/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Eclipse Public License, Version 1.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.eclipse.org/org/documents/epl-v10.php
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.ide.common.layout;
import static com.android.SdkConstants.ANDROID_URI;
import static com.android.SdkConstants.ATTR_LAYOUT_GRAVITY;
import static com.android.SdkConstants.GRAVITY_VALUE_BOTTOM;
import static com.android.SdkConstants.GRAVITY_VALUE_CENTER;
import static com.android.SdkConstants.GRAVITY_VALUE_CENTER_HORIZONTAL;
import static com.android.SdkConstants.GRAVITY_VALUE_CENTER_VERTICAL;
import static com.android.SdkConstants.GRAVITY_VALUE_FILL;
import static com.android.SdkConstants.GRAVITY_VALUE_FILL_HORIZONTAL;
import static com.android.SdkConstants.GRAVITY_VALUE_FILL_VERTICAL;
import static com.android.SdkConstants.GRAVITY_VALUE_LEFT;
import static com.android.SdkConstants.GRAVITY_VALUE_RIGHT;
import static com.android.SdkConstants.GRAVITY_VALUE_TOP;
import org.w3c.dom.Element;
/** Helper class for looking up the gravity masks of gravity attributes */
public class GravityHelper {
/** Bitmask for a gravity which includes left */
public static final int GRAVITY_LEFT = 1 << 0;
/** Bitmask for a gravity which includes right */
public static final int GRAVITY_RIGHT = 1 << 1;
/** Bitmask for a gravity which includes center horizontal */
public static final int GRAVITY_CENTER_HORIZ = 1 << 2;
/** Bitmask for a gravity which includes fill horizontal */
public static final int GRAVITY_FILL_HORIZ = 1 << 3;
/** Bitmask for a gravity which includes center vertical */
public static final int GRAVITY_CENTER_VERT = 1 << 4;
/** Bitmask for a gravity which includes fill vertical */
public static final int GRAVITY_FILL_VERT = 1 << 5;
/** Bitmask for a gravity which includes top */
public static final int GRAVITY_TOP = 1 << 6;
/** Bitmask for a gravity which includes bottom */
public static final int GRAVITY_BOTTOM = 1 << 7;
/** Bitmask for a gravity which includes any horizontal constraint */
public static final int GRAVITY_HORIZ_MASK = GRAVITY_CENTER_HORIZ | GRAVITY_FILL_HORIZ
| GRAVITY_LEFT | GRAVITY_RIGHT;
/** Bitmask for a gravity which any vertical constraint */
public static final int GRAVITY_VERT_MASK = GRAVITY_CENTER_VERT | GRAVITY_FILL_VERT
| GRAVITY_TOP | GRAVITY_BOTTOM;
/**
* Returns the gravity of the given element
*
* @param element the element to look up the gravity for
* @return a bit mask corresponding to the selected gravities
*/
public static int getGravity(Element element) {
String gravityString = element.getAttributeNS(ANDROID_URI, ATTR_LAYOUT_GRAVITY);
return getGravity(gravityString, GRAVITY_LEFT | GRAVITY_TOP);
}
/**
* Returns the gravity bitmask for the given gravity string description
*
* @param gravityString the gravity string description
* @param defaultMask the default/initial bitmask to start with
* @return a bitmask corresponding to the gravity description
*/
public static int getGravity(String gravityString, int defaultMask) {
int gravity = defaultMask;
if (gravityString != null && gravityString.length() > 0) {
String[] anchors = gravityString.split("\\|"); //$NON-NLS-1$
for (String anchor : anchors) {
if (GRAVITY_VALUE_CENTER.equals(anchor)) {
gravity = GRAVITY_CENTER_HORIZ | GRAVITY_CENTER_VERT;
} else if (GRAVITY_VALUE_FILL.equals(anchor)) {
gravity = GRAVITY_FILL_HORIZ | GRAVITY_FILL_VERT;
} else if (GRAVITY_VALUE_CENTER_VERTICAL.equals(anchor)) {
gravity = (gravity & GRAVITY_HORIZ_MASK) | GRAVITY_CENTER_VERT;
} else if (GRAVITY_VALUE_CENTER_HORIZONTAL.equals(anchor)) {
gravity = (gravity & GRAVITY_VERT_MASK) | GRAVITY_CENTER_HORIZ;
} else if (GRAVITY_VALUE_FILL_VERTICAL.equals(anchor)) {
gravity = (gravity & GRAVITY_HORIZ_MASK) | GRAVITY_FILL_VERT;
} else if (GRAVITY_VALUE_FILL_HORIZONTAL.equals(anchor)) {
gravity = (gravity & GRAVITY_VERT_MASK) | GRAVITY_FILL_HORIZ;
} else if (GRAVITY_VALUE_TOP.equals(anchor)) {
gravity = (gravity & GRAVITY_HORIZ_MASK) | GRAVITY_TOP;
} else if (GRAVITY_VALUE_BOTTOM.equals(anchor)) {
gravity = (gravity & GRAVITY_HORIZ_MASK) | GRAVITY_BOTTOM;
} else if (GRAVITY_VALUE_LEFT.equals(anchor)) {
gravity = (gravity & GRAVITY_VERT_MASK) | GRAVITY_LEFT;
} else if (GRAVITY_VALUE_RIGHT.equals(anchor)) {
gravity = (gravity & GRAVITY_VERT_MASK) | GRAVITY_RIGHT;
} else {
// "clip" not supported
}
}
}
return gravity;
}
/**
* Returns true if the given gravity bitmask is constrained horizontally
*
* @param gravity the gravity bitmask
* @return true if the given gravity bitmask is constrained horizontally
*/
public static boolean isConstrainedHorizontally(int gravity) {
return (gravity & GRAVITY_HORIZ_MASK) != 0;
}
/**
* Returns true if the given gravity bitmask is constrained vertically
*
* @param gravity the gravity bitmask
* @return true if the given gravity bitmask is constrained vertically
*/
public static boolean isConstrainedVertically(int gravity) {
return (gravity & GRAVITY_VERT_MASK) != 0;
}
/**
* Returns true if the given gravity bitmask is left aligned
*
* @param gravity the gravity bitmask
* @return true if the given gravity bitmask is left aligned
*/
public static boolean isLeftAligned(int gravity) {
return (gravity & GRAVITY_LEFT) != 0;
}
/**
* Returns true if the given gravity bitmask is top aligned
*
* @param gravity the gravity bitmask
* @return true if the given gravity bitmask is aligned
*/
public static boolean isTopAligned(int gravity) {
return (gravity & GRAVITY_TOP) != 0;
}
/** Returns a gravity value string from the given gravity bitmask
*
* @param gravity the gravity bitmask
* @return the corresponding gravity string suitable as an XML attribute value
*/
public static String getGravity(int gravity) {
if (gravity == 0) {
return "";
}
if ((gravity & (GRAVITY_CENTER_HORIZ | GRAVITY_CENTER_VERT)) ==
(GRAVITY_CENTER_HORIZ | GRAVITY_CENTER_VERT)) {
return GRAVITY_VALUE_CENTER;
}
StringBuilder sb = new StringBuilder(30);
int horizontal = gravity & GRAVITY_HORIZ_MASK;
int vertical = gravity & GRAVITY_VERT_MASK;
if ((horizontal & GRAVITY_LEFT) != 0) {
sb.append(GRAVITY_VALUE_LEFT);
} else if ((horizontal & GRAVITY_RIGHT) != 0) {
sb.append(GRAVITY_VALUE_RIGHT);
} else if ((horizontal & GRAVITY_CENTER_HORIZ) != 0) {
sb.append(GRAVITY_VALUE_CENTER_HORIZONTAL);
} else if ((horizontal & GRAVITY_FILL_HORIZ) != 0) {
sb.append(GRAVITY_VALUE_FILL_HORIZONTAL);
}
if (sb.length() > 0 && vertical != 0) {
sb.append('|');
}
if ((vertical & GRAVITY_TOP) != 0) {
sb.append(GRAVITY_VALUE_TOP);
} else if ((vertical & GRAVITY_BOTTOM) != 0) {
sb.append(GRAVITY_VALUE_BOTTOM);
} else if ((vertical & GRAVITY_CENTER_VERT) != 0) {
sb.append(GRAVITY_VALUE_CENTER_VERTICAL);
} else if ((vertical & GRAVITY_FILL_VERT) != 0) {
sb.append(GRAVITY_VALUE_FILL_VERTICAL);
}
return sb.toString();
}
}