Categories: Known Issue | Java ME | MMAPI (JSR-135)

This page was last modified 09:31, 14 September 2007.

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Overview

A Player object is created in order to capture an image from the phone’s camera. A VideoControl object is then created and appended to an LCDUI Form. When the Player object is started before setting the form as the current displayable, VideoControl does not show the captured content. The CustomItem control paints only white background.

Description

This happens whenever a Player object is started before Display.getDisplay() is called.

How to reproduce

 Form form = new Form("Camera");
 
 // Initializing VideoControl for snapshot taking
 player = Manager.createPlayer("capture://video");
 player.realize();
 vControl = (VideoControl)player.getControl("VideoControl");
 
 form.append((Item)(vControl.initDisplayMode(VideoControl.USE_GUI_PRIMITIVE, null)));       
 player.start(); // user can see where the camera points
 
 Display.getDisplay(this).setCurrent(form);
 
 vControl.setVisible(true); // the video control remains blank

Solution

There is currently no solution. However, the issue can be avoided if Display.getDisplay() is called at least once during the MIDlet’s lifecycle before starting the Player, e.g. in the beginning of MIDlet’s constructor.

 form.append((Item)(vControl.initDisplayMode(VideoControl.USE_GUI_PRIMITIVE, null)));       
 
 // Calling Display.getDisplay before starting the player
 Display.getDisplay(this).setCurrent(form);
 player.start(); // user can see where the camera points