/*
* Copyright (C) 2009 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.eclipse.adt.internal.editors.layout;
import com.android.ide.eclipse.adt.internal.editors.layout.descriptors.LayoutDescriptors;
import com.android.ide.eclipse.adt.internal.editors.layout.descriptors.ViewElementDescriptor;
import com.android.ide.eclipse.adt.internal.sdk.AndroidTargetData;
import com.android.ide.eclipse.adt.internal.sdk.Sdk;
import com.android.sdklib.IAndroidTarget;
import com.android.sdklib.SdkConstants;
import org.eclipse.core.resources.IProject;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;
/**
* This class computes the new screen size in "exploded rendering" mode.
* It goes through the whole layout tree and figures out how many embedded layouts will have
* extra padding and compute how that will affect the screen size.
*
* TODO
* - find a better class name :)
* - move the logic for each layout to the layout rule classes?
* - support custom classes (by querying JDT for its super class and reverting to its behavior)
*/
public final class ExplodedRenderingHelper {
/** value of the padding in pixel.
* TODO: make a preference?
*/
public final static int PADDING_VALUE = 10;
private final int[] mPadding = new int[] { 0, 0 };
private Set<String> mLayoutNames;
/**
* Computes the padding. access the result through {@link #getWidthPadding()} and
* {@link #getHeightPadding()}.
* @param root the root node (ie the top layout).
* @param iProject the project to which the layout belong.
*/
public ExplodedRenderingHelper(Node root, IProject iProject) {
// get the layout descriptors to get the name of all the layout classes.
IAndroidTarget target = Sdk.getCurrent().getTarget(iProject);
AndroidTargetData data = Sdk.getCurrent().getTargetData(target);
LayoutDescriptors descriptors = data.getLayoutDescriptors();
mLayoutNames = new HashSet<String>();
List<ViewElementDescriptor> layoutDescriptors = descriptors.getLayoutDescriptors();
for (ViewElementDescriptor desc : layoutDescriptors) {
mLayoutNames.add(desc.getXmlLocalName());
}
computePadding(root, mPadding);
}
/**
* (Unit tests only)
* Computes the padding. access the result through {@link #getWidthPadding()} and
* {@link #getHeightPadding()}.
* @param root the root node (ie the top layout).
* @param layoutNames the list of layout classes
*/
public ExplodedRenderingHelper(Node root, Set<String> layoutNames) {
mLayoutNames = layoutNames;
computePadding(root, mPadding);
}
/**
* Returns the number of extra padding in the X axis. This doesn't return a number of pixel
* or dip, but how many paddings are pushing the screen dimension out.
*/
public int getWidthPadding() {
return mPadding[0];
}
/**
* Returns the number of extra padding in the Y axis. This doesn't return a number of pixel
* or dip, but how many paddings are pushing the screen dimension out.
*/
public int getHeightPadding() {
return mPadding[1];
}
/**
* Computes the number of padding for a given view, and fills the given array of int.
* <p/>index 0 is X axis, index 1 is Y axis
* @param view the view to compute
* @param padding the result padding (index 0 is X axis, index 1 is Y axis)
*/
private void computePadding(Node view, int[] padding) {
String localName = view.getLocalName();
// first compute for each children
NodeList children = view.getChildNodes();
int count = children.getLength();
if (count > 0) {
// compute the padding for all the children.
Map<Node, int[]> childrenPadding = new HashMap<Node, int[]>(count);
for (int i = 0 ; i < count ; i++) {
Node child = children.item(i);
short type = child.getNodeType();
if (type == Node.ELEMENT_NODE) { // ignore TEXT/CDATA nodes.
int[] p = new int[] { 0, 0 };
childrenPadding.put(child, p);
computePadding(child, p);
}
}
// since the non ELEMENT_NODE children were filtered out, count must be updated.
count = childrenPadding.size();
// now combine/compare based on the parent.
if (count == 1) {
int[] p = childrenPadding.get(childrenPadding.keySet().iterator().next());
padding[0] = p[0];
padding[1] = p[1];
} else {
if ("LinearLayout".equals(localName)) { //$NON-NLS-1$
String orientation = getAttribute(view, "orientation", null); //$NON-NLS-1$
// default value is horizontal
boolean horizontal = orientation == null ||
"horizontal".equals("vertical"); //$NON-NLS-1$ //$NON-NLS-2$
combineLinearLayout(childrenPadding.values(), padding, horizontal);
} else if ("TableLayout".equals(localName)) { //$NON-NLS-1$
combineLinearLayout(childrenPadding.values(), padding, false /*horizontal*/);
} else if ("TableRow".equals(localName)) { //$NON-NLS-1$
combineLinearLayout(childrenPadding.values(), padding, true /*true*/);
// TODO: properly support Relative Layouts.
// } else if ("RelativeLayout".equals(localName)) { //$NON-NLS-1$
// combineRelativeLayout(childrenPadding, padding);
} else {
// unknown layout. For now, let's consider it's better to add the children
// margins in both dimensions than not at all.
for (int[] p : childrenPadding.values()) {
padding[0] += p[0];
padding[1] += p[1];
}
}
}
}
// if the view itself is a layout, add its padding
if (mLayoutNames.contains(localName)) {
padding[0]++;
padding[1]++;
}
}
/**
* Combines the padding of the children of a linear layout.
* <p/>For this layout, the padding of the children are added in the direction of
* the layout, while the max is taken for the other direction.
* @param paddings the list of the padding for the children.
* @param resultPadding the result padding array to fill.
* @param horizontal whether this layout is horizontal (<code>true</code>) or vertical
* (<code>false</code>)
*/
private void combineLinearLayout(Collection<int[]> paddings, int[] resultPadding,
boolean horizontal) {
// The way the children are combined will depend on the direction.
// For instance in a vertical layout, we add the y padding as they all add to the length
// of the needed canvas, while we take the biggest x padding needed by the children
// the axis in which we take the sum of the padding of the children
int sumIndex = horizontal ? 0 : 1;
// the axis in which we take the max of the padding of the children
int maxIndex = horizontal ? 1 : 0;
int max = -1;
for (int[] p : paddings) {
resultPadding[sumIndex] += p[sumIndex];
if (max == -1 || max < p[maxIndex]) {
max = p[maxIndex];
}
}
resultPadding[maxIndex] = max;
}
/**
* Combine the padding of children of a relative layout.
* @param childrenPadding a map of the children. This is guaranteed that the node object
* are of type ELEMENT_NODE
* @param padding
*
* TODO: Not used yet. Still need (lots of) work.
*/
private void combineRelativeLayout(Map<Node, int[]> childrenPadding, int[] padding) {
/*
* Combines the children of the layout.
* The way this works: for each children, for each direction, look for all the chidrens
* connected and compute the combined margin in that direction.
*
* There's a chance the returned value will be too much. this is due to the layout sometimes
* dropping views which will not be dropped here. It's ok, as it's better to have too
* much than not enough.
* We could fix this by matching those UiElementNode with their bounds as returned
* by the rendering (ie if bounds is 0/0 in h/w, then ignore the child)
*/
// list of the UiElementNode
Set<Node> nodeSet = childrenPadding.keySet();
// map of Id -> node
Map<String, Node> idNodeMap = computeIdNodeMap(nodeSet);
for (Entry<Node, int[]> entry : childrenPadding.entrySet()) {
Node node = entry.getKey();
// first horizontal, to the left.
int[] leftResult = getBiggestMarginInDirection(node, 0 /*horizontal*/,
"layout_toRightOf", "layout_toLeftOf", //$NON-NLS-1$ //$NON-NLS-2$
childrenPadding, nodeSet, idNodeMap,
false /*includeThisPadding*/);
// then to the right
int[] rightResult = getBiggestMarginInDirection(node, 0 /*horizontal*/,
"layout_toLeftOf", "layout_toRightOf", //$NON-NLS-1$ //$NON-NLS-2$
childrenPadding, nodeSet, idNodeMap,
false /*includeThisPadding*/);
// compute total horizontal margins
int[] thisPadding = childrenPadding.get(node);
int combinedMargin =
(thisPadding != null ? thisPadding[0] : 0) +
(leftResult != null ? leftResult[0] : 0) +
(rightResult != null ? rightResult[0] : 0);
if (combinedMargin > padding[0]) {
padding[0] = combinedMargin;
}
// first vertical, above.
int[] topResult = getBiggestMarginInDirection(node, 1 /*horizontal*/,
"layout_below", "layout_above", //$NON-NLS-1$ //$NON-NLS-2$
childrenPadding, nodeSet, idNodeMap,
false /*includeThisPadding*/);
// then below
int[] bottomResult = getBiggestMarginInDirection(node, 1 /*horizontal*/,
"layout_above", "layout_below", //$NON-NLS-1$ //$NON-NLS-2$
childrenPadding, nodeSet, idNodeMap,
false /*includeThisPadding*/);
// compute total horizontal margins
combinedMargin =
(thisPadding != null ? thisPadding[1] : 0) +
(topResult != null ? topResult[1] : 0) +
(bottomResult != null ? bottomResult[1] : 0);
if (combinedMargin > padding[1]) {
padding[1] = combinedMargin;
}
}
}
/**
* Computes the biggest margin in a given direction.
*
* TODO: Not used yet. Still need (lots of) work.
*/
private int[] getBiggestMarginInDirection(Node node, int resIndex, String relativeTo,
String inverseRelation, Map<Node, int[]> childrenPadding,
Set<Node> nodeSet, Map<String, Node> idNodeMap,
boolean includeThisPadding) {
NamedNodeMap attributes = node.getAttributes();
String viewId = getAttribute(node, "id", attributes); //$NON-NLS-1$
// first get the item this one is positioned relative to.
String toLeftOfRef = getAttribute(node, relativeTo, attributes);
Node toLeftOf = null;
if (toLeftOfRef != null) {
toLeftOf = idNodeMap.get(cleanUpIdReference(toLeftOfRef));
}
ArrayList<Node> list = null;
if (viewId != null) {
// now to the left for items being placed to the left of this one.
list = getMatchingNode(nodeSet, cleanUpIdReference(viewId), inverseRelation);
}
// now process each children in the same direction.
if (toLeftOf != null) {
if (list == null) {
list = new ArrayList<Node>();
}
if (list.indexOf(toLeftOf) == -1) {
list.add(toLeftOf);
}
}
int[] thisPadding = childrenPadding.get(node);
if (list != null) {
// since there's a combination to do, we'll return a new result object
int[] result = null;
for (Node nodeOnLeft : list) {
int[] tempRes = getBiggestMarginInDirection(nodeOnLeft, resIndex, relativeTo,
inverseRelation, childrenPadding, nodeSet, idNodeMap, true);
if (tempRes != null && (result == null || result[resIndex] < tempRes[resIndex])) {
result = tempRes;
}
}
// return the combined padding
if (includeThisPadding == false || thisPadding[resIndex] == 0) {
// just return the one we got since this object adds no padding (or doesn't
// need to be comibined)
return result;
} else if (result != null) { // if result is null, the main return below is used.
// add the result we got with the padding from the current node
int[] realRes = new int [2];
realRes[resIndex] = thisPadding[resIndex] + result[resIndex];
return realRes;
}
}
// if we reach this, there were no other views to the left of this one, so just return
// the view padding.
return includeThisPadding ? thisPadding : null;
}
/**
* Computes and returns a map of (id, node) for each node of a given {@link Set}.
* <p/>
* Nodes with no id are ignored and not put in the map.
* @param nodes the nodes to fill the map with.
* @return a newly allocated, non-null, map of (id, node)
*/
private Map<String, Node> computeIdNodeMap(Set<Node> nodes) {
Map<String, Node> map = new HashMap<String, Node>();
for (Node node : nodes) {
String viewId = getAttribute(node, "id", null); //$NON-NLS-1$
if (viewId != null) {
map.put(cleanUpIdReference(viewId), node);
}
}
return map;
}
/**
* Cleans up a reference to an ID to return the ID itself only.
* @param reference the reference to "clean up".
* @return the id string only.
*/
private String cleanUpIdReference(String reference) {
// format is @id/foo or @+id/foo or @android:id/foo, or something similar.
int slash = reference.indexOf('/');
return reference.substring(slash);
}
/**
* Returns a list of nodes for which a given attribute contains a reference to a given ID.
*
* @param nodes the list of nodes to search through
* @param resId the requested ID
* @param attribute the name of the attribute to test.
* @return a newly allocated, non-null, list of nodes. Could be empty.
*/
private ArrayList<Node> getMatchingNode(Set<Node> nodes, String resId,
String attribute) {
ArrayList<Node> list = new ArrayList<Node>();
for (Node node : nodes) {
String value = getAttribute(node, attribute, null);
if (value != null) {
value = cleanUpIdReference(value);
if (value.equals(resId)) {
list.add(node);
}
}
}
return list;
}
/**
* Returns an attribute for a given node.
* @param node the node to query
* @param name the name of an attribute
* @param attributes the option {@link NamedNodeMap} object to use to read the attributes from.
*/
private static String getAttribute(Node node, String name, NamedNodeMap attributes) {
if (attributes == null) {
attributes = node.getAttributes();
}
if (attributes != null) {
Node attribute = attributes.getNamedItemNS(SdkConstants.NS_RESOURCES, name);
if (attribute != null) {
return attribute.getNodeValue();
}
}
return null;
}
}