Is there any way in android to adjust the textsize in a textview to fit the space it occupies?
E.g. I'm using a TableLayout
and adding several TextView
s to each row. Since I don't want the TextView
s to wrap the text I rather see that it lowers the font size of the content.
Any ideas?
I have tried measureText
, but since I don't know the size of the column it seems troublesome to use.
This is the code where I want to change the font size to something that fits
TableRow row = new TableRow(this);
for (int i=0; i < ColumnNames.length; i++) {
TextView textColumn = new TextView(this);
textColumn.setText(ColumnNames[i]);
textColumn.setPadding(0, 0, 1, 0);
textColumn.setTextColor(getResources().getColor(R.drawable.text_default));
row.addView(textColumn, new TableRow.LayoutParams());
}
table.addView(row, new TableLayout.LayoutParams());
The solution below incorporates all of the suggestions here. It starts with what was originally posted by Dunni. It uses a binary search like gjpc's, but it is a bit more readable. It also include's gregm's bug fixes and a bug-fix of my own.
import android.content.Context;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.TextView;
public class FontFitTextView extends TextView {
public FontFitTextView(Context context) {
super(context);
initialise();
}
public FontFitTextView(Context context, AttributeSet attrs) {
super(context, attrs);
initialise();
}
private void initialise() {
mTestPaint = new Paint();
mTestPaint.set(this.getPaint());
//max size defaults to the initially specified text size unless it is too small
}
/* Re size the font so the specified text fits in the text box
* assuming the text box is the specified width.
*/
private void refitText(String text, int textWidth)
{
if (textWidth <= 0)
return;
int targetWidth = textWidth - this.getPaddingLeft() - this.getPaddingRight();
float hi = 100;
float lo = 2;
final float threshold = 0.5f; // How close we have to be
mTestPaint.set(this.getPaint());
while((hi - lo) > threshold) {
float size = (hi+lo)/2;
mTestPaint.setTextSize(size);
if(mTestPaint.measureText(text) >= targetWidth)
hi = size; // too big
else
lo = size; // too small
}
// Use lo so that we undershoot rather than overshoot
this.setTextSize(TypedValue.COMPLEX_UNIT_PX, lo);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int parentWidth = MeasureSpec.getSize(widthMeasureSpec);
int height = getMeasuredHeight();
refitText(this.getText().toString(), parentWidth);
this.setMeasuredDimension(parentWidth, height);
}
@Override
protected void onTextChanged(final CharSequence text, final int start, final int before, final int after) {
refitText(text.toString(), this.getWidth());
}
@Override
protected void onSizeChanged (int w, int h, int oldw, int oldh) {
if (w != oldw) {
refitText(this.getText().toString(), w);
}
}
//Attributes
private Paint mTestPaint;
}