UpdateRoutesListAction.java

package net.bitpot.railways.actions;

import com.intellij.openapi.actionSystem.AnAction;
import com.intellij.openapi.actionSystem.AnActionEvent;
import com.intellij.openapi.actionSystem.Presentation;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.project.Project;
import net.bitpot.railways.gui.RailwaysIcons;
import net.bitpot.railways.routesView.RoutesManager;
import net.bitpot.railways.routesView.RoutesView;
import org.jetbrains.annotations.NotNull;

/**
 * Updates the list of routes.
 */
public class UpdateRoutesListAction extends AnAction {
    @SuppressWarnings("unused")
    private static Logger log = Logger.getInstance(UpdateRoutesListAction.class.getName());

    // Presentation is stored to be used when asynchronous action icon needs to be updated.
    private static Presentation updateBtnPresentation = null;


    @Override
    public void actionPerformed(@NotNull AnActionEvent e) {
        Project project = e.getProject();
        if (project == null) return;

        RoutesManager rm = RoutesView.getInstance(project).getCurrentRoutesManager();
        if (rm == null) return;

        if (rm.isUpdating())
            rm.cancelRoutesUpdate();
        else {
            if (rm.updateRouteList()) {
                updateBtnPresentation = e.getPresentation();
                updatePresentation(project, e.getPresentation());
            }
        }
    }


    public static void updateIcon(@NotNull Project project) {
        if (updateBtnPresentation != null)
            updatePresentation(project, updateBtnPresentation);
    }


    private static void updatePresentation(@NotNull Project project,
                                           Presentation presentation) {
        RoutesManager rm = RoutesView.getInstance(project).getCurrentRoutesManager();
        if (rm == null) return;

        if (rm.isUpdating()) {
            presentation.setIcon(RailwaysIcons.SUSPEND);
            presentation.setText("Cancel route list update");
            presentation.setDescription("Stops updating the list of routes");
        } else {
            presentation.setIcon(RailwaysIcons.UPDATE);
            presentation.setText("Update route list");
            presentation.setDescription("Update the list of routes");
        }
    }


    /**
     * Updates the state of the action. Default implementation does nothing.
     * Override this method to provide the ability to dynamically change action's
     * state and(or) presentation depending on the context (For example
     * when your action state depends on the selection you can check for
     * selection and change the state accordingly).
     * This method can be called frequently, for instance, if an action is added to a toolbar,
     * it will be updated twice a second. This means that this method is supposed to work really fast,
     * no real work should be done at this phase. For example, checking selection in a tree or a list,
     * is considered valid, but working with a file system is not. If you cannot understand the state of
     * the action fast you should do it in the {@link #actionPerformed(AnActionEvent)} method and notify
     * the user that action cannot be executed if it's the case.
     *
     * @param e Carries information on the invocation place and data available
     */
    @Override
    public void update(@NotNull AnActionEvent e) {
        Project project = e.getProject();
        if (project == null) return;

        updatePresentation(project, e.getPresentation());
    }
}