org.ofdrw.layout.engine.render.CanvasRender Maven / Gradle / Ivy
package org.ofdrw.layout.engine.render;
import org.ofdrw.core.basicStructure.pageObj.layer.block.CT_PageBlock;
import org.ofdrw.core.basicType.ST_Box;
import org.ofdrw.core.basicType.ST_Loc;
import org.ofdrw.layout.element.Div;
import org.ofdrw.layout.element.canvas.Canvas;
import org.ofdrw.layout.element.canvas.DrawContext;
import org.ofdrw.layout.element.canvas.Drawer;
import org.ofdrw.layout.engine.ResManager;
import java.io.IOException;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Canvas 渲染器
*
* {@link org.ofdrw.layout.element.canvas.Canvas} 的渲染器
*
* @author 权观宇
* @since 2020-05-01 17:44:41
*/
public class CanvasRender implements Processor {
/**
* 执行Canvas 渲染器
*
* @param layer 将要渲染到的图层
* @param resManager 资源管理器
* @param canvas canvas对象
* @param maxUnitID 最大ID
* @throws RenderException 渲染发生错误
*/
public static void render(CT_PageBlock layer,
ResManager resManager,
Canvas canvas,
AtomicInteger maxUnitID) throws RenderException {
// 获取绘制器
Drawer drawer = canvas.getDrawer();
if (drawer == null) {
return;
}
// 尝试获取Canvas中的页块
CT_PageBlock block = canvas.getPreferBlock();
if (block == null) {
// 若页块为空，则创建新的页块
block = new CT_PageBlock();
block.setObjID(maxUnitID.incrementAndGet());
canvas.setPreferBlock(block);
// 添加到图层中
layer.addPageBlock(block);
}
// 根据盒式模型计算出加上 外边距、边框、内边距
ST_Box boundary = new ST_Box(
canvas.getX() + canvas.getMarginLeft() + canvas.getBorderLeft() + canvas.getPaddingLeft(),
canvas.getY() + canvas.getMarginTop() + canvas.getBorderTop() + canvas.getPaddingTop(),
canvas.getWidth(),
canvas.getHeight());
// 构建上下文
try (DrawContext ctx = new DrawContext(block, boundary, maxUnitID, resManager)) {
// 执行绘制工作
drawer.draw(ctx);
} catch (IOException e) {
throw new RenderException("Canvas绘制过程中发生异常", e);
}
}
/**
* 渲染Canvas对象
*
* @param pageLoc 页面在虚拟容器中绝对路径。
* @param layer 图片将要放置的图层
* @param resManager 资源管理器
* @param e Canvas对象
* @param maxUnitID 最大元素ID提供器
* @throws RenderException 渲染发生错误
*/
@Override
public void render(ST_Loc pageLoc, CT_PageBlock layer, ResManager resManager, Div e, AtomicInteger maxUnitID)throws RenderException {
if (e instanceof Canvas) {
render(layer, resManager, (Canvas) e, maxUnitID);
}
}
}