Android textview text get cut off on the sides with custom font

Reworked @Dmitry Kopytov solution:

  • in Kotlin
  • recycle the old bitmap
  • added documentation
  • fall back on default TextView rendering if the bitmap cannot be created (not enough memory)

Code:

/**
 * This TextView is able to draw text on the padding area.
 * It's mainly used to support italic texts in custom fonts that can go out of bounds.
 * In this case, you've to set an horizontal padding (or just end padding).
 *
 * This implementation is doing a render-to-texture procedure, as such it consumes more RAM than a standard TextView,
 * it uses an additional bitmap of the size of the view.
 */
class TextViewNoClipping(context: Context, attrs: AttributeSet?) : AppCompatTextView(context, attrs) {
    private class NonClippableCanvas(@NonNull val bitmap: Bitmap) : Canvas(bitmap) {
        override fun clipRect(left: Float, top: Float, right: Float, bottom: Float): Boolean {
            return true
        }
    }

    private var rttCanvas: NonClippableCanvas? = null

    override fun onSizeChanged(width: Int, height: Int,
                               oldwidth: Int, oldheight: Int) {
        if ((width != oldwidth || height != oldheight) && width > 0 && height > 0) {
            rttCanvas?.bitmap?.recycle()
            try {
                Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)?.let {
                    rttCanvas = NonClippableCanvas(it)
                }
            } catch (t: Throwable) {
                // If for some reasons the bitmap cannot be created, we fall back on default rendering (potentially cropping the text).
                rttCanvas?.bitmap?.recycle()
                rttCanvas = null
            }
        }

        super.onSizeChanged(width, height, oldwidth, oldheight)
    }

    override fun onDraw(canvas: Canvas) {
        rttCanvas?.let {
            // Clear the RTT canvas from the previous font.
            it.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR)

            // Draw on the RTT canvas (-> bitmap) that will use clipping on the NonClippableCanvas, resulting in no-clipping
            super.onDraw(it)

            // Finally draw the bitmap that contains the rendered text (no clipping used here, will display on top of padding)
            canvas.drawBitmap(it.bitmap, 0f, 0f, null)

        } ?: super.onDraw(canvas) // If rtt is not available, use default rendering process
    }
}

I have encountered the same problem and i found a one liner solution for thouse who are not using the TextView.shadowLayer.

this is based on the source code that [Dmitry Kopytov] brought here:

editTextOrTextView.setShadowLayer(editTextOrTextView.textSize, 0f, 0f, Color.TRANSPARENT)

that's it, now the canvas.clipRect in TextView.onDraw() won't cut off the curly font sides.


This answer has led me to the right path: https://stackoverflow.com/a/28625166/4420543

So, the solution is to create a custom Textview and override the onDraw method:

    @Override
    protected void onDraw(Canvas canvas) {
        final Paint paint = getPaint();
        final int color = paint.getColor();
        // Draw what you have to in transparent
        // This has to be drawn, otherwise getting values from layout throws exceptions
        setTextColor(Color.TRANSPARENT);
        super.onDraw(canvas);
        // setTextColor invalidates the view and causes an endless cycle
        paint.setColor(color);

        System.out.println("Drawing text info:");

        Layout layout = getLayout();
        String text = getText().toString();

        for (int i = 0; i < layout.getLineCount(); i++) {
            final int start = layout.getLineStart(i);
            final int end = layout.getLineEnd(i);

            String line = text.substring(start, end);

            System.out.println("Line:\t" + line);

            final float left = layout.getLineLeft(i);
            final int baseLine = layout.getLineBaseline(i);

            canvas.drawText(line,
                    left + getTotalPaddingLeft(),
                    // The text will not be clipped anymore
                    // You can add a padding here too, faster than string string concatenation
                    baseLine + getTotalPaddingTop(),
                    getPaint());
        }
    }

I encountered the same problem when I used some fonts in EditText.

My first attempt was to use padding. Size of view increased but text is still cropped.

enter image description here

Then I looked at the source code TextView. In method onDraw method Canvas.clipRect is called to perform this crop.

enter image description here

My solution to bypass cropping when use padding :

1) Сreate custom class inherited from Canvas and override method clipRect

public class NonClippableCanvas extends Canvas {

    public NonClippableCanvas(@NonNull Bitmap bitmap) {
        super(bitmap);
    }

    @Override
    public boolean clipRect(float left, float top, float right, float bottom) {
        return true;
    }
}

2) Create custom TextView and override methods onSizeChanged and onDraw.

In the method onSizeChanged create bitmap and canvas.

In the method onDraw draw on bitmap by passing our custom Canvas to method super.onDraw. Next, draw this bitmap on the target canvas.

public class CustomTextView extends AppCompatTextView {
    private Bitmap _bitmap;
    private NonClippableCanvas _canvas;

    @Override
    protected void onSizeChanged(final int width, final int height,
                             final int oldwidth, final int oldheight) {
        if (width != oldwidth || height != oldheight) {
            _bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
            _canvas = new NonClippableCanvas(_bitmap);
        }

        super.onSizeChanged(width, height, oldwidth, oldheight);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        _canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);

        super.onDraw(_canvas);

        canvas.drawBitmap(_bitmap, 0, 0, null);
    }
}

enter image description here