim)));
        }

        @Override
        protected void onDraw(Canvas canvas) {
                super.onDraw(canvas);
                canvas.drawLine(0f, 10f, getMeasuredWidth(), 10f, textPaint);
                float x, y = lineHeight + onBirim;
                for (Line line : linesCollection) {
                        x = leftPadding;
                        for (String s : line.getWords()) {
                                canvas.drawText(s, x, y, textPaint);
                                x += textPaint.measureText(s) + line.spacing;
                        }
                        y += lineHeight;
                }
        }

        public String getText() {
                return text;
        }

        public void setText(String text) {
                this.text = text;
        }

        public Typeface getFont() {
                return font;
        }

        public void setFont(Typeface font) {
                this.font = font;
        }

        public float getLineHeight() {
                return lineHeight;
        }

        public void setLineHeight(float lineHeight) {
                this.lineHeight = lineHeight;
        }

        public float getLeftPadding() {
                return leftPadding;
        }

        public void setLeftPadding(float leftPadding) {
                this.leftPadding = leftPadding;
        }

        public float getRightPadding() {
                return rightPadding;
        }

        public void setRightPadding(float rightPadding) {
                this.rightPadding = rightPadding;
        }

        public void setWordSpacing(float wordSpacing) {
                this.wordSpacing = wordSpacing;
        }

        public float getWordSpacing() {
                return wordSpacing;
        }

        public float getLineSpacing() {
                return lineSpacing;
        }

        public void setLineSpacing(float lineSpacing) {
                this.lineSpacing = lineSpacing;
        }

        class Line {
                ArrayList<String> words = new ArrayList<String>();
                float spacing = 15f;

                public Line() {
                }

                public Line(ArrayList<String> words, float spacing) {
                        this.words = words;
                        this.spacing = spacing;
                }

                public void setSpacing(float spacing) {
                        this.spacing = spacing;
                }

                public float getSpacing() {
                        return spacing;
                }

                public void addWord(String s) {
                        words.add(s);
                }

                public ArrayList<String> getWords() {
                        return words;
                }
        }
}