1 /* 2 * Copyright (C) 2015 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.launcher3.widget; 18 19 import android.content.Context; 20 import android.graphics.Color; 21 import android.support.v7.widget.LinearLayoutManager; 22 import android.util.AttributeSet; 23 import android.view.View; 24 import com.android.launcher3.BaseRecyclerView; 25 import com.android.launcher3.model.PackageItemInfo; 26 import com.android.launcher3.model.WidgetsModel; 27 28 /** 29 * The widgets recycler view. 30 */ 31 public class WidgetsRecyclerView extends BaseRecyclerView { 32 33 private static final String TAG = "WidgetsRecyclerView"; 34 private WidgetsListAdapter mAdapter; 35 WidgetsRecyclerView(Context context)36 public WidgetsRecyclerView(Context context) { 37 this(context, null); 38 } 39 WidgetsRecyclerView(Context context, AttributeSet attrs)40 public WidgetsRecyclerView(Context context, AttributeSet attrs) { 41 this(context, attrs, 0); 42 } 43 WidgetsRecyclerView(Context context, AttributeSet attrs, int defStyleAttr)44 public WidgetsRecyclerView(Context context, AttributeSet attrs, int defStyleAttr) { 45 // API 21 and below only support 3 parameter ctor. 46 super(context, attrs, defStyleAttr); 47 } 48 WidgetsRecyclerView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)49 public WidgetsRecyclerView(Context context, AttributeSet attrs, int defStyleAttr, 50 int defStyleRes) { 51 this(context, attrs, defStyleAttr); 52 } 53 54 @Override onFinishInflate()55 protected void onFinishInflate() { 56 super.onFinishInflate(); 57 addOnItemTouchListener(this); 58 // create a layout manager with Launcher's context so that scroll position 59 // can be preserved during screen rotation. 60 setLayoutManager(new LinearLayoutManager(getContext())); 61 } 62 getFastScrollerTrackColor(int defaultTrackColor)63 public int getFastScrollerTrackColor(int defaultTrackColor) { 64 return Color.WHITE; 65 } 66 67 @Override setAdapter(Adapter adapter)68 public void setAdapter(Adapter adapter) { 69 super.setAdapter(adapter); 70 mAdapter = (WidgetsListAdapter) adapter; 71 } 72 73 /** 74 * Maps the touch (from 0..1) to the adapter position that should be visible. 75 */ 76 @Override scrollToPositionAtProgress(float touchFraction)77 public String scrollToPositionAtProgress(float touchFraction) { 78 // Skip early if widgets are not bound. 79 if (isModelNotReady()) { 80 return ""; 81 } 82 83 // Stop the scroller if it is scrolling 84 stopScroll(); 85 86 int rowCount = mAdapter.getItemCount(); 87 float pos = rowCount * touchFraction; 88 int availableScrollHeight = getAvailableScrollHeight(); 89 LinearLayoutManager layoutManager = ((LinearLayoutManager) getLayoutManager()); 90 layoutManager.scrollToPositionWithOffset(0, (int) -(availableScrollHeight * touchFraction)); 91 92 int posInt = (int) ((touchFraction == 1)? pos -1 : pos); 93 return mAdapter.getSectionName(posInt); 94 } 95 96 /** 97 * Updates the bounds for the scrollbar. 98 */ 99 @Override onUpdateScrollbar(int dy)100 public void onUpdateScrollbar(int dy) { 101 // Skip early if widgets are not bound. 102 if (isModelNotReady()) { 103 return; 104 } 105 106 // Skip early if, there no child laid out in the container. 107 int scrollY = getCurrentScrollY(); 108 if (scrollY < 0) { 109 mScrollbar.setThumbOffsetY(-1); 110 return; 111 } 112 113 synchronizeScrollBarThumbOffsetToViewScroll(scrollY, getAvailableScrollHeight()); 114 } 115 116 @Override getCurrentScrollY()117 public int getCurrentScrollY() { 118 // Skip early if widgets are not bound. 119 if (isModelNotReady() || getChildCount() == 0) { 120 return -1; 121 } 122 123 View child = getChildAt(0); 124 int rowIndex = getChildPosition(child); 125 int y = (child.getMeasuredHeight() * rowIndex); 126 int offset = getLayoutManager().getDecoratedTop(child); 127 128 return getPaddingTop() + y - offset; 129 } 130 131 /** 132 * Returns the available scroll height: 133 * AvailableScrollHeight = Total height of the all items - last page height 134 */ 135 @Override getAvailableScrollHeight()136 protected int getAvailableScrollHeight() { 137 View child = getChildAt(0); 138 int height = child.getMeasuredHeight() * mAdapter.getItemCount(); 139 int totalHeight = getPaddingTop() + height + getPaddingBottom(); 140 int availableScrollHeight = totalHeight - getScrollbarTrackHeight(); 141 return availableScrollHeight; 142 } 143 isModelNotReady()144 private boolean isModelNotReady() { 145 return mAdapter.getItemCount() == 0; 146 } 147 }