Custom Context Menu

Overview

This section describes how to pop up a new customized context menu in a Spreadsheet like the image below:

The steps are simple:

1. Disable built-in context menu
2. Create your own context menu
3. Show custom context menu
4. Add application logic for context menu

Disable Built-in Context Menu

We should hide built-in context menu in order to show our customized one only.

Extracted from customContext.zul

	<window apply="org.zkoss.zss.essential.advanced.customization.CustomContextMenuComposer"
		width="100%" height="100%">
		<spreadsheet id="ss" width="100%" height="100%" showFormulabar="true"
			showContextMenu="false" showToolbar="true" showSheetbar="true" maxVisibleRows="100"
			maxVisibleColumns="20" src="/WEB-INF/books/blank.xlsx" />
	<!-- other components -->
	</window>

• Line 4: Specify showContextMenu="false" to hide built-in context menu.

Create Your Own Context Menu

Menupopup is the most suitable component to build a context menu.

Extracted from customContext.zul

			<menupopup id="myContext">
				<menuitem id="display" label="Display Information" />
				<menuitem id="open" label="Open Dialog" />
			</menupopup>

Show Custom Context Menu

We can listen CellMouseEvent to open our Menupopup.

package org.zkoss.zss.essential.advanced.customization;

import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.select.SelectorComposer;
import org.zkoss.zk.ui.select.annotation.*;
import org.zkoss.zss.ui.event.CellMouseEvent;
import org.zkoss.zul.Menupopup;

public class CustomContextMenuComposer extends SelectorComposer<Component> {

	@Wire
	private Menupopup myContext;

	@Listen("onCellRightClick = #ss")
	public void doContext(CellMouseEvent event) {
		myContext.open(event.getClientx(), event.getClienty());
		myContext.setAttribute("event", event);
	}
}

• Line 17: We could set CellMouseEvent as a Menupopup's attribute, and it could be used as a context information when implementing application logic for custom context menu.

Add Application Logic for Context Menu

You can implement the context menu's application logic in a separate composer which makes a system in good modularity and clear separation of responsibility.

		<div apply="org.zkoss.zss.essential.advanced.customization.MyContextMenuComposer">
			<menupopup id="myContext">
				<menuitem id="display" label="Display Information" />
				<menuitem id="open" label="Open Dialog" />
			</menupopup>
			<window id="dialog" title="My Dialog" mode="overlapped" closable="true"
				visible="false">
				Selection:
				<label id="content"></label>
			</window>
		</div>

The event listener displays the cell address of the cell a user right clicks on.

package org.zkoss.zss.essential.advanced.customization;

import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.event.*;
import org.zkoss.zk.ui.select.SelectorComposer;
import org.zkoss.zk.ui.select.annotation.*;
import org.zkoss.zk.ui.util.Clients;
import org.zkoss.zss.ui.Spreadsheet;
import org.zkoss.zss.ui.event.CellMouseEvent;
import org.zkoss.zul.*;

/**
 * @author Hawk
 *
 */
@SuppressWarnings("serial")
public class MyContextMenuComposer extends SelectorComposer<Component> {

	@Wire
	private Menupopup myContext;
	@Wire
	private Window dialog;
	@Wire("#dialog #content")
	private Label content;

	@Listen("onClick = #display")
	public void display(MouseEvent event) {
		CellMouseEvent cellMouseEvent = (CellMouseEvent)myContext.getAttribute("event");
		String message = "Selection: " + ((Spreadsheet)cellMouseEvent.getTarget()).getSelection().asString();
		Clients.showNotification(message);
	}

• Line 28: Get spreadsheet event from a component's attribute mentioned in previous section.

Invoke Built-in Menu Items

Although we hide the built-in context menu, you might want to reuse some items on it. The example code below demonstrates how to reuse "Clear" menu ite by passing an AuxActionEvent.

    @Listen("onClick = #clear")
    public void clear() throws Exception{
        CellMouseEvent cellMouseEvent = (CellMouseEvent)myContext.getAttribute("event");
        Spreadsheet ss = (Spreadsheet)cellMouseEvent.getTarget();
        AuxActionEvent event = new AuxActionEvent(Events.ON_AUX_ACTION, ss, ss.getSelectedSheet(), 
                AuxAction.CLEAR_ALL.toString(), ss.getSelection(), new HashMap());
        ((EventListener)ss.getUserActionManager()).onEvent(event);
    }

• Line 5: Each menu item has a corresponding constant in AuxAction. Pass the one you want to invoke.

All source code listed in this book is at Github.