FloatingWidgetService.java

/**
     * Add the view to the phone's window.
     */
    private void addToWindow() {
        //Add the view to the window.
        final WindowManager.LayoutParams params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_PHONE,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
                PixelFormat.TRANSLUCENT);

        //Specify the view position
        params.gravity = Gravity.TOP | Gravity.START;        //Initially view will be added to top-left corner
        params.x = 0;
        params.y = 100;

        //Add the view to the window
        mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        mWindowManager.addView(mFloatingView, params);

        //Drag and move floating view using user's touch action.
        mFloatingView.findViewById(R.id.root_container).setOnTouchListener(new View.OnTouchListener() {
            private int initialX;
            private int initialY;
            private float initialTouchX;
            private float initialTouchY;
            private long mStartTime;


            @Override
            public boolean onTouch(View v, MotionEvent event) {
                switch (event.getAction()) {
                    case MotionEvent.ACTION_DOWN:
                        mStartTime = System.currentTimeMillis();

                        //remember the initial position.
                        initialX = params.x;
                        initialY = params.y;


                        //get the touch location
                        initialTouchX = event.getRawX();
                        initialTouchY = event.getRawY();
                        return true;
                    case MotionEvent.ACTION_UP:
                        //Check for the click event
                        int Xdiff = (int) (event.getRawX() - initialTouchX);
                        int Ydiff = (int) (event.getRawY() - initialTouchY);

                        //The check for Xdiff <10 && YDiff< 10 because sometime elements moves a little while clicking.
                        //So that is click event.
                        if ((initialX < 10 || initialX > mDeviceWidth - 30) && Xdiff < 8 && Ydiff < 8) {
                            if (PermissionUtils.isDeviceAdminEnable(FloatingLockWidgetService.this)) {
                                Utils.lockDevice(FloatingLockWidgetService.this);
                            } else {
                                startActivity(LockWidgetErrorActivity.getLaunchIntenet(FloatingLockWidgetService.this));
                            }
                        }

                        //Stick to the verticle edges of the screen
                        float velocity = Math.abs(Xdiff / (System.currentTimeMillis() - mStartTime));
                        if (velocity > 0.2 || Math.abs(Xdiff) > mDeviceWidth / 2) {
                            if (initialX >= mDeviceWidth / 2) stickToLeftEdge();
                            else stickToRightEdge();
                        } else {
                            if (initialX >= mDeviceWidth / 2) stickToRightEdge();
                            else stickToLeftEdge();
                        }
                        return true;
                    case MotionEvent.ACTION_MOVE:
                        //Calculate the X and Y coordinates of the view.
                        params.x = initialX + (int) (event.getRawX() - initialTouchX);
                        params.y = initialY + (int) (event.getRawY() - initialTouchY);

                        //Update the layout with new X & Y coordinate
                        mWindowManager.updateViewLayout(mFloatingView, params);
                        return true;
                }
                return false;
            }

            /**
             * Stick the floating widget to the right edge of the screen.
             */
            private void stickToRightEdge() {
                for (int i = params.x; i <= mDeviceWidth; i++) {
                    params.x = i;
                    mWindowManager.updateViewLayout(mFloatingView, params);
                }
            }

            /**
             * Stick the floating widget to the left edge of the screen.
             */
            private void stickToLeftEdge() {
                for (int i = params.x; i >= 0; i--) {
                    params.x = i;
                    mWindowManager.updateViewLayout(mFloatingView, params);
                }
            }
        });

        isViewAdded = true;
    }