Drawing Lines on an Image (image graphics object returns null)

[nicenouman]

Guys i have a problem here. i have been able to read an image display it on my form. what i want to do now is draw lines on the image which i am showing. ihave few xy points which i have to draw on my image. Here is the CODE

CurrentImage=Image.createImage(b,0,b.length);
ImageItem image = new ImageItem("Image",CurrentImage, ImageItem.LAYOUT_CENTER, "Image Exceeds size");
form.append (image);

where b is the byte array containg image data.

i thought by getting the grahpics object of my image

Graphics g=CurrentImage.getGraphics();

i might be able to draw lines on it, but this function returns the graphics object as null. Am i missing something? any kind of help or code will be appreciated. i can use its d.drawline function to draw my lines on the image. i am using Nokia 6680

[nicenouman]

I manage to solve the problem by first creating an empty image of same size and then getting its graphics object. using the graphics objects drawimage method i drew my image into it. as this method takes an image and then using graphics object draw lines method i drew the necessary lines. it wasnt difficult.

[soku123]

Hi nicenouman,
i suppose you have succeded in drawing the line by replacing the form with a canvas.

thanks
Soku

[shmoove]

i might be able to draw lines on it, but this function returns the graphics object as null. Am i missing something?

Just to clear up any doubts: you were trying to draw on an immutable Image. From the Image docs:

Images are either mutable or immutable depending upon how they are created. Immutable images are generally created by loading image data from resource bundles, from files, or from the network. They may not be modified once created. Mutable images are created as blank images containing only white pixels. The application may render on a mutable image by calling getGraphics() on the Image to obtain a Graphics object expressly for this purpose.

shmoove

[nicenouman]

your 110% right shmoove. that was exactly the case.