Is it possible to re-show the last opened Form when the MIDlet was paused?

Question

The application is running , the user is making some TextField editing. Then a call is received , so the MIDlet enters the paused state. When the conversation is finished then the application is restarted , the startApp() method of the MIDlet is called and the main Form of the application is shown !

So how to dismiss this default behaviour so that the last opened Form with all the modifications are kept ?

Answer 1

I created a static Form in the MIDlet class :

public static Form lastForm = null;

Then I set it to the actual Form in every Form of my project :

if (!myMidlet.lastCanvas.isEmpty())
    myMidlet.lastCanvas.clear();    
myMidlet.lastForm = this;

Then in the startApp() I wrote :

public void startApp() {
        ...
        if (lastForm != null)
            lastForm.showBack();
        else
        {
            new MainForm(this).show();
        }
    }

---

EDIT :

For the canvas :

In the MIDlet class :

public static Hashtable lastCanvas = new Hashtable();

In the canvas class ( constructor ) :

if (myMidlet.lastForm != null)
    myMidlet.lastForm = null;

if (!myMidlet.lastCanvas.isEmpty())
    myMidlet.lastCanvas.clear();

myMidlet.lastCanvas.put(new String("Form"), this);

And in the startApp() :

public void startApp() {
        VKBImplementationFactory.init();
        Display.init(this);
        if (lastForm != null)
            lastForm.showBack();
        else if (!lastCanvas.isEmpty())
        {
            javax.microedition.lcdui.Display.getDisplay(this).setCurrent((Canvas)lastCanvas.get(new String("Form")));
        }
        else
            new MainForm(this).show();
    }

I think this approach of using a HashTable will work even for any lcdui Form.

Answer 2

In LWUIT, I use this

import com.sun.lwuit.Display;
......
......
......

public void startApp() {
    if (Display.isInitialized()) {
        if (Display.getInstance().isMinimized()) {
            Display.getInstance().getCurrent().showBack();
        }
    } else {
        //your normal initialization code.
    }
}