1、創建LandmarkEditorUI類文件
2、引入必要的類
package com.nokia.example.location.tourist.ui;
import Java.io.IOException;
import Java.util.Enumeration;
import Javax.microedition.lcdui.Alert;
import Javax.microedition.lcdui.AlertType;
import Javax.microedition.lcdui.Command;
import Javax.microedition.lcdui.CommandListener;
import Javax.microedition.lcdui.Displayable;
import Javax.microedition.lcdui.Form;
import Javax.microedition.lcdui.List;
import Javax.microedition.lcdui.StringItem;
import Javax.microedition.lcdui.TextFIEld;
import Javax.microedition.location.AddressInfo;
import Javax.microedition.location.Landmark;
import Javax.microedition.location.LandmarkException;
import Javax.microedition.location.QualifIEdCoordinates;
import com.nokia.example.location.tourist.TouristMIDlet;
import com.nokia.example.location.tourist.Utils;
import com.nokia.example.location.tourist.model.ControlPoints;
import com.nokia.example.location.tourist.model.TouristData;
3、創建LandmarkEditorUI類，並將其設置為對Form的擴展，運行CommandListener，定義Form需要的TextFIEld。
/**
* VIEwer class enabling landmarks address info monifications.
*/
class LandmarkEditorUI extends Form implements CommandListener
{
// Landmark fields, (*) = required fIEld
private TextField nameField = new TextFIEld("Name (*):", "", 20,
TextFIEld.ANY);
private TextField descField = new TextFIEld("Description (*):", "", 40,
TextFIEld.ANY);
// AddressInfo fIElds
private TextField countryField = new TextFIEld("Country:", "", 20,
TextFIEld.ANY);
private TextField stateField = new TextFIEld("State:", "", 20,
TextFIEld.ANY);
private TextField cityField = new TextField("City:", "", 20, TextFIEld.ANY);
private TextField streetField = new TextFIEld("Street:", "", 20,
TextFIEld.ANY);
private TextField buildingNameField = new TextFIEld("Building name (*):",
"", 20, TextFIEld.ANY);
定義坐標信息StringITems和陸標選擇所需要的命令和常量。QualifIEdCoordinates類用經度、緯度、海拔的方式來說明坐標。
更多信息，參考Location API。
// Coordinate information
private StringItem lat = new StringItem("Lat:", "");
private StringItem lon = new StringItem("Lon:", "");
private StringItem alt = new StringItem("Alt:", "");
/** Landmark selector list */
private List list = new List("Landmarks:", List.EXCLUSIVE);
private Command saveNewCmd = new Command("Save", Command.OK, 1);
private Command saveUpdatedCmd = new Command("Save", Command.OK, 1);
private Command updateCmd = new Command("Update", Command.OK, 1);
private Command removeCmd = new Command("Remove", Command.OK, 1);
private Command listCmd = new Command("List", Command.OK, 1);
private Command routeCmd = new Command("Route", Command.BACK, 1);
public static final int MODE_UPDATE = 0;
public static final int MODE_ADDNEW = 1;
private QualifIEdCoordinates coord = null;
private Displayable route = null;
private TouristData data = null;
4、建類結構
/**
* Construct Landmark Editor UI Form.
*
* @param route -
* a reference of Route UI.
* @param data -
* a reference to TouristData model layer class.
*/
public LandmarkEditorUI(Displayable route, TouristData data)
{
super("Landmark Editor");
this.route = route;
this.data = data;
// route and list commands always available on landmark editor
addCommand(routeCmd);
addCommand(listCmd);
setCommandListener(this);
// route command always available on landmarks list
list.addCommand(routeCmd);
list.setCommandListener(this);
}
5、建方法，初始化UI組件，並顯示路標編輯器。GetAltitude方法返回這個組件坐標的經度值！
/**
* Initialize
public void showEditor(QualifIEdCoordinates newCoord, int mode)
{
this.coord = newCoord;
// initialize coordinate values
lat.setText(Utils.formatDouble(newCoord.getLatitude(), 3));
lon.setText(Utils.formatDouble(newCoord.getLongitude(), 3));
alt.setText(Utils.formatDouble(newCoord.getAltitude(), 1));
// initialize editable test fIEld values
nameFIEld.setString("");
descFIEld.setString("");
countryFIEld.setString("");
stateFIEld.setString("");
cityFIEld.setString("");
streetFIEld.setString("");
buildingNameFIEld.setString("");
deleteAll();
append(nameFIEld);
append(descFIEld);
append(countryFIEld);
append(stateFIEld);
append(cityFIEld);
append(streetFIEld);
append(buildingNameFIEld);
append(lat);
append(lon);
append(alt);
// Update existing landmark.
if (mode == MODE_UPDATE)
{
Landmark lm = ControlPoints.getInstance().findNearestLandMark(
newCoord);
if (lm != null)
{
nameFIEld.setString(lm.getName());
descFIEld.setString(lm.getDescription());
AddressInfo info = lm.getAddressInfo();
if (info != null)
{
countryField.setString(info.getFIEld(AddressInfo.COUNTRY));
stateField.setString(info.getFIEld(AddressInfo.STATE));
cityField.setString(info.getFIEld(AddressInfo.CITY));
streetField.setString(info.getFIEld(AddressInfo.STREET));
buildingNameFIEld.setString(info
.getFIEld(AddressInfo.BUILDING_NAME));
}
}
removeCommand(updateCmd);
removeCommand(saveNewCmd);
addCommand(saveUpdatedCmd);
addCommand(listCmd);
}
// Add new landmark to the landmark store.
else if (mode == MODE_ADDNEW)
{
removeCommand(updateCmd);
removeCommand(saveUpdatedCmd);
addCommand(saveNewCmd);
addCommand(listCmd);
}
TouristMIDlet.getDisplay().setCurrent(this);
}
6、建方法，顯示陸標選擇列表。
/**
* Show landmark selector List. Content of the list is refreshed each time
* this method is called.
*/
public void showList()
{
list.deleteAll();
Landmark lm = null;
Enumeration landmarks = ControlPoints.getInstance().getLandMarks();
// Check whether landmarks can be founds from the Landmark store.
if (landmarks != null)
{
while (landmarks.hasMoreElements())
{
lm = ((Landmark) landmarks.nextElement());
list.append(lm.getName(), null);
}
list.addCommand(updateCmd);
list.addCommand(removeCmd);
}
// No landmarks found (list is empty)
else
{
list.removeCommand(updateCmd);
list.removeCommand(removeCmd);
}
TouristMIDlet.getDisplay().setCurrent(list);
}
7、建方法，檢測所必需的區域並不缺少。
/**
* Check whether any required fields are missing. (*) on the TextFIElds label
* indicates that fIEld is mandatory.
*
* @return Name of the missing fIEld name or null indicating no required
* fIElds are missing.
*/
private String checkRequiredFIElds()
{
if (nameFIEld.getString().equals(""))
{
return "Name";
}
else if (nameFIEld.getString().equals(""))
{
return "Description";
}
else if (buildingNameFIEld.getString().equals(""))
{
return "Building name";
}
return null;
}
8、建方法，通過UI組件繼承路標。
/**
* Generate landmark from UI component values.
*
* @return Genereated Landmark.
*/
private Landmark generateLandmark()
{
String field = checkRequiredFIElds();
if (fIEld != null)
{
Alert alert = new Alert("Error", "Value for required fIEld "
+ fIEld + " is missing.", null, AlertType.ERROR);
alert.setTimeout(3000); // 3 secs
TouristMIDlet.getDisplay().setCurrent(alert, this);
return null;
}
AddressInfo info = new AddressInfo();
info.setField(AddressInfo.COUNTRY, countryFIEld.getString());
info.setField(AddressInfo.STATE, stateFIEld.getString());
info.setField(AddressInfo.CITY, cityFIEld.getString());
info.setField(AddressInfo.STREET, streetFIEld.getString());
info.setField(AddressInfo.BUILDING_NAME, buildingNameFIEld.getString());
Landmark lm = new Landmark(nameFIEld.getString(),
descFIEld.getString(), coord, info);
return lm;
}
9、測按鍵輸入
/**
* Event indicating when a command button is pressed.
*
* @see Javax.microedition.lcdui.CommandListener#commandAction
(Javax.microedition.lcdui.Command,
* Javax.microedition.lcdui.Displayable)
*/
public void commandAction(Command command, Displayable displayable)
{
Landmark landmark = null;
// Add new Landmark to the LandmarkStore
if (command == saveNewCmd)
{
landmark = generateLandmark();
if (landmark != null)
{
try
{
ControlPoints.getInstance().addLandmark(landmark);
data.createProximityListener(coord);
}
catch (IOException e)
{
Alert alert = new Alert("Error",
"I/O Error during add Operation", null,
AlertType.ERROR);
alert.setTimeout(3000); // 3 secs
TouristMIDlet.getDisplay().setCurrent(alert);
}
// New landmark is available on the list
showList();
}
}
// Update existing landmark
else if (command == saveUpdatedCmd)
{
landmark = generateLandmark();
if (landmark != null)
{
try
{
ControlPoints.getInstance().updateLandmark(landmark);
data.createProximityListener(coord);
}
catch (IOException e)
{
Alert alert = new Alert("Error",
"I/O Error during update Operation", null,
AlertType.ERROR);
alert.setTimeout(3000); // 3 secs
TouristMIDlet.getDisplay().setCurrent(alert);
}
catch (LandmarkException e)
{
// Landmark instance passed as the parameter does not
// belong to this LandmarkStore or does not exist in the
// store any more.
Alert alert = new Alert("Error",
"Unexpected error: can not find landmark from "
+ "the landmark store.", null,
AlertType.ERROR);
alert.setTimeout(3000); // 3 secs
TouristMIDlet.getDisplay().setCurrent(alert);
}
// Updated landmark is available on the list
showList();
}
}
// Go back to the previous screen
else if (command == routeCmd)
{
TouristMIDlet.getDisplay().setCurrent(route);
}
// Show landmark editor for the selected landmark.
else if (command == updateCmd)
{
int index = list.getSelectedIndex();
landmark = ControlPoints.getInstance().findLandmark(index);
showEditor(landmark.getQualifIEdCoordinates(), MODE_UPDATE);
}
// Remove selected Landmark from LandmarkStore
else if (command == removeCmd)
{
try
{
int index = list.getSelectedIndex();
landmark = ControlPoints.getInstance().findLandmark(index);
ControlPoints.getInstance().removeLandmark(landmark);
Alert alert = new Alert("Information",
"Landmark removed successfully.", null, AlertType.INFO);
alert.setTimeout(3000); // 3 secs
TouristMIDlet.getDisplay().setCurrent(alert);
}
catch (IOException e)
{
Alert alert = new Alert("Error", "I/O Error during Operation",
null, AlertType.ERROR);
alert.setTimeout(3000); // 3 secs
TouristMIDlet.getDisplay().setCurrent(alert);
}
catch (LandmarkException le)
{
Alert alert = new Alert("Error",
"landmark can not be found from the landmark store.",
null, AlertType.ERROR);
alert.setTimeout(3000); // 3 secs
TouristMIDlet.getDisplay().setCurrent(alert);
}
showList();
}
// Show the list of Landmarks
else if (command == listCmd)
{
showList();
}
}
