Used to draw a custom overly over a target view

ViewFrameIndicator.java

package cn.ipanel.android.widget;

import cn.ipanel.android.Logger;
import android.animation.TypeEvaluator;
import android.animation.ValueAnimator;
import android.annotation.TargetApi;
import android.app.Activity;
import android.graphics.Rect;
import android.os.Build;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.view.ViewGroup.MarginLayoutParams;
import android.view.ViewParent;
import android.view.animation.Animation;
import android.view.animation.Transformation;
import android.widget.FrameLayout;
import android.widget.ImageView;

/**
 * Used to draw a custom overly over a target view
 * 
 * @author Zexu
 * 
 */
public class ViewFrameIndicator {
  private ImageView mImg;

	public ViewFrameIndicator(Activity context) {
		mImg = new ImageView(context);
		context.addContentView(mImg, new LayoutParams(
				LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
		mImg.setVisibility(View.INVISIBLE);
	}

	public void setFrameResouce(int resid) {
		mImg.setBackgroundResource(resid);
	}

	public ImageView getImageView() {
		return mImg;
	}

	/**
	 * 如果是 .9.png, 会自动设置padding, 调用此方法会覆盖.9.png的padding
	 * 
	 * @param left
	 * @param top
	 * @param right
	 * @param bottom
	 */
	public void setPadding(int left, int top, int right, int bottom) {
		mImg.setPadding(left, top, right, bottom);
	}

	public void setFrameColor(int color) {
		mImg.setBackgroundColor(color);
	}

	public void moveFrmaeTo(View v) {
		moveFrameTo(v, true, false);
	}
	
	public int getLeftInScrren(View v){
		ViewParent vp = v.getParent();
		if(vp instanceof View){
			return (int) (v.getLeft() - v.getScrollX()+getLeftInScrren((View)vp));
		}
		return v.getLeft() - v.getScrollX();
	}

	public int getTopInScrren(View v){
		ViewParent vp = v.getParent();
		if(vp instanceof View){
			return v.getTop() - v.getScrollY()+getTopInScrren((View) vp);
		}
		return v.getTop() - v.getScrollY();
	}

	@TargetApi(Build.VERSION_CODES.HONEYCOMB)
	public void moveFrameTo(View v, boolean animated, boolean hideFrame) {

		if (Build.VERSION.SDK_INT < Build.VERSION_CODES.ICE_CREAM_SANDWICH)
			return;
		View follower = mImg;

		if (v != null) {
			int[] xy = new int[2];
//			v.getLocationOnScreen(xy);
			xy[0] = getLeftInScrren(v);
			xy[1] = getTopInScrren(v);
			Rect r = new Rect();
			v.getFocusedRect(r);
			xy[0] += r.left;
			xy[1] += r.top;
			int w = r.width();
			int h = r.height();
			Logger.d(String.format("follower: %d x %d, %f, %f",follower.getWidth(), follower.getHeight(),follower.getScaleX(), follower.getScaleY()));
			Logger.d(String.format("class: %s, x: %d, y: %d, w:%d,h:%d", v.getClass().getName(), xy[0], xy[1], w, h));
			MarginLayoutParams start = (MarginLayoutParams) follower.getLayoutParams();

			FrameLayout.LayoutParams end = new FrameLayout.LayoutParams(w
					+ follower.getPaddingLeft() + follower.getPaddingRight(), h
					+ follower.getPaddingTop() + follower.getPaddingBottom());
			end.leftMargin = xy[0] - follower.getPaddingLeft();
			end.topMargin = xy[1] - follower.getPaddingTop();
			boolean wasVisible = follower.getVisibility() == View.VISIBLE;
			if (hideFrame) {
				follower.setVisibility(View.INVISIBLE);
			} else {
				follower.setVisibility(View.VISIBLE);
			}
			if (animated && !hideFrame && wasVisible){
				if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
					ValueAnimator.ofObject(new LayoutEvaluator(follower), start, end).setDuration(100).start();
				} else {
					LayoutAnimation ani = new LayoutAnimation(follower, start,
							end);
					ani.setDuration(100);
					follower.setAnimation(ani);
				}
			}else
				follower.setLayoutParams(end);
		} else {
			follower.setVisibility(View.INVISIBLE);
		}
	}
	
	class LayoutAnimation extends Animation{
		View follower;
		MarginLayoutParams startValue;
		MarginLayoutParams endValue;
		public LayoutAnimation (View v, MarginLayoutParams start, MarginLayoutParams end){
			this.follower = v;
			this.startValue = start;
			this.endValue = end;
		}
		
		@Override
		protected void applyTransformation(float fraction,
				Transformation t) {
			int width = (int) (startValue.width + fraction
					* (endValue.width - startValue.width));
			int height = (int) (startValue.height + fraction
					* (endValue.height - startValue.height));

			FrameLayout.LayoutParams p = new FrameLayout.LayoutParams(width,
					height);
			p.leftMargin = (int) (startValue.leftMargin + fraction
					* (endValue.leftMargin - startValue.leftMargin));
			p.topMargin = (int) (startValue.topMargin + fraction
					* (endValue.topMargin - startValue.topMargin));
			follower.setLayoutParams(p);
		}
		
	}

	class LayoutEvaluator implements TypeEvaluator<MarginLayoutParams> {
		View follower;

		public LayoutEvaluator(View v) {
			this.follower = v;
		}

		@Override
		public MarginLayoutParams evaluate(float fraction,
				MarginLayoutParams startValue, MarginLayoutParams endValue) {
			int width = (int) (startValue.width + fraction
					* (endValue.width - startValue.width));
			int height = (int) (startValue.height + fraction
					* (endValue.height - startValue.height));

			FrameLayout.LayoutParams p = new FrameLayout.LayoutParams(width,
					height);
			p.leftMargin = (int) (startValue.leftMargin + fraction
					* (endValue.leftMargin - startValue.leftMargin));
			p.topMargin = (int) (startValue.topMargin + fraction
					* (endValue.topMargin - startValue.topMargin));
			follower.setLayoutParams(p);
			return p;
		}
	}

}