FitWidth ImageView和TopCrop ImageView

FitWidth ImageView: 宽度自适应

public class FitWidthImageView extends ImageView
{
   
    public FitWidthImageView(Context context) {
        super(context);
        setup();
    }
   
    public FitWidthImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setup();
    }
   
    public FitWidthImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        setup();
    }
   
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = width * getDrawable().getIntrinsicHeight() / getDrawable().getIntrinsicWidth();
        setMeasuredDimension(width, height);
    }
   
    private void setup() {
        setScaleType(ScaleType.CENTER_CROP);
    }

}

TopCrop ImageView : 从头部Crop而不是center

 

自己改名

public class FitWidthImageView extends ImageView
{
   
    public FitWidthImageView(Context context) {
        super(context);
        setup();
    }
   
    public FitWidthImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setup();
    }
   
    public FitWidthImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        setup();
    }
   
    private void setup() {
        setScaleType(ScaleType.CENTER_CROP);
        setScaleType(ScaleType.MATRIX);
    }
   
    @Override
    protected boolean setFrame(int frameLeft, int frameTop, int frameRight, int frameBottom) {
        float frameWidth = frameRight - frameLeft;
        float frameHeight = frameBottom - frameTop;
       
        float originalImageWidth = (float) getDrawable().getIntrinsicWidth();
        float originalImageHeight = (float) getDrawable().getIntrinsicHeight();
       
        float usedScaleFactor = 1;
       
        if ((frameWidth > originalImageWidth) || (frameHeight > originalImageHeight)) {
            // If frame is bigger than image
            // => Crop it, keep aspect ratio and position it at the bottom and center horizontally
           
            float fitHorizontallyScaleFactor = frameWidth / originalImageWidth;
            float fitVerticallyScaleFactor = frameHeight / originalImageHeight;
           
            usedScaleFactor = Math.max(fitHorizontallyScaleFactor, fitVerticallyScaleFactor);
        }
       
        float newImageWidth = originalImageWidth * usedScaleFactor;
        float newImageHeight = originalImageHeight * usedScaleFactor;
       
        Matrix matrix = getImageMatrix();
        matrix.setScale(usedScaleFactor, usedScaleFactor, 0, 0); // Replaces the old matrix completly
        // matrix.postTranslate((frameWidth - newImageWidth) / 2, frameHeight - newImageHeight);//BottomCrop
        matrix.postTranslate((frameWidth - newImageWidth) / 2, 0);//Top Crop
        setImageMatrix(matrix);
        return super.setFrame(frameLeft, frameTop, frameRight, frameBottom);
    }
}