自定义TextView之drawableLeft与文本一起居中显示

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.drawable.Drawable;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.widget.TextView;

/**
 * 自定义TextView，实现drawableLeft与文本一起居中显示
 */
public class DrawableCenterTextView extends TextView {

    private Drawable drawableLeft; // 左侧图片
    private int drawableWidth; // 左侧图片的宽度
    private int drawableHeight; // 左侧图片的高度
    private int textWidth; // 文本的宽度
    private int textHeight; // 文本的高度
    private int totalWidth; // 总宽度
    private int totalHeight; // 总高度

    public DrawableCenterTextView(Context context) {
        super(context);
        init();
    }

    public DrawableCenterTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public DrawableCenterTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        // 获取左侧图片
        drawableLeft = getCompoundDrawables()[0];
        if (drawableLeft != null) {
            // 获取左侧图片的宽高
            drawableWidth = drawableLeft.getIntrinsicWidth();
            drawableHeight = drawableLeft.getIntrinsicHeight();
        }
        // 获取文本的宽高
        textWidth = (int) getPaint().measureText(getText().toString());
        textHeight = (int) getPaint().getTextSize();
        // 计算总宽度和总高度
        totalWidth = drawableWidth + textWidth + getCompoundDrawablePadding();
        totalHeight = Math.max(drawableHeight, textHeight);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        // 绘制左侧图片
        if (drawableLeft != null) {
            int left = (totalWidth - drawableWidth) / 2;
            int top = (totalHeight - drawableHeight) / 2;
            drawableLeft.setBounds(left, top, left + drawableWidth, top + drawableHeight);
            drawableLeft.draw(canvas);
        }
        // 绘制文本
        Paint paint = getPaint();
        paint.setColor(getCurrentTextColor());
        int left = (totalWidth - textWidth) / 2;
        int baseline = (totalHeight - textHeight) / 2 + textHeight;
        canvas.drawText(getText().toString(), left, baseline, paint);
    }

    @SuppressLint("DrawAllocation")
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        int widthSize = MeasureSpec.getSize(widthMeasureSpec);
        int heightMode = MeasureSpec.getMode(heightMeasureSpec);
        int heightSize = MeasureSpec.getSize(heightMeasureSpec);
        // 计算控件的宽高
        int width;
        int height;
        if (widthMode == MeasureSpec.EXACTLY) {
            width = widthSize;
        } else {
            width = totalWidth;
        }
        if (heightMode == MeasureSpec.EXACTLY) {
            height = heightSize;
        } else {
            height = totalHeight;
        }
        setMeasuredDimension(width, height);
    }

    /**
     * 设置左侧图片
     *
     * @param drawableLeft 左侧图片
     */
    public void setDrawableLeft(Drawable drawableLeft) {
        this.drawableLeft = drawableLeft;
        init();
        invalidate(); // 重新绘制控件
    }

    /**
     * 获取左侧图片
     *
     * @return 左侧图片
     */
    public Drawable getDrawableLeft() {
        return drawableLeft;
    }
}

自定义TextView，实现drawableLeft与文本一起居中显示，可应用于各种自定义控件场景。