How to highlight ImageView when focused or clicked

Question

A good example of this is either on the Twitter launch screen (the screen with the large icons that is seen when the application is first launch) or even just look at the application tray when you focus an application icon.

Basically I need to highlight an ImageView where the highlight contours to the image within the ImageView and looks like it's a border to that image. I would also like to customize the highlight to have it be a certain color and for it to fade out.

Thanks,

groomsy

Answer 1

This is an extension of mklimek. I couldn't make it work properly from his snippet. I edited a bit

 ImageView testImage = (ImageView)findViewById(R.id.imageView);
 testImage.setOnTouchListener(listener);

 View.OnTouchListener listener = new View.OnTouchListener() {
        private Rect rect;
        @Override
        public boolean onTouch(View v, MotionEvent event) {


            ImageView image = (ImageView) v;
            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    image.getDrawable().setColorFilter(0x77000000,PorterDuff.Mode.SRC_ATOP);
                    image.invalidate();                        
                    break;

                case MotionEvent.ACTION_UP:                        
                case MotionEvent.ACTION_CANCEL: {
                    //clear the overlay
                    image.getDrawable().clearColorFilter();
                    image.invalidate();
                    break;
                }
            }

            return true;
        }
    };

Answer 2

My solution, custom attribute for ImageView :
https://github.com/henrychuangtw/Android-ImageView-hover

Step 1 : declare-styleable

<declare-styleable name="MyImageViewAttr">
    <attr name="hover_res" format="reference" />
</declare-styleable>

Step 2 : custom ImageView

public class MyImageView extends ImageView {

int resID, resID_hover;

public MyImageView(Context context) {
    super(context);
    // TODO Auto-generated constructor stub
}
public MyImageView(Context context, AttributeSet attrs) {
    super(context, attrs);
    // TODO Auto-generated constructor stub

    TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.MyImageViewAttr);
    resID_hover = array.getResourceId(R.styleable.MyImageViewAttr_hover_res, -1);
    if(resID_hover != -1){
        int[] attrsArray = new int[] {
                android.R.attr.src 
            };

        TypedArray ta = context.obtainStyledAttributes(attrs, attrsArray);
        resID = ta.getResourceId(0 , View.NO_ID);           
        ta.recycle();

        setOnTouchListener(listener_onTouch);
    }

    array.recycle();

}
public MyImageView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    // TODO Auto-generated constructor stub
    TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.MyImageViewAttr);
    resID_hover = array.getResourceId(R.styleable.MyImageViewAttr_hover_res, -1);
    if(resID_hover != -1){
        int[] attrsArray = new int[] {
                android.R.attr.src 
            };

        TypedArray ta = context.obtainStyledAttributes(attrs, attrsArray);
        resID = ta.getResourceId(0 , View.NO_ID);           
        ta.recycle();

        setOnTouchListener(listener_onTouch);
    }

    array.recycle();
}



OnTouchListener listener_onTouch = new OnTouchListener() {

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        // TODO Auto-generated method stub

        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            setImageResource(resID_hover);
            break;

        case MotionEvent.ACTION_MOVE:

            break;

        case MotionEvent.ACTION_UP:
            setImageResource(resID);
            break;

        default:
            break;
        }


        return false;
    }
};

}

Step 3 : declare myattr : xmlns:myattr="http://schemas.android.com/apk/res-auto" in layout xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:myattr="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

Step 4 : set myattr:hover_res for MyImageView

<dev.henrychuang.component.MyImageView 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="true"
        myattr:hover_res="@drawable/icon_home_h"
        android:src="@drawable/icon_home"/>