How to initialize a toggle button's selection state in a view's toolbarin an eclipse rcp

I contributed a toggle-style toolbar contribution to my view in my RCP. Now, i want to know how to set the button's state (since it'开发者_如何学Pythons a toggle button) from my view. Or, at least, how to initialize it's state after the view is loaded (the toggle state can vary, its not static)

I tried to call from my view: getViewSite().getActionBars().getMenuManager().getItems() (returns an array of IContributionElements), which i iterated over and looked for the id. but the array only contains the models of the buttons, and there is no possibility to change the selection through these objects.

Help!!

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In the definition of your command (in plug-in.xml) that the CommandContributionItem calls into, define a state element like the following:

<state class="org.eclipse.ui.handlers.RegistryToggleState:true"
     id="org.eclipse.ui.commands.toggleState">
</state>

The above will initialise the state (toggle on/off) to either true/false depending on what you specify after the 'RegistryToggleState:' section.

To change the state within your code, first get the reference to your ParamterizedCommand like you did before. Then get the reference to the underyling Commandobject from the ParamaterizedCommmand and call:

 HandlerUtil.toggleCommandState(command);

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You can cast the item to ActionContributionItem, get the Action and call setChecked():

((ActionContributionItem) item).getAction().setChecked(true);

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To change the state to a specific one, try command.getState(), and state.setValue() methods, as shown in example:

private void refreshToggleButtonState(String commandID, String constantID) {

    ICommandService commandService = (ICommandService) PlatformUI.getWorkbench().getService(ICommandService.class);  
    Command command = commandService.getCommand(commandID);  

    State state = command.getState(RegistryToggleState.STATE_ID);
    if (Activator.getDefault().getPreferenceStore().getBoolean(constantID)) {
        state.setValue(Boolean.TRUE);
    } else {
        state.setValue(Boolean.FALSE);
    }
}

constantID is a preference store parameter, assuming you have one.