The VideoCanvas class:
Draws the video or camera viewfinder on a Canvas
Draws the ControlBar on top of the Canvas
Controls video playback with the overlay buttons
The following code initializes the video player:
public void initPlayer() {
initializingVideo = true;
// Always start player in normal mode
fsMode = false;
this.setFullScreenMode(fsMode);
try {
if (this.type == VideoOverlayMIDlet.CAMERA) {
player = Manager.createPlayer("capture://video");
} else {
InputStream is = this.getClass().getResourceAsStream(
this.VIDEO_LOCATOR);
player = Manager.createPlayer(is,
this.VIDEO_LOCATOR.substring(
this.VIDEO_LOCATOR.lastIndexOf('.') + 1));
}
player.realize();
player.prefetch();
videoControl = (VideoControl) player.getControl("VideoControl");
if (videoControl != null) {
videoControl.initDisplayMode(
VideoControl.USE_DIRECT_VIDEO, this);
videoControl.setDisplayFullScreen(true);
if (this.type == VideoOverlayMIDlet.CAMERA) {
addCommand(captureCommand);
} else {
player.setLoopCount(-1);
}
this.controlBar.setX(videoControl.getDisplayX());
this.controlBar.setY(videoControl.getDisplayY());
videoControl.setVisible(true);
player.start();
// Empty paint is called to ensure
// that videoControl area is clear
emptyPaint = true;
repaint();
serviceRepaints();
emptyPaint = false;
}
The code above can raise a number of exceptions:
} catch (IOException ioe) {
discardPlayer();
System.out.println(ioe.getMessage());
Display.getDisplay(this.midlet).setCurrent(
new Alert("IOException:", ioe.getMessage(),
null, AlertType.ERROR));
} catch (MediaException me) {
discardPlayer();
System.out.println(me.getMessage());
Display.getDisplay(this.midlet).setCurrent(
new Alert("MediaException:", me.getMessage(),
null, AlertType.ERROR));
} catch (SecurityException se) {
discardPlayer();
System.out.println(se.getMessage());
Display.getDisplay(this.midlet).setCurrent(
new Alert("SecurityException", se.getMessage(),
null, AlertType.ERROR));
} catch (Exception e) {
discardPlayer();
System.out.println(e.getMessage());
Display.getDisplay(this.midlet).setCurrent(
new Alert("Exception", e.getMessage(),
null, AlertType.ERROR));
} finally {
initializingVideo = false;
}
}
The paint method is called when the video player
needs to be drawn on the screen.
The following code first checks if it should draw "nothing" in
order to clear the screen. Then, if the player is being initialized,
it draws a string on the screen. If the player is done, it calls the paintOverlay method.
public void paint(Graphics g) {
if (emptyPaint == true) {
// Do not draw anything
// Ensure that videoControl area is clear
return;
}
int state = Player.UNREALIZED;
if (player != null) {
state = player.getState();
}
if (initializingVideo) {
paintInitString(g);
} else {
switch (state) {
case Player.PREFETCHED:
paintOverlay(g);
break;
case Player.STARTED:
paintOverlay(g);
break;
case Player.CLOSED:
paintString("Closing...", g);
break;
case Player.UNREALIZED:
break;
case Player.REALIZED:
break;
default:
g.setColor(BACKGROUND_COLOR);
g.fillRect(0, 0, getWidth(), getHeight());
paintString("Closing...", g);
break;
}
}
prevRepaint = System.currentTimeMillis();
}
The paintOverlay method paints the controls on
top of the player canvas:
private void paintOverlay(Graphics g) {
// Check if canvas changes (e.g., in screen rotation)
if (canvasW != getWidth()
|| canvasH != getHeight()) {
canvasW = getWidth();
canvasH = getHeight();
// Setting new location
this.controlBar.setX(videoControl.getDisplayX());
this.controlBar.setY(videoControl.getDisplayY());
}
video_x = videoControl.getDisplayX();
video_y = videoControl.getDisplayY();
videoW = videoControl.getDisplayWidth();
videoH = videoControl.getDisplayHeight();
// Clear areas outside the videoControl
g.setColor(BACKGROUND_COLOR);
g.fillRect(0, 0, canvasW, video_y);
g.fillRect(0, video_y + videoH, canvasW, canvasH);
g.fillRect(0, 0, video_x, videoH);
g.fillRect(video_x + videoW, 0, canvasW, canvasH);
// Stop painting if clearing flag is up
if (hideControlBar) {
return;
}
// Setting ControlBar boundaries
// Height is fixed size
controlBar.setWidth(videoW / 2);
// Control Bar
this.drawButtons(g);
// In fullscreen mode, drawing exit button
if (fsMode) {
// Portrait
if (canvasH > canvasW) {
exitX = videoW - (videoW / 3);
exitY = canvasH - (back_icon.getHeight() + 20);
} // Landscape
else {
exitX = videoW;
exitY = videoH - (back_icon.getHeight() + 20);
}
g.drawImage(back_icon,
(exitX + canvasW) / 2, exitY,
Graphics.TOP | Graphics.HCENTER);
}
}
The MIDlet takes pictures using the takeSnapshot method:
private void takeSnapshot() {
if (player != null) {
try {
byte pngImage[] =
videoControl.getSnapshot(
"encoding=png&width=" + videoControl.getDisplayWidth()
+ "&height=" + videoControl.getDisplayHeight());
player.stop();
midlet.cameraCanvasCaptured(pngImage);
} catch (MediaException me) {
System.out.println(me.getMessage());
Display.getDisplay(this.midlet).setCurrent(
new Alert("MediaException:", me.getMessage(),
null, AlertType.ERROR));
} catch (Exception e) {
System.out.println(e.getMessage());
Display.getDisplay(this.midlet).setCurrent(
new Alert("Exception:", e.getMessage(),
null, AlertType.ERROR));
}
}
}
The above code calls the getSnapshot method of the VideoControl class and saves the result in a byte array. It then calls the main
MIDlet's cameraCanvasCaptured method, which changes
the view to the image view.
Since it is possible to move the video controls, the class listens
for the pointerPressed and pointerDragged events. When these events
occur, the class changes the position of the video controls.