Image View Top Crop / Bottom Crop

attrs.xml

<resources>
  
    <declare-styleable name="ImageScaleView">
        <attr name="matrixType" format="enum">
            <enum name="top_center" value="0" />
            <enum name="bottom_center" value="1" />
        </attr>
    </declare-styleable>
    
</resources>

example_view_layout.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
  
  <com.sromku.views.ImageScaleView
        android:layout_width="200dp"
        android:layout_height="130dp"
        android:scaleType="matrix"
        app:matrixType="top_center"
        android:src="@drawable/bg_big"/>
  
</LinearLayout>

ImageScaleView.java

/**
 * Scale to center top or scale to center bottom
 * 
 * @author sromku
 */
public class ImageScaleView extends ImageView {

	private MatrixCropType mMatrixType = MatrixCropType.TOP_CENTER; // default

	private enum MatrixCropType {
		TOP_CENTER(0),
		BOTTOM_CENTER(1);

		private int mValue;

		private MatrixCropType(int value) {
			mValue = value;
		}

		public static MatrixCropType fromValue(int value) {
			for (MatrixCropType matrixCropType : values()) {
				if (matrixCropType.mValue == value) {
					return matrixCropType;
				}
			}

			// default
			return MatrixCropType.TOP_CENTER;
		}
	}

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

	public ImageScaleView(Context context, AttributeSet attrs) {
		this(context, attrs, 0);
	}

	public ImageScaleView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);

		// get attributes
		if (attrs != null) {
			TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.ImageScaleView, 0, 0);
			try {
				mMatrixType = MatrixCropType.fromValue(a.getInteger(R.styleable.ImageScaleView_matrixType, 0));
			}
			finally {
				a.recycle();
			}
		}
	}

	@Override
	protected boolean setFrame(int frameLeft, int frameTop, int frameRight, int frameBottom) {

		Drawable drawable = getDrawable();
		if (drawable != null) {

			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);

			switch (mMatrixType) {
			case TOP_CENTER:
				matrix.postTranslate((frameWidth - newImageWidth) / 2, 0);
				break;
			case BOTTOM_CENTER:
				matrix.postTranslate((frameWidth - newImageWidth) / 2, frameHeight - newImageHeight);
				break;

			default:
				break;
			}

			setImageMatrix(matrix);
		}
		return super.setFrame(frameLeft, frameTop, frameRight, frameBottom);
	}

}

great