1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Eclipse Public License, Version 1.0 (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.eclipse.org/org/documents/epl-v10.php 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 package com.android.ide.common.layout; 17 18 import static com.android.SdkConstants.ANDROID_URI; 19 import static com.android.SdkConstants.ATTR_LAYOUT_GRAVITY; 20 import static com.android.SdkConstants.GRAVITY_VALUE_BOTTOM; 21 import static com.android.SdkConstants.GRAVITY_VALUE_CENTER; 22 import static com.android.SdkConstants.GRAVITY_VALUE_CENTER_HORIZONTAL; 23 import static com.android.SdkConstants.GRAVITY_VALUE_CENTER_VERTICAL; 24 import static com.android.SdkConstants.GRAVITY_VALUE_FILL; 25 import static com.android.SdkConstants.GRAVITY_VALUE_FILL_HORIZONTAL; 26 import static com.android.SdkConstants.GRAVITY_VALUE_FILL_VERTICAL; 27 import static com.android.SdkConstants.GRAVITY_VALUE_LEFT; 28 import static com.android.SdkConstants.GRAVITY_VALUE_RIGHT; 29 import static com.android.SdkConstants.GRAVITY_VALUE_TOP; 30 31 import org.w3c.dom.Element; 32 33 /** Helper class for looking up the gravity masks of gravity attributes */ 34 public class GravityHelper { 35 /** Bitmask for a gravity which includes left */ 36 public static final int GRAVITY_LEFT = 1 << 0; 37 38 /** Bitmask for a gravity which includes right */ 39 public static final int GRAVITY_RIGHT = 1 << 1; 40 41 /** Bitmask for a gravity which includes center horizontal */ 42 public static final int GRAVITY_CENTER_HORIZ = 1 << 2; 43 44 /** Bitmask for a gravity which includes fill horizontal */ 45 public static final int GRAVITY_FILL_HORIZ = 1 << 3; 46 47 /** Bitmask for a gravity which includes center vertical */ 48 public static final int GRAVITY_CENTER_VERT = 1 << 4; 49 50 /** Bitmask for a gravity which includes fill vertical */ 51 public static final int GRAVITY_FILL_VERT = 1 << 5; 52 53 /** Bitmask for a gravity which includes top */ 54 public static final int GRAVITY_TOP = 1 << 6; 55 56 /** Bitmask for a gravity which includes bottom */ 57 public static final int GRAVITY_BOTTOM = 1 << 7; 58 59 /** Bitmask for a gravity which includes any horizontal constraint */ 60 public static final int GRAVITY_HORIZ_MASK = GRAVITY_CENTER_HORIZ | GRAVITY_FILL_HORIZ 61 | GRAVITY_LEFT | GRAVITY_RIGHT; 62 63 /** Bitmask for a gravity which any vertical constraint */ 64 public static final int GRAVITY_VERT_MASK = GRAVITY_CENTER_VERT | GRAVITY_FILL_VERT 65 | GRAVITY_TOP | GRAVITY_BOTTOM; 66 67 /** 68 * Returns the gravity of the given element 69 * 70 * @param element the element to look up the gravity for 71 * @return a bit mask corresponding to the selected gravities 72 */ 73 public static int getGravity(Element element) { 74 String gravityString = element.getAttributeNS(ANDROID_URI, ATTR_LAYOUT_GRAVITY); 75 return getGravity(gravityString, GRAVITY_LEFT | GRAVITY_TOP); 76 } 77 78 /** 79 * Returns the gravity bitmask for the given gravity string description 80 * 81 * @param gravityString the gravity string description 82 * @param defaultMask the default/initial bitmask to start with 83 * @return a bitmask corresponding to the gravity description 84 */ 85 public static int getGravity(String gravityString, int defaultMask) { 86 int gravity = defaultMask; 87 if (gravityString != null && gravityString.length() > 0) { 88 String[] anchors = gravityString.split("\\|"); //$NON-NLS-1$ 89 for (String anchor : anchors) { 90 if (GRAVITY_VALUE_CENTER.equals(anchor)) { 91 gravity = GRAVITY_CENTER_HORIZ | GRAVITY_CENTER_VERT; 92 } else if (GRAVITY_VALUE_FILL.equals(anchor)) { 93 gravity = GRAVITY_FILL_HORIZ | GRAVITY_FILL_VERT; 94 } else if (GRAVITY_VALUE_CENTER_VERTICAL.equals(anchor)) { 95 gravity = (gravity & GRAVITY_HORIZ_MASK) | GRAVITY_CENTER_VERT; 96 } else if (GRAVITY_VALUE_CENTER_HORIZONTAL.equals(anchor)) { 97 gravity = (gravity & GRAVITY_VERT_MASK) | GRAVITY_CENTER_HORIZ; 98 } else if (GRAVITY_VALUE_FILL_VERTICAL.equals(anchor)) { 99 gravity = (gravity & GRAVITY_HORIZ_MASK) | GRAVITY_FILL_VERT; 100 } else if (GRAVITY_VALUE_FILL_HORIZONTAL.equals(anchor)) { 101 gravity = (gravity & GRAVITY_VERT_MASK) | GRAVITY_FILL_HORIZ; 102 } else if (GRAVITY_VALUE_TOP.equals(anchor)) { 103 gravity = (gravity & GRAVITY_HORIZ_MASK) | GRAVITY_TOP; 104 } else if (GRAVITY_VALUE_BOTTOM.equals(anchor)) { 105 gravity = (gravity & GRAVITY_HORIZ_MASK) | GRAVITY_BOTTOM; 106 } else if (GRAVITY_VALUE_LEFT.equals(anchor)) { 107 gravity = (gravity & GRAVITY_VERT_MASK) | GRAVITY_LEFT; 108 } else if (GRAVITY_VALUE_RIGHT.equals(anchor)) { 109 gravity = (gravity & GRAVITY_VERT_MASK) | GRAVITY_RIGHT; 110 } else { 111 // "clip" not supported 112 } 113 } 114 } 115 116 return gravity; 117 } 118 119 /** 120 * Returns true if the given gravity bitmask is constrained horizontally 121 * 122 * @param gravity the gravity bitmask 123 * @return true if the given gravity bitmask is constrained horizontally 124 */ 125 public static boolean isConstrainedHorizontally(int gravity) { 126 return (gravity & GRAVITY_HORIZ_MASK) != 0; 127 } 128 129 /** 130 * Returns true if the given gravity bitmask is constrained vertically 131 * 132 * @param gravity the gravity bitmask 133 * @return true if the given gravity bitmask is constrained vertically 134 */ 135 public static boolean isConstrainedVertically(int gravity) { 136 return (gravity & GRAVITY_VERT_MASK) != 0; 137 } 138 139 /** 140 * Returns true if the given gravity bitmask is left aligned 141 * 142 * @param gravity the gravity bitmask 143 * @return true if the given gravity bitmask is left aligned 144 */ 145 public static boolean isLeftAligned(int gravity) { 146 return (gravity & GRAVITY_LEFT) != 0; 147 } 148 149 /** 150 * Returns true if the given gravity bitmask is top aligned 151 * 152 * @param gravity the gravity bitmask 153 * @return true if the given gravity bitmask is aligned 154 */ 155 public static boolean isTopAligned(int gravity) { 156 return (gravity & GRAVITY_TOP) != 0; 157 } 158 159 /** Returns a gravity value string from the given gravity bitmask 160 * 161 * @param gravity the gravity bitmask 162 * @return the corresponding gravity string suitable as an XML attribute value 163 */ 164 public static String getGravity(int gravity) { 165 if (gravity == 0) { 166 return ""; 167 } 168 169 if ((gravity & (GRAVITY_CENTER_HORIZ | GRAVITY_CENTER_VERT)) == 170 (GRAVITY_CENTER_HORIZ | GRAVITY_CENTER_VERT)) { 171 return GRAVITY_VALUE_CENTER; 172 } 173 174 StringBuilder sb = new StringBuilder(30); 175 int horizontal = gravity & GRAVITY_HORIZ_MASK; 176 int vertical = gravity & GRAVITY_VERT_MASK; 177 178 if ((horizontal & GRAVITY_LEFT) != 0) { 179 sb.append(GRAVITY_VALUE_LEFT); 180 } else if ((horizontal & GRAVITY_RIGHT) != 0) { 181 sb.append(GRAVITY_VALUE_RIGHT); 182 } else if ((horizontal & GRAVITY_CENTER_HORIZ) != 0) { 183 sb.append(GRAVITY_VALUE_CENTER_HORIZONTAL); 184 } else if ((horizontal & GRAVITY_FILL_HORIZ) != 0) { 185 sb.append(GRAVITY_VALUE_FILL_HORIZONTAL); 186 } 187 188 if (sb.length() > 0 && vertical != 0) { 189 sb.append('|'); 190 } 191 192 if ((vertical & GRAVITY_TOP) != 0) { 193 sb.append(GRAVITY_VALUE_TOP); 194 } else if ((vertical & GRAVITY_BOTTOM) != 0) { 195 sb.append(GRAVITY_VALUE_BOTTOM); 196 } else if ((vertical & GRAVITY_CENTER_VERT) != 0) { 197 sb.append(GRAVITY_VALUE_CENTER_VERTICAL); 198 } else if ((vertical & GRAVITY_FILL_VERT) != 0) { 199 sb.append(GRAVITY_VALUE_FILL_VERTICAL); 200 } 201 202 return sb.toString(); 203 } 204 } 205
