Android MaskedImage

在这次UI设计中，有圆形图片，圆角图片，不排除以后还有其他图片，如椭圆图片之类的，所以这次UI组件的开发也采用了继承的方法。

下面就来看下代码实现：

MaskedImage抽象基类

package com.boohee.widgets;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Xfermode;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

public abstract class MaskedImage extends ImageView {
    private static final Xfermode MASK_XFERMODE;
    private Bitmap mask;
    private Paint paint;

    static {
        PorterDuff.Mode localMode = PorterDuff.Mode.DST_IN;
        MASK_XFERMODE = new PorterDuffXfermode(localMode);
    }

    public MaskedImage(Context paramContext) {
        super(paramContext);
    }

    public MaskedImage(Context paramContext, AttributeSet paramAttributeSet) {
        super(paramContext, paramAttributeSet);
    }

    public MaskedImage(Context paramContext, AttributeSet paramAttributeSet, int paramInt) {
        super(paramContext, paramAttributeSet, paramInt);
    }

    public abstract Bitmap createMask();

    protected void onDraw(Canvas paramCanvas) {
        Drawable localDrawable = getDrawable();
        if (localDrawable == null)
            return;
        try {
            if (this.paint == null) {
                Paint localPaint1 = new Paint();
                this.paint = localPaint1;
                this.paint.setFilterBitmap(false);
                Paint localPaint2 = this.paint;
                Xfermode localXfermode1 = MASK_XFERMODE;
                Xfermode localXfermode2 = localPaint2.setXfermode(localXfermode1);
            }
            float f1 = getWidth();
            float f2 = getHeight();
            int i = paramCanvas.saveLayer(0.0F, 0.0F, f1, f2, null, 31);
            int j = getWidth();
            int k = getHeight();
            localDrawable.setBounds(0, 0, j, k);
            localDrawable.draw(paramCanvas);
            if ((this.mask == null) || (this.mask.isRecycled())) {
                Bitmap localBitmap1 = createMask();
                this.mask = localBitmap1;
            }
            Bitmap localBitmap2 = this.mask;
            Paint localPaint3 = this.paint;
            paramCanvas.drawBitmap(localBitmap2, 0.0F, 0.0F, localPaint3);
            paramCanvas.restoreToCount(i);
            return;
        } catch (Exception localException) {
            StringBuilder localStringBuilder = new StringBuilder()
                    .append("Attempting to draw with recycled bitmap. View ID = ");
            System.out.println("localStringBuilder=="+localStringBuilder);
        }
    }
}

CircularImage（圆形图片）实现类

public class CircularImage extends MaskedImage {
    public CircularImage(Context paramContext) {
        super(paramContext);
    }

    public CircularImage(Context paramContext, AttributeSet paramAttributeSet) {
        super(paramContext, paramAttributeSet);
    }

    public CircularImage(Context paramContext, AttributeSet paramAttributeSet, int paramInt) {
        super(paramContext, paramAttributeSet, paramInt);
    }

    public Bitmap createMask() {
        int i = getWidth();
        int j = getHeight();
        Bitmap.Config localConfig = Bitmap.Config.ARGB_8888;
        Bitmap localBitmap = Bitmap.createBitmap(i, j, localConfig);
        Canvas localCanvas = new Canvas(localBitmap);
        Paint localPaint = new Paint(1);
        localPaint.setColor(-16777216);
        float f1 = getWidth();
        float f2 = getHeight();
        RectF localRectF = new RectF(0.0F, 0.0F, f1, f2);
        localCanvas.drawOval(localRectF, localPaint);
        return localBitmap;
    }
}
RoundedCornersImage（圆角图片）实现类
public class RoundedCornersImage extends MaskedImage {
    private static final int DEFAULT_CORNER_RADIUS = 8;
    private int cornerRadius = DEFAULT_CORNER_RADIUS;

    public RoundedCornersImage(Context paramContext) {
        super(paramContext);
    }

    public RoundedCornersImage(Context paramContext, AttributeSet paramAttributeSet) {
        super(paramContext, paramAttributeSet);
        int[] arrayOfInt = R.styleable.RoundedCornersImage;
        TypedArray a = paramContext.obtainStyledAttributes(paramAttributeSet, arrayOfInt);
        int i = a.getDimensionPixelSize(0, DEFAULT_CORNER_RADIUS);
        this.cornerRadius = i;
        a.recycle();
    }

    public Bitmap createMask() {
        int i = getWidth();
        int j = getHeight();
        Bitmap.Config localConfig = Bitmap.Config.ARGB_8888;
        Bitmap localBitmap = Bitmap.createBitmap(i, j, localConfig);
        Canvas localCanvas = new Canvas(localBitmap);
        Paint localPaint = new Paint(1);
        localPaint.setColor(-16777216);
        float f1 = getWidth();
        float f2 = getHeight();
        RectF localRectF = new RectF(0.0F, 0.0F, f1, f2);
        float f3 = this.cornerRadius;
        float f4 = this.cornerRadius;
        localCanvas.drawRoundRect(localRectF, f3, f4, localPaint);
        return localBitmap;
    }
}

如果以后新增了椭圆图片，那么只须新建一个椭圆图片累继承自MaskedImage,然后重写createMask()方法即可。

至此，代码实现已完成，只需要在xml中像使用android自带组件的方式使用我们的自定义组件即可，如：

<com.boohee.widgets.RoundedCornersImage
    android:id="@+id/rounded_image"
    android:layout_width="60dp"
    android:layout_height="60dp" />