itemmidlet.java

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            form.append(new ImageItem("Right", red, ImageItem.LAYOUT_RIGHT, null));
            
            // (4)
            form.append(new ImageItem("Default", red, ImageItem.LAYOUT_DEFAULT, null));
            
            // ImageItems with no labels
            // (5)
            form.append(new ImageItem(null, blue, 
                    ImageItem.LAYOUT_NEWLINE_BEFORE | 
                    ImageItem.LAYOUT_CENTER | 
                    ImageItem.LAYOUT_NEWLINE_AFTER, null));
            
            // (6)
            form.append(new ImageItem(null, blue, 
                    ImageItem.LAYOUT_NEWLINE_BEFORE | 
                    ImageItem.LAYOUT_DEFAULT | 
                    ImageItem.LAYOUT_NEWLINE_AFTER, null));
            
            // (7)
            form.append(new ImageItem(null, blue, 
                    ImageItem.LAYOUT_NEWLINE_BEFORE | 
                    ImageItem.LAYOUT_RIGHT | 
                    ImageItem.LAYOUT_NEWLINE_AFTER, null));
            
            // (8)
            form.append(new ImageItem(null, blue, ImageItem.LAYOUT_DEFAULT, null)); 
            form.append(new ImageItem(null, blue, ImageItem.LAYOUT_DEFAULT, null)); 
        } catch (IOException ex) {
            form.append("Failed to load images");
        }
        
        addCommands(form);
        return form;
    }
    
    // Example for Gauge
    private Form createGaugeForm() {
        Form form = new Form("Gauge");
        
        form.append(new Gauge(null, true, 100, 50));
        form.append(new Gauge(null, true, 100, 25));
        form.append(new Gauge(null, false, 100, 50));
        
        addCommands(form);
        return form;
    }
    
    // Example for ChoiceGroup
    private Form createChoiceGroupForm() {
        Form form = new Form("ChoiceGroup");
        
        try {
            Image red = Image.createImage("/ora/ch4/resources/red.png");
            Image green = Image.createImage("/ora/ch4/resources/green.png");
            Image blue = Image.createImage("/ora/ch4/resources/blue.png");

            // Exclusive choice group
            String[] strings = new String[] { "Red", "Green", "Blue" };
            Image[] images = new Image[] { red, green, blue };
            ChoiceGroup exGroup = new ChoiceGroup("Choose one", ChoiceGroup.EXCLUSIVE,
                                                        strings, images);
            form.append(exGroup);

            // Multiple choice group
            ChoiceGroup multiGroup = new ChoiceGroup("Choose any", ChoiceGroup.MULTIPLE);
            form.append(multiGroup);
            multiGroup.append("Use SSL", null);
            multiGroup.append("Reconnect on failure", null);
            multiGroup.append("Enable tracing", null);
        } catch (IOException ex) {
            form.append("Failed to load images");
        }
        
        addCommands(form);
        return form;
    }
    
    // Example for List
    private Screen createListExample() {
        List list = new List("List", List.IMPLICIT);

        try {
            Image red = Image.createImage("/ora/ch4/resources/red.png");
            Image green = Image.createImage("/ora/ch4/resources/green.png");
            Image blue = Image.createImage("/ora/ch4/resources/blue.png");
            
            list.append("Red", red);
            list.append("Green", green);
            list.append("Blue", blue);
        } catch (IOException ex) {
            Form form = new Form("Error");
            form.append("Failed to load images");
            return form;
        }
        
        addCommands(list);
        return list;
    }
    
    // Example for Alert
    private Screen createAlertForm() {
        final Form form = new Form("Alert");
        
        // A ChoiceGroup that allows the user to choose between
        // a modal Alert or an Alert with a finite timeout.
        final ChoiceGroup limitGroup = new ChoiceGroup("Timeout", Choice.EXCLUSIVE);
        limitGroup.append("Forever", null);
        limitGroup.append("Bounded 5s", null);
        form.append(limitGroup);
        
        // A Gauge that allows the user to choose the 
        // timeout for the Alert. This appears only if
        // the "Bounded" option is selected.
        final Gauge gauge = new Gauge(null, true, 30, 5);
        
        // A ChoiceGroup that lets the user pick the 
        // type of Alert
        final ChoiceGroup group = createAlertChoiceGroup(true); 
        form.append(group);  
        
        // A Command that is used to display the Alert
        final Command okCommand = new Command("OK", Command.OK, 0);
        
        // Add CommandListener for back/exit commands
        // and the OK command, which is specific to this Form
        form.addCommand(okCommand);
        form.addCommand(exitCommand);
        form.addCommand(backCommand);
        form.setCommandListener(new CommandListener() {
            public void commandAction(Command c, Displayable d) {
                if (c == okCommand) {
                    // Create and display the Alert
                    
                    // Get the alert type from the 
                    // second ChoiceGroup
                    int selectedType = group.getSelectedIndex();
                    AlertType alertType = alertTypes[selectedType];
                    String name = alertTypeNames[selectedType];
                    
                    // Get the timeout. This is FOREVER if the
                    // first item in the first ChoiceGroup is
                    // selected. Otherwise it is the value in
                    // the Gauge
                    int timeout = Alert.FOREVER;
                    String timeoutString = "none";
                    if (limitGroup.isSelected(1)) {
                        // "Bounded" selected - get the timeout.
                        timeout = gauge.getValue() * 1000;
                        timeoutString = gauge.getValue() + "s";                        
                    }
                    
                    // Create the Alert and set the timeout
                    Alert alert = new Alert("Alert!",
                        "Alert type: " + name + "\nTimeout = " + timeoutString,
                        null, alertType);
                    alert.setTimeout(timeout);
                    
                    // Display the Alert.
                    display.setCurrent(alert);                               
                } else {
                    // Delegate others to the usual commandAction
                    ItemMIDlet.this.commandAction(c, d);
                }                
            }
        });
        
        // Set our own ItemStateListener
        form.setItemStateListener(new ItemStateListener() {
            public void itemStateChanged(Item item) {
                if (item == limitGroup) {
                    if (limitGroup.getSelectedIndex() == 0) {
                        // Get rid of the Gauge
                        form.delete(1);
                    } else {
                        // Add the Gauge
                        form.insert(1, gauge);
                    }
                } else if (item == gauge) {               
                    int value = gauge.getValue();
                    limitGroup.set(1, "Bounded " + value + "s", null);
                }
            }
        });
        return form;
    }
    
        
    // Example for Sounds
    private Screen createSoundsForm() {
        final Form form = new Form("Sounds");
        
        // A ChoiceGroup that lets the user pick the 
        // type of sound
        final ChoiceGroup group = createAlertChoiceGroup(false); 
        form.append(group);  

        addCommands(form);
        
        // Set our own ItemStateListener
        form.setItemStateListener(new ItemStateListener() {
            public void itemStateChanged(Item item) {
                // Get the alert type from the ChoiceGroup
                int selectedType = group.getSelectedIndex();
                AlertType alertType = alertTypes[selectedType];
                boolean result = alertType.playSound(display);
                System.out.println("A sound was " + (result ? "" : "not ")
                                    + "played.");
                
            }
        });
        return form;
    }
    
    // Handles the selection for a Choice 
    private void handleChoiceSelection(Choice choice) {
        int count = choice.size();
        boolean[] states = new boolean[count];
        int selCount = choice.getSelectedFlags(states);
        if (selCount > 0) {
            System.out.println("Selected items:");
            for (int i = 0; i < count; i++) {
                if (states[i]) {
                    System.out.println("\t" + choice.getString(i));
                }
            }
        } else {
            System.out.println("No selected items.");
        }
        int selectedIndex = choice.getSelectedIndex();
        System.out.println("Selected index is " + selectedIndex);        
    }
    
    // Creates a ChoiceGroup containing a set of Alert types
    private ChoiceGroup createAlertChoiceGroup(boolean includeNone) {
        ChoiceGroup group = new ChoiceGroup("Alert Type", Choice.EXCLUSIVE);
        int count = includeNone ? alertTypeNames.length : alertTypeNames.length - 1;
        for (int i = 0; i < count; i++) {
            group.append(alertTypeNames[i], null);
        }
        return group;
    }
}