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- /*
- * Copyright 1999-2004 The Apache Software Foundation.
- *
- * 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.
- */
-
- /* $Id$ */
-
- package org.apache.fop.area;
-
- // FOP
- import org.apache.fop.render.Renderer;
-
- // Java
- import java.util.List;
- import java.util.Iterator;
-
- /**
- * This uses the store pages model to store the pages
- * each page is either rendered if ready or prepared
- * for later rendering.
- * Once a page is rendered it is cleared to release the
- * contents but the PageViewport is retained. So even
- * though the pages are stored the contents are discarded.
- */
- public class RenderPagesModel extends StorePagesModel {
- /**
- * The renderer that will render the pages.
- */
- protected Renderer renderer;
- /**
- * Pages that have been prepared but not rendered yet.
- */
- protected List prepared = new java.util.ArrayList();
- private List pendingExt = new java.util.ArrayList();
- private List endDocExt = new java.util.ArrayList();
-
- /**
- * Create a new render pages model with the given renderer.
- * @param rend the renderer to render pages to
- */
- public RenderPagesModel(Renderer rend) {
- renderer = rend;
- }
-
- /**
- * Start a new page sequence.
- * This tells the renderer that a new page sequence has
- * started with the given title.
- * @param title the title of the new page sequence
- */
- public void startPageSequence(Title title) {
- super.startPageSequence(title);
- renderer.startPageSequence(title);
- }
-
- /**
- * Add a page to the render page model.
- * If the page is finished it can be rendered immediately.
- * If the page needs resolving then if the renderer supports
- * out of order rendering it can prepare the page. Otherwise
- * the page is added to a queue.
- * @param page the page to add to the model
- */
- public void addPage(PageViewport page) {
- super.addPage(page);
-
- // for links the renderer needs to prepare the page
- // it is more appropriate to do this after queued pages but
- // it will mean that the renderer has not prepared a page that
- // could be referenced
- boolean done = renderer.supportsOutOfOrder() && page.isResolved();
- if (done) {
- try {
- renderer.renderPage(page);
- } catch (Exception e) {
- // use error handler to handle this FOP or IO Exception
- e.printStackTrace();
- }
- page.clear();
- } else {
- preparePage(page);
- }
-
-
- // check prepared pages
- boolean cont = checkPreparedPages(page);
-
- if (cont) {
- renderExtensions(pendingExt);
- pendingExt.clear();
- }
- }
-
- /**
- * Check prepared pages
- *
- * @param newpage the new page being added
- * @return true if the current page should be rendered
- * false if the renderer doesn't support out of order
- * rendering and there are pending pages
- */
- protected boolean checkPreparedPages(PageViewport newpage) {
- for (Iterator iter = prepared.iterator(); iter.hasNext();) {
- PageViewport p = (PageViewport)iter.next();
- if (p.isResolved()) {
- try {
- renderer.renderPage(p);
- } catch (Exception e) {
- // use error handler to handle this FOP or IO Exception
- e.printStackTrace();
- }
- p.clear();
- iter.remove();
- } else {
- // if keeping order then stop at first page not resolved
- if (!renderer.supportsOutOfOrder()) {
- break;
- }
- }
- }
- return renderer.supportsOutOfOrder() || prepared.isEmpty();
- }
-
- /**
- * Prepare a page.
- * An unresolved page can be prepared if the renderer supports
- * it and the page will be rendered later.
- * @param page the page to prepare
- */
- protected void preparePage(PageViewport page) {
- if (renderer.supportsOutOfOrder()) {
- renderer.preparePage(page);
- }
- prepared.add(page);
- }
-
- /**
- * Add an extension to this model.
- * If handle immediately then send directly to the renderer.
- * The after page ones are handled after the next page is added.
- * End of document extensions are added to a list to be
- * handled at the end.
- * @param ext the extension
- * @param when when to render the extension
- */
- public void addExtension(TreeExt ext, int when) {
- switch(when) {
- case TreeExt.IMMEDIATELY:
- renderer.renderExtension(ext);
- break;
- case TreeExt.AFTER_PAGE:
- pendingExt.add(ext);
- break;
- case TreeExt.END_OF_DOC:
- endDocExt.add(ext);
- break;
- }
- }
-
- private void renderExtensions(List list) {
- for (int count = 0; count < list.size(); count++) {
- TreeExt ext = (TreeExt)list.get(count);
- renderer.renderExtension(ext);
- }
- }
-
- /**
- * End the document. Render any end document extensions.
- */
- public void endDocument() {
- // render any pages that had unresolved ids
- checkPreparedPages(null);
-
- renderExtensions(pendingExt);
- pendingExt.clear();
-
- renderExtensions(endDocExt);
- }
- }
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