/*
This file is part of Subsonic.
Subsonic is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Subsonic is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Subsonic. If not, see <http://www.gnu.org/licenses/>.
Copyright 2015 (C) Scott Jackson
*/
package github.daneren2005.dsub.view;
import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.RecyclerView.AdapterDataObserver;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView;
import github.daneren2005.dsub.R;
import static android.support.v7.widget.RecyclerView.OnScrollListener;
public class FastScroller extends LinearLayout {
private static final String TAG = FastScroller.class.getSimpleName();
private static final int BUBBLE_ANIMATION_DURATION = 100;
private static final int TRACK_SNAP_RANGE = 5;
private TextView bubble;
private View handle;
private RecyclerView recyclerView;
private final ScrollListener scrollListener = new ScrollListener();
private int height;
private int visibleRange = -1;
private RecyclerView.Adapter adapter;
private AdapterDataObserver adapterObserver;
private boolean visibleBubble = true;
private boolean hasScrolled = false;
private ObjectAnimator currentAnimator = null;
public FastScroller(final Context context,final AttributeSet attrs,final int defStyleAttr) {
super(context,attrs,defStyleAttr);
initialise(context);
}
public FastScroller(final Context context) {
super(context);
initialise(context);
}
public FastScroller(final Context context,final AttributeSet attrs) {
super(context, attrs);
initialise(context);
}
private void initialise(Context context) {
setOrientation(HORIZONTAL);
setClipChildren(false);
LayoutInflater inflater = LayoutInflater.from(context);
inflater.inflate(R.layout.fast_scroller,this,true);
bubble = (TextView)findViewById(R.id.fastscroller_bubble);
handle = findViewById(R.id.fastscroller_handle);
bubble.setVisibility(INVISIBLE);
setVisibility(GONE);
}
@Override
protected void onSizeChanged(int w,int h,int oldw,int oldh) {
super.onSizeChanged(w,h,oldw,oldh);
height = h;
visibleRange = -1;
}
@Override
public boolean onTouchEvent(@NonNull MotionEvent event) {
final int action = event.getAction();
switch(action)
{
case MotionEvent.ACTION_DOWN:
if(event.getX() < (handle.getX() - 30)) {
return false;
}
if(currentAnimator != null)
currentAnimator.cancel();
if(bubble.getVisibility() == INVISIBLE) {
if(visibleBubble) {
showBubble();
}
} else if(!visibleBubble) {
hideBubble();
}
handle.setSelected(true);
case MotionEvent.ACTION_MOVE:
setRecyclerViewPosition(event.getY());
return true;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
handle.setSelected(false);
hideBubble();
return true;
}
return super.onTouchEvent(event);
}
public void attachRecyclerView(RecyclerView recyclerView) {
this.recyclerView = recyclerView;
recyclerView.addOnScrollListener(scrollListener);
registerAdapter();
visibleRange = -1;
}
public void detachRecyclerView() {
recyclerView.removeOnScrollListener(scrollListener);
recyclerView.setVerticalScrollBarEnabled(true);
unregisterAdapter();
recyclerView = null;
setVisibility(View.GONE);
}
public boolean isAttached() {
return recyclerView != null;
}
private void setRecyclerViewPosition(float y) {
if(recyclerView != null) {
if(recyclerView.getChildCount() == 0) {
return;
}
int itemCount = recyclerView.getAdapter().getItemCount();
float proportion = getValueInRange(0, 1f, y / (float) height);
float targetPosFloat = getValueInRange(0, itemCount - 1, proportion * (float)itemCount);
int targetPos = (int) targetPosFloat;
// Immediately make sure that the target is visible
LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
// layoutManager.scrollToPositionWithOffset(targetPos, 0);
View firstVisibleView = recyclerView.getChildAt(0);
// Calculate how far through this position we are
int columns = Math.round(recyclerView.getWidth() / firstVisibleView.getWidth());
int firstVisiblePosition = recyclerView.getChildPosition(firstVisibleView);
int remainder = (targetPos - firstVisiblePosition) % columns;
float offsetPercentage = (targetPosFloat - targetPos + remainder) / columns;
if(offsetPercentage < 0) {
offsetPercentage = 1 + offsetPercentage;
}
int firstVisibleHeight = firstVisibleView.getHeight();
if(columns > 1) {
firstVisibleHeight += (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, GridSpacingDecoration.SPACING, firstVisibleView.getResources().getDisplayMetrics());
}
int offset = (int) (offsetPercentage * firstVisibleHeight);
layoutManager.scrollToPositionWithOffset(targetPos, -offset);
onUpdateScroll(1, 1);
try {
String bubbleText = null;
RecyclerView.Adapter adapter = recyclerView.getAdapter();
if(adapter instanceof BubbleTextGetter) {
bubbleText = ((BubbleTextGetter) adapter).getTextToShowInBubble(targetPos);
}
if(bubbleText == null) {
visibleBubble = false;
bubble.setVisibility(View.INVISIBLE);
} else {
bubble.setText(bubbleText);
bubble.setVisibility(View.VISIBLE);
visibleBubble = true;
}
} catch(Exception e) {
Log.e(TAG, "Error getting text for bubble", e);
}
}
}
private float getValueInRange(float min, float max, float value) {
float minimum = Math.max(min, value);
return Math.min(minimum,max);
}
private void setBubbleAndHandlePosition(float y) {
int bubbleHeight = bubble.getHeight();
int handleHeight = handle.getHeight();
handle.setY(getValueInRange(0,height-handleHeight,(int)(y-handleHeight/2)));
bubble.setY(getValueInRange(0, height - bubbleHeight - handleHeight / 2, (int) (y - bubbleHeight)));
}
private void showBubble() {
bubble.setVisibility(VISIBLE);
if(currentAnimator != null)
currentAnimator.cancel();
currentAnimator = ObjectAnimator.ofFloat(bubble,"alpha",0f,1f).setDuration(BUBBLE_ANIMATION_DURATION);
currentAnimator.start();
}
private void hideBubble() {
if(currentAnimator != null)
currentAnimator.cancel();
currentAnimator = ObjectAnimator.ofFloat(bubble,"alpha",1f,0f).setDuration(BUBBLE_ANIMATION_DURATION);
currentAnimator.addListener(new AnimatorListenerAdapter(){
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
bubble.setVisibility(INVISIBLE);
currentAnimator = null;
}
@Override
public void onAnimationCancel(Animator animation) {
super.onAnimationCancel(animation);
bubble.setVisibility(INVISIBLE);
currentAnimator = null;
}
});
currentAnimator.start();
}
private void registerAdapter() {
RecyclerView.Adapter newAdapter = recyclerView.getAdapter();
if(newAdapter != adapter) {
unregisterAdapter();
}
if(newAdapter != null) {
adapterObserver = new AdapterDataObserver() {
@Override
public void onChanged() {
visibleRange = -1;
}
@Override
public void onItemRangeChanged(int positionStart, int itemCount) {
visibleRange = -1;
}
@Override
public void onItemRangeInserted(int positionStart, int itemCount) {
visibleRange = -1;
}
@Override
public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
visibleRange = -1;
}
@Override
public void onItemRangeRemoved(int positionStart, int itemCount) {
visibleRange = -1;
}
};
newAdapter.registerAdapterDataObserver(adapterObserver);
adapter = newAdapter;
}
}
private void unregisterAdapter() {
if(adapter != null) {
adapter.unregisterAdapterDataObserver(adapterObserver);
adapter = null;
adapterObserver = null;
}
}
private class ScrollListener extends OnScrollListener {
@Override
public void onScrolled(RecyclerView rv,int dx,int dy) {
onUpdateScroll(dx, dy);
}
}
private void onUpdateScroll(int dx, int dy) {
if(recyclerView.getWidth() == 0) {
return;
}
registerAdapter();
View firstVisibleView = recyclerView.getChildAt(0);
if(firstVisibleView == null) {
return;
}
int firstVisiblePosition = recyclerView.getChildPosition(firstVisibleView);
int itemCount = recyclerView.getAdapter().getItemCount();
int columns = Math.round(recyclerView.getWidth() / firstVisibleView.getWidth());
if(visibleRange == -1) {
visibleRange = recyclerView.getChildCount();
}
// Add the percentage of the item the user has scrolled past already
float pastFirst = -firstVisibleView.getY() / firstVisibleView.getHeight() * columns;
float position = firstVisiblePosition + pastFirst;
// Scale this so as we move down the visible range gets added to position from 0 -> visible range
float scaledVisibleRange = position / (float) (itemCount - visibleRange) * visibleRange;
position += scaledVisibleRange;
float proportion = position / itemCount;
setBubbleAndHandlePosition(height * proportion);
if((visibleRange * 2) < itemCount) {
if (!hasScrolled && (dx > 0 || dy > 0)) {
setVisibility(View.VISIBLE);
hasScrolled = true;
recyclerView.setVerticalScrollBarEnabled(false);
}
} else if(hasScrolled) {
setVisibility(View.GONE);
hasScrolled = false;
recyclerView.setVerticalScrollBarEnabled(true);
}
}
public interface BubbleTextGetter {
String getTextToShowInBubble(int position);
}
}