| /* |
| * Copyright 2009 Google Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 |
| * |
| * 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.google.gwt.uibinder.elementparsers; |
| |
| import com.google.gwt.core.ext.UnableToCompleteException; |
| import com.google.gwt.core.ext.typeinfo.JClassType; |
| import com.google.gwt.uibinder.rebind.FieldWriter; |
| import com.google.gwt.uibinder.rebind.UiBinderWriter; |
| import com.google.gwt.uibinder.rebind.XMLElement; |
| |
| /** |
| * Parses {@link com.google.gwt.user.client.ui.LayoutPanel LayoutPanel} widgets. |
| */ |
| public class LayoutPanelParser implements ElementParser { |
| |
| private static final String ERR_PAIRING = "'%s' must be paired with '%s' or '%s'."; |
| private static final String ERR_TOO_MANY = "There are too many %s constraints."; |
| private static final String ERR_NEGATIVE_WIDTH = "Attribute 'width' can not be negative."; |
| private static final String ERR_NEGATIVE_HEIGHT = "Attribute 'height' can not be negative."; |
| private static final String LAYER = "layer"; |
| |
| public void parse(XMLElement elem, String fieldName, JClassType type, |
| UiBinderWriter writer) throws UnableToCompleteException { |
| |
| // Parse children. |
| for (XMLElement layerElem : elem.consumeChildElements()) { |
| // Get the layer element. |
| if (!isElementType(elem, layerElem, LAYER)) { |
| writer.die(layerElem, "Only <%s:%s> children are allowed.", |
| elem.getPrefix(), LAYER); |
| } |
| |
| // Get the child widget element. |
| FieldWriter childField = writer.parseElementToField(layerElem.consumeSingleChildElement()); |
| writer.addStatement("%1$s.add(%2$s);", fieldName, childField.getNextReference()); |
| |
| // Parse the horizontal layout constraints. |
| String left = layerElem.consumeLengthAttribute("left"); |
| String right = layerElem.consumeLengthAttribute("right"); |
| String width = layerElem.consumeLengthAttribute("width"); |
| if (isNegative(width)) { |
| writer.die(layerElem, ERR_NEGATIVE_WIDTH); |
| } |
| |
| if (left != null) { |
| if (right != null) { |
| if (width != null) { |
| writer.die(layerElem, ERR_TOO_MANY, "horizontal"); |
| } |
| generateConstraint(fieldName, childField.getNextReference(), "LeftRight", left, |
| right, writer); |
| } else if (width != null) { |
| generateConstraint(fieldName, childField.getNextReference(), "LeftWidth", left, |
| width, writer); |
| } else { |
| writer.die(layerElem, ERR_PAIRING, "left", "right", "width"); |
| } |
| } else if (right != null) { |
| if (width != null) { |
| generateConstraint(fieldName, childField.getNextReference(), "RightWidth", right, |
| width, writer); |
| } else { |
| writer.die(layerElem, ERR_PAIRING, "right", "left", "width"); |
| } |
| } |
| |
| // Parse the vertical layout constraints. |
| String top = layerElem.consumeLengthAttribute("top"); |
| String bottom = layerElem.consumeLengthAttribute("bottom"); |
| String height = layerElem.consumeLengthAttribute("height"); |
| if (isNegative(height)) { |
| writer.die(layerElem, ERR_NEGATIVE_HEIGHT); |
| } |
| |
| if (top != null) { |
| if (bottom != null) { |
| if (height != null) { |
| writer.die(layerElem, ERR_TOO_MANY, "vertical"); |
| } |
| generateConstraint(fieldName, childField.getNextReference(), "TopBottom", top, |
| bottom, writer); |
| } else if (height != null) { |
| generateConstraint(fieldName, childField.getNextReference(), "TopHeight", top, |
| height, writer); |
| } else { |
| writer.die(layerElem, ERR_PAIRING, "top", "bottom", "height"); |
| } |
| } else if (bottom != null) { |
| if (height != null) { |
| generateConstraint(fieldName, childField.getNextReference(), "BottomHeight", bottom, |
| height, writer); |
| } else { |
| writer.die(layerElem, ERR_PAIRING, "bottom", "top", "height"); |
| } |
| } |
| } |
| } |
| |
| private void generateConstraint(String panelName, String widgetName, |
| String constraintName, String first, String second, UiBinderWriter writer) { |
| writer.addStatement("%s.setWidget%s(%s, %s, %s);", panelName, |
| constraintName, widgetName, first, second); |
| } |
| |
| private boolean isElementType(XMLElement parent, XMLElement child, String type) { |
| return parent.getNamespaceUri().equals(child.getNamespaceUri()) |
| && type.equals(child.getLocalName()); |
| } |
| |
| /** |
| * @return <code>true</code> if in given <code>value, unit</code> expression |
| * <code>value</code> part is obviously negative. |
| */ |
| private boolean isNegative(String expression) { |
| if (expression != null && expression.length() >= 2 |
| && expression.charAt(0) == '-') { |
| char secondChar = expression.charAt(1); |
| return Character.isDigit(secondChar); |
| } |
| return false; |
| } |
| } |