TextView 必填项pro版

雨点打透心脏的1/2处 2023-10-13 19:28 8阅读 0赞

优点

> 基本解决对齐方式,可以设置前缀隐藏和显示

/**
     * https://blog.csdn.net/u013982652/article/details/94404711
     * Android自定义TextView实现必填项前面的*号
     * 另一种实现方式(推荐使用这种,有非必填情况的话不会有对齐问题)
     * <p>
     * <cn.mvp.mlibs.weight.MiRequiredTextViewPro
     * android:layout_width="wrap_content"
     * android:layout_height="wrap_content"
     * android:paddingLeft="12dp"
     * android:text="Hello World!"
     * app:prefixText="c11 "
     * app:prefixTextColor="@color/red"
     * app:prefixVisibility="invisible" />
     */
    public class MiRequiredTextViewPro extends androidx.appcompat.widget.AppCompatTextView {
    
        private String prefixText;
        private int prefixTextColor;
        private int prefixVisibility;
        private int visible = 0, invisible = 1, gone = 2;
    
        public MiRequiredTextViewPro(Context context) {
            super(context);
            init(null);
        }
    
        public MiRequiredTextViewPro(Context context, AttributeSet attrs) {
            super(context, attrs);
            init(attrs);
        }
    
        public MiRequiredTextViewPro(Context context, AttributeSet attrs, int defStyleAttr) {
            super(context, attrs, defStyleAttr);
            init(attrs);
        }
    
        private void init(AttributeSet attrs) {
            if (attrs != null) {
                TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.CustomTextView);
                prefixText = a.getString(R.styleable.CustomTextView_prefixText);
                prefixTextColor = a.getColor(R.styleable.CustomTextView_prefixTextColor, Color.RED);
                prefixVisibility = a.getInt(R.styleable.CustomTextView_prefixVisibility, View.VISIBLE);
                a.recycle();
            }
            updatePrefixVisibility();
            updatePrefixText();
            updatePrefixTextColor();
        }
    
        private void updatePrefixText() {
            if (prefixText != null) {
                setText(prefixText + getText());
            }
        }
    
        private void updatePrefixTextColor() {
            if (prefixText == null) {
                return;
            }
            SpannableString spannableString = new SpannableString(getText());
            spannableString.setSpan(new ForegroundColorSpan(prefixTextColor), 0, prefixText.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            setText(spannableString);
        }
    
        /**
         * invisible:不显示,但是占位置
         * gone:彻底不显示,不占位置
         */
        private void updatePrefixVisibility() {
            if (prefixVisibility == invisible) {
                Paint paint = new Paint();
                paint.setTextSize(getTextSize());
                float textWidth = paint.measureText(prefixText);
                prefixText = "";
                setPadding((int) textWidth + getPaddingLeft(), getPaddingTop(), getPaddingRight(), getPaddingBottom());
            } else if (prefixVisibility == gone) {
                prefixText = "";
            }
        }
    
        public void setPrefixText(String prefixText) {
            this.prefixText = prefixText;
            updatePrefixText();
        }
    
        public void setPrefixTextColor(int prefixTextColor) {
            this.prefixTextColor = prefixTextColor;
            updatePrefixTextColor();
        }
    
        public void setPrefixVisibility(int prefixVisibility) {
            this.prefixVisibility = prefixVisibility;
            updatePrefixVisibility();
        }
    }

样式

<declare-styleable name="CustomTextView">
            <attr name="prefixText" format="string" />
            <attr name="prefixTextColor" format="color" />
            <attr name="prefixVisibility">
                <enum name="visible" value="0" />
                <enum name="invisible" value="1" />
                <enum name="gone" value="2" />
            </attr>
        </declare-styleable>

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[9d2d69b7829f4677b6fe8b56f215c327.png]: https://img-blog.csdnimg.cn/9d2d69b7829f4677b6fe8b56f215c327.png