1 /* 2 * Copyright 2018 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 androidx.percentlayout.widget; 18 19 import android.content.Context; 20 import android.content.res.TypedArray; 21 import android.util.AttributeSet; 22 import android.view.ViewGroup; 23 import android.widget.RelativeLayout; 24 25 /** 26 * Subclass of {@link android.widget.RelativeLayout} that supports percentage based dimensions and 27 * margins. 28 * 29 * You can specify dimension or a margin of child by using attributes with "Percent" suffix. Follow 30 * this example: 31 * 32 * <pre class="prettyprint"> 33 * <androidx.percentlayout.widget.PercentRelativeLayout 34 * xmlns:android="http://schemas.android.com/apk/res/android" 35 * xmlns:app="http://schemas.android.com/apk/res-auto" 36 * android:layout_width="match_parent" 37 * android:layout_height="match_parent"> 38 * <ImageView 39 * app:layout_widthPercent="50%" 40 * app:layout_heightPercent="50%" 41 * app:layout_marginTopPercent="25%" 42 * app:layout_marginLeftPercent="25%"/> 43 * </androidx.percentlayout.widget.PercentRelativeLayout> 44 * </pre> 45 * 46 * The attributes that you can use are: 47 * <ul> 48 * <li>{@code layout_widthPercent} 49 * <li>{@code layout_heightPercent} 50 * <li>{@code layout_marginPercent} 51 * <li>{@code layout_marginLeftPercent} 52 * <li>{@code layout_marginTopPercent} 53 * <li>{@code layout_marginRightPercent} 54 * <li>{@code layout_marginBottomPercent} 55 * <li>{@code layout_marginStartPercent} 56 * <li>{@code layout_marginEndPercent} 57 * <li>{@code layout_aspectRatio} 58 * </ul> 59 * 60 * It is not necessary to specify {@code layout_width/height} if you specify {@code 61 * layout_widthPercent.} However, if you want the view to be able to take up more space than what 62 * percentage value permits, you can add {@code layout_width/height="wrap_content"}. In that case 63 * if the percentage size is too small for the View's content, it will be resized using 64 * {@code wrap_content} rule. 65 * 66 * <p> 67 * You can also make one dimension be a fraction of the other by setting only width or height and 68 * using {@code layout_aspectRatio} for the second one to be calculated automatically. For 69 * example, if you would like to achieve 16:9 aspect ratio, you can write: 70 * <pre class="prettyprint"> 71 * android:layout_width="300dp" 72 * app:layout_aspectRatio="178%" 73 * </pre> 74 * This will make the aspect ratio 16:9 (1.78:1) with the width fixed at 300dp and height adjusted 75 * accordingly. 76 * 77 * @deprecated consider using ConstraintLayout and associated layouts instead. The following shows 78 * how to replicate the functionality of percentage layouts with a ConstraintLayout. The Guidelines 79 * are used to define each percentage break point, and then a Button view is stretched to fill 80 * the gap: 81 * 82 * <pre class="prettyprint"> 83 * <androidx.constraintlayout.widget.ConstraintLayout 84 * xmlns:android="http://schemas.android.com/apk/res/android" 85 * xmlns:app="http://schemas.android.com/apk/res-auto" 86 * android:layout_width="match_parent" 87 * android:layout_height="match_parent"> 88 * 89 * <androidx.constraintlayout.widget.Guideline 90 * android:layout_width="wrap_content" 91 * android:layout_height="wrap_content" 92 * android:id="@+id/left_guideline" 93 * app:layout_constraintGuide_percent=".15" 94 * android:orientation="vertical"/> 95 * 96 * <androidx.constraintlayout.widget.Guideline 97 * android:layout_width="wrap_content" 98 * android:layout_height="wrap_content" 99 * android:id="@+id/right_guideline" 100 * app:layout_constraintGuide_percent=".85" 101 * android:orientation="vertical"/> 102 * 103 * <androidx.constraintlayout.widget.Guideline 104 * android:layout_width="wrap_content" 105 * android:layout_height="wrap_content" 106 * android:id="@+id/top_guideline" 107 * app:layout_constraintGuide_percent=".15" 108 * android:orientation="horizontal"/> 109 * 110 * <androidx.constraintlayout.widget.Guideline 111 * android:layout_width="wrap_content" 112 * android:layout_height="wrap_content" 113 * android:id="@+id/bottom_guideline" 114 * app:layout_constraintGuide_percent=".85" 115 * android:orientation="horizontal"/> 116 * 117 * <Button 118 * android:text="Button" 119 * android:layout_width="0dp" 120 * android:layout_height="0dp" 121 * android:id="@+id/button" 122 * app:layout_constraintLeft_toLeftOf="@+id/left_guideline" 123 * app:layout_constraintRight_toRightOf="@+id/right_guideline" 124 * app:layout_constraintTop_toTopOf="@+id/top_guideline" 125 * app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline" /> 126 * 127 * </androidx.constraintlayout.widget.ConstraintLayout> 128 */ 129 @Deprecated 130 public class PercentRelativeLayout extends RelativeLayout { 131 private final PercentLayoutHelper mHelper = new PercentLayoutHelper(this); 132 133 public PercentRelativeLayout(Context context) { 134 super(context); 135 } 136 137 public PercentRelativeLayout(Context context, AttributeSet attrs) { 138 super(context, attrs); 139 } 140 141 public PercentRelativeLayout(Context context, AttributeSet attrs, int defStyle) { 142 super(context, attrs, defStyle); 143 } 144 145 @Override 146 protected LayoutParams generateDefaultLayoutParams() { 147 return new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); 148 } 149 150 @Override 151 public LayoutParams generateLayoutParams(AttributeSet attrs) { 152 return new LayoutParams(getContext(), attrs); 153 } 154 155 @Override 156 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 157 mHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec); 158 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 159 if (mHelper.handleMeasuredStateTooSmall()) { 160 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 161 } 162 } 163 164 @Override 165 protected void onLayout(boolean changed, int left, int top, int right, int bottom) { 166 super.onLayout(changed, left, top, right, bottom); 167 mHelper.restoreOriginalParams(); 168 } 169 170 /** 171 * @deprecated this class is deprecated along with its parent class. 172 */ 173 @Deprecated 174 public static class LayoutParams extends RelativeLayout.LayoutParams 175 implements PercentLayoutHelper.PercentLayoutParams { 176 private PercentLayoutHelper.PercentLayoutInfo mPercentLayoutInfo; 177 178 public LayoutParams(Context c, AttributeSet attrs) { 179 super(c, attrs); 180 mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c, attrs); 181 } 182 183 public LayoutParams(int width, int height) { 184 super(width, height); 185 } 186 187 public LayoutParams(ViewGroup.LayoutParams source) { 188 super(source); 189 } 190 191 public LayoutParams(MarginLayoutParams source) { 192 super(source); 193 } 194 195 @Override 196 public PercentLayoutHelper.PercentLayoutInfo getPercentLayoutInfo() { 197 if (mPercentLayoutInfo == null) { 198 mPercentLayoutInfo = new PercentLayoutHelper.PercentLayoutInfo(); 199 } 200 201 return mPercentLayoutInfo; 202 } 203 204 @Override 205 protected void setBaseAttributes(TypedArray a, int widthAttr, int heightAttr) { 206 PercentLayoutHelper.fetchWidthAndHeight(this, a, widthAttr, heightAttr); 207 } 208 } 209 } 210
