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 import android.compat.annotation.UnsupportedAppUsage;
20 
21 public class ScrollBarUtils {
22 
23     @UnsupportedAppUsage
getThumbLength(int size, int thickness, int extent, int range)24     public static int getThumbLength(int size, int thickness, int extent, int range) {
25         // Avoid the tiny thumb.
26         final int minLength = thickness * 2;
27         int length = Math.round((float) size * extent / range);
28         if (length < minLength) {
29             length = minLength;
30         }
31         return length;
32     }
33 
getThumbOffset(int size, int thumbLength, int extent, int range, int offset)34     public static int getThumbOffset(int size, int thumbLength, int extent, int range, int offset) {
35         // Avoid the too-big thumb.
36         int thumbOffset = Math.round((float) (size - thumbLength) * offset / (range - extent));
37         if (thumbOffset > size - thumbLength) {
38             thumbOffset = size - thumbLength;
39         }
40         return thumbOffset;
41     }
42 }
43