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.calculator2; 18 19 import android.content.Context; 20 import android.util.AttributeSet; 21 import android.view.View; 22 import android.view.ViewGroup; 23 import android.widget.HorizontalScrollView; 24 25 import static android.view.View.MeasureSpec.UNSPECIFIED; 26 import static android.view.ViewGroup.LayoutParams.MATCH_PARENT; 27 import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT; 28 29 public class CalculatorScrollView extends HorizontalScrollView { 30 CalculatorScrollView(Context context)31 public CalculatorScrollView(Context context) { 32 this(context, null /* attrs */); 33 } 34 CalculatorScrollView(Context context, AttributeSet attrs)35 public CalculatorScrollView(Context context, AttributeSet attrs) { 36 this(context, attrs, 0 /* defStyleAttr */); 37 } 38 CalculatorScrollView(Context context, AttributeSet attrs, int defStyleAttr)39 public CalculatorScrollView(Context context, AttributeSet attrs, int defStyleAttr) { 40 super(context, attrs, defStyleAttr); 41 } 42 getChildMeasureSpecCompat(int spec, int padding, int childDimension)43 private static int getChildMeasureSpecCompat(int spec, int padding, int childDimension) { 44 if (MeasureSpec.getMode(spec) == UNSPECIFIED 45 && (childDimension == MATCH_PARENT || childDimension == WRAP_CONTENT)) { 46 final int size = Math.max(0, MeasureSpec.getSize(spec) - padding); 47 return MeasureSpec.makeMeasureSpec(size, UNSPECIFIED); 48 } 49 return ViewGroup.getChildMeasureSpec(spec, padding, childDimension); 50 } 51 52 @Override measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec)53 protected void measureChild(View child, int parentWidthMeasureSpec, 54 int parentHeightMeasureSpec) { 55 // Allow child to be as wide as they want. 56 parentWidthMeasureSpec = MeasureSpec.makeMeasureSpec( 57 MeasureSpec.getSize(parentWidthMeasureSpec), UNSPECIFIED); 58 59 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 60 final int childWidthMeasureSpec = getChildMeasureSpecCompat(parentWidthMeasureSpec, 61 0 /* padding */, lp.width); 62 final int childHeightMeasureSpec = getChildMeasureSpecCompat(parentHeightMeasureSpec, 63 getPaddingTop() + getPaddingBottom(), lp.height); 64 65 child.measure(childWidthMeasureSpec, childHeightMeasureSpec); 66 } 67 68 @Override measureChildWithMargins(View child, int parentWidthMeasureSpec, int widthUsed, int parentHeightMeasureSpec, int heightUsed)69 protected void measureChildWithMargins(View child, int parentWidthMeasureSpec, int widthUsed, 70 int parentHeightMeasureSpec, int heightUsed) { 71 // Allow child to be as wide as they want. 72 parentWidthMeasureSpec = MeasureSpec.makeMeasureSpec( 73 MeasureSpec.getSize(parentWidthMeasureSpec), UNSPECIFIED); 74 75 final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams(); 76 final int childWidthMeasureSpec = getChildMeasureSpecCompat(parentWidthMeasureSpec, 77 lp.leftMargin + lp.rightMargin, lp.width); 78 final int childHeightMeasureSpec = getChildMeasureSpecCompat(parentHeightMeasureSpec, 79 getPaddingTop() + getPaddingBottom() + lp.topMargin + lp.bottomMargin, lp.height); 80 81 child.measure(childWidthMeasureSpec, childHeightMeasureSpec); 82 } 83 } 84