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| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
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| // to you under the Apache License, Version 2.0 (the |
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| // http://www.apache.org/licenses/LICENSE-2.0 |
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| |
| = DevFaqWindowsTopComponentLookup |
| :jbake-type: wiki |
| :jbake-tags: wiki, devfaq, needsreview |
| :jbake-status: published |
| :keywords: Apache NetBeans wiki DevFaqWindowsTopComponentLookup |
| :description: Apache NetBeans wiki DevFaqWindowsTopComponentLookup |
| :toc: left |
| :toc-title: |
| :syntax: true |
| |
| === Why does `TopComponent` have a `getLookup()` method? What is it for? |
| |
| The windowing system is what manages link:DevFaqTrackGlobalSelection.asciidoc[global selection]. In olden times, selection meant the activated link:DevFaqWhatIsANode.asciidoc[Node]. |
| |
| In modern NetBeans, the global selection is really whatever objects are in the focused `link:DevFaqWindowsTopComponent.asciidoc[TopComponent]`'s link:DevFaqLookup.asciidoc[Lookup]. It so happens that most standard TopComponents display `link:DevFaqWhatIsANode.asciidoc[Node]`s - so for most `TopComponent`s, the component's `Lookup` is just proxying the `Lookup` of the selected Node. |
| |
| Rather than thinking of the selection as some specific object or Node, it is more useful to think of it as a grab bag of stuff provided by whatever component happens to have focus. If you use `link:DevFaqTrackGlobalSelection.asciidoc[Utilities.actionsGlobalContext()]`, you do not have to track all the different grab-bags of stuff provided by different components - you can get one grab bag of stuff which whose content will simply change (notifying you in the process) when focus moves to a different component. |
| |
| So the `TopComponent`'s `Lookup` is a way to provide your particular grab bag of stuff - it can be the lookup of a `Node` if you want, or it can be/contain whatever else or in addition you'd like to put there. |
| |
| === Apache Migration Information |
| |
| The content in this page was kindly donated by Oracle Corp. to the |
| Apache Software Foundation. |
| |
| This page was exported from link:http://wiki.netbeans.org/DevFaqWindowsTopComponentLookup[http://wiki.netbeans.org/DevFaqWindowsTopComponentLookup] , |
| that was last modified by NetBeans user Admin |
| on 2009-11-06T16:06:27Z. |
| |
| |
| *NOTE:* This document was automatically converted to the AsciiDoc format on 2018-02-07, and needs to be reviewed. |
