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간단한 Custom View 작성

간단한 Custom View 작성

1. attr.xml
2. .java
1. constructor(생성자)
2. onDraw()
3. onMeasure()

source codes

values/attr.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

  <declare-styleable name="DividerView">
    <attr name="dvColor" format="color" />
    <attr name="dvHeight" format="dimension" />
    <attr name="dvThickness" format="dimension" />
  </declare-styleable>

</resources>

DividerView.java

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;

import com.hbwhale.seedmoney.R;

/**
 * Created by namh on 2016-03-26.
 */
public class DividerView extends View {

    private Paint _paint;
    private int _lineHeight;

    public DividerView(Context context, AttributeSet attrs) {
        super(context, attrs);
        int dashGap, lineHeight;
        int color;

        TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.DividerView, 0, 0);

        try {
            lineThickness = a.getDimensionPixelSize(R.styleable.DividerView_dvThickness, 1);
            _lineHeight = a.getDimensionPixelSize(R.styleable.DividerView_dvHeight, getSuggestedMinimumHeight());
            color = a.getColor(R.styleable.DividerView_dvColor, 0xff000000);
        } finally {
            a.recycle();
        }

        _paint = new Paint();
        _paint.setAntiAlias(true);
        _paint.setColor(color);
        _paint.setStyle(Paint.Style.STROKE);
        _paint.setStrokeWidth(lineThickness);
        // _paint.setPathEffect(new DashPathEffect(new float[] { lineLength, dashGap, }, 0));
    }

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

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int height = getSuggestedMinimumHeight();
        if(_lineHeight != height){
            height = _lineHeight;
        }
        setMeasuredDimension(getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec),
                getDefaultSize(height, heightMeasureSpec));


    }

    @Override
    protected void onDraw(Canvas canvas) {

        float bottom = getHeight();
        float hcenter = getWidth() * 0.5f;
        canvas.drawLine(hcenter, 0, hcenter, _lineHeight, _paint); // v-line
        canvas.drawLine(0, bottom, getWidth(), bottom, _paint); // h-line

    }
}

사용법

activity_main.xml

<com.mytest.DividerView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:dvHeight="15dp"
    />

onMeasure() 를 override 한 이유

<com.mytest.DividerView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:minHeight="5dp"
    />

Reference

1. xml - Creating horizontal and vertical dotted lines in android - Stack Overflow