Add horizontal list scrubber to UICommon

* Add option to use either ListView or RecyclerView as the source
* Add optional fade in/out behavior on list idle

Change-Id: Idf2751c6201a23f4a25b3a1c55af13f60dd69793

7 files changed, 531 insertions, 0 deletions

diff --git a/res/drawable-nodpi/letter_indicator.9.png b/res/drawable-nodpi/letter_indicator.9.png
new file mode 100644
index 0000000..af3578e
--- /dev/null
+++ b/res/drawable-nodpi/letter_indicator.9.png
diff --git a/res/drawable/scrubber_back.xml b/res/drawable/scrubber_back.xml
new file mode 100644
index 0000000..8d2be51
--- /dev/null
+++ b/res/drawable/scrubber_back.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <solid android:color="#99333333"/>
+    <corners android:radius="5dip"/>
+</shape>
diff --git a/res/drawable/seek_back.xml b/res/drawable/seek_back.xml
new file mode 100644
index 0000000..358c022
--- /dev/null
+++ b/res/drawable/seek_back.xml
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="line">
+    <stroke android:width="4dp" android:color="#FFF"/>
+    <size android:height="2dp" />
+</shape>
diff --git a/res/layout/scrub_layout.xml b/res/layout/scrub_layout.xml
new file mode 100644
index 0000000..2f725da
--- /dev/null
+++ b/res/layout/scrub_layout.xml
@@ -0,0 +1,87 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/scrubberWidget"
+    android:orientation="vertical"
+    android:layout_width="match_parent"
+    android:layout_marginRight="20dp"
+    android:layout_marginLeft="20dp"
+    android:layout_height="wrap_content">
+
+    <LinearLayout
+        android:clickable="true"
+        android:layout_marginTop="-5dp"
+        android:layout_below="@+id/scrubberIndicator"
+        android:orientation="horizontal"
+        android:background="@drawable/scrubber_back"
+        android:layout_width="match_parent"
+        android:layout_height="50dp">
+
+        <Space
+            android:layout_weight="0.1"
+            android:layout_width="0dp"
+            android:layout_height="match_parent" />
+
+        <TextView
+            android:id="@+id/firstSection"
+            android:gravity="center"
+            android:textColor="@android:color/white"
+            android:paddingRight="10dp"
+            android:textStyle="bold"
+            style="?android:attr/textAppearanceLarge"
+            android:layout_width="wrap_content"
+            android:layout_height="match_parent" />
+
+        <LinearLayout
+            android:layout_weight="0.9"
+            android:layout_width="0dp"
+            android:layout_gravity="center"
+            android:orientation="vertical"
+            android:layout_height="match_parent">
+
+            <com.cyngn.uicommon.view.ListScrubberSeekBar
+                android:id="@+id/scrubber"
+                android:paddingLeft="0dp"
+                android:paddingRight="0dp"
+                android:layout_marginRight="-10dp"
+                android:layout_marginLeft="-10dp"
+                android:thumb="@android:color/transparent"
+                android:thumbOffset="-10dp"
+                android:progressDrawable="@drawable/seek_back"
+                android:layout_width="match_parent"
+                android:layout_gravity="center"
+                android:layout_height="match_parent" />
+
+        </LinearLayout>
+
+
+        <TextView
+            android:gravity="center"
+            android:id="@+id/lastSection"
+            android:paddingLeft="10dp"
+            android:textColor="@android:color/white"
+            android:textStyle="bold"
+            style="?android:attr/textAppearanceLarge"
+            android:layout_width="wrap_content"
+            android:layout_height="match_parent" />
+
+        <Space
+            android:layout_weight="0.1"
+            android:layout_width="0dp"
+            android:layout_height="match_parent" />
+
+    </LinearLayout>
+
+    <TextView
+        android:id="@+id/scrubberIndicator"
+        android:background="@drawable/letter_indicator"
+        android:layout_width="80dp"
+        android:textSize="30sp"
+        android:gravity="center"
+        android:textColor="@android:color/white"
+        android:clickable="false"
+        android:layout_marginBottom="-20dp"
+        android:visibility="invisible"
+        android:layout_height="100dp" />
+
+</RelativeLayout>
diff --git a/src/com/cyngn/uicommon/view/ListScrubber.java b/src/com/cyngn/uicommon/view/ListScrubber.java
new file mode 100644
index 0000000..f4e9596
--- /dev/null
+++ b/src/com/cyngn/uicommon/view/ListScrubber.java
@@ -0,0 +1,233 @@
+/*
+ * Copyright (C) 2014 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.cyngn.uicommon.view;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.content.Context;
+import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.widget.AbsListView;
+import android.widget.HeaderViewListAdapter;
+import android.widget.LinearLayout;
+import android.widget.ListAdapter;
+import android.widget.ListView;
+import android.widget.RelativeLayout;
+import android.widget.SectionIndexer;
+import android.widget.SeekBar;
+import android.widget.TextView;
+import com.cyngn.uicommon.R;
+
+/**
+ * Widget to fast scroll through a list view with a horizontal scrubber.
+ * Usage:
+ *     scrubber = new ListScrubber(context);
+ *     scrubber.setFadeInOnMotion(true); // optional
+ *     scrubber.setSource(listView); // call when adapter is ready
+ */
+public class ListScrubber extends LinearLayout implements OnClickListener {
+
+    private SectionIndexer mSectionIndexer;
+    private RelativeLayout mScrubberWidget;
+    private ListView mListView;
+    private RecyclerView mRecyclerView;
+    private TextView mFirstIndicator, mLastIndicator;
+    private TextView mScrubberIndicator;
+    private SeekBar mSeekBar;
+    private String[] mSections;
+    private int mHeaderCount = 0;
+    private boolean mFadeInOnMotion;
+    private ListScrubberFadeHelper mFadeHelper;
+
+    public ListScrubber(Context context) {
+        super(context);
+        LayoutInflater.from(context).inflate(R.layout.scrub_layout, this);
+        mScrubberWidget = (RelativeLayout)findViewById(R.id.scrubberWidget);
+        mFirstIndicator = ((TextView) findViewById(R.id.firstSection));
+        mFirstIndicator.setOnClickListener(this);
+        mLastIndicator = ((TextView) findViewById(R.id.lastSection));
+        mLastIndicator.setOnClickListener(this);
+        mScrubberIndicator = (TextView) findViewById(R.id.scrubberIndicator);
+        mSeekBar = (SeekBar) findViewById(R.id.scrubber);
+        init();
+    }
+
+    public void updateSections() {
+        mSections = (String[]) mSectionIndexer.getSections();
+        if (mSections.length > 0) {
+            mSeekBar.setMax(mSections.length - 1);
+            mFirstIndicator.setText(mSections[0]);
+            mLastIndicator.setText(mSections[mSections.length - 1]);
+        }
+    }
+
+    public void setSource(ListView listView) {
+        resetSource();
+        mListView = listView;
+
+        ListAdapter adapter = listView.getAdapter();
+        if (adapter instanceof HeaderViewListAdapter) {
+            mHeaderCount = ((HeaderViewListAdapter) adapter).getHeadersCount();
+            adapter = ((HeaderViewListAdapter) adapter).getWrappedAdapter();
+        }
+
+        if (adapter instanceof SectionIndexer) {
+            mSectionIndexer = (SectionIndexer)adapter;
+        } else {
+            throw new IllegalArgumentException("ListView adapter must implement SectionIndexer");
+        }
+    }
+
+    public void setSource(RecyclerView recyclerView) {
+        resetSource();
+        mRecyclerView = recyclerView;
+        mSectionIndexer = (SectionIndexer)mRecyclerView.getAdapter();
+
+    }
+
+    private void resetSource() {
+        mRecyclerView = null;
+        mListView = null;
+    }
+
+    private boolean isReady() {
+        return (mListView != null || mRecyclerView != null) &&
+                mSectionIndexer != null &&
+                mSections != null;
+    }
+
+    private void init() {
+        mSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
+            @Override
+            public void onProgressChanged(SeekBar seekBar, final int progress, boolean fromUser) {
+                if (!isReady()) {
+                    return;
+                }
+                resetScrubber();
+                mScrubberIndicator.setTranslationX((progress * seekBar.getWidth()) / mSections.length);
+                String section = String.valueOf(mSections[progress]);
+                scrollToPositionWithOffset(mSectionIndexer.getPositionForSection(progress)
+                        + mHeaderCount, 0);
+                mScrubberIndicator.setText(section);
+            }
+
+            @Override
+            public void onStartTrackingTouch(SeekBar seekBar) {
+                if (!isReady()) {
+                    return;
+                }
+                resetScrubber();
+                mScrubberIndicator.setAlpha(1f);
+                mScrubberIndicator.setVisibility(View.VISIBLE);
+                if (mFadeInOnMotion) {
+                    mFadeHelper.onEvent(ListScrubberFadeHelper.Event.SCRUBBER_TOUCH);
+                }
+            }
+
+            @Override
+            public void onStopTrackingTouch(SeekBar seekBar) {
+                if (!isReady()) {
+                    return;
+                }
+                resetScrubber();
+                mScrubberIndicator.animate().alpha(0f).translationYBy(20f)
+                    .setDuration(200).setListener(new AnimatorListenerAdapter() {
+                    @Override
+                    public void onAnimationEnd(Animator animation) {
+                        mScrubberIndicator.setVisibility(View.INVISIBLE);
+                    }
+                });
+                if (mFadeInOnMotion) {
+                    mFadeHelper.onEvent(ListScrubberFadeHelper.Event.SCRUBBER_RELEASE);
+                }
+            }
+
+            private void resetScrubber() {
+                mScrubberIndicator.animate().cancel();
+                mScrubberIndicator.setTranslationY(0f);
+            }
+        });
+    }
+
+    @Override
+    public void onClick(View v) {
+        if (v == mFirstIndicator) {
+            int positionForFirstSection = mSectionIndexer.getPositionForSection(0);
+            scrollToPositionWithOffset(positionForFirstSection, 0);
+        } else if (v == mLastIndicator) {
+            int positionForLastSection = mSectionIndexer.getPositionForSection(mSections.length - 1);
+            scrollToPositionWithOffset(positionForLastSection, 0);
+        }
+    }
+
+    /**
+     * If set to true, the scrubber appears once the list is scrolled and disappears when
+     * the list is idle for some predetermined amount of time.
+     *
+     * Defaults to false
+     *
+     * @param fadeInOnMotion true to enable fading behavior
+     */
+    public void setFadeInOnMotion(boolean fadeInOnMotion) {
+        if (fadeInOnMotion) {
+            mFadeHelper = new ListScrubberFadeHelper(mScrubberWidget);
+            mFadeHelper.updateState(ListScrubberFadeHelper.State.HIDDEN);
+        }
+        else {
+            mFadeHelper = null;
+        }
+        mFadeInOnMotion = fadeInOnMotion;
+    }
+
+    public boolean isFadeInOnMotion() {
+        return mFadeInOnMotion;
+    }
+
+    private void scrollToPositionWithOffset(int position, int y) {
+        if (mListView != null) {
+            mListView.setSelectionFromTop(position, y);
+        }
+        else if (mRecyclerView != null) {
+            LinearLayoutManager layoutManager =
+                    (LinearLayoutManager)mRecyclerView.getLayoutManager();
+            layoutManager.scrollToPositionWithOffset(position, y);
+        }
+    }
+
+    public void handleScrollStateChanged(int scrollState) {
+        if (!mFadeInOnMotion)
+            return;
+
+        switch (scrollState) {
+            case AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL:
+                mFadeHelper.onEvent(ListScrubberFadeHelper.Event.LIST_SCROLL);
+                break;
+            case AbsListView.OnScrollListener.SCROLL_STATE_FLING:
+                mFadeHelper.onEvent(ListScrubberFadeHelper.Event.LIST_FLING);
+                break;
+            case AbsListView.OnScrollListener.SCROLL_STATE_IDLE:
+                mFadeHelper.onEvent(ListScrubberFadeHelper.Event.LIST_IDLE);
+                break;
+        }
+    }
+
+    public void setHeaderCount(int count) {
+        mHeaderCount = count;
+    }
+}
\ No newline at end of file
diff --git a/src/com/cyngn/uicommon/view/ListScrubberFadeHelper.java b/src/com/cyngn/uicommon/view/ListScrubberFadeHelper.java
new file mode 100644
index 0000000..7b20c5c
--- /dev/null
+++ b/src/com/cyngn/uicommon/view/ListScrubberFadeHelper.java
@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 2014 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.cyngn.uicommon.view;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.os.Handler;
+import android.view.View;
+import android.view.ViewGroup;
+
+/**
+ * State machine to manage fading the list scrubber in and out when the user interacts
+ * with the list view or the scrubber itself.
+ */
+public class ListScrubberFadeHelper {
+
+    private static final int FADE_OUT_DELAY = 2000;
+
+    public static enum State {
+        VISIBLE,
+        HIDDEN,
+        FADING_IN,
+        FADING_OUT,
+        FADE_OUT_SCHEDULED,
+    };
+
+    public static enum Event {
+        LIST_FLING,
+        LIST_SCROLL,
+        LIST_IDLE,
+        LIST_IDLE_TIMEOUT,
+        SCRUBBER_TOUCH,
+        SCRUBBER_RELEASE,
+    }
+
+    private ViewGroup mScrubber;
+    private Handler mHandler;
+    private Runnable mFadeOutRunnable;
+    private State mState;
+
+    class FadeOutRunnable implements Runnable {
+        @Override
+        public void run() {
+            onEvent(Event.LIST_IDLE_TIMEOUT);
+        }
+    }
+
+    public ListScrubberFadeHelper(ViewGroup scrubber) {
+        mScrubber = scrubber;
+        mHandler = new Handler();
+    }
+
+    public void onEvent(Event event) {
+        switch (event) {
+            case LIST_FLING:
+            case LIST_SCROLL:
+                if (mState == State.FADING_OUT || mState == State.FADE_OUT_SCHEDULED) {
+                    cancelFade();
+                    updateState(State.VISIBLE);
+                } else if (mState == State.HIDDEN) {
+                    updateState(State.FADING_IN);
+                }
+                break;
+
+            case LIST_IDLE:
+                updateState(State.FADE_OUT_SCHEDULED);
+                break;
+
+            case LIST_IDLE_TIMEOUT:
+                updateState(State.FADING_OUT);
+                break;
+
+            case SCRUBBER_TOUCH:
+                if (mState == State.FADING_OUT || mState == State.FADE_OUT_SCHEDULED) {
+                    cancelFade();
+                }
+                break;
+
+            case SCRUBBER_RELEASE:
+                updateState(State.FADE_OUT_SCHEDULED);
+                break;
+        }
+    }
+
+    public void updateState(State state) {
+        mState = state;
+        switch (state) {
+            case VISIBLE:
+                mScrubber.setAlpha(1f);
+                mScrubber.setVisibility(View.VISIBLE);
+                break;
+            case HIDDEN:
+                mScrubber.setAlpha(0f);
+                mScrubber.setVisibility(View.INVISIBLE);
+                break;
+            case FADING_IN:
+                mScrubber.animate().alpha(1f).setDuration(200)
+                        .setListener(new AnimatorListenerAdapter() {
+                            @Override
+                            public void onAnimationEnd(Animator animation) {
+                                // strange that this is required...
+                                updateState(State.VISIBLE);
+                            }
+                            @Override
+                            public void onAnimationCancel(Animator animation) {
+                                updateState(State.VISIBLE);
+                            }
+                        });
+                break;
+            case FADING_OUT:
+                mScrubber.animate().alpha(0f).setDuration(200)
+                        .setListener(new AnimatorListenerAdapter() {
+                            @Override
+                            public void onAnimationEnd(Animator animation) {
+                                // strange that this is required...
+                                updateState(State.HIDDEN);
+                            }
+                            @Override
+                            public void onAnimationCancel(Animator animation) {
+                                updateState(State.HIDDEN);
+                            }
+                        });
+                break;
+            case FADE_OUT_SCHEDULED:
+                mFadeOutRunnable = new FadeOutRunnable();
+                mHandler.postDelayed(mFadeOutRunnable, FADE_OUT_DELAY);
+                break;
+        }
+    }
+
+    private void cancelFade() {
+        if (mFadeOutRunnable != null) {
+            mHandler.removeCallbacks(mFadeOutRunnable);
+            mFadeOutRunnable = null;
+        }
+        mScrubber.animate().cancel();
+    }
+}
diff --git a/src/com/cyngn/uicommon/view/ListScrubberSeekBar.java b/src/com/cyngn/uicommon/view/ListScrubberSeekBar.java
new file mode 100644
index 0000000..83ce176
--- /dev/null
+++ b/src/com/cyngn/uicommon/view/ListScrubberSeekBar.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2014 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.cyngn.uicommon.view;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.widget.SeekBar;
+
+/**
+ * Override SeekBar for use in list scrubber
+ */
+public class ListScrubberSeekBar extends SeekBar {
+
+    public ListScrubberSeekBar(Context context) {
+        super(context);
+    }
+
+    public ListScrubberSeekBar(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public ListScrubberSeekBar(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+    }
+
+    @Override
+    public boolean isInScrollingContainer() {
+        // For the list scrubber seek bar we can simplify things by assuming this
+        // is false.  This would only backfire if we attempt to put a list scrubber
+        // inside a list item.
+        return false;
+    }
+}