GWT: Change padding of tree rows?_问答_开发者_运维开发者技术经验分享

A GWT tree looks roughly like this:

<div class="gwt-Tree">
    <div style="padding-top: 3px; padding-right: 3px;
                padding-bottom: 3px; margin-left: 0px;
                padding-left: 23px;">
         <div style="display:inline;" class="gwt-TreeItem">
              <table>
                   ...
              </table>
         </div>
    </div>
开发者_高级运维    <div ...>
    </div>
    ...
</div>

My question is: how should I change the padding of the individual tree rows? I suppose I could do something along the lines of setting CSS rules for .gwt-Tree > div but that seems hacky. Is there a more elegant way?

Resolution: Apparently there is NOT a more elegant way. Here is what we did, FWIW:

 .gwt-Tree > div:first-child { 
      width: 0px !important; 
      height: 0px !important; 
      margin: 0px !important; 
      padding: 0px !important; 
 } 

 .gwt-Tree > div {
      padding: 0px 5px !important;
 }

 .gwt-Tree > div[hidefocus=true] {
      width: 0px !important;
      height: 0px !important;

      margin: 0px !important;
      padding: 0px !important;
 }

I had the same problem and tried as well to solve it with CSS, but no luck. Finally I managed to change the top and bottom padding in the java code:

/**
    * handle top and bottom padding issue of leafs the grandparent DOM element (div) has disturbing top and bottom
    * padding of 3px, which is changed here to 0px
    * 
    * @param uiObject
    *           uiObject which is a leaf in the tree
    */
   private static void correctStyle(final UIObject uiObject) {
      if (uiObject instanceof TreeItem) {
         if (uiObject != null && uiObject.getElement() != null) {
            Element element = uiObject.getElement();
            element.getStyle().setPaddingBottom(0, Unit.PX);
            element.getStyle().setPaddingTop(0, Unit.PX);
         }
      } else {
         if (uiObject != null && uiObject.getElement() != null && uiObject.getElement().getParentElement() != null
               && uiObject.getElement().getParentElement().getParentElement() != null
               && uiObject.getElement().getParentElement().getParentElement().getStyle() != null) {
            Element element = uiObject.getElement().getParentElement().getParentElement();
            element.getStyle().setPaddingBottom(0, Unit.PX);
            element.getStyle().setPaddingTop(0, Unit.PX);
         }
      }
   }

I use the method like this in the code:

Anchor fileDownloadLink = new Anchor();
fileDownloadLink.setStyleName(ViewConstants.STYLE_LINK_FILE_DOWNLOAD);
fileDownloadLink.setText(subSubStructure.getName());
fileDownloadLink.setHref(ViewConstants.HREF_DOWNLOAD_FILE_EXTRACTED_DATA + subSubStructure.getPath());
treeItem.addItem(fileDownloadLink);
StyleCorrector.correctStyle(fileDownloadLink);

You could do it like this:

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Test</title>
    <style type="text/css">
    .gwt-Tree {background:green;}
    .gwt-Tree div {padding-top: 3px; padding-right: 3px;padding-bottom: 3px; margin-left: 0px;padding-left: 23px;background:gray;}
    .gwt-Tree div .gwt-TreeItem {padding:0;margin:0;background:red;color:#fff;}
    </style> 
</head>
<body>
<div class="gwt-Tree">
    <div>
         <div class="gwt-TreeItem">
            random
         </div>
    </div>
    <div>
         <div class="gwt-TreeItem">
            random
         </div>
    </div>
</div> 
</body>
</html>

Note that .gwt-Tree div will affect all child divs, so you have to reset them back to the style you want with .gwt-Tree div .gwtTreeItem.

About the "hacky >" you said - > selector is supported in all browsers except for IE6 who won't recognize it.

I took a look at the GWT Tree Documentation. The CSS style rules for the tree and tree items are

CSS Style Rules

.gwt-Tree
the tree itself

.gwt-Tree .gwt-TreeItem
a tree item

.gwt-Tree .gwt-TreeItem-selected
a selected tree item

You probably want to add the padding to .gwt-Tree .gwt-TreeItem and to .gwt-Tree .gwt-TreeItem-selected