DaThiN
asked on
Run time exception when loading an Image.
I'm here again. I'm trying the following. First of all, I want to program a menu with buttons. I created two classes: Menu and Opcion. Menu is the main class and Opcion is a class for a button. In Menu Class, I've created 9 objects of Opcion class (that is, 9 buttons). I've used: boton[i] = new Opcion( "list of paramaters to the constructor" ). In the Opcion class, I have a method called create( ) which creates the button. Here is the code:
protected void create( ) {
MediaTracker t;
if( off_im == null ) {
try {
boton = getImage( getDocumentBase( ), img_src );
t = new MediaTracker( this );
t.addImage( boton, 0 );
t.waitForID( 0 );
} catch( Exception e) {
showStatus( "Ha ocurrido el error en el Applet: " + e );
}
}
width = boton.getWidth( this );
height = boton.getHeight( this );
Font fuente = new Font( fontname, Font.BOLD, ( width/length ) );
Color color = new Color( fontcolor );
off_im = createImage( width, height );
off_graph = off_im.getGraphics( );
off_graph.setColor( color );
off_graph.setFont( fuente );
FontMetrics fm = off_graph.getFontMetrics( );
while( fm.stringWidth( ltext ) < width - 30 ) {
fuente = new Font( fontname, Font.BOLD, fuente.getSize( ) + 1 );
off_graph.setFont( fuente );
fm = off_graph.getFontMetrics( );
}
off_graph.drawImage( boton, 0, 0, this );
drawCenteredString( label, width, height, off_graph );
}
The problem is that after boton = getImage( getDocumentBase( ), img_src );, boton contains "null" and an run-time exception occures. The img_src string is "Imagenes/boton.gif" which does exist. I had this code before inside the paint( ) method of Menu Class and it worked well, now I moved it to the Opcion class, and it didn't.
What is the problem?
thanks in advance
Jaime
protected void create( ) {
MediaTracker t;
if( off_im == null ) {
try {
boton = getImage( getDocumentBase( ), img_src );
t = new MediaTracker( this );
t.addImage( boton, 0 );
t.waitForID( 0 );
} catch( Exception e) {
showStatus( "Ha ocurrido el error en el Applet: " + e );
}
}
width = boton.getWidth( this );
height = boton.getHeight( this );
Font fuente = new Font( fontname, Font.BOLD, ( width/length ) );
Color color = new Color( fontcolor );
off_im = createImage( width, height );
off_graph = off_im.getGraphics( );
off_graph.setColor( color );
off_graph.setFont( fuente );
FontMetrics fm = off_graph.getFontMetrics( );
while( fm.stringWidth( ltext ) < width - 30 ) {
fuente = new Font( fontname, Font.BOLD, fuente.getSize( ) + 1 );
off_graph.setFont( fuente );
fm = off_graph.getFontMetrics( );
}
off_graph.drawImage( boton, 0, 0, this );
drawCenteredString( label, width, height, off_graph );
}
The problem is that after boton = getImage( getDocumentBase( ), img_src );, boton contains "null" and an run-time exception occures. The img_src string is "Imagenes/boton.gif" which does exist. I had this code before inside the paint( ) method of Menu Class and it worked well, now I moved it to the Opcion class, and it didn't.
What is the problem?
thanks in advance
Jaime
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class. You might want to duplicate this implementation inside the Opcion class. Basically put the code that initializes the graphics of the button in a paint method instead
of the create method you have shown above.