Rakesh Iyer | 5b3278f | 2017-04-19 11:28:26 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2017 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License |
| 15 | */ |
| 16 | |
| 17 | package com.android.systemui.statusbar.car; |
| 18 | |
| 19 | import android.content.Context; |
| 20 | import android.content.res.TypedArray; |
| 21 | import android.database.DataSetObserver; |
| 22 | import android.graphics.Canvas; |
| 23 | import android.graphics.Paint; |
| 24 | import android.support.v4.view.PagerAdapter; |
| 25 | import android.support.v4.view.ViewPager; |
| 26 | import android.util.AttributeSet; |
| 27 | import android.util.Log; |
| 28 | import android.util.TypedValue; |
| 29 | import android.view.Gravity; |
| 30 | import android.view.View; |
| 31 | import android.view.ViewGroup; |
| 32 | import android.view.ViewParent; |
| 33 | |
| 34 | import com.android.systemui.R; |
| 35 | |
| 36 | import java.lang.ref.WeakReference; |
| 37 | |
| 38 | /** |
| 39 | * Displays the dots underneath the ViewPager on the lock screen. This is really just a simplified |
| 40 | * version of PagerTitleStrip. We don't inherit from there because it's impossible to bypass some |
| 41 | * of the overriden logic in that class. |
| 42 | */ |
| 43 | public class PageIndicator extends View { |
| 44 | private static final String TAG = "PageIndicator"; |
| 45 | // These can be made a styleable attribute in the future if necessary. |
| 46 | private static final int SELECTED_COLOR = 0xFFF5F5F5; // grey 100 |
| 47 | private static final int UNSELECTED_COLOR = 0xFFBDBDBD; // grey 400 |
| 48 | private final PageListener mPageListener = new PageListener(); |
| 49 | |
| 50 | private ViewPager mPager; |
| 51 | private WeakReference<PagerAdapter> mWatchingAdapter; |
| 52 | |
| 53 | private int mPageCount; |
| 54 | private int mCurrentPosition; |
| 55 | private Paint mPaint; |
| 56 | private int mRadius; |
| 57 | private int mStep; |
| 58 | |
| 59 | public PageIndicator(Context context) { |
| 60 | super(context); |
| 61 | init(); |
| 62 | } |
| 63 | |
| 64 | public PageIndicator(Context context, AttributeSet attrs) { |
| 65 | super(context, attrs); |
| 66 | init(); |
| 67 | } |
| 68 | |
| 69 | private void init() { |
| 70 | mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); |
| 71 | mPaint.setStyle(Paint.Style.FILL); |
| 72 | mRadius = getResources().getDimensionPixelSize(R.dimen.car_page_indicator_dot_diameter) / 2; |
| 73 | mStep = mRadius * 3; |
| 74 | } |
| 75 | |
| 76 | public void setupWithViewPager(ViewPager pager) { |
| 77 | mPager = pager; |
| 78 | |
| 79 | final PagerAdapter adapter = (PagerAdapter) pager.getAdapter(); |
| 80 | pager.addOnPageChangeListener(mPageListener); |
| 81 | pager.addOnAdapterChangeListener(mPageListener); |
| 82 | updateAdapter(mWatchingAdapter != null ? mWatchingAdapter.get() : null, adapter); |
| 83 | invalidate(); |
| 84 | } |
| 85 | |
| 86 | @Override |
| 87 | protected void onDetachedFromWindow() { |
| 88 | super.onDetachedFromWindow(); |
| 89 | if (mPager != null) { |
| 90 | updateAdapter(mPager.getAdapter(), null); |
| 91 | mPager.removeOnPageChangeListener(mPageListener); |
| 92 | mPager.removeOnAdapterChangeListener(mPageListener); |
| 93 | mPager = null; |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | @Override |
| 98 | protected void onDraw(Canvas canvas) { |
| 99 | super.onDraw(canvas); |
| 100 | |
Bryan Eyler | 8991d65 | 2017-07-19 13:19:36 -0700 | [diff] [blame] | 101 | // Don't draw anything unless there's multiple pages to scroll through. No need to clear |
| 102 | // any previous dots, since onDraw provides a canvas that's already cleared. |
| 103 | if (mPageCount <= 1) |
| 104 | return; |
| 105 | |
Rakesh Iyer | 5b3278f | 2017-04-19 11:28:26 -0700 | [diff] [blame] | 106 | int x = canvas.getWidth() / 2 - (mPageCount / 2) * mStep; |
| 107 | int y = canvas.getHeight() / 2; |
| 108 | |
| 109 | for (int i = 0; i < mPageCount; i++) { |
| 110 | if (i == mCurrentPosition) { |
| 111 | mPaint.setColor(SELECTED_COLOR); |
| 112 | } else { |
| 113 | mPaint.setColor(UNSELECTED_COLOR); |
| 114 | } |
| 115 | |
| 116 | canvas.drawCircle(x, y, mRadius, mPaint); |
| 117 | x += mStep; |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | void updateAdapter(PagerAdapter oldAdapter, PagerAdapter newAdapter) { |
| 122 | if (oldAdapter != null) { |
| 123 | oldAdapter.unregisterDataSetObserver(mPageListener); |
| 124 | mWatchingAdapter = null; |
| 125 | } |
| 126 | |
| 127 | if (newAdapter != null) { |
| 128 | newAdapter.registerDataSetObserver(mPageListener); |
| 129 | mWatchingAdapter = new WeakReference<>(newAdapter); |
| 130 | } |
| 131 | |
| 132 | updateDots(); |
| 133 | |
| 134 | if (mPager != null) { |
| 135 | requestLayout(); |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | private <T> T getRef(WeakReference<T> weakRef) { |
| 140 | if (weakRef == null) { |
| 141 | return null; |
| 142 | } |
| 143 | return weakRef.get(); |
| 144 | } |
| 145 | |
| 146 | private void updateDots() { |
| 147 | PagerAdapter adapter = getRef(mWatchingAdapter); |
| 148 | if (adapter == null) { |
| 149 | return; |
| 150 | } |
| 151 | |
| 152 | int count = adapter.getCount(); |
| 153 | if (mPageCount == count) { |
| 154 | // Nothing to be done. |
| 155 | return; |
| 156 | } |
| 157 | |
| 158 | mPageCount = count; |
| 159 | mCurrentPosition = 0; |
| 160 | invalidate(); |
| 161 | } |
| 162 | |
| 163 | private class PageListener extends DataSetObserver implements ViewPager.OnPageChangeListener, |
| 164 | ViewPager.OnAdapterChangeListener { |
| 165 | |
| 166 | @Override |
| 167 | public void onPageScrolled(int unused1, float unused2, int unused3) { } |
| 168 | |
| 169 | @Override |
| 170 | public void onPageSelected(int position) { |
| 171 | if (mCurrentPosition == position) { |
| 172 | return; |
| 173 | } |
| 174 | |
| 175 | if (mPageCount <= position) { |
| 176 | Log.e(TAG, "Position out of bounds, position=" + position + " size=" + mPageCount); |
| 177 | return; |
| 178 | } |
| 179 | |
| 180 | mCurrentPosition = position; |
| 181 | invalidate(); |
| 182 | } |
| 183 | |
| 184 | @Override |
| 185 | public void onPageScrollStateChanged(int state) { } |
| 186 | |
| 187 | @Override |
| 188 | public void onAdapterChanged(ViewPager viewPager, PagerAdapter oldAdapter, |
| 189 | PagerAdapter newAdapter) { |
| 190 | updateAdapter(oldAdapter, newAdapter); |
| 191 | } |
| 192 | |
| 193 | @Override |
| 194 | public void onChanged() { |
| 195 | updateDots(); |
| 196 | } |
| 197 | } |
| 198 | } |