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Difference between revisions of "Menu Contributions/Update checked state"
(→Update the toolbar item checked state) |
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= Update the toolbar item checked state = | = Update the toolbar item checked state = | ||
| − | The active handler can update any UI elements registered against the its command. | + | The active handler can update any UI elements registered against the its command. It does this by requesting the <tt>ICommandService</tt> to refresh any registered <tt>UIElement</tt>s. |
| − | As a handler becomes active and implement IElementUpdater like org.eclipse.ui.tests.menus.ToggleContextHandler, the command service calls <code>public void updateElement(UIElement element, Map parameters)</code> for every UIElement registered against the command. | + | As a handler becomes active and implement <tt>IElementUpdater</tt> like <tt>org.eclipse.ui.tests.menus.ToggleContextHandler</tt>, the command service calls <code>public void updateElement(UIElement element, Map parameters)</code> for every <tt>UIElement</tt> registered against the command. |
| − | + | <source lang="java"> | |
| − | + | public class ToggleContextHandler extends AbstractHandler implements | |
| − | + | IElementUpdater { | |
| − | + | private static final String TOGGLE_ID = "toggleContext.contextId"; | |
| − | + | // ... | |
| − | + | public void updateElement(UIElement element, Map parameters) { | |
| − | + | // the checked state depends on if we have an activation for that | |
| − | + | // context ID or not | |
| − | + | String contextId = (String) parameters.get(TOGGLE_ID); | |
| − | + | element.setChecked(contextActivations.get(contextId) != null); | |
| − | + | } | |
| + | } | ||
| + | </source> | ||
Latest revision as of 18:29, 7 November 2011
Update the toolbar item checked state
The active handler can update any UI elements registered against the its command. It does this by requesting the ICommandService to refresh any registered UIElements.
As a handler becomes active and implement IElementUpdater like org.eclipse.ui.tests.menus.ToggleContextHandler, the command service calls public void updateElement(UIElement element, Map parameters) for every UIElement registered against the command.
public class ToggleContextHandler extends AbstractHandler implements IElementUpdater { private static final String TOGGLE_ID = "toggleContext.contextId"; // ... public void updateElement(UIElement element, Map parameters) { // the checked state depends on if we have an activation for that // context ID or not String contextId = (String) parameters.get(TOGGLE_ID); element.setChecked(contextActivations.get(contextId) != null); } }