Android create layers in canvas

Question

I want to learn how can I create layers (like in photoshop) in my android application. I want to achieve one basic thing: when I add an image in my canvas, which will be some figure for example, I want to be able to paint the canvas, but the painting must not effect the lines of figure. And then I need to save that image on my Sd card.

Any suggestions/advice/examples? What can I use to achieve this?

Have you looked into `PorterDuff.Mode`? I am assuming your layers are static and once drawn can't be removed or moved. Is That correct or do you want layers exactly like Photoshop? — techi.services, May 20 '12 at 16:49
Yeah, I want to create something similar like layers in photoshop. — Android-Droid, May 20 '12 at 19:17
No, the only thing that I want is only to add the paths which user draw on the first layout...and the images on the second..so the second one with the images can be at the top of the first one. And when drawing paths,not to cross the added images. I don't want to move or remove them.There will be only two layers : paths and images. — Android-Droid, May 20 '12 at 19:46

score 1 · Answer 1 · answered May 20 '12 at 19:10

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The order how you paint makes layers. Create some stack of objects what you paint and then modify individual objects (painting in layer) or move them in this stack (changing layers). Use the same order to create your image to save.

answered May 20 '12 at 19:10

Alex

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score 1 · Answer 2 · answered Mar 07 '19 at 00:31

Layers in Canvas.

    Bitmap bitmap=Bitmap.createBitmap(500,500, Bitmap.Config.ARGB_8888);
    Canvas canvas=new Canvas(bitmap);
    Paint paint_outer=new Paint();
    paint_outer.setColor(Color.parseColor("#DEB887"));
    paint_outer.setStrokeWidth(140);
    paint_outer.setStyle(Paint.Style.STROKE);
    canvas.drawCircle(250,250,150,paint_outer);

    Paint paint_inner=new Paint();
    ComposePathEffect pathEffect=new ComposePathEffect(new CornerPathEffect(40),new DiscretePathEffect(60f,25f));
    paint_inner.setPathEffect(pathEffect);
    paint_inner.setColor(Color.parseColor("#8B4513"));
    paint_inner.setStrokeWidth(90);
    paint_inner.setStyle(Paint.Style.STROKE);
    canvas.drawCircle(250,250,150,paint_inner);
    iv.setImageBitmap(bitmap);

score 0 · Answer 3 · answered May 20 '12 at 20:35

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Have a look at the various Xfermodes that you can apply to a Paint. PorterDuff.Mode offers some options like you get in Photoshop, such as, screen and multiply, lighten and darken. The AvoidXferMode may suit your needs more however.

answered May 20 '12 at 20:35

techi.services

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score 0 · Answer 4 · edited May 23 '17 at 12:09

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You can compose your layers in a FrameLayout. You might need some trickery to ensure touch events get passed to the correct layer.

Once you have android composing your views how you like, you can mFrameLayout.onDraw(Canvas c) to draw the entire thing to a canvas.

This article has some info on how to turn your viewgroup into a jpeg Image on canvas to JPEG file

edited May 23 '17 at 12:09

Community

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answered May 25 '12 at 23:16

HaMMeReD

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Android create layers in canvas

4 Answers4