CustomSlidingDrawer

package com.arasthel.wfspain.views;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Point;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Display;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;

import com.arasthel.wfspain.R;

/**
 * Created by Arasthel on 12/10/13.
 */
public class CustomSlidingDrawer extends RelativeLayout {

    private ImageView headerImgView;
    private LinearLayout contentView;

    private int marginTop = 0;
    private int oldY = 0;
    private float screenPercent = (float) 0.4;

    private boolean touched = false;

    public CustomSlidingDrawer(Context context) {
        super(context);
        createView();
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);

        RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        marginTop = (int)(h*screenPercent);
        params.setMargins(0, marginTop, 0, 0);
        contentView.setLayoutParams(params);
        headerImgView.setLayoutParams(new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, (int)(h*screenPercent)));

    }

    private void createView() {

        headerImgView = new ImageView(getContext());
        headerImgView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        headerImgView.setImageDrawable(getResources().getDrawable(R.drawable.intro_01));

        contentView = new LinearLayout(getContext());
        contentView.setBackgroundColor(Color.WHITE);
        if(!isInEditMode()) {
            contentView.setOnTouchListener(drawerTouchListener);
        }
        addView(headerImgView);

        addView(contentView);
    }

    private OnTouchListener drawerTouchListener = new OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            int newY = (int)event.getRawY();
            switch(event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    if(newY > marginTop) {
                        touched = true;
                    }
                    break;
                case MotionEvent.ACTION_UP:
                    touched = false;
                    oldY = 0;
                    break;
                case MotionEvent.ACTION_CANCEL:
                    touched = false;
                    oldY = 0;
                    break;
                case MotionEvent.ACTION_MOVE:
                    if(touched) {
                        if(newY != marginTop) {
                            if(oldY != 0) {
                                int deltaY = newY - oldY;
                                int newTop = marginTop + deltaY;
                                if(newTop > 0 && newTop < (int)(screenPercent*getHeight())) {
                                    RelativeLayout.LayoutParams params = (LayoutParams) contentView.getLayoutParams();
                                    params.setMargins(0, newTop, 0, 0);
                                    contentView.setLayoutParams(params);
                                    invalidate();
                                    marginTop = newTop;
                                } else {
                                    if(newTop <= 0) {
                                        RelativeLayout.LayoutParams params = (LayoutParams) contentView.getLayoutParams();
                                        params.setMargins(0, 0, 0, 0);
                                        contentView.setLayoutParams(params);
                                        invalidate();
                                        marginTop = 0;
                                    }
                                    int drawerHeight = (int)(screenPercent*getHeight());
                                    if(newTop >= drawerHeight) {
                                        RelativeLayout.LayoutParams params = (LayoutParams) contentView.getLayoutParams();
                                        params.setMargins(0, drawerHeight, 0, 0);
                                        contentView.setLayoutParams(params);
                                        invalidate();
                                        marginTop = drawerHeight;
                                    }
                                }
                            }
                            oldY = newY;
                        }
                    }
            }
            return true;
        }
    };

    public CustomSlidingDrawer(Context context, AttributeSet attrs) {
        super(context, attrs);
        createView();
    }

    public CustomSlidingDrawer(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        createView();
    }

    public void setImage(int drawableId) {
        headerImgView.setImageDrawable(getResources().getDrawable(drawableId));
    }

    public void setContentView(int layoutId) {
        LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View v = inflater.inflate(layoutId, contentView, false);
        contentView.removeAllViews();
        contentView.addView(v);
    }

}