1 /* 2 * Copyright (C) 2016 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.internal.widget; 18 19 public class ScrollBarUtils { 20 getThumbLength(int size, int thickness, int extent, int range)21 public static int getThumbLength(int size, int thickness, int extent, int range) { 22 // Avoid the tiny thumb. 23 final int minLength = thickness * 2; 24 int length = Math.round((float) size * extent / range); 25 if (length < minLength) { 26 length = minLength; 27 } 28 return length; 29 } 30 getThumbOffset(int size, int thumbLength, int extent, int range, int offset)31 public static int getThumbOffset(int size, int thumbLength, int extent, int range, int offset) { 32 // Avoid the too-big thumb. 33 int thumbOffset = Math.round((float) (size - thumbLength) * offset / (range - extent)); 34 if (thumbOffset > size - thumbLength) { 35 thumbOffset = size - thumbLength; 36 } 37 return thumbOffset; 38 } 39 } 40