Put back fast scrolling for artists, podcasts, and playlists

1 files changed, 208 insertions, 0 deletions

diff --git a/app/src/main/java/github/daneren2005/dsub/view/FastScroller.java b/app/src/main/java/github/daneren2005/dsub/view/FastScroller.java
new file mode 100644
index 00000000..ee7aef4b
--- /dev/null
+++ b/app/src/main/java/github/daneren2005/dsub/view/FastScroller.java
@@ -0,0 +1,208 @@
+/*
+  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.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView;
+import android.util.AttributeSet;
+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 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 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;
+	}
+
+	@Override
+	public boolean onTouchEvent(@NonNull MotionEvent event) {
+		final int action = event.getAction();
+		switch(action)
+		{
+			case MotionEvent.ACTION_DOWN:
+				if(event.getX()<handle.getX())
+					return false;
+				if(currentAnimator != null)
+					currentAnimator.cancel();
+				if(bubble.getVisibility() == INVISIBLE)
+					showBubble();
+				handle.setSelected(true);
+			case MotionEvent.ACTION_MOVE:
+				final float y = event.getY();
+				setBubbleAndHandlePosition(y);
+				setRecyclerViewPosition(y);
+				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);
+		recyclerView.setVerticalScrollBarEnabled(false);
+		setVisibility(View.VISIBLE);
+	}
+	public void detachRecyclerView() {
+		recyclerView.removeOnScrollListener(scrollListener);
+		recyclerView.setVerticalScrollBarEnabled(true);
+		recyclerView = null;
+		setVisibility(View.GONE);
+	}
+	public boolean isAttached() {
+		return recyclerView != null;
+	}
+
+	private void setRecyclerViewPosition(float y) {
+		if(recyclerView != null)
+		{
+			int itemCount = recyclerView.getAdapter().getItemCount();
+			float proportion;
+			if(handle.getY() == 0)
+				proportion = 0f;
+			else if(handle.getY()+handle.getHeight()>=height-TRACK_SNAP_RANGE)
+				proportion = 1f;
+			else
+				proportion = y/(float)height;
+			int targetPos = getValueInRange(0,itemCount-1,(int)(proportion*(float)itemCount));
+			((LinearLayoutManager)recyclerView.getLayoutManager()).scrollToPositionWithOffset(targetPos,0);
+			String bubbleText = ((BubbleTextGetter)recyclerView.getAdapter()).getTextToShowInBubble(targetPos);
+			bubble.setText(bubbleText);
+		}
+	}
+
+	private int getValueInRange(int min,int max,int value) {
+		int 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() {
+		AnimatorSet animatorSet = new AnimatorSet();
+		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 class ScrollListener extends OnScrollListener {
+		@Override
+		public void onScrolled(RecyclerView rv,int dx,int dy) {
+			View firstVisibleView = recyclerView.getChildAt(0);
+			int firstVisiblePosition = recyclerView.getChildPosition(firstVisibleView);
+			int visibleRange = recyclerView.getChildCount();
+			int lastVisiblePosition = firstVisiblePosition+visibleRange;
+			int itemCount = recyclerView.getAdapter().getItemCount();
+			int position;
+			if(firstVisiblePosition == 0)
+				position = 0;
+			else if(lastVisiblePosition == itemCount)
+				position = itemCount;
+			else
+				position = (int)(((float)firstVisiblePosition/(((float)itemCount-(float)visibleRange)))*(float)itemCount);
+			float proportion = (float)position/(float)itemCount;
+			setBubbleAndHandlePosition(height*proportion);
+		}
+	}
+
+	public interface BubbleTextGetter {
+		String getTextToShowInBubble(int position);
+	}
+}