Action Panel Helper - For those popup panels from Action Buttons

ActionPanelHelper.java

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.PixelFormat;
import android.os.Build;
import android.support.annotation.LayoutRes;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.widget.FrameLayout;


/**
 * Action Panel Helper
 * <p>
 * Created by Simon Lightfoot on 15/11/2015.
 */
public class ActionPanelHelper
{
	private final Context mContext;
	private final WindowManager mWindowManager;

	private WindowManager.LayoutParams mLayoutParams = new WindowManager.LayoutParams();
	private boolean mShowing = false;

	private PopupFrame mPopupFrame;
	private View mContentView;
	private int mAnimationStyle = -1;
	private int mSoftInputMode = WindowManager.LayoutParams.SOFT_INPUT_STATE_UNSPECIFIED;
	private boolean mFocusable = true;

	private OnDismissListener mOnDismissListener;


	public ActionPanelHelper(Context context)
	{
		mContext = context;
		mWindowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
	}

	public View setContentView(View view)
	{
		mContentView = view;
		if(mPopupFrame == null){
			mPopupFrame = new PopupFrame(mContext, null);
		}
		mPopupFrame.removeAllViews();
		mPopupFrame.addView(mContentView);
		return mContentView;
	}

	public View setContentView(@LayoutRes int layoutResId)
	{
		setContentView(LayoutInflater.from(mContext).inflate(layoutResId, null));
		return mContentView;
	}

	public View getContentView()
	{
		return mContentView;
	}

	public void setSoftInputMode(int softInputMode)
	{
		mSoftInputMode = softInputMode;
	}

	public void setFocusable(boolean focusable)
	{
		mFocusable = focusable;
	}

	public void setOnDismissListener(OnDismissListener onDismissListener)
	{
		mOnDismissListener = onDismissListener;
	}

	public void show(View anchor, int horizontalMargin, int verticalMargin)
	{
		if(!mShowing){
			int measureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
			mPopupFrame.measure(measureSpec, measureSpec);

			int[] location = new int[2];
			anchor.getLocationInWindow(location);
			mLayoutParams.x = (location[0] + anchor.getWidth()) - (mPopupFrame.getMeasuredWidth() - horizontalMargin);
			mLayoutParams.y = location[1] + verticalMargin;
			mLayoutParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
			mLayoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
			mLayoutParams.gravity = Gravity.START | Gravity.TOP;
			mLayoutParams.flags =
				WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL |
				WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN |
				WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH;
			if(!mFocusable){
				mLayoutParams.flags |= WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
				if(mSoftInputMode != WindowManager.LayoutParams.SOFT_INPUT_STATE_UNSPECIFIED){
					mLayoutParams.flags |= WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM;
				}
			}
			mLayoutParams.softInputMode = mSoftInputMode;
			mLayoutParams.type   = WindowManager.LayoutParams.TYPE_APPLICATION;
			mLayoutParams.format = PixelFormat.TRANSLUCENT;
			mLayoutParams.windowAnimations = mAnimationStyle;
			mWindowManager.addView(mPopupFrame, mLayoutParams);
			mShowing = true;
		}
	}

	public boolean isShowing()
	{
		return mShowing;
	}

	public void dismiss()
	{
		if(mShowing){
			mWindowManager.removeView(mPopupFrame);
			mShowing = false;
			if(mOnDismissListener != null){
				mOnDismissListener.onDismiss();
			}
		}
	}

	private class PopupFrame extends FrameLayout
	{
		@SuppressWarnings("deprecation")
		public PopupFrame(Context context, AttributeSet attrs)
		{
			super(context, attrs);

			int[] ATTRS = {
				android.R.attr.popupBackground,
				android.R.attr.popupAnimationStyle,
			};
			TypedArray a = context.obtainStyledAttributes(attrs, ATTRS,
				R.attr.listPopupWindowStyle, 0);
			if(a.hasValue(0)){
				setBackgroundDrawable(a.getDrawable(0));
			}
			if(a.hasValue(1)){
				mAnimationStyle = a.getResourceId(1, 0);
			}
			a.recycle();

			if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP){
				int[] ATTRS_L = { android.R.attr.popupElevation };
				a = context.obtainStyledAttributes(attrs, ATTRS_L,
					R.attr.listPopupWindowStyle, 0);
				if(a.hasValue(0)){
					setElevation(a.getDimension(0, 0));
				}
				a.recycle();
			}
		}

		@Override
		public boolean onTouchEvent(MotionEvent event)
		{
			final int x = (int) event.getX();
			final int y = (int) event.getY();

			if((event.getAction() == MotionEvent.ACTION_DOWN) &&
				((x < 0) || (x >= getWidth()) || (y < 0) || (y >= getHeight())))
			{
				dismiss();
				return true;
			}
			else if(event.getAction() == MotionEvent.ACTION_OUTSIDE){
				dismiss();
				return true;
			}
			else{
				return super.onTouchEvent(event);
			}
		}

		@Override
		public boolean dispatchKeyEvent(KeyEvent event)
		{
			if(event.getKeyCode() == KeyEvent.KEYCODE_BACK){
				final KeyEvent.DispatcherState state = getKeyDispatcherState();
				if(state == null){
					return super.dispatchKeyEvent(event);
				}
				if(event.getAction() == KeyEvent.ACTION_DOWN && event.getRepeatCount() == 0){
					state.startTracking(event, this);
					return true;
				}
				else if(event.getAction() == KeyEvent.ACTION_UP){
					if(state.isTracking(event) && !event.isCanceled()){
						dismiss();
						return true;
					}
				}
				return super.dispatchKeyEvent(event);
			}
			else{
				return super.dispatchKeyEvent(event);
			}
		}
	}

	public interface OnDismissListener {
		void onDismiss();
	}
}

Example of its use.

/*
<style name="Widget.App.PopupWindow" parent="ThemeOverlay.AppCompat.Light" />
*/
public class SomeActivity extends AppCompatActivity
{
    private ActionPanelHelper mActionPanelHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.something);
        createPopupWindow();
    }

    private void createPopupWindow()
    {
        Context context = new ContextThemeWrapper(this, R.style.Widget_App_PopupWindow);
        mActionPanelHelper = new ActionPanelHelper(context);

        View viewGroup = mActionPanelHelper.setContentView(R.layout.panel_text_size);
        SeekBar seekBar = (SeekBar) viewGroup.findViewById(R.id.text_size);
        seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener()
        {
            @Override
            public void onStartTrackingTouch(SeekBar seekBar)
            {
                mContentView.startTextSizeTracking();
            }

            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser)
            {
                mContentView.setTextSize(progress);
            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar)
            {
                mContentView.stopTextSizeTracking();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    {
        getMenuInflater().inflate(R.menu.activity_article, menu);
        return true;
    }

    @Override
    public boolean onPrepareOptionsMenu(Menu menu)
    {
        MenuItem textSize = menu.findItem(R.id.action_text_size);
        final View textSizeView = MenuItemCompat.getActionView(textSize);
        textSizeView.setOnClickListener((v) -> {
            mActionPanelHelper.show(v, 8, 8);
        });
        return super.onPrepareOptionsMenu(menu);
    }
}