Java tutorial
/* * Copyright 2013 Julien Dramaix. * * 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.resources.gss; import static com.google.common.css.compiler.passes.PassUtil.ALTERNATE; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableList.Builder; import com.google.common.collect.Lists; import com.google.common.css.SourceCodeLocation; import com.google.common.css.compiler.ast.CssCommentNode; import com.google.common.css.compiler.ast.CssCompilerPass; import com.google.common.css.compiler.ast.CssDeclarationNode; import com.google.common.css.compiler.ast.CssFunctionArgumentsNode; import com.google.common.css.compiler.ast.CssFunctionNode; import com.google.common.css.compiler.ast.CssFunctionNode.Function; import com.google.common.css.compiler.ast.CssLiteralNode; import com.google.common.css.compiler.ast.CssPropertyNode; import com.google.common.css.compiler.ast.CssPropertyValueNode; import com.google.common.css.compiler.ast.CssValueNode; import com.google.common.css.compiler.ast.DefaultTreeVisitor; import com.google.common.css.compiler.ast.ErrorManager; import com.google.common.css.compiler.ast.GssError; import com.google.common.css.compiler.ast.MutatingVisitController; import com.google.gwt.core.ext.typeinfo.JClassType; import com.google.gwt.core.ext.typeinfo.JMethod; import com.google.gwt.core.ext.typeinfo.NotFoundException; import com.google.gwt.resources.client.ImageResource; import com.google.gwt.resources.client.ImageResource.ImageOptions; import com.google.gwt.resources.client.ImageResource.RepeatStyle; import com.google.gwt.resources.ext.ResourceContext; import com.google.gwt.resources.ext.ResourceGeneratorUtil; import com.google.gwt.resources.gss.ast.CssDotPathNode; import java.util.List; public class ImageSpriteCreator extends DefaultTreeVisitor implements CssCompilerPass { private static final String SPRITE_PROPERTY_NAME = "gwt-sprite"; private final MutatingVisitController visitController; private final ErrorManager errorManager; private final ResourceContext context; private final JClassType imageResourceType; private final String resourceThisPrefix; public ImageSpriteCreator(MutatingVisitController visitController, ResourceContext context, ErrorManager errorManager) { this.visitController = visitController; this.errorManager = errorManager; this.context = context; this.imageResourceType = context.getGeneratorContext().getTypeOracle() .findType(ImageResource.class.getName()); this.resourceThisPrefix = context.getImplementationSimpleSourceName() + ".this"; } @Override public boolean enterDeclaration(CssDeclarationNode declaration) { String propertyName = declaration.getPropertyName().getPropertyName(); if (SPRITE_PROPERTY_NAME.equals(propertyName)) { createSprite(declaration); return true; } return super.enterDeclaration(declaration); } @Override public void runPass() { assert imageResourceType != null; visitController.startVisit(this); } private CssDeclarationNode buildBackgroundDeclaration(String imageResource, String repeatText, SourceCodeLocation location) { // build the url function CssFunctionNode urlFunction = new CssFunctionNode(Function.byName("url"), location); CssDotPathNode imageUrl = new CssDotPathNode(resourceThisPrefix, imageResource + ".getSafeUri" + ".asString", null, null, location); CssFunctionArgumentsNode urlFunctionArguments = new CssFunctionArgumentsNode(); urlFunctionArguments.addChildToBack(imageUrl); urlFunction.setArguments(urlFunctionArguments); // build left offset CssDotPathNode left = new CssDotPathNode(resourceThisPrefix, imageResource + ".getLeft", "-", "px", location); // build top offset CssDotPathNode top = new CssDotPathNode(resourceThisPrefix, imageResource + ".getTop", "-", "px", location); // build repeat CssLiteralNode repeat = new CssLiteralNode(repeatText, location); CssPropertyNode propertyNode = new CssPropertyNode("background", location); CssPropertyValueNode propertyValueNode = new CssPropertyValueNode( ImmutableList.of(urlFunction, left, top, repeat)); propertyValueNode.setSourceCodeLocation(location); return createDeclarationNode(propertyNode, propertyValueNode, location, true); } private CssDeclarationNode buildHeightDeclaration(String imageResource, SourceCodeLocation location) { CssPropertyNode propertyNode = new CssPropertyNode("height", location); CssValueNode valueNode = new CssDotPathNode(resourceThisPrefix, imageResource + ".getHeight", null, "px", location); CssPropertyValueNode propertyValueNode = new CssPropertyValueNode(ImmutableList.of(valueNode)); return createDeclarationNode(propertyNode, propertyValueNode, location, true); } private CssDeclarationNode buildOverflowDeclaration(SourceCodeLocation location) { CssPropertyNode propertyNode = new CssPropertyNode("overflow", location); CssValueNode valueNode = new CssLiteralNode("hidden", location); CssPropertyValueNode propertyValueNode = new CssPropertyValueNode(ImmutableList.of(valueNode)); return createDeclarationNode(propertyNode, propertyValueNode, location, true); } private CssDeclarationNode buildWidthDeclaration(String imageResource, SourceCodeLocation location) { CssPropertyNode propertyNode = new CssPropertyNode("width", location); CssValueNode valueNode = new CssDotPathNode(resourceThisPrefix, imageResource + ".getWidth", null, "px", location); CssPropertyValueNode propertyValueNode = new CssPropertyValueNode(ImmutableList.of(valueNode)); return createDeclarationNode(propertyNode, propertyValueNode, location, true); } private void createSprite(CssDeclarationNode declaration) { List<CssValueNode> valuesNodes = declaration.getPropertyValue().getChildren(); if (valuesNodes.size() != 1) { errorManager.report(new GssError(SPRITE_PROPERTY_NAME + " must have exactly one value", declaration.getSourceCodeLocation())); } String imageResource = valuesNodes.get(0).getValue(); JMethod imageMethod; try { imageMethod = ResourceGeneratorUtil.getMethodByPath(context.getClientBundleType(), getPathElement(imageResource), imageResourceType); } catch (NotFoundException e) { errorManager.report(new GssError( "Unable to find ImageResource method " + imageResource + " in " + context.getClientBundleType().getQualifiedSourceName() + " : " + e.getMessage(), declaration.getSourceCodeLocation())); return; } ImageOptions options = imageMethod.getAnnotation(ImageOptions.class); RepeatStyle repeatStyle = options != null ? options.repeatStyle() : RepeatStyle.None; Builder<CssDeclarationNode> listBuilder = ImmutableList.builder(); SourceCodeLocation sourceCodeLocation = declaration.getSourceCodeLocation(); String repeatText; switch (repeatStyle) { case None: repeatText = " no-repeat"; listBuilder.add(buildHeightDeclaration(imageResource, sourceCodeLocation)); listBuilder.add(buildWidthDeclaration(imageResource, sourceCodeLocation)); break; case Horizontal: repeatText = " repeat-x"; listBuilder.add(buildHeightDeclaration(imageResource, sourceCodeLocation)); break; case Vertical: repeatText = " repeat-y"; listBuilder.add(buildWidthDeclaration(imageResource, sourceCodeLocation)); break; case Both: repeatText = " repeat"; break; default: errorManager.report(new GssError("Unknown repeatStyle " + repeatStyle, sourceCodeLocation)); return; } listBuilder.add(buildOverflowDeclaration(sourceCodeLocation)); listBuilder.add(buildBackgroundDeclaration(imageResource, repeatText, sourceCodeLocation)); visitController.replaceCurrentBlockChildWith(listBuilder.build(), false); } private List<String> getPathElement(String imageResourcePath) { return Lists.newArrayList(imageResourcePath.split("\\.")); } private CssDeclarationNode createDeclarationNode(CssPropertyNode propertyNode, CssPropertyValueNode propertyValueNode, SourceCodeLocation location, boolean useAlternate) { CssDeclarationNode replaceNode = new CssDeclarationNode(propertyNode, propertyValueNode); replaceNode.setSourceCodeLocation(location); if (useAlternate) { replaceNode.setComments(ImmutableList.of(new CssCommentNode(ALTERNATE, location))); } return replaceNode; } }