I implemented this for my ChartDroid project. Create VerticalLabelView.java
:
public class VerticalLabelView extends View {
private TextPaint mTextPaint;
private String mText;
private int mAscent;
private Rect text_bounds = new Rect();
final static int DEFAULT_TEXT_SIZE = 15;
public VerticalLabelView(Context context) {
super(context);
initLabelView();
}
public VerticalLabelView(Context context, AttributeSet attrs) {
super(context, attrs);
initLabelView();
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.VerticalLabelView);
CharSequence s = a.getString(R.styleable.VerticalLabelView_text);
if (s != null) setText(s.toString());
setTextColor(a.getColor(R.styleable.VerticalLabelView_textColor, 0xFF000000));
int textSize = a.getDimensionPixelOffset(R.styleable.VerticalLabelView_textSize, 0);
if (textSize > 0) setTextSize(textSize);
a.recycle();
}
private final void initLabelView() {
mTextPaint = new TextPaint();
mTextPaint.setAntiAlias(true);
mTextPaint.setTextSize(DEFAULT_TEXT_SIZE);
mTextPaint.setColor(0xFF000000);
mTextPaint.setTextAlign(Align.CENTER);
setPadding(3, 3, 3, 3);
}
public void setText(String text) {
mText = text;
requestLayout();
invalidate();
}
public void setTextSize(int size) {
mTextPaint.setTextSize(size);
requestLayout();
invalidate();
}
public void setTextColor(int color) {
mTextPaint.setColor(color);
invalidate();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
mTextPaint.getTextBounds(mText, 0, mText.length(), text_bounds);
setMeasuredDimension(
measureWidth(widthMeasureSpec),
measureHeight(heightMeasureSpec));
}
private int measureWidth(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.EXACTLY) {
// We were told how big to be
result = specSize;
} else {
// Measure the text
result = text_bounds.height() + getPaddingLeft() + getPaddingRight();
if (specMode == MeasureSpec.AT_MOST) {
// Respect AT_MOST value if that was what is called for by measureSpec
result = Math.min(result, specSize);
}
}
return result;
}
private int measureHeight(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
mAscent = (int) mTextPaint.ascent();
if (specMode == MeasureSpec.EXACTLY) {
// We were told how big to be
result = specSize;
} else {
// Measure the text
result = text_bounds.width() + getPaddingTop() + getPaddingBottom();
if (specMode == MeasureSpec.AT_MOST) {
// Respect AT_MOST value if that was what is called for by measureSpec
result = Math.min(result, specSize);
}
}
return result;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
float text_horizontally_centered_origin_x = getPaddingLeft() + text_bounds.width()/2f;
float text_horizontally_centered_origin_y = getPaddingTop() - mAscent;
canvas.translate(text_horizontally_centered_origin_y, text_horizontally_centered_origin_x);
canvas.rotate(-90);
canvas.drawText(mText, 0, 0, mTextPaint);
}
}
And in attrs.xml
:
<resources>
<declare-styleable name="VerticalLabelView">
<attr name="text" format="string" />
<attr name="textColor" format="color" />
<attr name="textSize" format="dimension" />
</declare-styleable>
</resources>