Adjust text size to fit button in Android

Question

I have a number of buttons in a LinearLayout. The buttons have 1 weight, so they are placed evenly into the layout. I want to do something like this

for (int i = 0; i < texts.size(); ++i) {
  Button button = new Button(/*context*/);
  button.setLayoutParams(/*WRAP_CONTENT, MATCH_PARENT, 1.0f*/)
  button.setText(texts[i]);
  float fontSize = 20.0f;
  button.setTextSize();
  while (textDoesNotFitIntoButton(button)) {
    fontSize -= 2.0f;
    button.setTextSize(fontSize);
  }
  linearLayout.addView(button);
}

How do I check if text does not fit into the button?

The point is to fill all the button with text in such a way, that text occupies all available space and gets neither truncated nor split into lines.

E.g. String[] texts = new String[] { "0", "sin^-1" }; If I choose a single text size for "0" to occupy the whole space then I either get "sin" split into two lines "sin^" and "-1" or "0" appears smaller than it should.

This does work, but it creates text views. Now I need to turn these text views into buttons. — sasha199568, Jul 21 '16 at 20:26
And it is not quite what I need. It does not change text size in order to fit the text into the view. It changes the view's size. In the end all the text fits into the views, but views differ in size. — sasha199568, Jul 21 '16 at 21:36

score 0 · Answer 1 · answered Oct 28 '18 at 08:53

I have edited the answer given by @Jaswanth Manigundan to make it extend from android.support.v7.widget.AppCompatButton. Have a look at the below scripts:

FontFitTextView.java

import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.util.TypedValue;

public class FontFitTextView extends android.support.v7.widget.AppCompatButton
{
private static final float THRESHOLD = 0.5f;

private enum Mode { Width, Height, Both, None }

private int minTextSize = 1;
private int maxTextSize = 50;

private Mode mode = Mode.None;
private boolean inComputation;
private int widthMeasureSpec;
private int heightMeasureSpec;

public FontFitTextView(Context context) {
    super(context);
}

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

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

    TypedArray tAttrs = context.obtainStyledAttributes(attrs, R.styleable.FontFitTextView, defStyle, 0);
    maxTextSize = tAttrs.getDimensionPixelSize(R.styleable.FontFitTextView_maxTextSize, maxTextSize);
    minTextSize = tAttrs.getDimensionPixelSize(R.styleable.FontFitTextView_minTextSize, minTextSize);
    tAttrs.recycle();
}

private void resizeText() {
    if (getWidth() <= 0 || getHeight() <= 0)
        return;
    if(mode == Mode.None)
        return;

    final int targetWidth = getWidth();
    final int targetHeight = getHeight();

    inComputation = true;
    float higherSize = maxTextSize;
    float lowerSize = minTextSize;
    float textSize = getTextSize();
    while(higherSize - lowerSize > THRESHOLD) {
        textSize = (higherSize + lowerSize) / 2;
        if (isTooBig(textSize, targetWidth, targetHeight)) {
            higherSize = textSize;
        } else {
            lowerSize = textSize;
        }
    }
    setTextSize(TypedValue.COMPLEX_UNIT_PX, lowerSize);
    measure(widthMeasureSpec, heightMeasureSpec);
    inComputation = false;
}

private boolean isTooBig(float textSize, int targetWidth, int targetHeight) {
    setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize);
    measure(0, 0);
    if(mode == Mode.Both)
        return getMeasuredWidth() >= targetWidth || getMeasuredHeight() >= targetHeight;
    if(mode == Mode.Width)
        return getMeasuredWidth() >= targetWidth;
    else
        return getMeasuredHeight() >= targetHeight;
}

private Mode getMode(int widthMeasureSpec, int heightMeasureSpec) {
    int widthMode = MeasureSpec.getMode(widthMeasureSpec);
    int heightMode = MeasureSpec.getMode(heightMeasureSpec);
    if(widthMode == MeasureSpec.EXACTLY && heightMode == MeasureSpec.EXACTLY)
        return Mode.Both;
    if(widthMode == MeasureSpec.EXACTLY)
        return Mode.Width;
    if(heightMode == MeasureSpec.EXACTLY)
        return Mode.Height;
    return Mode.None;
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    if(!inComputation) {
        this.widthMeasureSpec = widthMeasureSpec;
        this.heightMeasureSpec = heightMeasureSpec;
        mode = getMode(widthMeasureSpec, heightMeasureSpec);
        resizeText();
    }
}

protected void onTextChanged(final CharSequence text, final int start, final int before, final int after) {
    resizeText();
}

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    if (w != oldw || h != oldh)
        resizeText();
}

public int getMinTextSize() {
    return minTextSize;
}

public void setMinTextSize(int minTextSize) {
    this.minTextSize = minTextSize;
    resizeText();
}

public int getMaxTextSize() {
    return maxTextSize;
}

public void setMaxTextSize(int maxTextSize) {
    this.maxTextSize = maxTextSize;
    resizeText();
}
}

style.xml:

<resources>

<declare-styleable name="FontFitTextView">
    <attr name="minTextSize" format="dimension" />
    <attr name="maxTextSize" format="dimension" />
</declare-styleable>
</resources>

And in my activity_main.xml, I used the FontFitTextView tag instead of Button:

<com.example.myname.testsidebar.FontFitTextView
            android:id="@+id/userDetailsBtn"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:drawableTop="@drawable/user_details"
            android:gravity="center"
            android:background="#00FFFFFF"
            android:paddingTop="10sp"
            android:textSize="15sp"
            android:text="Your Details"
            android:drawableTint="#ED1B2F"
            android:textColor="#797369"
            android:layout_weight="1"
            android:layout_gravity="center"/>

Hope it helps.

Adjust text size to fit button in Android

1 Answers1