如何在RCP程序中添加一个banner栏
前言：这段时间还算比较空闲，我准备把过去做过的有些形形色色，甚至有些奇怪的研究总结一下，也许刚好有人用的着也不一定，不枉为之抓耳挠腮的时光和浪费的电力。以前有个客户提出要在RCP程序中添加一个banner栏，研究了很久才搞定。代码是基于eclipse4.3.2的。
先看一下效果预览：
为了添加一个banner栏，我们必须重写RCP程序最外层的layout类，即TrimmedPartLayout.java。这个layout类是用来控制menu，toolbar等最基本的layout布局的。我们写一个CustomTrimmedPartLayout 类，继承自TrimmedPartLayout：
public class CustomTrimmedPartLayout extends TrimmedPartLayout { public Composite banner; /** * This layout is used to support parts that want trim for their containing * composites. * * @param trimOwner */ public CustomTrimmedPartLayout(Composite parent) { super(parent); banner= new Composite(parent, SWT.NONE); GridLayout gridLayout = new GridLayout(1, false); gridLayout.horizontalSpacing=0; gridLayout.verticalSpacing = 0; gridLayout.marginHeight = 0; gridLayout.marginWidth = 0
; banner.setLayout(gridLayout); //banner.setLayoutData(new GridData(GridData.FILL_BOTH)); } protected void layout(Composite composite, boolean flushCache) { Rectangle ca = composite.getClientArea(); Rectangle caRect = new Rectangle(ca.x, ca.y, ca.width, ca.height);// 'banner' spans the entire area if (banner != null && banner.isVisible() ) { Point bannerSize = banner.computeSize(caRect.width, SWT.DEFAULT, true); // Don't layout unless we've changed Rectangle newBounds = new Rectangle(caRect.x, caRect.y, bannerSize.x, bannerSize.y); caRect.y += bannerSize.y; caRect.height -= bannerSize.y; if (!
newBounds.equals(banner.getBounds())) { banner.setBounds(newBounds); } } // 'Top' spans the entire area if (top != null && top.isVisible()) { Point topSize = top.computeSize(caRect.width, SWT.DEFAULT, true); // Don't layout unless we've changed Rectangle newBounds = new Rectangle(caRect.x, caRect.y, caRect.width, topSize.y); if (!newBounds.equals(top.getBounds())) { top.setBounds(newBounds); } caRect.y += topSize.y; caRect.height -= topSize.y; } // Include the gutter whether there is a top area or not. caRect.y += gutterTop; caRect.height -= gutterTop; // 'Bottom' spans the entire area if (bottom != null && bottom.isVisible()) { Point bottomSize = bottom.computeSize(caRect.width, SWT.DEFAULT, true); caRect.height -= bottomSize.y; // Don't layout unless we've changed Rectangle newBounds = new Rectangle(caRect.x, caRect.y + caRect.height, caRect.width, bottomSize.y); if (!newBounds.equals(bottom.getBounds())) { bottom.setBounds(newBounds); } } caRect.height -= gutterBottom; // 'Left' spans between 'top' and 'bottom' if (left != null && left.isVisible()) { Point leftSize = left.computeSize(SWT.DEFAULT, caRect.height, true); caRect.x += leftSize.x; caRect.width -= leftSize.x; // Don't layout unless we've changed Rectangle newBounds = new Rectangle(caRect.x - leftSize.x, caRect.y, leftSize.x, caRect.height); if (!newBounds.equals(left.getBounds())) { left.setBounds(newBounds); } } caRect.x += gutterLeft; caRect.width -= gutterLeft; // 'Right' spans between 'top' and 'bottom' if (right != null && right.isVisible()) { Point rightSize = right.computeSize(SWT.DEFAULT, caRect.height, true); caRect.width -= rightSize.x; // Don't layout unless we've changed Rectangle newBounds = new Rectangle(caRect.x + caRect.width, caRect.y, rightSize.x, caRect.height); if (!newBounds.equals(right.getBounds())) { right.setBounds(newBounds); } } caRect.width -= gutterRight; // Don't layout unless we've changed if (!caRect.equals(clientArea.getBounds())) { clientArea.setBounds(caRect); } } }
如果我们希望Banner放在工具栏下面，而不是上面，只要稍微修改一下代码的位置
public class CustomTrimmedPartLayout extends TrimmedPartLayout { public Composite banner; /** * This layout is used to support parts that want trim for their containing * composites. * * @param trimOwner */ public CustomTrimmedPartLayout(Composite parent) { super(parent); banner= new Composite(parent, SWT.NONE); GridLayout gridLayout = new GridLayout(1, false); gridLayout.horizontalSpacing=0; gridLayout.verticalSpacing = 0; gridLayout.marginHeight = 0; gridLayout.marginWidth = 0
; banner.setLayout(gridLayout); //banner.setLayoutData(new GridData(GridData.FILL_BOTH)); } protected void layout(Composite composite, boolean flushCache) { Rectangle ca = composite.getClientArea(); Rectangle caRect = new Rectangle(ca.x, ca.y, ca.width, ca.height); // 'Top' spans the entire area if (top != null && top.isVisible()) { Point topSize = top.computeSize(caRect.width, SWT.DEFAULT, true); // Don't layout unless we've changed Rectangle newBounds = new Rectangle(caRect.x, caRect.y, caRect.width, topSize.y); if (!newBounds.equals(top.getBounds())) { top.setBounds(newBounds); } caRect.y += topSize.y; caRect.height -= topSize.y; }// 'banner' spans the entire area if (banner != null && banner.isVisible()) { Point bannerSize = banner.computeSize(caRect.width, SWT.DEFAULT, true); // Don't layout unless we've changed Rectangle newBounds = new Rectangle(caRect.x, caRect.y, bannerSize.x, bannerSize.y); caRect.y += bannerSize.y; caRect.height -= bannerSize.y; if (!
newBounds.equals(banner.getBounds())) { banner.setBounds(newBounds); } } // Include the gutter whether there is a top area or not. caRect.y += gutterTop; caRect.height -= gutterTop; // 'Bottom' spans the entire area if (bottom != null && bottom.isVisible()) { Point bottomSize = bottom.computeSize(caRect.width, SWT.DEFAULT, true); caRect.height -= bottomSize.y; // Don't layout unless we've changed Rectangle newBounds = new Rectangle(caRect.x, caRect.y + caRect.height, caRect.width, bottomSize.y); if (!newBounds.equals(bottom.getBounds())) { bottom.setBounds(newBounds); } } caRect.height -= gutterBottom; // 'Left' spans between 'top' and 'bottom' if (left != null && left.isVisible()) { Point leftSize = left.computeSize(SWT.DEFAULT, caRect.height, true); caRect.x += leftSize.x; caRect.width -= leftSize.x; // Don't layout unless we've changed Rectangle newBounds = new Rectangle(caRect.x - leftSize.x, caRect.y, leftSize.x, caRect.height); if (!newBounds.equals(left.getBounds())) { left.setBounds(newBounds); } } caRect.x += gutterLeft; caRect.width -= gutterLeft; // 'Right' spans between 'top' and 'bottom' if (right != null && right.isVisible()) { Point rightSize = right.computeSize(SWT.DEFAULT, caRect.height, true); caRect.width -= rightSize.x; // Don't layout unless we've changed Rectangle newBounds = new Rectangle(caRect.x + caRect.width, caRect.y, rightSize.x, caRect.height); if (!newBounds.equals(right.getBounds())) { right.setBounds(newBounds); } } caRect.width -= gutterRight; // Don't layout unless we've changed if (!caRect.equals(clientArea.getBounds())) { clientArea.setBounds(caRect); } } }
最后，我们需要把shell加载的layout从TrimmedPartLayout替换为CustomTrimmedPartLayout。
在ApplicationWorkbenchWindowAdvisor 的preWindowOpen中添加如下代码：
public class ApplicationWorkbenchWindowAdvisor extends WorkbenchWindowAdvisor { ... public void preWindowOpen() { IWorkbenchWindowConfigurer configurer = getWindowConfigurer(); configurer.setInitialSize(new Point(600, 400)); configurer.setShowCoolBar(true); configurer.setShowPerspectiveBar(true); configurer.setShowStatusLine(true); configurer.setShowProgressIndicator(false); configurer.setShowFastViewBars(false); IWorkbenchWindow workbenchWindow= configurer.getWindow(); workbenchWindow= configurer.getWindow(); Shell shell= workbenchWindow.getShell(); TrimmedPartLayout layout = (TrimmedPartLayout)shell.getLayout(); CustomTrimmedPartLayout customLayout = new CustomTrimmedPartLayout(layout.clientArea.getParent()); customLayout.clientArea =
layout.clientArea;
shell.setLayout(customLayout);
Label bannerLabel
= new Label(customLayout.banner, SWT.SIMPLE|SWT.CENTER); customLayout.banner.setBackground(…); GridData gridData = new GridData(SWT.FILL, SWT.FILL, true, true); bannerLabel.setLayoutData(gridData); Image image =
Activator.getImageDescriptor(bannerExtensionPoint.getImage()).createImage();
bannerLabel.setImage(image);
}
....
}
其中 ---
标记为绿色的代码是用来替换Layout类的
标记为蓝色的代码是用来在banner中创建一个Label，并加载一张作为banner的图片。
