mainmenu.java

基于J2ME的手机地图客户端源码

package org.sreid.j2me.gmapviewer;

import java.util.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
import org.sreid.j2me.util.*;

public class MainMenu extends Form implements CommandListener {

	private final GMapViewer app;

	private static final String VIEW_MAP = "View map!";
	private static final String MAP_PIN_MENU = "Map pin menu";
	private static final String SEARCH_MENU = "Search menu";
	private static final String CACHE_INFO = "Cache info";
	private static final String VALIDATE_CACHE = "Validate cache";
	private static final String CLEAR_CACHE = "Clear cache";
	private static final String VIEW_LOG = "View error log";
	private static final String PREFERENCES = "Preferences";
	private static final String QUIT = "Quit";

	MainMenu(GMapViewer app) {
		super("GMapViewer");
		this.app = app;
		setCommandListener(this);
		addCommand(new Command(VIEW_MAP, Command.SCREEN, 1));
		addCommand(new Command(MAP_PIN_MENU, Command.SCREEN, 2));
		addCommand(new Command(SEARCH_MENU, Command.SCREEN, 2));
		addCommand(new Command(CACHE_INFO, Command.SCREEN, 3));
		addCommand(new Command(VALIDATE_CACHE, Command.SCREEN, 3));
		addCommand(new Command(CLEAR_CACHE, Command.SCREEN, 3));
		addCommand(new Command(VIEW_LOG, Command.SCREEN, 3));
		addCommand(new Command(PREFERENCES, Command.SCREEN, 3));
		addCommand(new Command(QUIT, Command.EXIT, 4));
		append("GMapViewer\nUnauthorized Google Maps viewer for J2ME.\n\nSelect an option from the menu.");
	}

	public void commandAction(Command c, Displayable d) {
		String cmd = c.getLabel();
		if (cmd.equals(VIEW_MAP)) {
			app.display.setCurrent(app.canvas);
		}
		else if (cmd.equals(MAP_PIN_MENU)) {
			app.mapPinMenu.cameFrom = this;
			app.mapPinMenu.loadList();
			app.display.setCurrent(app.mapPinMenu);
		}
		else if (cmd.equals(SEARCH_MENU)) {
			app.searchMenu.cameFrom = this;
			app.searchMenu.loadList();
			app.display.setCurrent(app.searchMenu);
		}
		else if (cmd.equals(CACHE_INFO)) {
			app.cache.cacheMaintenance(); // force update stats
			Alert a = new Alert("Cache info", app.cache.getInfo(), null, null);
			a.setTimeout(Alert.FOREVER);
			app.alert(a);
		}
		else if (cmd.equals(VALIDATE_CACHE)) {
			Dialog dlg = Dialog.createConfirmationDialog("Validating", "Validating map tile cache.\nPlease wait...", "", "");
			dlg.showOn(app, dlg); // cannot be dismissed
			app.display.callSerially(new Runnable() { public void run() {
				String memResult, rmsResult;
				try {
					memResult = app.cache.validateMem();
				}
				catch (Throwable e) {
					memResult = "Problem validating memory cache:\n" + e;
				}
				try {
					rmsResult = app.cache.validateRMS();
				}
				catch (Throwable e) {
					rmsResult = "Problem validating RMS cache:\n" + e;
				}
				Dialog dlg2 = Dialog.createConfirmationDialog("Validate complete", "Memory cache:\n" + memResult + "\nRMS cache:\n" + rmsResult, "OK", "");
				dlg2.showOn(app, MainMenu.this);
			}});
		}
		else if (cmd.equals(CLEAR_CACHE)) {
			final Dialog dlg = Dialog.createConfirmationDialog("Clear cache?", "Are you sure you want to clear the cache? All map tiles will have to be re-downloaded.", "OK", "Cancel");
			dlg.setCallback(new Runnable() { public void run() {
				if (dlg.getUserResponse() == Dialog.USER_CONFIRMED) {
					try {
						app.cache.clearCache();
						app.alert("Cache cleared", "Cleared tile cache and deleted record store.");
					}
					catch (Exception e) {
						app.exception("Error clearing the cache.", e);
					}
				}
			}});
			dlg.showOn(app, MainMenu.this);
		}
		else if (cmd.equals(VIEW_LOG)) {
			StringBuffer sb = new StringBuffer();
			for (Enumeration enum = app.log.elements() ; enum.hasMoreElements() ; ) {
				Object o = enum.nextElement();
				sb.append(o.toString());
				sb.append('\n');
			}
			if (sb.length() == 0) sb.append("No events logged.\nAll is well in GMapViewer land.");
			Dialog dlg = Dialog.createConfirmationDialog("Error log", sb.toString(), "OK", "");
			dlg.showOn(app);
		}
		else if (cmd.equals(PREFERENCES)) {
			app.display.setCurrent(app.prefsEditor);
		}
		else if (cmd.equals(QUIT)) {
			app.quit();
		}
	}

}