字体自适应大小的TextView

可根据控件宽度自动改变字体大小。

package com.hcb.fixorder.widget;

import android.content.Context;
import android.graphics.Canvas;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.TypedValue;

import com.hcb.base.common.util.DisplayUtils;

/**
 * 字体大小自适应宽度
 * ps:必须给出具体宽度才有效
 *
 * @author 陈聪 2020-09-03 19:10
 */
public class AutoAlignTextView extends androidx.appcompat.widget.AppCompatTextView {

    public AutoAlignTextView(Context context) {
        this(context, null);
    }

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

    public AutoAlignTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context, attrs);
    }

    public void init(Context context, AttributeSet attrs) {
        setMaxLines(1);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        adjustTvTextSize();
    }

    /**
     * 动态修改字体大小
     */
    private void adjustTvTextSize() {
        String text = getText().toString();
        int avaiWidth = (int) (this.getWidth() - getPaddingLeft() - getPaddingRight() - DisplayUtils.dip2px(getContext(), 2));
        if (avaiWidth <= 0) {
            return;
        }
        TextPaint textPaintClone = new TextPaint(getPaint());
        float trySize = textPaintClone.getTextSize();
        if (startTxSize == 0) {
            startTxSize = trySize;
        } else {
            trySize = startTxSize;
        }
        textPaintClone.setTextSize(trySize);
        while (textPaintClone.measureText(text) > avaiWidth) {
            trySize--;
            textPaintClone.setTextSize(trySize);
        }
        setTextSize(TypedValue.COMPLEX_UNIT_PX, trySize);
    }

    /** 缓存初始字体大小，防止出现字体一直变小的情况 */
    private float startTxSize = 0;

    public void refresh() {
        adjustTvTextSize();
    }

}